Friday, November 21, 2008

Some astronomy poems

The Shortest Day

Ann R. Cantu

December calls on the Status Quo
to mingle and snuggle, sigh and glow,
to look to the heavens and pray for snow.
Yet there's something different we long to know.
Feathered beings would beg to differ
that a warmer clime is better for winter.
For who can sleep when it's 10 below
and your home is naught but a hedgerow?

It's months from purple martin time.
An order must be followed, by the bye.
But we ride along a strange frontier, where
science takes a back seat and storm clouds drive.

Wee folk dance with sugared dreams.
Things scurry invisible through forest cover.
Tapestries woven from all we call known
display complacent ancestory, bound in time.

When you look to the sky, what common denominator
cries out that nature makes us brothers and sisters,
Defying genetics, heritage and convention,
above our chemistry, a mystery in history?

So exactly what will the Fates allow?
Have yourself a merry little Solstice.

The Star-Splitter


Robert Frost

You know Orien always comes up sideways.
Throwing a leg up over our fence of mountains,
And rising on his hands, he looks in on me
Busy outdoors by lantern-light with something
I should have done by daylight, and indeed,
After the ground is frozen, I should have done
Before it froze, and a gust flings a handful
Of waste leaves at my smoky lantern chimney
To make fun of my way of doing things,
Or else fun of Orion's having caught me.
Has a man, I should like to ask, no rights
These forces are obliged to pay respect to?"
So Brad McLaughlin mingled reckless talk
Of heavenly stars with hugger-mugger farming,
Till having failed at hugger-mugger farming,
He burned his house down for the fire insurance
And spent the proceeds on a telescope
To satisfy a life-long curiosity
About our place among the infinities.
"What do you want with one of those blame things?"
I asked him well beforehand. "Don't you get one!"
"Don't call it blamed; there isn't anything
More blameless in the sense of being less
A weapon in our human fight," he said.
"I'll have one if I sell my farm to buy it."
There where he moved the rocks to plow the ground
And plowed between the rocks he couldn't move,
Few farms changed hands; so rather than spend years
Trying to sell his farm and then not selling,
He burned his house down for the fire insurance
And bought the telescope with what it came to.
He had been heard to say by several:
"The best thing that we're put here for's to see;
The strongest thing that's given us to see with's
A telescope. Someone in every town
Seems to me owes it to the town to keep one.
In Littleton it may as well be me."
After such loose talk it was no surprise
When he did what he did and burned his house down.
Mean laughter went about the town that day
To let him know we weren't the least imposed on,
And he could wait--we'd see to him to-morrow.
But the first thing next morning we reflected
If one by one we counted people out
For the least sin, it wouldn't take us long
To get so we had no one left to live with.
For to be social is to be forgiving.
Our thief, the one who does our stealing from us,
We don't cut off from coming to church suppers,
But what we miss we go to him and ask for.
He promptly gives it back, that is if still
Uneaten, unworn out, or undisposed of.
It wouldn't do to be too hard on Brad
About his telescope. Beyond the age
Of being given one's gift for Christmas,
He had to take the best way he knew how
To find himself in one. Well, all we said was
He took a strange thing to be roguish over.
Some sympathy was wasted on the house,
A good old-timer dating back along;
But a house isn't sentient; the house
Didn't feel anything. And if it did,
Why not regard it as a sacrifice,
And an old-fashioned sacrifice by fire,
Instead of a new-fashioned one at auction?
Out of a house and so out of a farm
At one stroke (of a match), Brad had to turn
To earn a living on the Concord railroad,
As under-ticket-agent at a station
Where his job, when he wasn't selling tickets,
Was setting out up track and down, not plants
As on a farm, but planets, evening stars
That varied in their hue from red to green.
He got a good glass for six hundred dollars.
His new job gave him leisure for star-gazing.
Often he bid me come and have a look
Up the brass barrel, velvet black inside,
At a star quaking in the other end.
I recollect a night of broken clouds
And underfoot snow melted down to ice,
And melting further in the wind to mud.
Bradford and I had out the telescope.
We spread our two legs as it spread its three,
Pointed our thoughts the way we pointed it,
And standing at our leisure till the day broke,
Said some of the best things we ever said.
That telescope was christened the Star-splitter,
Because it didn't do a thing but split
A star in two or three the way you split
A globule of quicksilver in your hand
With one stroke of your finger in the middle.
It's a star-splitter if there ever was one
And ought to do some good if splitting stars
'Sa thing to be compared with splitting wood.
We've looked and looked, but after all where are we?
Do we know any better where we are,
And how it stands between the night to-night
And a man with a smoky lantern chimney?
How different from the way it ever stood?

Bright Star


John Keats

Bright Star, Would I Were Steadfast as Thou Art
Bright star, would I were steadfast as thou art--
Not in lone splendour hung aloft the night
And watching, with eternal lids apart,
Like nature's patient, sleepless Eremite,
The moving waters at their priest like task
Of pure ablution round earth's human shores,
Or gazing on the new soft-fallen mask
Of snow upon the mountains and the moors--
No--yet still steadfast, still unchangeable,
Pillow'd upon my fair love's ripening breast,
To feel for ever its soft fall and swell,
Awake for ever in a sweet unrest,
Still, still to hear her tender-taken breath,
And so live ever--or else swoon to death.

Star Watcher




The moon tonight is elsewhere
Dark scudding cloud cover
Heavy grumbles through the air
Misty touch like a lover

Stay and laugh for just awhile
Illuminating flashes
Something here makes me smile
Whipping wind giving lashes

Above beyond the rain cloud
Rainbows follow stormy weather
Clustered starshine light so
Still wish us together

Sudden small opening break
Want to touch and then to hold
A bright star begins an ache
Embrace to enfold

The moon tonight is elsewhere
And so should I be, too
Not just to stand and stare
Star watcher thinks of you

Monday, November 17, 2008

Lawrence H. Summers speech on January 14th, 2005

This is the January 14th, 2005 speech given behind closed doors at Harvard by President Lawrence H. Summers.

LAWRENCE SUMMERS, Harvard President: I asked Richard, when he invited me to come here and speak, whether he wanted an institutional talk about Harvard's policies toward diversity or whether he wanted some questions asked and some attempts at provocation, because I was willing to do the second and didn't feel like doing the first. And so we have agreed that I am speaking unofficially and not using this as an occasion to lay out the many things we're doing at Harvard to promote the crucial objective of diversity. There are many aspects of the problems you're discussing and it seems to me they're all very important from a national point of view.

I'm going to confine myself to addressing one portion of the problem, or of the challenge we're discussing, which is the issue of women's representation in tenured positions in science and engineering at top universities and research institutions, not because that's necessarily the most important problem or the most interesting problem, but because it's the only one of these problems that I've made an effort to think in a very serious way about.

The other prefatory comment that I would make is that I am going to, until most of the way through, attempt to adopt an entirely positive, rather than normative approach, and just try to think about and offer some hypotheses as to why we observe what we observe without seeing this through the kind of judgmental tendency that inevitably is connected with all our common goals of equality.

It is after all not the case that the role of women in science is the only example of a group that is significantly underrepresented in an important activity and whose underrepresentation contributes to a shortage of role models for others who are considering being in that group. To take a set of diverse examples, the data will, I am confident, reveal that Catholics are substantially underrepresented in investment banking, which is an enormously high-paying profession in our society; that white men are very substantially underrepresented in the National Basketball Association; and that Jews are very substantially underrepresented in farming and in agriculture. These are all phenomena in which one observes underrepresentation, and I think it's important to try to think systematically and clinically about the reasons for underrepresentation.

There are three broad hypotheses about the sources of the very substantial disparities that this conference's papers document and have been documented before with respect to the presence of women in high-end scientific professions. One is what I would call the -- I'll explain each of these in a few moments and comment on how important I think they are -- the first is what I call the high-powered job hypothesis. The second is what I would call different availability of aptitude at the high end, and the third is what I would call different socialization and patterns of discrimination in a search. And in my own view, their importance probably ranks in exactly the order that I just described.

Maybe it would be helpful to just, for a moment, broaden the problem, or the issue, beyond science and engineering. I've had the opportunity to discuss questions like this with chief executive officers at major corporations, the managing partners of large law firms, the directors of prominent teaching hospitals, and with the leaders of other prominent professional service organizations, as well as with colleagues in higher education.

In all of those groups, the story is fundamentally the same. Twenty or 25 years ago, we started to see very substantial increases in the number of women who were in graduate school in this field. Now the people who went to graduate school when that started are 40, 45, 50 years old. If you look at the top cohort in our activity, it is not only nothing like 50-50, it is nothing like what we thought it was when we started having a third of the women, a third of the law school class being female, 20 or 25 years ago. And the relatively few women who are in the highest ranking places are disproportionately either unmarried or without children, with the emphasis differing depending on just who you talk to. And that is a reality that is present and that one has exactly the same conversation in almost any high-powered profession.

What does one make of that? I think it is hard -- and again, I am speaking completely descriptively and non-normatively -- to say that there are many professions and many activities, and the most prestigious activities in our society expect of people who are going to rise to leadership positions in their 40s near total commitments to their work. They expect a large number of hours in the office, they expect a flexibility of schedules to respond to contingency, they expect a continuity of effort through the life cycle, and they expect -- and this is harder to measure -- but they expect that the mind is always working on the problems that are in the job, even when the job is not taking place.

And it is a fact about our society that that is a level of commitment that a much higher fraction of married men have been historically prepared to make than of married women. That's not a judgment about how it should be, not a judgment about what they should expect. But it seems to me that it is very hard to look at the data and escape the conclusion that that expectation is meeting with the choices that people make and is contributing substantially to the outcomes that we observe. One can put it differently. Of a class, and the work that Claudia Goldin and Larry Katz are doing will, I'm sure, over time, contribute greatly to our understanding of these issues and for all I know may prove my conjectures completely wrong.

Another way to put the point is to say, what fraction of young women in their mid-20s make a decision that they don't want to have a job that they think about 80 hours a week. What fraction of young men make a decision that they're unwilling to have a job that they think about 80 hours a week, and to observe what the difference is. And that has got to be a large part of what is observed. Now that begs entirely the normative questions -- which I'll get to a little later -- of, is our society right to expect that level of effort from people who hold the most prominent jobs? Is our society right to have familial arrangements in which women are asked to make that choice and asked more to make that choice than men? Is our society right to ask of anybody to have a prominent job at this level of intensity, and I think those are all questions that I want to come back to.

But it seems to me that it is impossible to look at this pattern and look at its pervasiveness and not conclude that something of the sort that I am describing has to be of significant importance. To buttress conviction and theory with anecdote, a young woman who worked very closely with me at the Treasury and who has subsequently gone on to work at Google highly successfully, is a 1994 graduate of Harvard Business School. She reports that of her first year section, there were 22 women, of whom three are working full time at this point. That may, the dean of the Business School reports to me, that that is not an implausible observation given their experience with their alumnae. So I think in terms of positive understanding, the first very important reality is just what I would call the, who wants to do high-powered intense work?

The second thing that I think one has to recognize is present is what I would call the combination of, and here, I'm focusing on something that would seek to answer the question of why is the pattern different in science and engineering, and why is the representation even lower and more problematic in science and engineering than it is in other fields. And here, you can get a fair distance, it seems to me, looking at a relatively simple hypothesis.

It does appear that on many, many different human attributes-height, weight, propensity for criminality, overall IQ, mathematical ability, scientific ability -- there is relatively clear evidence that whatever the difference in means -- which can be debated -- there is a difference in the standard deviation, and variability of a male and a female population. And that is true with respect to attributes that are and are not plausibly, culturally determined.

If one supposes, as I think is reasonable, that if one is talking about physicists at a top 25 research university, one is not talking about people who are two standard deviations above the mean. And perhaps it's not even talking about somebody who is three standard deviations above the mean. But it's talking about people who are three-and-a-half, four standard deviations above the mean in the one in 5,000, one in 10,000 class. Even small differences in the standard deviation will translate into very large differences in the available pool substantially out.

I did a very crude calculation, which I'm sure was wrong and certainly was unsubtle, 20 different ways. I looked at the Xie and Shauman paper -- looked at the book, rather -- looked at the evidence on the sex ratios in the top 5 percent of twelfth graders. If you look at those -- they're all over the map, depends on which test, whether it's math, or science, and so forth -- but 50 percent women, one woman for every two men, would be a high-end estimate from their estimates. From that, you can back out a difference in the implied standard deviations that works out to be about 20 percent. And from that, you can work out the difference out several standard deviations.

If you do that calculation -- and I have no reason to think that it couldn't be refined in a hundred ways -- you get five to one, at the high end. Now, it's pointed out by one of the papers at this conference that these tests are not a very good measure and are not highly predictive with respect to people's ability to do that. And that's absolutely right. But I don't think that resolves the issue at all.

Because if my reading of the data is right -- it's something people can argue about -- that there are some systematic differences in variability in different populations, then whatever the set of attributes are that are precisely defined to correlate with being an aeronautical engineer at MIT or being a chemist at Berkeley, those are probably different in their standard deviations as well. So my sense is that the unfortunate truth -- I would far prefer to believe something else, because it would be easier to address what is surely a serious social problem if something else were true -- is that the combination of the high-powered job hypothesis and the differing variances probably explains a fair amount of this problem.

There may also be elements, by the way, of differing, there is some, particularly in some attributes, that bear on engineering, there is reasonably strong evidence of taste differences between little girls and little boys that are not easy to attribute to socialization.

I just returned from Israel, where we had the opportunity to visit a kibbutz, and to spend some time talking about the history of the kibbutz movement, and it is really very striking to hear how the movement started with an absolute commitment, of a kind one doesn't encounter in other places, that everybody was going to do the same jobs. Sometimes the women were going to fix the tractors, and the men were going to work in the nurseries, sometimes the men were going to fix the tractors and the women were going to work in the nurseries, and just under the pressure of what everyone wanted, in a hundred different kibbutzes, each one of which evolved, it all moved in the same direction.

So, I think, while I would prefer to believe otherwise, I guess my experience with my 2-and-a-half-year-old twin daughters, who were not given dolls and who were given trucks, and found themselves saying to each other, look, daddy truck is carrying the baby truck, tells me something. And I think it's just something that you probably have to recognize.

There are two other hypotheses that are all over. One is socialization. Somehow little girls are all socialized towards nursing and little boys are socialized towards building bridges. No doubt there is some truth in that. I would be hesitant about assigning too much weight to that hypothesis for two reasons. First, most of what we've learned from empirical psychology in the last 15 years has been that people naturally attribute things to socialization that are in fact not attributable to socialization. We've been astounded by the results of separated twins studies. The confident assertions that autism was a reflection of parental characteristics that were absolutely supported and that people knew from years of observational evidence have now been proven to be wrong. And so, the human mind has a tendency to grab to the socialization hypothesis when you can see it, and it often turns out not to be true.

The second empirical problem is that girls are persisting longer and longer. When there were no girls majoring in chemistry, when there were no girls majoring in biology, it was much easier to blame parental socialization. Then, as we are increasingly finding today, the problem is what's happening when people are 20, or when people are 25, in terms of their patterns, with which they drop out. Again, to the extent it can be addressed, it's a terrific thing to address.

The most controversial in a way, question, and the most difficult question to judge, is what is the role of discrimination? To what extent is there overt discrimination? Surely there is some. Much more tellingly, to what extent are there pervasive patterns of passive discrimination and stereotyping in which people like to choose people like themselves, and the people in the previous group are disproportionately white male, and so they choose people who are like themselves, who are disproportionately white male. No one who's been in a university department or who has been involved in personnel processes can deny that this kind of taste does go on, and it is something that happens, and it is something that absolutely, vigorously needs to be combated.

On the other hand, I think before regarding it as pervasive, and as the dominant explanation of the patterns we observe, there are two points that should make one hesitate. The first is the fallacy of composition. No doubt it is true that if any one institution makes a major effort to focus on reducing stereotyping, on achieving diversity, on hiring more people, no doubt it can succeed in hiring more. But each person it hires will come from a different institution, and so everyone observes that when an institution works very hard at this, to some extent they are able to produce better results. If I stand up at a football game and everybody else is sitting down, I can see much better, but if everybody stands up, the views may get a little better, but they don't get a lot better.

And there's a real question as to how plausible it is to believe that there is anything like half as many people who are qualified to be scientists at top 10 schools and who are now not at top 10 schools, and that's the argument that one has to make in thinking about this as a national problem rather than an individual institutional problem.

The second problem is the one that Gary Becker very powerfully pointed out in addressing racial discrimination many years ago. If it was really the case that everybody was discriminating, there would be very substantial opportunities for a limited number of people who were not prepared to discriminate to assemble remarkable departments of high quality people at relatively limited cost simply by the act of their not discriminating, because of what it would mean for the pool that was available.

And there are certainly examples of institutions that have focused on increasing their diversity to their substantial benefit, but if there was really a pervasive pattern of discrimination that was leaving an extraordinary number of high-quality potential candidates behind, one suspects that in the highly competitive academic marketplace, there would be more examples of institutions that succeeded substantially by working to fill the gap. And I think one sees relatively little evidence of that.

So my best guess, to provoke you, of what's behind all of this is that the largest phenomenon, by far, is the general clash between people's legitimate family desires and employers' current desire for high power and high intensity, that in the special case of science and engineering, there are issues of intrinsic aptitude, and particularly of the variability of aptitude, and that those considerations are reinforced by what are in fact lesser factors involving socialization and continuing discrimination. I would like nothing better than to be proved wrong, because I would like nothing better than for these problems to be addressable simply by everybody understanding what they are, and working very hard to address them.

What's to be done? And what further questions should one know the answers to? Let me take a second, first to just remark on a few questions that it seems to me are ripe for research, and for all I know, some of them have been researched.

First, it would be very useful to know, with hard data, what the quality of marginal hires are when major diversity efforts are mounted. When major diversity efforts are mounted, and consciousness is raised, and special efforts are made, and you look five years later at the quality of the people who have been hired during that period, how many are there who have turned out to be much better than the institutional norm who wouldn't have been found without a greater search. And how many of them are plausible compromises that aren't unreasonable, and how many of them are what the right-wing critics of all of this suppose represent clear abandonments of quality standards. I don't know the answer, but I think if people want to move the world on this question, they have to be willing to ask the question in ways that could face any possible answer that came out.

Second, and by the way, I think a more systematic effort to look at citation records of male and female scholars in disciplines where citations are relatively well-correlated with academic rank and with people's judgments of quality would be very valuable. Of course, most of the critiques of citations go to reasons why they should not be useful in judging an individual scholar. Most of them are not reasons why they would not be useful in comparing two large groups of scholars and so there is significant potential, it seems to me, for citation analysis in this regard.

Second, what about objective versus subjective factors in hiring? I've been exposed, by those who want to see the university hiring practices changed to favor women more and to assure more diversity, to two very different views. One group has urged that we make the processes consistently more clear-cut and objective, based on papers, numbers of papers published, numbers of articles cited, objectivity, measurement of performance, no judgments of potential, no reference to other things, because if it's made more objective, the subjectivity that is associated with discrimination and which invariably works to the disadvantage of minority groups will not be present.

I've also been exposed to exactly the opposite view, that those criteria and those objective criteria systematically bias the comparisons away from many attributes that those who contribute to the diversity have: a greater sense of collegiality, a greater sense of institutional responsibility. Somebody ought to be able to figure out the answer to the question of, if you did it more objectively versus less objectively, what would happen. Then you can debate whether you should or whether you shouldn't, if objective or subjective is better. But that question ought to be a question that has an answer, that people can find.

Third, the third kind of question is, what do we know about search procedures in universities? Is it the case that more systematic comprehensive search processes lead to minority group members who otherwise would have not been noticed being noticed? Or does fetishizing the search procedure make it very difficult to pursue the targets of opportunity that are often available arising out of particular family situations or particular moments, and does fetishizing and formalizing search procedures further actually work to the disadvantage of minority group members. Again, everybody's got an opinion; I don't think anybody actually has a clue as to what the answer is.

Fourth, what do we actually know about the incidence of financial incentives and other support for child care in terms of what happens to people's career patterns. I've been struck at Harvard that there's something unfortunate and ironic about the fact that if you're a faculty member and you have a kid who's 18 who goes to college, we in effect, through an interest-free loan, give you about $9,000. If you have a 6-year-old, we give you nothing. And I don't think we're very different from most other universities in this regard, but there is something odd about that strategic choice, if the goal is to recruit people to come to the university. But I don't think we know much about the child care issue.

The fifth question -- which it seems to me would be useful to study and to actually learn the answer to -- is what do we know, or what can we learn, about the costs of career interruptions. There is something we would like to believe. We would like to believe that you can take a year off, or two years off, or three years off, or be half-time for five years, and it affects your productivity during the time, but that it really doesn't have any fundamental effect on the career path. And a whole set of conclusions would follow from that in terms of flexible work arrangements and so forth. And the question is, in what areas of academic life and in what ways is it actually true.

Somebody reported to me on a study that they found, I don't remember who had told me about this -- maybe it was you, Richard -- that there was a very clear correlation between the average length of time, from the time a paper was cited. That is, in fields where the average papers cited had been written nine months ago, women had a much harder time than in fields where the average thing cited had been written 10 years ago. And that is suggestive in this regard. On the discouraging side of it, someone remarked once that no economist who had gone to work at the President's Council of Economic Advisors for two years had done highly important academic work after they returned.

Now, I'm sure there are counterexamples to that, and I'm sure people are kind of processing that Tobin's Q is the best-known counterexample to that proposition, and there are obviously different kinds of effects that happen from working in Washington for two years. But it would be useful to explore a variety of kinds of natural interruption experiments, to see what actual difference it makes, and to see whether it's actually true, and to see in what ways interruptions can be managed, and in what fields it makes a difference. I think it's an area in which there's conviction but where it doesn't seem to me there's an enormous amount of evidence.

What should we all do? I think the case is overwhelming for employers trying to be the [unintelligible] employer who responds to everybody else's discrimination by competing effectively to locate people who others are discriminating against, or to provide different compensation packages that will attract the people who would otherwise have enormous difficulty with child care. I think a lot of discussion of issues around child care, issues around extending tenure clocks, issues around providing family benefits, are enormously important. I think there's a strong case for monitoring and making sure that searches are done very carefully and that there are enough people looking and watching that that pattern of choosing people like yourself is not allowed to take insidious effect. But I think it's something that has to be done with very great care because it slides easily into pressure to achieve given fractions in given years, which runs the enormous risk of people who were hired because they were terrific being made to feel, or even if not made to feel, being seen by others as having been hired for some other reason. And I think that's something we all need to be enormously careful of as we approach these issues, and it's something we need to do, but I think it's something that we need to do with great care.

Let me just conclude by saying that I've given you my best guesses after a fair amount of reading the literature and a lot of talking to people. They may be all wrong. I will have served my purpose if I have provoked thought on this question and provoked the marshalling of evidence to contradict what I have said. But I think we all need to be thinking very hard about how to do better on these issues and that they are too important to sentimentalize rather than to think about in as rigorous and careful ways as we can. That's why I think conferences like this are very, very valuable. Thank you.

Questions and Answers

Q: Well, I don't want to take up much time because I know other people have questions, so, first of all I'd like to say thank you for your input. It's very interesting -- I noticed it's being recorded so I hope that we'll be able to have a copy of it. That would be nice.

LAWRENCE SUMMERS: We'll see. (Laughter)

Q: Secondly, you make a point, which I very much agree with, that this is a wonderful opportunity for other universities to hire women and minorities, and you said you didn't have an example of an instance in which that is being done. The chemistry department at Rutgers is doing that, and they are bragging about it and they are saying, "Any woman who is having problems in her home department, send me your resume." They are now at 25 percent women, which is double the national average -- among the top 50 universities -- so I agree with you on that. I think it is a wonderful opportunity and I hope others follow that example.

One thing that I do sort of disagree with is the use of identical twins that have been separated and their environment followed. I think that the environments that a lot of women and minorities experience would not be something that would be -- that a twin would be subjected to if the person knows that their environment is being watched. Because a lot of the things that are done to women and minorities are simply illegal, and so they'll never experience that.

LAWRENCE SUMMERS: I don't think that. I don't actually think that's the point at all. My point was a very different one. My point was simply that the field of behavioral genetics had a revolution in the last 15 years, and the principal thrust of that revolution was the discovery that a large number of things that people thought were due to socialization weren't, and were in fact due to more intrinsic human nature, and that set of discoveries, it seemed to me, ought to influence the way one thought about other areas where there was a perception of the importance of socialization. I wasn't at all trying to connect those studies to the particular experiences of women and minorities who were thinking about academic careers.

Q: Raising that particular issue, as a biologist, I neither believe in all genetic or all environment, that in fact behavior in any other country actually develops [unintelligible] interaction of those aspects. And I agree with you, in fact, that it is wrong-headed to just dismiss the biology. But to put too much weight to it is also incredibly wrong-headed, given the fact that had people actually had different kinds of opportunities, and different opportunities for socialization, there is good evidence to indicate in fact that it would have had different outcomes.

I cite by way of research the [unintelligible] project in North Carolina, which essentially shows that, where every indicator with regard to mother's education, socioeconomic status, et cetera, would have left a kid in a particular place educationally, that, essentially, they are seeing totally different outcomes with regard to performance, being referred to special education, et cetera, so I think that there is some evidence on that particular side.

The other issue is this whole question about objective versus subjective. I think that it is very difficult to have anything that is basically objective, and the work of [unintelligible] I think point out that in a case where you are actually trying to -- this case from the Swedish Medical Council, where they were trying to identify very high-powered research opportunities for, I guess it was post-docs by that point, that indicated that essentially that it ended up with larger numbers of men than women.

Two of the women who were basically in the affected group were able to utilize the transparency rules that were in place in Sweden, get access to the data, get access to the issues, and in fact, discovered that it was not as objective as everyone claimed, and that in fact, different standards were actually being used for the women as well as for the men, including the men's presence in sort of a central network, the kinds of journals that they had to publish in to be considered at the same level, so I think that there are pieces of research that begin to actually relate to this -- yes, there is the need to look more carefully at a lot of these areas.

I would -- in addition looking at this whole question of the quality of marginal hires -- I would also like to look at the quality of class one hires, in terms of seeing who disappoints, and what it was that they happened to be looking at and making judgments on, and then what the people could not deliver.

So I think that there is a real great need on both sides to begin to talk about whether or not we can predict. I hate to use a sports metaphor, but I will. This is drawn basically from an example from Claude Steele, where he says, he starts by using free throws as a way of actually determining, who should -- you've got to field a basketball team, and you clearly want the people who make 10 out of 10, and you say, "Well, I may not want the people who make zero out of 10," but what about the people who make four out of 10. If you use that as the measure, Shaq will be left on the sidelines.

LAWRENCE SUMMERS: I understand. I think you're obviously right that there's no absolute objectivity, and you're -- there's no question about that. My own instincts actually are that you could go wrong in a number of respects fetishizing objectivity for exactly the reasons that you suggest.

There is a very simple and straightforward methodology that was used many years ago in the case of baseball. Somebody wrote a very powerful article about baseball, probably in the seventies, in which they basically said, look, it is true that if you look at people's salaries, and you control for their batting averages and their fielding averages and whatnot, whites and blacks are in the same salary once you control. It is also true that there are no black .240 hitters in the major leagues, that the only blacks who are in the major leagues are people who bat over .300 -- I'm exaggerating -- and that is exactly what you'd predict on a model of discrimination, that because there's a natural bias against.

And there's an absolute and clear prediction. The prediction is that if there's a discriminated-against group, that if you measure subsequent performance, their subsequent performance will be stronger than that of the non-discriminated-against group. And that's a simple prediction of a theory of discrimination. And it's a testable prediction of a theory of discrimination, and it would be a revolution, and it would be an enormously powerful finding in this field, to demonstrate, and I suspect there are contexts in which that can be demonstrated, but there's a straightforward methodology, it seems to me, for testing exactly that idea. I'm going to run out of time. But, let me take-if people ask very short questions, I will give very short answers.

Q: What about the rest of the world. Are we keeping up? Physics, France, very high powered women in science in top positions. Same nature, same hormones, same ambitions we have to assume. Different cultural, given.

LAWRENCE SUMMERS: Good question. Good question. I don't know much about it. My guess is that you'll find that in most of those places, the pressure to be high powered, to work eighty hours a week, is not the same as it is in the United States. And therefore it is easier to balance on both sides. But I thought about that, and I think that you'll find that's probably at least part of the explanation.

Q: [unintelligible] because his book was referred to.


Q: I would like to make an on observation and then make a suggestion. The observation is that of the three. There is a contradiction in your three major observations that is the high-powered intensive need of scientific work -- that's the first -- and then the ability, and then the socialization, the social process. Would it be possible the first two result from the last one and that math ability could be a result of education, parenting, a lot of things. We only observe what happens, we don't know the reason for why there's a variance.

I'll give you another thing, a suggestion. The suggestion is that one way to read your remarks is to say maybe those are not the things we can solve immediately. Especially as leaders of higher education because they are just so wide, so deep, and involves all aspects of society, institution, education, a lot of things, parenting, marriages are institutions, for example. We could have changed the institution of those things a lot of things we cannot change. Rather, it's not nature and nurture, it is really pre-college versus post-college. From your college point of view maybe those are things too late and too little you can do but a lot of things which are determined by sources outside the college you're in. Is that...


Q: That's a different read on your set of remarks.

LAWRENCE SUMMERS: I think your observation goes much more to my second point about the abilities and the variances than it does to the first point about what married woman....

Q: [unintelligible]

LAWRENCE SUMMERS: Yeah, look anything could be social, ultimately in all of that. I think that if you look at the literature on behavioral genetics and you look at the impact, the changed view as to what difference parenting makes, the evidence is really quite striking and amazing. I mean, just read Judith Rich Harris's book. It is just very striking that people's -- and her book is probably wrong and its probably more than she says it is, and I know there are 13 critiques and you can argue about it and I am not certainly a leading expert on that -- but there is a lot there. And I think what it surely establishes is that human intuition tends to substantially overestimate the role -- just like teachers overestimate their impact on their students relative to fellow students on other students -- I think we all have a tendency with our intuitions to do it. So, you may be right, but my guess is that there are some very deep forces here that are going to be with us for a long time.

Q: You know, in the spirit of speaking truth to power, I'm not an expert in this area but a lot of people in the room are, and they've written a lot of papers in here that address ....

LAWRENCE SUMMERS: I've read a lot of them.

Q: And, you know, a lot of us would disagree with your hypotheses and your premises...


Q: So it's not so clear.

LAWRENCE SUMMERS: It's not clear at all. I think I said it wasn't clear. I was giving you my best guess but I hope we could argue on the basis of as much evidence as we can marshal.

Q: It's here.

LAWRENCE SUMMERS: No, no, no. Let me say. I have actually read that and I'm not saying there aren't rooms to debate this in, but if somebody, but with the greatest respect -- I think there's an enormous amount one can learn from the papers in this conference and from those two books -- but if somebody thinks that there is proof in these two books, that these phenomenon are caused by something else, I guess I would very respectfully have to disagree very very strongly with that. I don't presume to have proved any view that I expressed here, but if you think there is proof for an alternative theory, I'd want you to be hesitant about that.

Q: Just one quick question in terms of the data. We saw this morning lots of data showing the drop in white males entering science and engineering, and I'm having trouble squaring that with your model of who wants to work 80 hours a week. It's mostly people coming from other countries that have filled that gap in terms of men versus women.

LAWRENCE SUMMERS: I think there are two different things, frankly, actually, is my guess -- I'm not an expert. Somebody reported to me that -- someone who is knowledgeable -- said that it is surprisingly hard to get Americans rather than immigrants or the children of immigrants to be cardiac surgeons. Cardiac surgeon is about prestigious, certain kind of prestige as you can be, fact is that people want control of their lifestyles, people want flexibility, they don't want to do it, and it's disproportionately immigrants that want to do some of the careers that are most demanding in terms of time and most interfering with your lifestyle.

So I think that's exactly right and I think it's precisely the package of number of hours' work what it is, that's leading more Americans to choose to have careers of one kind or another in business that are less demanding of passionate thought all the time and that includes white males as well.

Q: That's my point, that social-psychological in nature [unintelligible].

LAWRENCE SUMMERS: I would actually much rather stay -- yes, and then I'm on my way out.

Q: I have no idea how you would evaluate the productivity of the marginal hire if this person is coming into an environment where [unintelligible] is marginal and there's [unintelligible].

LAWRENCE SUMMERS: You're absolutely right. You're absolutely right. I used the term -- I realized I had not spoken carefully -- I used the term marginal in the economic sense to mean, only additional, to only mean...

Q: [unintelligible].

LAWRENCE SUMMERS: No, to mean only the additional [unintelligible]. Yeah, obviously [unintelligible] going to identify X is the additional hire, is the marginal hire, the question you can ask is, you know, here is a time when, as a consequence of an effort, there was a very substantial increase in the number of people who were hired in a given group, what was the observed ex post quality? And what was the observed ex post performance? It's hard to believe that that's not a useful thing to try to know. It may well be that one will produce powerful evidence that the people are much better than the people who were there and that the institutions went up in quality and that made things much better.

All I'm saying is one needs to ask the question. And as for the groping in the kitchen, and whatnot, look, it's absolutely important that in every university in America there be norms of civility and proper treatment of colleagues that be absolutely established and that that be true universally, and that's a hugely important part of this, and that's why at Harvard we're doing a whole set of things that are making junior faculty positions much more real faculty positions with real mentoring, real feedback, serious searches before the people are hired, and much greater prospects for tenure than there ever have been before because exactly that kind of collegiality is absolutely central to the academic enterprise.

Thank you.

Return to "Lawrence H. Summers...remember him?"

Friday, November 14, 2008

"Jewel of the Earth"--transcript

"Jewel of the Earth"


February 14th, 2006

NARRATOR: Amber: its jewel-like beauty has held humans spellbound for thousands of years, but inside an even greater treasure glows.

DAVID ATTENBOROUGH: It's hard to imagine a more perfect time capsule than this. This little bee has been trapped in there for literally millions of years.

NARRATOR: Suspended in time, these tiny prisoners have tales to tell of a world that belonged to the dinosaurs, of enemies long extinct, of supercontinents that no longer exist. Now scientists can peer deeper into these time machines than they ever did before, opening the door to the unthinkable, bringing dinosaurs back to life.

DAVID GRIMALDI (American Museum of Natural History): I was astounded at the possibility of DNA being preserved.

ROBERTA POINAR (Oregon State University): Every once in a while, in your life, you witness something that's just too spectacular for words, and this was one of the times.

NARRATOR: Host David Attenborough takes you on a quest for amber. Jewel of the Earth, right now on NOVA.

Google is proud to support NOVA in the search for knowledge: Google.

Major funding for NOVA is provided by the Howard Hughes Medical Institute, serving society through biomedical research and science education: HHMI.

Major funding for NOVA is also provided by the Corporation for Public Broadcasting, and by PBS viewers like you. Thank you.

DAVID ATTENBOROUGH: There is a substance so strange and so beautiful that whenever people encountered it, they thought they had found something magical. And its magic is real, because this material has traveled through time, bringing with it passengers from the distant past that have wonderful tales to tell.

This extraordinary substance has fascinated me since I first held a piece, this piece, when I was 12. My first piece of amber arrived in a very unexpected way.

In 1938, during the build up to the Second World War, my parents helped some of the many children fleeing from Germany. They had left their families behind and were allowed to bring almost nothing with them. I remember one girl, in particular. Her name was Marianne. She was 12, about the same age as I was, and she came from a city on the Baltic coast where her father was a doctor.

He had given her one small but precious thing, as a sign of his thanks to whoever it was who was going to look after his daughter. And this is it. It felt surprisingly warm and light in my hand, but what made me fall in love with amber was what I discovered inside it. I found something miraculous.

There were insects preserved in astonishing detail. I burned with questions. What sort of world were they from? They must have lived a long time ago, but how long? Years later, my brother Richard would play a scientist in a movie which made amber famous the world over.

RICHARD ATTENBOROUGH (Actor/John Hammond in clip from "Jurassic Park"): Welcome to Jurassic Park.

DAVID ATTENBOROUGH: Richard's character extracted DNA from dinosaur's blood trapped in amber and, with it, brought dinosaurs back to life. Could that ever be done?

SAM NEILL (Actor/Dr. Alan Grant in clip from "Jurassic Park"): How did you do this?

RICHARD ATTENBOROUGH (Actor/John Hammond in clip from "Jurassic Park"): I'll show you.

DAVID ATTENBOROUGH: I started my journey with the amber time machine by taking Marianne's gift back to where it came from, to the shores of the Baltic Sea.

The amber comes from rocks on the seabed, some distance out from the coast, but people don't find it until it washes up on the shore. Little bits like this are quite common. Sometimes, if you are lucky, particularly after a storm, you can find bigger bits. Some even have barnacles still attached to them. People have been collecting such bits for thousands of years but had no idea how amber originated. Some said it was solidified sunshine, some that it was the tears of the gods.

Then, around the year 77 A.D., a great Roman naturalist, Pliny the Elder, conducted a simple experiment. He did this.

The smell? Unmistakable: pine resin.

Several types of plants, among them conifers, seal any wound inflicted by storms or insect attack, by producing a sticky resin which oozes out from them. And because it continues to gently flow around whatever it traps, it can preserve creatures in the finest detail. As the resin hardens around its captives, they become suspended in time.

Of course, many creatures are fossilized in rock, like this small flat fish, for example. It's a kind of ray. It was squashed, its soft parts decayed, even its little spines turned into rock.

But amber preserves creatures in a quite different fashion. When this little bee touched this drop of resin she was caught by its stickiness, and she was instantly and perfectly preserved in three dimensions. These eyes saw a world which existed long before mankind evolved. She scented flowers before the first human being ever smelled one. And I can even tell that she was working hard when she died, by the bundles of cargo on her hind legs.

It's hard to imagine a more perfect time capsule than this. This little bee has been trapped in there for, literally, millions of years.

Amber's ability to travel through time can take us back into more recent history, our history. Stonehenge is one of the earliest man-made structures in the world. These stones have been standing here for something like three and a half thousand years, and we know that, even then, the people who erected them treasured amber.

But they weren't the first. It was considered to be precious way back in the Stone Age, and this may be why. When you scrape its rough surface, with a flint blade, perhaps, you quickly reveal the wonderful golden color inside. It's quite magical.

Stone Age people also carved bone and stone in order to make tools, but amber was different. It seemed to have had no practical use, so they must have valued it for some other reason.

The carvings they made, around 10,000 years ago, give us an idea of how they viewed the world, and, in particular, which animals mattered most to them. Imagine the value of amber to a Stone Age hunter who believed that capturing an animal's spirit by carving it in amber made the animal itself easier to hunt.

The people who built the great stone circle at Stonehenge lived in the Bronze Age, several thousand years later, but they, too, treasured amber. None but the wealthiest of them could afford a material as rare as this.

Once, there were a thousand beads in this necklace. Over 3,000 years, their surfaces have become opaque and crumbly. But when they were new, and freshly polished, and glowing, it must have been a wondrous piece of jewelry.

One woman's grave contained a rather more mysterious object, a disc of amber, now browned with age, encircled by gold. It was certainly a remarkable piece of personal decoration, but maybe it had a rather deeper significance.

The sun is central to our understanding of Stonehenge. The monument may have been used as a solar calendar, and it may be that its builders treasured amber, because it captured the warmth and the light of the sun. It may or may not have been considered magical in prehistoric Britain, but it was most certainly rare, for it came from far away.

This is the Baltic city of Gdansk, in Poland. The jewelry worn by the people of Stonehenge, and buried with them, came from around here. It is evidence of one of the world's first long distance trade routes.

But what brought the big boom in amber was the rise of Imperial Rome. The Romans bought it for prestige. Amber carvings cost more than the best slaves, and even the emperor Nero treasured it. He decorated his amphitheaters with tons of it, to show how unbelievably wealthy he was.

So Baltic amber can take us back at least 10,000 years into our own past, but it reaches back much further than that.

To find out how far, I went to one of the Gdansk workshops where amber jewelry is made, to meet Elzbieta Sontag.

ELZBIETA SONTAG (University of Gdansk): ...very thin, it's most probably with inclusion inside.

DAVID ATTENBOROUGH: Elzbieta is a biologist who comes here to look for "inclusions," animals and plants trapped in the amber.

It takes a practiced eye to search through as much raw amber as this, and I was delighted to get a lesson from the expert.

How do I start? I mean, there are a million pieces, all right a thousand pieces. there a particular color I should look for?

ELZBIETA SONTAG: Sometime color yes, because white and milky is without inclusion.





DAVID ATTENBOROUGH: Okay, I'm not interested in that.

ELZBIETA SONTAG: Okay, I avoid it, that kind of color.


ELZBIETA SONTAG: I'm looking for transparent.

DAVID ATTENBOROUGH: Would that one be any good?

ELZBIETA SONTAG: Yes. I think, yes. We can split it.




ELZBIETA SONTAG: And may be something is inside.

DAVID ATTENBOROUGH: How many pieces do you look at before you find something?

ELZBIETA SONTAG: Oh, about 20.


ELZBIETA SONTAG: Not good, shape is not good.

DAVID ATTENBOROUGH: Why is it the wrong shape? Twelve.


DAVID ATTENBOROUGH: Thirteen...spit...there's a lot of bubbles. Fourteen...

ELZBIETA SONTAG: Wow! Oh, no. Maybe.

DAVID ATTENBOROUGH: Fifteen, nothing. Yes, I think so, 16. It's a mosquito.

ELZBIETA SONTAG: No mosquito, midges.

DAVID ATTENBOROUGH: Oh, but this is beautiful. The midge looks as though it took off from its twig only yesterday. But, amazingly, it has been frozen in flight for around 40 million years.

So what about the creatures in my piece? What exactly were they? I could see them clearly, for Elzbieta's microscope had a projection screen.

Oh, well that's an old friend, because it's quite big and it's near the surface, and I've known it for a long time. So it's a fly but what kind of a fly?

ELZBIETA SONTAG: It's a long-legged fly.

DAVID ATTENBOROUGH: A long-legged fly? And in what part of the forest do they live?

ELZBIETA SONTAG: Low on the forest. Sometimes sit on the bark.

DAVID ATTENBOROUGH: So the likelihood is, then, that this fly, and therefore this piece of amber, this gum, this resin, was low down on the tree.

ELZBIETA SONTAG: Yes, low down on the floor.

DAVID ATTENBOROUGH: Okay, what else is there?

With her powerful microscope, Elzbieta was exploring far deeper into my amber than I had been able to do, and there she found another fly, a fungus gnat. It must have died searching for rotten wood, for that is where it lays its eggs.

Then Elzbieta found an aphid and, right above it, an ant. Perhaps they had fallen together from a leaf where they were feeding. I think that's a fantastic picture. I mean, I...and it's deep in the amber. I know, because I've never seen it like this before.

But the last animal she found was the most surprising. Ah, what a monster! What is it?

ELZBIETA SONTAG: There is a mite.


ELZBIETA SONTAG: Yes, a very small monster.

DAVID ATTENBOROUGH: Yes. That's tiny though, isn't it? How big is that?

ELZBIETA SONTAG: That one? Half a millimeter.

DAVID ATTENBOROUGH: Half a millimeter.

I've never seen it before. So we've got a whole community-and we know that they all lived together because, because they all died together-in my one piece of amber. And that alone has given us a whole rounded picture of a tiny little ecosystem, at the bottom of a tree, 40 million years ago.


DAVID ATTENBOROUGH: Amazing. Thank you very much.

It had taken me more than 60 years to find and identify all the animals inside my amber. And seeing them together had given me something more, a glimpse of their world.

By comparing many amber animals to modern forms, scientists like Elzbieta are sure that the forest they inhabited was a temperate one. But how broad a picture can these time travelers give us? Could it encompass a whole forest or even a whole continent?

Well, in the 1960s, on a Caribbean mountainside, science discovered a new source of amber which seemed perfectly suited to answer those questions. I had a chance to visit it 15 years ago. I hoped that for the first time, I, myself, might collect some amber.

Here in the Dominican Republic, amber is mined. And by dating the mudstones that contain it, we can tell that it is about 20 million years old, rather younger than Baltic amber.

Picking a piece of amber from the mudstones in which it has lain for so long was hugely exciting. I brought a small collection back home with me. So what kind of forest did this amber come from? Well thanks to some remarkable detective work, we can answer that question in amazing detail.

In this piece, there's a leaf from the plants that produced the amber. And this is what those plants looked like. They were giant bean trees. But what matters most about them is not what they looked like but where they grew. They were tropical.

Scientists had long imagined that the ancient tropical forests contained a vast diversity of life, but very few fossilized traces had ever been found, until they discovered these.

Dominican amber preserves such a huge variety of animals and plants, with such perfection, that it inspired two scientists, George and Roberta Poinar, to try something that had previously been thought impossible. In the same way that Elzbieta reconstructed the world around a single Baltic tree, they started to use these tiny fossils to bring a whole tropical forest back to life.

I had found a piece which contained a little bee. She must have been familiar with many of the plants in that forest, indeed she depended on them. So, based on the Poinar's findings, and with a little bit of amber magic, we can follow her back home.

This tiny flower shows that the amber trees were not the only giants reaching up into the forest canopy. It belonged to a sebo, whose great trunk is supported by wide buttress roots.

But the commonest flowers of all came from a different tree, the nazareno. It seems likely that these trees dominated the forest canopy. When one of these giants fell, it would have opened up a light gap, which other, faster-growing plants could fill, plants like palms.

And here are their flowers, confirming that palms were another key element of that forest.

So we have built up a picture of what part of the forest was like and even identified some of the flowers which might have tempted my bee. But I don't think she died collecting nectar.

She was searching the forest for something else. Remember those bundles on her back legs? They are clues to what she was after. She was collecting resin, and not just any resin, but resin from the amber trees themselves. And that was a very dangerous thing to do. She was a stingless bee, very skilled at handling resin. Even so, there was a real chance that while collecting it, a bee might get stuck. Stingless bees are among the most common animals trapped in Dominican amber. Why did they take the risk?

Resin is very valuable to these bees. Mixed with plant waxes and fibers, it makes a strong building material for their nests. But it also brings another benefit. It contains antibiotics which disinfect the wounds in the bark of the tree from which it oozes. By bringing it here, into the nests, the bees protect their developing young from infection.

So now we know exactly what this little bee was doing in that forest 20 million years ago. This piece of amber has not only trapped her body, it also caught her behavior. And we know from other pieces of amber, too, that she had enemies.

This is an assassin bug. It hunts stingless bees, and their addiction to resin makes it easy for it to find them. The bug can't move swiftly enough to snatch a bee from midair, but it's strong enough to pull off strands of resin. With these sticky gloves it can hold on to any bee which touches them. It's using resin to set a trap. Now the assassin stabs its dagger-like mouthparts into a weak point behind the bee's head and injects its saliva, paralyzing the bee. As she dies, she releases a pheromone, a scent calling for help, which normally rallies other bees to defend the nest, and that entices them into the assassin's reach.

But one assassin lost its grip and now lies in amber, together with its victim. Once small animals like this were in the resin's grip they were as doomed as flies on fly paper. But, even so, amber sometimes contains animals that, normally, would never go near it.

How can George Poinar explain his next discovery? It was an amber tadpole. It couldn't have come into contact with resin underwater, yet when he looked further, he found other pond animals: a young marsh beetle, even a diving beetle.

The challenge was to explain how they had found their way into a flow of resin on the trunk of a tree. This is a poison dart frog. She is only half the size of your thumb, and, remarkably, she is carrying a tadpole on her back. She moves in a very determined and purposeful way, and starts to climb a tree.

These are what she is looking for: plants that collect water, called tank bromeliads. No one has yet found a piece of a bromeliad in amber, but we know they were there because there are amber damselflies of a kind which today lays its eggs between the tightly packed leaves of bromeliads.

She's reached a branch. Her tadpole will soon have a nursery. She lowers her rear end into the bromeliad's pond.

Other animals also lived in these tiny ponds. Up here they may have been safe from predators but not, it seems, from resin. So bromeliads held tiny complete worlds high up above the ground, but, even so, they probably didn't contain enough food to sustain a fast growing tadpole. What, then, did it eat? Amazingly the piece of amber that held the tadpole also contained the answer.

Poison dart frogs are very attentive parents. Every few days the tadpole's mother climbs back up the tree to the bromeliad to care for her youngster. She's laying an egg. That's what the other object was in the amber. These eggs are sterile and don't grow into frogs, they are food. But occasionally these little worlds up in the branches were shattered. And at least one falling tadpole came to a sticky end.

Who would have thought that amber could reveal such intimate details of life in tiny ponds high up in such trees as these?

But what about the bigger animals of the forest? Amber surely can't tell us anything about the presence or absence of these. Or can it?

Remarkably, amber does contain evidence of one such creature, thanks to some very oddly shaped seeds. These are the seeds of a kind of bamboo. The hooks on them get stuck in the hairs of animals so that the seeds travel with them and so are dispersed. But what sort of animals carried these seeds? Well, sometimes such seeds have hairs still attached to them, and the only animals with hairs are mammals.

There were certainly a number of mammals around 20 million years ago, but can these hairs help us to be a little more specific as to which mammals were here? They can.

The shape of the scales on the surface of hairs varies, and George Poinar used them to narrow down the possibilities. They came from some kind of carnivore.

It seems there were big cats in the ancient forest. Perhaps they even hunted the ancestors of modern coatis. So that's one more animal that I know that lived in that forest, but what about organisms for which there is not even a hair to serve as evidence?

Amber really is astonishing, because, as well as carrying animals' bodies through time, it can bring clues to their relationships. And that is what makes me certain that the forest contained enormous fig trees like this, although no trace of such a tree has yet been found in amber.

Let me explain. George Poinar found the crucial evidence. Exhibit A: a minute wasp. This wasp proves that the forest had figs, but to find out what makes it such a conclusive witness, we need to see what goes on today, inside the figs themselves. Although they look like fruit, figs are really containers for the tree's flowers and its developing seeds. But some also house wasps. Fig wasps spend almost all their lives inside figs, which are sealed so nothing but a fig wasp can collect their pollen. And that is how the wasps repay the fig trees for providing their nursery, by distributing their pollen.

These two organisms have come to rely on each other so closely that it's impossible for one to exist without the other. That is why a single wasp can guarantee that the forest contained fig trees. The partnership between figs and wasps is one of the most intimate in the whole of nature.

But that piece of amber had something else to reveal, something that was rather more sinister. The rear end of the wasp is surrounded by minute nematode worms. As the wasps emerge inside a fig, so do these nematodes. Each has just a few minutes to find a wasp and burrow into its body before it leaves the fig. But these are not conventional parasites. The only thing they will take from the wasps is a free ride to the next fig. Only amber could have preserved such minute details and, with them, revealed an extraordinary fact.

The relationship between the forest's fig trees, their wasps and worms, that we know today, clearly existed 20 million years ago. Amber, again and again, demonstrates this constancy.

Take this, for example. It looks like a death scene, a scale insect in the jaws of a predatory ant. But the truth is very different. Scale insects drink the stress, anxiety or panic of pods, but this takes time. Predators would soon pick them off, if it wasn't for the teams of ant bodyguards that protect them. And in exchange, the ants receive a share of the sap. By providing ants with food that they can't otherwise reach, the scale insects have made themselves indispensable. This relationship was so important that, far from eating her captive, this queen ant was gently carrying it away, so it would set up a new colony beside her own. And for 20 million years neither partner has had any reason to change.

What does this astonishing absence of change imply? If conditions had altered radically, many of these complex relationships would have disappeared. So their presence tells us that tropical forests must have existed, largely unchanged, for at least 20 million years.

But now George Poinar has traveled back even further in time. One of his latest finds in Dominican amber takes us back not just 20 million years, but 150 million, for it has implications about the Earth's geological history. And this startling new evidence comes from a single ant.

I have come across its modern relatives myself, and their behavior can tell us something unexpected about the Dominican amber forest. They are honeypot ants whose workers have become jars in which the colony stores honey to help it through times when liquid and nectar are scarce in the dry season.

So this amber honeypot ant suggests that the ancient forest also had a dry season. And if the modern ants are anything to go by, then it lasted around three to four months.

So, now, amber can tell us how often it rained 20 million years ago. But it is also evidence of an event that occurred even further back in time, because the living honeypot ants I found don't occur in the Dominican Republic or even in South America; they live in Australia.

So these little ants are evidence not only of climate, but the fact that once Australia and South America were joined together in one supercontinent. Who would have thought a single ant could tell us so much?

The amber time machine could hardly illuminate a more global event than the drift of continents, but it can also take us to the opposite extreme. What surprises might we find inside an amber animal?

Dr. David Grimaldi, of the American Museum of Natural History, is especially interested in lizards. These Anolis lizards are very territorial and the males take great risks to secure a patch of bark for themselves. They spend a lot of time displaying aggressively to one another, doing press-ups and erecting their throat flaps. And sometimes they fall. A few have achieved fame and immortality in amber, but such specimens are very rare, and not surprisingly. A lizard should be strong enough to unstick itself from a flow of resin. But some did not, and that puzzled David Grimaldi.

He wondered whether they could be as well-preserved inside as they were outside. Could he actually look inside an amber lizard? He turned to the latest high tech scanners.

DAVID GRIMALDI: These are scans that use very high intensity x-rays that are too high for medical purposes, and we have incredible detail in any view that we want. This scan of a gecko's head shows the finest details of its skull and even its teeth. Amber's preservation is clearly more than skin deep but nothing in this scan could explain why this gecko was trapped.

DAVID ATTENBOROUGH: So David Grimaldi turned to another gecko and looked at its whole body, this time with conventional x-rays.

DAVID GRIMALDI: The x-ray revealed that the bones were beautifully preserved. Bones of the skull, delicate little toe bones, bones of the leg and even individual vertebrae are revealed. But, from the jumble of bones, it is clear that the gecko's back was broken. It had probably been picked up and dropped, perhaps by a bird of prey. It didn't escape from the resin because, when it hit it, it was already dead.

DAVID ATTENBOROUGH: As researchers started finding even smaller internal details preserved by amber, they began to ask themselves something almost unthinkable. Could amber have preserved molecular structures inside an animal? Perhaps even its DNA? Some people even imagined that such DNA could bring monsters back to life. And look where that got us. But there are no remains of dinosaurs in amber. Surely their DNA is beyond our reach.

The Poinars dared to wonder if that was so. The story begins 20 years ago, when Roberta first focused an electron microscope on an amber animal. Inside a fungus gnat, like the one in my piece of Baltic amber, she discovered something quite amazing.

ROBERTA POINAR: It's like a miracle. Every once in a while, in your life, you witness something that's just too spectacular for words, and this was one of the times.

DAVID ATTENBOROUGH: The Poinars had found 40-million-year-old cells, and more than that, even the minute structures inside the cells were clear to see.

GEORGE POINAR (Oregon State University): We were kind of flabbergasted that it was possible to have such a degree of preservation after such a long time.

ROBERTA POINAR: And so I, you know, zoomed on up to a higher magnification and just was amazed to see that there were nuclei with bits of chromatin in the nucleus. And that is the step that led us to believe that DNA was there, in the cell, and could, perhaps, be pulled out and looked at.

DAVID ATTENBOROUGH: It was an astonishing discovery. The prospect of finding such ancient DNA electrified the scientific community. And Hollywood wasn't far behind. The storyline of Jurassic Park is very ingenious. My brother, who played the scientist, didn't actually need to find bits of dinosaur in amber. Nature had already extracted their DNA in blood cells and preserved it inside an amber mosquito. But that's pure fiction isn't it?

DAVID GRIMALDI: Surely it is impossible to recover DNA from any animal which lived in the distant past.

DAVID ATTENBOROUGH: Well, two teams set out to attempt exactly that. One of them included David Grimaldi. The other was set up by the Poinars. Both knew that their only chance of finding DNA was in the best-preserved animals, so the Poinars chose to use my favorites, some stingless bees, while the other team decided to work on an amber termite.

DAVID GRIMALDI: We had no expectations-at least I didn't-when we did the study. We did the extractions. We tried it. Several of the extractions were unsuccessful.

DAVID ATTENBOROUGH: But then both teams struck gold. Tissue extracted from the Poinar's bees tested positive for DNA, and David Grimaldi got the same result from the termite.

DAVID GRIMALDI: Our first reaction, particularly mine, was really disbelief. I was astounded at the possibility of DNA being preserved.

DAVID ATTENBOROUGH: It really was astounding. They were claiming to have recovered DNA from animals which had died 20 million years before; not yet as old as the dinosaurs, but that's what a new team, including the Poinars, turned to next. And when they said what they had found, they caught the attention of the world. They had DNA from an insect older than T. Rex. So could Hollywood possibly have got it right?

GEORGE POINAR: We felt that bringing back an entire dinosaur was not in the realm of possibility, at this time.

DAVID GRIMALDI: Barraged with the common question, when are you going to clone extinct organisms, we constantly had to repeat ourselves: "We are not going to do that."


DAVID GRIMALDI: If DNA is indeed preserved in amber, it is so chopped up, so fragmentary, that it is impossible to reconstruct the entire genome and then insert it into some surrogate organism, and then have a complete resurrected extinct species out of that. That is absolutely impossible.

DAVID ATTENBOROUGH: As the blaze of publicity surrounding the film faded, so other scientists tried to extract DNA from amber insects. And their results, when they were published, were bad news for the Poinars and David Grimaldi. None of them had found even a trace of ancient DNA. But what went wrong?

DAVID GRIMALDI: What some of them found, in fact, were contaminant DNA sequences. And I have to admit, by that point, that I was pretty much convinced that the original reports of DNA sequences in amber were of contaminant DNA.

GEORGE POINAR: And some of the scientists that did make an attempt got all kinds of strange things. They would get fish DNA. Well, perhaps they had a tuna fish sandwich that day and were careless.

DAVID ATTENBOROUGH: Like most other researchers, David Grimaldi has changed his mind. But George Poinar is still confident that a few rare pieces of amber do contain DNA. And some insects certainly could have drunk the blood of dinosaurs.

These sandflies have been preserved in amber for 100 million years. Who knows what might be inside them?

And that is why amber fascinates me so much. It has brought us so many surprises. The prospect of it preserving DNA brought dinosaurs back, at least in our imaginations. And the creatures that traveled in it through time bring us vivid snapshots of the Caribbean forest as it was 20 million years ago. And my piece of Baltic amber, the first I ever owned, has preserved creatures with such perfection that they are still startlingly beautiful.

What a journey amber has taken me on! And it all came from a gift from a small girl over 60 years ago. I imagine Marianne and her father found my piece of amber by walking along a Baltic shore, just as thousands of people had done before them. Its magic may not extend to recreating a dinosaur, but, for me, amber remains a substance of wonder, a time machine that can show us exactly how some things looked tens of millions of years ago.

Return to "Amber's encapsulated gems"