From: Dace (edace@earthlink.net)
Date: Mon 12 Jul 2004 - 20:12:11 GMT
From an interview conducted with Ernst Mayr by Skeptic magazine four years
ago. Mayr turned 100 on the 5th of July.
--TD
Skeptic: You were born in 1904 when the grand old man of biology was Alfred
Russel Wallace, who was 84 (and who would live to be 91). Evolutionary
biology was still largely pursued by naturalists and was mostly an
observational enterprise. The theory was still struggling for acceptance as
a serious science. Looking back on the century, give us your opinion on the
most significant contributions to evolutionary biology that have helped to
elevate it to the status it holds today.
Mayr: The first one was the great debate that led to the evolutionary
synthesis. Dobzhansky's book in 1937, Genetics and the Origin of Species,
was very crucial because he was a "born naturalist," became a beetle
specialist and so forth.Then at the age of 27 he came to America, worked for
10 years in Morgan's lab where he learned all about the genetic aspects of
organisms, then combined the two.
Skeptic: Did Dobzhansky's book influence your work significantly?
Mayr: It didn't change it, but it filled in the gaps in my knowledge of
genetics. Dobzhansky's book was still weak in the diversity aspects. He made
a good start on defining the isolating mechanisms, but he erred by including
geographic barriers among them. At the time, however, everyone thought that
now all the problems were solved. And it was almost true. But there was
still one major problem and that was the relative role of the gene versus
the individual. I accepted the individual as the target of selection.
Geneticists said that evolution is a change in gene frequencies among
populations. But this is nonsense. Changes in gene frequencies are the
result of evolution, not the mechanism . By about 1970s the majority of
evolutionary biologists agreed that the individual was the primary target of
selection.
Skeptic: What about group selection?
Mayr: George Williams and Richard Dawkins have made a mistake, in my
opinion, in completely rejecting group selection. But we have to be careful
here to define what we mean by a group. There are different kinds of groups.
There is one type of group that is a target of selection, and that is the
social group. Darwin knew this and identified it very clearly in 1871 in The
Descent of Man. Hominid groups of hunter-gatherers were constantly competing
with other hominid groups; some were superior and succeeded and others were
not. It becomes quite clear that those groups who had highly cooperative and
altruistic individuals were more successful than the ones torn apart by
internal strife and egotism.
Skeptic: The social environment is as important as the physical environment?
Mayr: The essential point is that if you are altruistic and make your group
more successful, you thereby also increase the fitness of the altruistic
individual (yourself)!
Skeptic: But isn't it still the individual being selected for these
characteristics, not the group?
Mayr: There is no question that the groups that were most successful had
these individuals that were cooperative and altruistic, and those traits are
genetic. But the group itself was the unit that was selected.
Skeptic: You developed your theory of allopatric speciation in the 1940s and
1950s. In the 1970s Niles Eldredge and Stephen Jay Gould applied that to the
fossil record and called it punctuated equilibrium. Was this just a spinoff
from what you had already done? What was new in punctuated equilibrium?
Mayr: I published that theory in a 1954 paper ("Change of Genetic
Environment and Evolution," in Huxley, J., A.C. Hardy, and E. B. Ford, Eds.,
Evolution as a Process, London: Allen and Unwin), and I clearly related it
to paleontology. Darwin argued that the fossil record is very incomplete
because some species fossilize better than others. But what I derived from
my research in the South Sea Islands is that in these isolated little
populations it is much easier to make a genetic restructuring because when
the numbers are small it takes rather few steps to become a new species. A
small local population that changes very rapidly. I noted that you are never
going to find evidence of a small local population that changed very rapidly
in the fossil record. My essential point was that gradual populational
shifts in founder populations appear in the fossil record as gaps.
Skeptic: Isn't that what Eldredge and Gould argued in their 1972 paper,
citing your 1963 book Animal Species and Evolution several times?
Mayr: Gould was my course assistant at Harvard where I presented this theory
again and again for three years. So he knew it thoroughly. So did Eldredge.
In fact, in his 1971 paper Eldredge credited me with it. But that was lost
over time.
Skeptic: Okay, but since you are also a historian and philosopher of science
surely you recognize that there is a social factor here-the marketing and
selling of an idea to a community of scientists.
Mayr: There are two kinds of scientists: media scientists and scientists'
scientists. Gould, Dawkins and E.O. Wilson are media scientists (in the
sense of publishing for the public).
Skeptic: Hasn't Wilson taken your early philosophy of biology distinction
between how and why questions to the nth degree in Consilience in looking
for the ultimate causes of human behavior?
Mayr: Wilson is difficult to evaluate. To give him justice, he is a
tremendous enthusiast. He is always euphoric. The future is always
beautiful. He's an evangelist, a scientific evangelist.
Skeptic: You are smiling when you say that.
Mayr: He's such a nice guy and so optimistic. Maybe because I grew up in
Germany where things always went wrong, and I lost my father at a young age,
I grew up to be a realist, maybe even a pessimist. I can't make all these
enormous predictions as Wilson does in his books.
Skeptic: How does evolution as a historical science differ from experimental
sciences?
Mayr: If you go to the literature in the philosophy of science you read
about how experiment is the key to science. Hell no! Experiment in
evolutionary biology is not useful at all except in certain cases. Darwin's
method of asking "why" questions, then developing historical analogies, is
how we "test" evolutionary hypotheses. If you want to explain why the
dinosaurs became extinct you cannot run an experiment. You construct a
scenario and see how well it explains the data. Could it have been microbes
that wiped them out? Gradual environmental changes? A meteor? You see which
of these different scenarios best explains all the data.
If Wilson has taken anything of mine without giving sufficient credit it
would be the theory of island biogeography. You will find papers by me in
1939 and 1941 about continuous colonization and extinction.Wilson and
MacArthur have even used figures that I published in those papers, but
nowhere do they say that this theory of theirs was similar to mine. And the
irony is that they may have never noticed the similarity.
Skeptic: Now wait a moment. Are you talking about Robert MacArthur and E. O.
Wilson's theory of island biogeography? Are you saying that it is a
derivative of your own ideas?
Mayr: I published the fundamental principles of that theory in 1939 and
1941. Others have pointed this out as well. It's not just my claim. But
MacArthur and Wilson probably didn't think they were the same ideas because
they believe something isn't scientific until it has been translated into
mathematics, which they did.
Skeptic: You mean the equilibrium model?
Mayr: Yes, but they didn't realize that this is dangerous because there are
too many exceptions and, of course, you can be proven wrong. For example,
they were wrong in their predictions about bird colonization of Krakatoa and
Hawaii. So Olson wrote this paper that said that island biogeography is
dead. But because I did not make my ideas mathematical they are still viable
science.
Skeptic: Are you saying that they were wrong because they gave incorrect
figures, or that they were wrong to even be making such specific
predictions?
Mayr: The mistake is in thinking that through mathematical formulae, you can
arrive at the truth. That's wrong. I used the naturalist's way of thinking
and predicted that there should be, say, 73 species colonizing or whatever.
I didn't use any formula or mathematics. I just used the empirical evidence.
I find that this invariably gives you better figures. The problem is the
belief that mathematics is the royal road to truth.
Skeptic: Is this a problem of physics envy or reductionism?
Mayr: Wilson is just full of physics envy. Wilson was always trying to get
mathematicians into the department. He's entitled to that, and he might have
been right, but it turns out that he was not right.
Skeptic: In 20th century philosophy and history of science, the publication
of Thomas Kuhn's classic work The Structure of Scientific Revolutions (1962)
appears to mark a watershed. One could almost say there was a paradigm shift
in this field, from science as progressivism to science as social
constructivism. How would you characterize this shift and, indeed, is this
the watershed that many think it is?
Mayr: Kuhn's description of how scientific revolutions happen does not apply
to any biological revolution. To be very frank, I cannot understand how this
book could have been such a success. The general thesis was not new, and
when he did assert specific claims he was almost always wrong!
Kuhn's book mainly appealed to historians and social scientists. It was they
who built it up into a big thing. It was vague, and vagueness always appeals
to historians and social scientists.
Skeptic: Do the biological sciences need a different explanation for how
they developed?
Mayr: My recent book, This Is Biology, if I say so myself, is in many ways
quite revolutionary. I don't think anyone before me has said quite so
strongly, and documented so carefully, the differences between the physical
and biological sciences. The physical sciences have characteristics to them
that do not help us understand the biological sciences, and the biological
sciences have characteristics to them that are not applicable to inanimate
objects. This Is Biology should have had a much greater impact than Kuhn's
book. I get letters from scientists saying that This Is Biology has changed
their whole way of thinking about these problems, but the general public
doesn't even know about the book.
Skeptic: Let's shift to another hot topic in the field-sociobiology and
evolutionary psychology. Are these just spin-offs from Darwin?
Mayr: I don't use the word sociobiology. Neither do people like William
Hamilton, Richard Alexander, or Robert Trivers. I think Wilson was envious,
in fact, that others had contributed to the evolutionary synthesis, so he
wanted to create another great synthesis. So he nominated social behavior as
a candidate and called it a synthesis.
Skeptic: Surely you don't object to the principle of applying Darwinian
thinking to studying social behavior?
Mayr: Lots of people were already doing that. And, furthermore, look at his
sociobiology- most of that was already done before by ethologists. And he
left out a lot. He neglected the establishment and maintenance of social
rank order. He completely ignored the study of social migrations, which had
been done for decades-this is the study of social behavior. So he singled
out portions, what I call selection for reproductive success, and calls it
sociobiology.
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