1.   Again and again in recent years evolutionary biologists have found themselves returning to the theme of parasites.

2.   Secondly, evolutionary biologists have tested their theories by searching for expected patterns of behaviour across different human cultures.

3.   And in any case evolutionary biologists have produced plausible and widely accepted explanations for why life spans should have genetically determined limits.

4.   And that gets to the crux of a debate that has galvanized evolutionary biologists, psychologists and neuroscientists alike.

5.   Bruce Levin, an evolutionary biologist at Emory University, was one of the signers of the declaration.

6.   But as evolutionary biologists and conservationists see it, Paradise is fast being lost.

7.   But as Amherst College evolutionary biologist Paul Ewald has shown, microbial life involves trade-offs.

8.   But similarities aside, the importance of the new findings is that they seem to contradict in several ways the longstanding theory of aging developed by evolutionary biologists.

9.   Dr. David Hartl, an evolutionary biologist at Harvard University who found the first mariner transposon, agreed with that theory.

10.   Dr. Douglas J. Futuyma, an evolutionary biologist at the State University of New York at Stony Brook, said the new study served to strengthen the classic story.