RE: virus: Gould
Deron Stewart (deron@direct.ca)
Thu, 11 Feb 1999 13:42:00 -0800
joe dees [SMTP:joedees@bellsouth.net]:
<<
Whose idea was the theory of Punctuated Equilibrium; the idea that like
quantum states, some mutations were discrete and - in a sense - digital?
>>
That was Gould. It more or less says that evolution proceeds by long
periods of stasis "punctuated" by short rapid periods of change (on the
geologic time scale but still gradual at a population time scale); as
opposed to the continuous slow change that Darwin talks about.
(It's true that Darwin more or less states the entire principle of PE in
_Origin of Species_ but if you read the book cover to cover the
overwhelming sense that Darwin gives is of slow and gradual change...)
Off the top of my head, Gould's main "sound bites" are:
- Punctuated Equilibrium (with Niles Eldridge)
- Exaptation: a renaming of the ill-chosen term "pre-adaptation", the idea
that organs may have evolved originally for a different purpose than their
current use (e.g. feathers that started out as insulation, or swim bladders
that started as lungs)
- "Just-So Stories": a derisive name for what is perceived as arm waving
adaptationist explanations
- "Spandrels": the idea that some features of an organism are just
side-effects of other features, and do not require adaptationist
explanations, they just happen automatically.
- "Cambrian Explosion": a reinterpretation of the Burgess Shale which
shows a "sudden" appearance of virtually all the extant phyla (as well as
many others).
- "rewinding the tape of life": the idea that evolution is "massively
contingent", i.e. it would never turn out the same way twice if it could be
done over again (basically that the dynamic of the tree of life is chaotic,
I guess)
Some of the ideas are very good (and there are lots more like them), but I
had just meant that none of them is a show stopper (like Natural Selection,
or General Relativity, or even the idea of an Evolutionarily Stable
Strategy, say).
Cheers,
Deron