Re: phylogeny recapitulates phylogeny

From: Eugen Leitl (eugen@leitl.org)
Date: Thu Jan 16 2003 - 23:30:06 MST


On Thu, 16 Jan 2003, spike66 wrote:

> Consider the cockroach. These bugs have it all. In addition
> all the other breaks nature has provided, they can fly. They
> seldom do so, however. I am not surprised if their evolutionary
> path shows their wings coming an going periodically. spike

If a phenotype is absent it doesn't mean the original DNA has been lost
from the genome.

There is no rule forbidding that a once traversed path may not be taken.
Sole reason is vague handwaving about trajectories in genespace, which
doesn't bite doubly. For once, a given phenotype is not a point but a
manifold embedded in genespace, and convergent evolution does create
gradients.

Furthermore, do we know the DNA has really gone, and wasn't just
temporarily silenced, or was lost and introduced horizontally?



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