What is Salty's 'semi-meiotic hypothesis'

quote:

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'My own view is that having lost the swim bladder, they discovered the rapidly flowing stream.'

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Isn't that natural selection?The ones that didn't find rapidly flowing streams died out,
the ones that did thrived.Adaptation to an environment (in NS terms) isn't promoted by the
environment, it's just about whether or not a change in a population
leads to any kind of advantage or not.

Adapting to an environment BECUASE the environment
changes isn't natural selection, therefore not everything
is natural selection.You said that, in your opinion, the mutation allowed the
individuals without swim bladders to exploit an environment
with a fast flowing stream in such a way that they did
not require swim bladders, and thus survived.How is that anything but natural selection?

There is an interesting article in last weeks New Scinetist
(in the UK) that suggests that the divergence into man
and chimpanzee was actually a very gradual process.The genetic changes observable now are suggested to have come about
in one location (rather than with geographic isolation)
such that some offspring could freely interbreed while others
began to have a reproductive isolation from one another.It all depends upon which genetic variation the two partners
have inherited.It also seems to be very much like the case we have with horses
and donkeys (to some extent), but especially with Zebras in the
present.