Re: Reproductive Selection

John Harshman wrote:
Treus wrote:

John Harshman wrote:

Treus wrote:


Treus wrote:


John Harshman wrote:


<snip>

Why, even if you were correct about all this, would that make evolution
without natural selection?


<snip>

The evolution of R(S1,x) to R(S2,x) where R(S1,S2)<R(S1,S1) requires
S1 to evolve contrary its advange under reproductive selection (which
acts on the post-mating capacity to generate offspring). What other
form of natural selection could govern such a development?


Your pseudo-math is unclear. What is this species x for?

The expression R(S1,x) is an abbreviated way of saying "the
reproductive selection advantage that accrues to a member of
population S1 from its ability to interact with a specific mate from
population x (meaning any given population)." It is a more useful and
precise way of expressing reproductive compatibility.

I don't find it to be either.

The abbreviated expressions are a courtesy to anyone who may want to
read or contribute to this thread. I have and will, if necessary,
continue to explain what they mean. I feel they are necessary to make
communicating these ideas as brief as possible. Otherwise it can take
several sentences to make a simple point.

We have covered this before. I'll summarize.

1. Selection acts on individuals; "reproductive selection" is an
artificial abstraction.

Calling it an "artificial abstraction" doesn't make it go away. Its
effects are very real.

It's an artificial distinction. Selection is selection.

And force is force, yet gravitation is distinct.

If some characteristic is disadvantageous under
reproductive selection alone, that says nothing about whether it's
advantageous to the individual.

Of course.

And so there is no scientific advantage to be gained from considering
"reproductive selection" separately.

Like the abstraction of gravity, it is useful insofar as its effects
can be differentiated.

2. I have shown you a simple way in which reproductive incompatibility
can arise without any disadvantage in reproductive selection. Remember
the 2-locus model?

Incompatibility can arise as a byproduct of natural selection acting for
other purposes, and it can arise as a consequence of drift.

Mere incompatibility is not the question. What needs explaining are
the functionally new features of the RC of the new population without
the influence of natural selection.

How does a significantly novel, and backward incompatible, post-mating
capacity to generate offspring arise against (or even neutral to) the
tendency of the selection pressure acting to preserve the post-mating
capacity to generate offspring?

Is this hard to understand? Post-mating capacity to generate offspring
does not arise. It's not novel. It's inherited.

The post-mating capacity to generate offspring proper to a new genus
must arise precisely because it is not inherited.

In other words, how do the novel features of R(S2,x), meaning the
reproductive compatibility particular to S2, originate when the
relevant differences between S1 and S2 can't be accounted for by
genetic drift alone?

Reproductive compatibility doesn't arise. This idea of "novel features
of R(S2,x)" is meaningless. At most, it's maintained by the absence of
incompatible genes. Compatibility within a population does not require
this "backward-compatibility" you keep talking about, as; the 2-allele
model shows. Why do you keep ignoring it?

If R(S2,x)>R(S1,x) for *any* x, then where did that new functionality
of S2 with respect to S1 come from, if not drift or reproductive
selection?

<snip>

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Relevant Pages

  • Re: Reproductive Selection
    ... incompatibility), which is itself the result of a known physical basis: ... Now selection certainly can explain why reproductive ... to stick with the operational definition of reproductive compatibility ... Looks like reproductive selection. ...
    (talk.origins)
  • Re: Reproductive Selection
    ... S1 to evolve contrary its advange under reproductive selection (which ... form of natural selection could govern such a development? ... precise way of expressing reproductive compatibility. ...
    (talk.origins)
  • Re: Reproductive Selection
    ... Environmental selection acts on the capacity to survive. ... Reproductive selection acts on the post-mating capacity to generate ... about the interfertility of two different populations, ...
    (talk.origins)
  • Re: Reproductive Selection
    ... S1 to evolve contrary its advange under reproductive selection (which ... form of natural selection could govern such a development? ... How does a significantly novel, and backward incompatible, post-mating ...
    (talk.origins)
  • Re: Reproductive Selection
    ... >>>S1 to evolve contrary its advange under reproductive selection (which ... > precise way of expressing reproductive compatibility. ... > Mere incompatibility is not the question. ...
    (talk.origins)