@memester,
Quote:oh, so success is a biological change ?
See the word 'relative'?
Obviously in that context, it would result in a change in AF. Think about it - what does relative success even mean, relative to what?
Where does all this extra nutrition come from, and what happens if one population monopolises it?
West-Eberhard's paper is interesting, but even she admits that...
"
Adaptive responsiveness to conditions in the
external and internal environment has long been
considered a universal property of living things.
Large subdisciplines of the biological sciences,
including physiology, endocrinology, neurobiology,
ethology, embryology, cell biology, and the molecular
biology of gene expression, study the
mechanisms of adaptive responsiveness, but its
significance for the process of evolution has not
been extensively explored."
So presenting it as anything more than a hypothesis at this stage seems to indicate you have more faith in it than the auteur does herself.
Also, check this out:
"
The following model is intended to describe the
evolutionary origin of all kinds of adaptive traits-
morphological, physiological and behavioral,
whether induced by a mutation or an environ-
mental factor-at all levels of organization. This is
a brief summary of concepts presented in more
detail and with more complete supporting evidence
elsewhere (West-Eberhard, 2003):"
What's the fourth point of the model?
"
Genetic accommodation (change in gene frequencies
under selection): Given genetic variation
in the phenotypic response of different
individuals, the initial spread produces a
population that is variable in its sensitivity
to the new input, and in the form of its
response. If the phenotypic variation is associated
with variation in reproductive success,
natural selection results; and to the degree
that the variants acted upon by selection are
genetically variable, selection will produce
genetic accommodation, or adaptive evolutionary
adjustment of the regulation and form of
the novel trait."
Later she sums up the model, and notes...
"
There is no conflict between this model and the
standard view of adaptive evolution as involving
variation, selection, and gene-frequency change."
So it's not like her ideas redefine evolution - according to her - and she doesn't think it can be divorced from selection along genetic lines and her model is based on that assumption.
She does propose an extra degree of detail in some cases, and it is an interesting idea. I'll give you that. Good effort.
---------- Post added 01-20-2010 at 07:39 PM ----------
prothero;121392 wrote:Evolution is a complex process resulting from the interaction of multiple factors which results in changes in gene (or allele) frequency in populations over time.
The problem with this definition is that it isn't true in every case (what if the factors resulting in a change are not multiple, or even apparent as in the case of drift) and that it uses terms with no intrinsic value (complex in comparison to what - what timescales do we use).
I don't mean to suggest it's wrong - but I think the fat can be trimmed:
Evolution is a complex process resulting from the interaction of multiple factors which results in
changes in gene (or allele) frequency in populations over time.
I don't mean to come across an anal twerp - but everything that isn't bold is either:
a) Subject to exception (complex, multiple, factors).
b) Implied by other words (change implies time, I think process is inherent in the sentence).
Yes - this alteration in AF is SOMETIMES driven by this that or the other - but if we are rooting for a brass tacks definition of what the biological gestalt say evolution ALWAYS is* - that's it.
Quote:When you define evolution purely in terms of changes in gene frequency in populations, one gives the wrong impression, making the result of evolution (changes in gene frequency) appear to be the cause of evolution which it is not.
No.
AF is not the result of evolution - it IS evolution*. When you see evolution happen that's what you see.
Now - for pedeological purposes you might be very right saying it's not a good way to teach it - and I would agree.
I'd say talking about wavelengths of light is no way to teach kids what red, yellow and blue are. The practical application and degree of interest in such a veiw is limited. Better to get the paints out - say yellow and blue mix to make green - that sort of thing.
But it is what they are. Cherries aren't red - they just reflect it. But the kids don't need to know that until they grasp more practical aspects.
* In an attempt not to get caught out I'll supply a few caveats for memester - I'm not talking about the evolution of the airplane, or as it was understood in the 12th century, or necessarily suggesting that some or other hypothesis might teach us something new tomorrow. I'm talking about the scientific gestalt's understanding of the variation of organisms as I see it at the moment.
