[ExI] Ants for spike! Dawkins and Wilson
hkeithhenson at gmail.com
Wed Nov 18 21:24:10 UTC 2009
On Wed, Nov 18, 2009 at 4:00 AM, Robert Masters <rob4332000 at yahoo.com> wrote:
> Regarding the two Wilsons' defense of group selection, Keith Henson wrote:
> <<The article is hand waving and bonhomie.>>
> Bonhomie? You're accusing the Wilsons of "good-natured easy friendliness"?
As opposed to logical thinking suitable for the subject, yes.
> Regarding your other comments, I'm having trouble understanding exactly what you're saying. It would help if I could get clear on an earlier statement you made (14 Nov.):
> <<Group selection for humans cannot logically happen because human groups swap women around.? Biological evolution is changes in gene frequencies.? If due to some group selection effects a group has an accumulation of advantageous genes in their gene pool, it is lost to nearby competing groups as the women take the advantageous genes with them when they are swapped.? QED.>>
> Is that really the reason why group selection cannot work? As Damien Broderick pointed out, many competing human groups DON'T exchange women. Are you saying that, in those cases, group selection DOES work?
I missed Damien's post. Not necessarily, but at least groups
selection is not logically impossible if you can show reproductive
isolation. I am not aware of any human groups in the EEA (environment
of evolutionary adaptivenes particularly hunter-gatherer groups which
don't exchange women one way or the other (raids to take women for
For any evolution (selection) to take place, there must be sustained
reproductive success differences over some tens of generations.
Gregory Clark says this happened to the English population between the
late middle ages and 1800 where the psychological traits for
accumulating wealth were rewarded by higher reproductive success.
"In a time when the
rich were taking over genetically people were becoming more
middle class in their orientation: time preference rates were lower,
hours of work longer, and numeracy and literacy increasing. Thus
the long delay between the Neolithic Revolution of 6,000 BC
which established settled agriculture and the eventual Industrial
Revolution may in part be explained by the time necessary for the
formation of preference consistent with modern capitalism."
This is ordinary selection at the gene level.
For group selection to take place, the group, nominally of the same
species, must be (largely if not entirely) reproductively isolated and
in competition at the group level with at least one other group.
Unless the groups are someway ecologically differentiated (different
ways of making a living) then this would normally result in a
population replacement, i.e., the extinction of one group.
This may have happened to earlier versions of Homo. I would tend to
call this species replacements rather than "group selection." The new
group may or may not be considered a new species depending on the
level of isolation from ones with which they could breed. The closely
related barred owl seems to be replacing the spotted owl of the
Northwest in the last few years.
However, the barred owls are pushing out, mating with or killing
spotted owls on an individual basis and (as far as I know) not as a
group. If you know of an animal example, please cite it.
There are a few human groups that are or were isolated enough to make
group selection possible. The Hutterites come to mind, possibly
gypsies in historical times, and for a time Jews. But in early
historical times the Jews were not reproductively isolated.
17: Now therefore, kill every male among the little ones, and kill
every woman who has known man by lying with him.
18: But all the young girls who have not known man by lying with him,
keep alive for yourselves.
(Book of Numbers, from The holy Bible, King James version Chapter 31)
If you want to make a case for group selection, be specific, use
examples and show that group selection predicts selection different
from ordinary selection.
More information about the extropy-chat