Darwin-L Message Log 1:178 (September 1993)

Academic Discussion on the History and Theory of the Historical Sciences

This is one message from the Archives of Darwin-L (1993–1997), a professional discussion group on the history and theory of the historical sciences.

Note: Additional publications on evolution and the historical sciences by the Darwin-L list owner are available on SSRN.

<1:178>From LANGDON@GANDLF.UINDY.EDU  Mon Sep 20 10:47:21 1993

Date: Mon, 20 Sep 1993 10:47:21 -0500
To: darwin-l@ukanaix.cc.ukans.edu
Subject: Re: Lamarkianism in linguistic change

In message <930918095527.26402829@FENNEL.WT.UWA.EDU.AU>  writes:
> noted in a very good anaylsis of the danger of purely allelic defintions of
> evolution that
> > Including some notion of genetic or hereditary change is important.
> 				  ~~~~~~~~~~~~~~
> > Evolution hasn't happened unless there is some difference between the
> > characteristics of ancestors and descendants.
> As a biologist/archaeologist who works with evolution in a purely
> phenotypic system (human culture), I think the "or" in his statement is
> exceedingly important.  Non-genetic hereditary stytems are quite as
> amenable to Darwinian analysis as genetic ones (which is no surprise given
> that the model was developed well before we knew anything about genetic
> systems!).

To me, heritable implies genetic or some other biologically determined change.
Culture is not heritable and the evolution of culture is not better than an
analogy with organic evolution. What non-genetic systems do you have in mind?

  The important factor in ALL systems capable of evolution, of
> course, is selection in terms of fitness (something that seems to have been
> a tad overlooked in the "definitions" of evolution posted thus far).  Seen
> in these terms, evolution is the result of the selection of hereditable
> traits over time (hence, changes in allelic frequencies, etc., are merely
> CONSEQUENCES of selection and therefore provide a fairly poor basis for a
> definition of it).

Changes in allelic frequences are part of the definition of evolution, not
selection. Evolution may reflect selection, but may also reflect non-selected
changes. The two should not be interchanged.

Incidently, I disagree that evolution cannot be applied to systems that change
without selection for fitness-- e.g. geological change is evolution even though
there is nothing giving direction to it.

JOHN H. LANGDON         email  langdon@gandlf.uindy.edu
DEPARTMENT OF BIOLOGY       phone (317) 788-3447

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