Evolution is not progress

frist at ccu.umanitoba.ca frist at ccu.umanitoba.ca
Wed Jul 8 17:50:38 EST 1992


In article <3711 at news.duke.edu> una at phy.duke.edu (Una Smith) writes:
>
>I'll stand by this, however much people in this newsgroup
>or elsewhere argue that, by defining "progress" in the
>right way, it can be made synonymous with "evolution".
>On an off day, I would even take the hard line that not
>even my list of emergent levels of organization fit the
>usual criteria of "progress".
>
>	Una

Another poster defined 'progress' as movement along an axis, and I
have no problem with the concept that evolution can result in progress. By
this definition of progress, increasing complexity is movement along
an axis.

I do agree that evolution is not synonymous with progress. Evolution
is change, regardless of the underlying causes (eg. mutation, migration,
random drift, genetic hitchiking, and oh yes, the biggie: selection).
While the process of evolution can cause progress (ie. movement along
a parametric axis)  not all evolution results in net progress. This is
particularly true is you are using the narrow definition of evolution: a
change in allele frequencies in a population.
 
Since 'progress' is not a formally recognized term in evolutionary theory,
I guess what we're doing here is talking about whether it is useful to
have such a term. I can cite a few examples which may help narrow
the definition.

First, consider fixation of an allele in a population. This most tightly
fits the definition of progress as  movement along an axis, because the
frequency of that allele increases over a succession of generations.

Second, consider adaptation of primordial cetaceans to live in an aquatic
environment. In this case, a series of physiological, anatomical and
behavioral adaptations go through concurrent refinement, all of which
improve the fitness of the species for living in water. This  would be
a broader example of 'progress'. We don't need any 'special pleadings' here
to make the case that the evolution that has taken place here is more than
simply change. A land mammal has adapted to a completely new environment.
Progress, in this case, could be measured as in increase in fitness in the
aquatic environment.
 
To summarize, then, evolution is change in population parameters, whether
measured as a change in allele frequency or in a phenotype. Progress is 
change with direction. This would be analogous to the distinction between
vectors (progress) and scalers (evolution) in physics.

However, this may not be adequate to justify creation of a new term, since the
same concepts could be said to be encompassed by the terms 'microevolution'
and 'macroevolution'. To further justify the term progress, there has to
be something more than just directionality. For example, speciation is
strongly directional, yet I don't think that speciation per se constitutes
progress. Speciation in tropical insects probably occurs very frequently.
I don't feel compelled to call such rapid speciation progress
because what seems to be occurring is the generation of a large 
number of variations on the same basic design.

If we need to have a term like progress, it probably should focus on the
directional aspect of evolution, encompassing ideas such as increasing
complexity and fitness. Regardless of how jaded your view of evolution is,
I think it is useful to have a term that distinguishes such things as the 
evolution of the eukaryotic cell, or multicellular vs. unicellular
organisms, or sex, or intelligence, from the rest of evolution. 

In trying to pin down the meaning of progress, I am struck by the
observation that those things I would consider progress generally seem
to be associated with fundamental changes that facilitate a lot of 
subsequent evolution. The evolution of the eukaryotic cell made it possible
for many new cellular functions to arise which could not exist in the
absence of cellular compartmentalization. Multicellularity opened up many
new avenues for the evolution of specialized organs. Sex provided a new
way of generating genetic variation. Intelligence made it possible
for the individual to do something akin to what a species does when it
adapts to a new environment. Further progress in the evolution of
intelligence brought this analogy closer to genetic adaptation, in that
cultural information took to place of genetic information, making it
possible for offspring to 'inherit' learned adaptations from their parents.
In all cases cited, progress seems to be associated with evolutionary 
changes that facilitate the process of evolution itself.
 
There's nothing wrong with giving names to concepts that may be difficult
to define. What would we do without the terms 'gene' or 'life'? These are
useful terms, but their underlying meanings are very slippery to pin
down. 

===============================================================================
Brian Fristensky                |  
Department of Plant Science     | "Ya don't have to be a rocket surgeon
University of Manitoba          |  ta know who's who!" 
Winnipeg, MB R3T 2N2  CANADA    |
frist at ccu.umanitoba.ca          | 
Office phone:   204-474-6085    |  - the incomparable Don Cherry 
FAX:            204-261-5732    |
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