The struggles of defining evolution

It has been a while since I last blogged...I've been focusing on teaching and I would say my classes have been better.  However, I miss this deeply...

My friend asked me how I would define evolution.  A simple task I thought.  Evidence contradicts that thought though, as we have shared 20+ email responses of considerable lengths (though some have not been completely related).  There were many fine details that needed to be ironed out before evolution could be defined.  The most important was determining what time scale should be included.  We agreed entirely that evolution leads to the most able organisms continuing to exist, yet the idea of what influences or defines the most able is extremely difficult.  Also, the question, Are humans evolving? was quite a barrier.  This is where the discussion got interesting, for I posed the idea that the common definition of evolution needs to change.  Evolution currently, to my knowledge, focuses on the genes only.  However, if one considers humans, the success strongly correlates to the level of education/learning one has.  This leads one to pose an inquiry: Should evolution also include the alterations of an organism's brain while living?

I will share one part of an email I wrote which highlights the problem stated above.

I disagree that ALL organisms learn, which is why I am unsure to include it within the definition of evolution.  

The most important parts of defining organismal evolution that I can think of are the following:  

• a change has occurred
• competition is the driving force
• alterations to the genetics of a population is the mechanism

The ability to learn is a product from evolution, yet it allows the individual to evolve during its lifetime and to influence the competitiveness of its population.  Most biologists refer only to genetic change when speaking of evolution, but it may very well be time to change that to better model our world.

The fact our ideas change throughout our lifetime and influences our lives is fascinating and complicated.  My friend and I are close to a definition of evolution, which I will share below, but I still am unsure about including or not including learning.  Like I mention in the email, it may be time to change our definition of evolution to better model our world.


Organismal evolution:  A reproductively advantageous change to a population due to alterations of genetic material caused by mutations.