Download Evolution as a Statistical Process

Evolution as a Statistical
Process
Evolution Maintains Statistical
equilibrium; this equilibrium can be
disrupted by external influence/control
Natural Selection
Random pairings of traits
Ecosystem survival rules
Each paired trait has a different survival
probability
If Ecosystem remains largely unchanged,
end result is a distribution of most
probable values
http://homework.uoregon.edu:8080/chimer
a/worksheet.jnlp
Implications
External disruption changes the ecosystem
survival rules and therefore changes
evolutionary pathways
Change takes much time to appear as statistical
processes require a large number of generations
to manifest themselves.
In the short term, things may appear to be stable
Only the long term matters
Perturbations
• Random large scale catastrophes (to be
discussed next week) can reset both the
evolutionary clock and the evolutionary
timescale
• This is been a very important component
of evolution on Earth.