La paleontologa y la evolucin: Tendencias evolutivas

La analoga del borracho

VariacinHerenciaSeleccin Descendencia

La historia evolutiva de los foraminferos

Daniel W. McSheaLa complejidad de un sistema es funcin del nmero de partes distintas que lo integran y de la irregularidad de su disposicin...QU ES COMPLEJIDAD?

2. Natural Selection + additional factors, such as the environment - this would best be exemplified by Stephen Jay Gould's and Niles Elderidge's PUNCTUATED EQUILIBRIUM theory, which holds that natural selection only works in short spurts amongst long relatively stable periods of stasis, lasting hundreds of millions of years, in which species don't change.

Evidence FOR Intelligent Design: I think even Richard Dawkins would not deny that complex organisms are designed. (Of course Dawkins would say that it was NATURE doing the designing, not God - but who is he to say what God can and cannot do??) To their credit, the Creationists DO try to fully explain the reason why we see the sudden appearance of complexity, and also they provide a good explanation for the apparent "directionality" towards complexity. Evidence AGAINST Intelligent Design: To be honest, it seems most of the time the "evidence" for intelligent design is more an appeal to ignorance. For example, Behe will say things like "no one has published a single paper about the evolution of flagella". Even if this was true, it does not at all necessarily imply (as Behe insists) that there is evidence of divine intervention (in fact there's been HUNDREDS of papers published on this subject, but Behe chooses to ignore them!)

1. Natural Selection ("gradualism", or traditional Darwinian evolution. One of the more recent neo-Darwinists is Richard Dawkins). Remember, there are THREE MAIN criteria necessary for evolution to occur via natural selection (see lecture notes from 25-Feb-98).

Evidence FOR Natural Selection: The FACT that evolution can occur by natural selection is no longer really questioned by most biologists - but whether natural selection ALONE can explain the evolution of complexity is a different issue. Evidence AGAINST Natural Selection: Even Darwin himself strongly objected to the idea that Natural Selection can explain ALL aspects of evolution - in particular the apparent "directionality" towards complexity. I personally have a difficult time with Dawkins' assertion that we are mere vehicles for DNA to replicate itself - surely there must be more to life than this!

Evidence FOR Punctuated Equilibrium: Again, there are abundant FACTS within the fossil record that evolution in a manner as proposed by Gould and Elderidge. Actually, the theory of punctuated equilibrium was first proposed on the basis of paleontological findings. Evidence AGAINST Punctuated Equilibrium: As with Dawkin's point of view, punctuated equilibrium does not fully explain the reason why we see the sudden appearance of complexity, nor does it explain the apparent "directionality" towards complexity.