MadSci Network: Evolution |
S. van den Berg: In regard to your question about the expectation of the evolution of people, I believe first that there is no doubt that we humans continue to evolve. However, becoming bigger or smaller in the future implies a directionality which is just not present in reality. There is no reason to to think that evolution entails progression. For example, in the case of cranial capacity, there has been no increase since the Paleolithic. In fact, Neandertals had a larger cranial capacity than modern humans. Yet, there are numerous evolutionary pressures on modern humans, albeit they are different ones than existed in the past. Most scientists think that the environment is changing in big ways--ozone depletion, bigger el ninos, world temperatures on the rise... Beyond this, consider the rise of new diseases like AIDS, new staff infections which immune to our antibiotics, Bird Flu etc. Certainly some humans will be more immune to these things than others. I believe that in America the sickle cell alleles are gradually decreasing compared to in Africa because there does not exist the environmental pressure to have the alleles. Evolution continues for us humans as it does for all living things. Dr. Dave
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