Teaching Evolution

A blog devoted to teaching evolution, both in our schools and in our communities.

Monday, July 18, 2005

How Humans Hurry Evolution

One of the reasons that I don't understand those who deny Darwinism is that it's incredibly obvious to anyone who looks at how other species respond to humans' actions. As the Sunday Times reports, elephants have smaller tusks than they used to because

When a large proportion of the individuals with a particular trait — in the case of the Asian elephant, large tusks — are eliminated before they reach their maximum breeding potential, more of the animals without these qualities pass their genes on to the next generation.

The smaller-tusked elephants are in effect better adapted to their environment, in which having large tusks makes animals a target for hunting. If the breeding population is small, even the elimination of a few large-tusked animals can have a large effect on overall genetic make-up.


We see our own impact on the evolution of other species all the time. When we develop antibiotics, resistant bacteria evolve. Racehorses get faster as human breeders select parents with the traits for speed. Evolution is right in front of us, no matter how many people can't see it.

1 Comments:

At 7:23 AM, Blogger dhodge said...

It seems like there quite a few people who have no qualms about the microevolution that is all around us, but refuse to believe that humans were not plopped down on earth in their current form by the Creator. I don't know if these people seriously maintain simultaneous beliefs in microevolution and divine creation or they figure people will think they are ignorant if they dismiss evolution outright so they embrace the less controvesial parts of microevolution to make their views sound well-informed.

 

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