Reads for the weekend: When humanity screws with evolution
March 15th, 2008This week’s “Reads for the weekend” is completely off-topic, but is on a subject that I find fascinating: evolution.
Many interpret evolution as the continual “improvement” of a species over time, but this is an over-simplification. Evolution makes no assumptions on what is “good” or what is an “improvement”. It does not favour the fastest or the strongest but rather whatever characteristics ensure survival and spur reproduction.
This week’s links show three observations that have clued us into how we humans play a role in the evolution of other species. Interestingly, the changes in these cases are not of the sort one might expect to be favoured by evolution; it is also certain, that if it were not for our influence, these species would evolve rather differently.
It is also often assumed that evolution, generally a long and slow process, can not be observed, but we have seen that sudden changes to a species’ ecosystem (in these cases as a result of human influence) can lead to a rapid evolutionary response.
Urban weed seeds stay close to home – Pavement-dominated urban areas provide a different set of rules for reproduction than do rural areas. It turns out that “spreading your seed” isn’t always the right way to go.
Scientists say rules may keep timid fish – Due to our fishing habits, different fish species are beginning to shrink, not in population but in physical size*. This idea has been around for a while now, but this is likely one of the first times (if not the first) the hypothesis has been tested in a controlled environment that limits possible outside factors.
Elephants evolve smaller tusks due to poaching – After those first two links, you are probably getting the hang of this. This article’s title says it all.
*I was going to make a joke about big fish in small ponds, but it looks like the Scientific American beat me to it, and thus saved me from embarrassing myself.
