Thread: evolution
View Single Post
Old 12-21-03, 11:58 PM   #9 (permalink)
Zoe's Avatar
Join Date: Mar-2002
Location: Ottawa
Age: 30
Posts: 3,288
Send a message via MSN to Zoe
Also, it should be noted that there is a difference between ADAPTION and EVOLVING. I can only explain it in french, so I'll give you examples to understand:
Say there is a population of light grey butterflies, and they live on trunks of trees that are the same colour. Therefore, they are camouflaged and survive better. Now let's say that there are a few darker individuals of the same species - their numbers stay low, because they are easily spotted on the light trunks and eaten.
Now, a certain factor (for example polution) gets into the environment and the trunks turns dark brown over a few months. The pale individuals will diminish in number because they can no longer blend with the trunks, and the darker butterflies will reproduce and many of their offspring will survive because they are camouflaged. There are, of course, still a few light ones left, but not nearly as many.
Just to further the example, let's say that years later the trunks turn pale again (because the polution was eliminated). Most of the dark ones would die and the pale ones would again take over.

THAT is evolution.

Now, let's say that when the trunks turned dark, the butterflies developped more melanin and the same individual that used to be light was now dark, to blend with the trunks - that is Adaptation.

If these silkworms grew accustomed to the cold, that would be adaptation, even if it happened over a few generations. If certain individuals had, say, a mutation that lessened the effects that the cold had on them, and if the temps went down they survived and 'took over' the population, that would evolution.

I hope that made sense, I know it isn't completely relevant to the idea but I just thought I would mention it.

Zoe is offline