MadSci Network: Evolution |
Dear Charlie, that's a tricky question, in order to study evolution in action you need to use real organisms and follow them over many generations. Scientists spend months or years studying evolution of very simple traits in bacteria and insects (because they have such a short generation time). They do this by collecting a sample of organisms from a population, imposing a selection pressure, and measuring the response of the population over a large number of generations. An example would be keeping a population of mites in an open top jar which is placed in a water bath, so that those mites which disperse (leave the jar) drown. In a number of generations when you compare the behaviour of the mites which have been housed in the jar with those from the wild you may see a difference in their dispersal behaviour. Another approach would be to study a particular inherited trait in a plant or animal and see if you can figure out why it might have evolved. Shell, skin or coat colour is an easy to see, non-destructive character that's often inherited, why don't you try looking for snails in different areas of the garden (under leaf litter, in grass, on branches of trees) and seeing what colours and patterns their shells are. Evolution predicts that you may get well camouflaged snails to protect them from predators like hedgehogs, badgers and birds. Are snails coloured or patterned to fit into the backgrounds you find them in? Of course you need to remember that a hedgehog or bird might see the world differently to you and you might want to go out at night as well as in the day to see if that makes a difference. I hope this gives you some ideas for what might be possible. Yvonne
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