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Asked by miss chanandler bong to Anne, Florence, Mark, Neil, Sinead on 16 Nov 2015.
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Sinead Balgobin answered on 16 Nov 2015:
Looking at organisms over long periods of time, we can see that related species seem to change and adapt to their environment. Darwin, on a trip to the Galapagos islands, saw that depending on the food source in a particular area, the finches had different types of beak. Some were adapted for eating plants, others insects.
We can follow this in a shorter period of time if we look at smaller organisms, like bacteria. For example, there are bacteria today who are resistant to antibiotics- molecules we have made to kill bacteria. These antibiotic-resistant bacteria did not exist before we started treating bacterial infections with antibiotics, and have evolved a defense mechanism to stop the antibiotics from killing them. Bacteria which have the ability to survive our treatments, usually by a random mutation in their genetics, continue to live and reproduce- they are naturally selected to survive. The flu virus evolves to combat our immune system’s defenses, which is why we have to keep improving the vaccine.
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Florence McCarthy answered on 17 Nov 2015:
The evidence is everywhere from as far away as the galapagos islands to right here at home. The problem with seeing evolution is that the changes are not obvious as they occur over thousands of years. So if we take a tiger as an example, why are there so many breeds of tiger and why not just one. The reason is that each tiger is adapted to its environment (jungle tiger has stripes for camouflage, Asian mountain tiger has more fur to keep warm). Overall this evolution took place as the tigers moved up the mountains and their environment dictated that tigers with more fur would survive for longer at altitude. This separation happened over thousands of years but this is a small fraction of the amount of time tigers have been on this earth.
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