EVOLUTION

Mutations and Evolutionary Trees

Mutations and Evolutionary Trees

Mutations

Mouse

Mutations

Mutations, on the other hand, cause a much faster change in genes than natural selection. If there’s a change in the environment, for example, a mutation gene can survive and change a species. This is strong evidence for Darwin’s theory.

The deer mouse

The deer mouse is one example of fast evolution. This particular species is found in Nebraska where it lives in sandy soil. To blend into its surrounding it has a pale coat. However, the deer mouse found throughout the rest of North America has a dark coat so that it can hide in dark soils. Scientists discovered that the mice had developed not just a new trait but a whole new gene. This gene had emerged 4,000 years ago which corresponded to the time at which deer mice started living in the sandy environment. It’s clear that this gene offered a big advantage and so was able to survive.

Antibiotic-resistant bacteria

mutationsMicroorganisms, which include viruses and bacteria, are able to evolve very quickly. When their DNA is damaged or changed usually the microorganism dies. However, sometimes a mutation can be an advantage.

E.coli is one example. This bacterium can be deadly to humans and usually antibiotics can be used to kill it. However, if the E.coli mutation allows the bacteria to be resistant to antibiotics then this strain is able to survive and reproduce. In hospitals this is a very serious issue.

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Evolutionary trees

By looking at the similarities and differences in organisms it’s possible to classify them into three main groups:

  • animals
  • plants
  • microorganisms

By doing so we can gain a better understanding of both evolutionary and ecological relationships and see more clearly how organisms relate to one another.

Evolutionary trees are a good visual interpretation of relationships between species. It’s clear to see which species share a common ancestor and where species specialised into different organisms.