Blog Post 4
The circumstances that high and low mutation rates might be adaptive are in places where the ecosystem or habitat is constantly changing around a species or where the environment around a group of organisms stays fairly constant. There are parts of the DNA that code for reparation and replication; this means there is a way for the rate of mutation to become heritable.
Darwin's postulates say that individuals are varied in the traits that they exhibit; which probably means the mutation rate of individuals is also varied, due to the different genetic makeup in the regions of the DNA that code for reparation and replication. If the rate of mutation is possibly different quantitatively from individual to individual, then from species to species, it must differ greatly. Do large organisms have a higher or lower rate of mutation than smaller animals? Do viruses and bacteria have higher mutation rates than higher order organisms?
Another one of Darwin's postulates is that survival and reproduction of offspring is directly influenced by the traits they inherit from their parents. To what point in an organisms development can we test mutation rate for? Only organisms with mutations that are beneficial or only slightly hindering are able to be seen. Lethal mutations are probably not easily observed in a nature setting, and therefore may not be considered when calculating mutation rate. Environmental factors must play a part in the way mutations occur and are passed on, as they can directly affect the DNA. Environments with high levels of environmental chemical exposure or sun exposure would mostly likely increase mutation rates within a population.
Heritability would probably have to be calculated in order to get a quantitative look at how genes that directly affect mutation rates are inherited from generation to generation.
Here is an interesting scientific article regarding mutation rates in E.coli
Information from the chapter 3 reading assignment in module 3 was used in this post
Hi Megan,
ReplyDeleteyou make a fascinating point about how lethal mutations are possible, not seen in the variation of mutation rate; I had not yet thought about that point. I also like how you mention the way the environment can harm genetics and influence these mutations and randomly increase the rate of mutation.
Hi Megan! I enjoyed reading your post, you had some great thoughts about this weeks questions! I said that mutation rates are heritable and I think that it is pretty easy to see that once you begin comparing it to Darwins postulates.
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