Genetic variation is sometimes thought to be eliminated as selection occurs through generation. From this approach, one would assume that as more generations accrue and the species become better adapted, which then causes the species in that environment have the same traits and genomic coding. So the question remains, why is genetic variation not eroded over time?
One reason that genetic variation is not depleted is due to changing in environments. As we know with the ever increasing climate change, habitats and environments are changing yearly. With this change, an adaptation that may have been advantageous before may no longer be. Therefore, the offspring will not be as successful as they might have be 5 years previously.
Other causes that maintain genetic variation include evolutionary forces that are not natural selection. For example, migration of populations can introduce new alleles from another environment. A force that can also influence would be gene drift. Additionally, the force of mutation is a HUGE factor as to why diversity still remains. Mutations don't necessarily have to have negative or positive effects, they can be neutral. These neutral, yet heritable changes in the genome, can be effective in later generations. You could say the randomness of mutation likes to keep things spicy.
Generally speaking, this assumption of selection reducing population variation means that there is A) An ideal form of the species that this selection is working towards and B)That we live in a tube. To disprove A, there is no "best" species or else all animals in a habitat would look the same. But once all of the animals have the same niche, it is longer good to keep that trait since it would have the animals competing for the same resources. As for B, we don't live in a tube? Overall, genetic variation is important for reducing inbreeding and a species surviving through this crazy changing world.
Haha I love how you called mutation spicy. That was awesome. Additionally, I like how you emphasized the changing nature of the world's environments as a reason why genetic variation still exists despite selection. You explained it really well but in a simple enough way to understand. Good job.
ReplyDeleteYou're explanations are concise and make a lot of sense. Breaking it down into the assumptions that are being made was a great way to have a "prove/disprove" point. Great job!
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