Blog 8 The Never Ending Variation

    Selection is often assumed to eliminate genetic variation. So, why is genetic variation then not eroded over time? Based on what you have learned in the past modules, from the basic mechanisms of evolution to quantitative genetics, reflect on the diversity of mechanisms that can explain why genetic variation is maintained in populations. 

    The most common discussed explanation that came to mind is mutations. While yes, there are traits that are preffered and that are then passed down through generation, but I feel like the sole reason why genetic variation still exits and not all species are genetically the exact same is because of the often occurance of mutations. If it weren't for mutations than each species would eventually all turn out to be genetically the same which could be very unfavorable if a drastic change in the environment or disease were to take place, effecing that species. Given that selection strives for benefiting the species in the long run, this does not always occur. 

    Another important mechanism or explanation to why genetic variation does not erode over time is due to gene flow or migration. Natural selection plays a strong role in gene flow especially when species migrate to new areas and introduce their own genetic information and pass them down through future offspring. This aids in more variation along with more possible mutations to occur as well. The new genes/alleles being brought in then interfere with the already existing ones. This interferes with the fitness of the existing alleles due to new variations being brought in.