Compare And Contrast The Forces Of Evolution

The forces of evolution are:

1)Gene Flow. Gene flow is the result of a new population being added or mixed with an existing population. When a new population comes in, it brings with it various new alleleles. When these two populations breed, the alleles from the new population mixes in with the old. This can be either random or non random

2)Genetic Drift. This is the opposite of Gene Flow in that it is when a population leaves its original population and condenses the available gene pool. Genetic Drift results in the loss or the maximizing of multiple alleles due to the small population size. If two people mate, a specific allele may be non fixed and lost forever between those two people. This is not really a problem in a large

This is the most common form of evolution, this is simply where those traits that are most beneficial for survival will inevitably carry on through the population, and those traits which hinder survival or don't help are more likely to die off. This makes sense. If a giraffe has a short neck, that giraffe will not have the same access to food as those with long necks. Eventually, the short neck giraffes will die off.

4)Mutation. Mutation is a completely random occurrence where new alleles are created resulting in completely new dna constructs. While this is not quite the same as a new species, it is a new DNA pattern at least.

B)The sickle-cell anemia example brought up two seemingly disconnected phenomena, that people in malaria rich nations also happened to be carriers of the sickle-cell disease. This became even more weird when they discovered that those with sickle-cell anemia were somehow immune to malaria. Balanced Polymorphism accounts for that discrepancy. It turns out that the mutation which causes sickle-cell anemia also protects against Malaria. The explanation for its prevalence in specific, malaria risky areas is due to natural selection. Those whose bodies were in Balanced Polymorphism were both safe from the malaria disease due to the anemia mutation, but also safe from the anemia because they only carried hald the allele, lived and had off spring. those who had zero of the sickle-cell anemia alleles died from malaria, and those who had both alleles died from the