Gene flow vs. genetic drift

<p>GAH! so I was taking a bio practice test yesterday and I STILL couldn't remember the difference between "Gene flow" and "genetic drift." Does anybody have a good way of remembering these two?</p>

<p>Someone correct me if I’m wrong, but my understanding is that gene flow is kinda like the opposite of speciation. A population will, in gene flow, add an allele(s) to another population’s gene pool. </p>

<p>Genetic drift is just the change of the frequency of given alleles in a population’s gene pool. So let’s say, for example, the blue-eye allele begins to appear more often than brown-eye allele. Genetic drift is random, but if a certain allele increases the organisms fitness, the environment will select for that allele and that given trait will be more prevalent.</p>

<p>How is gene flow the opposite of speciation? I know gene flow has to do with emigration/immigration, but a species can still form i guess. and genetic drift = chance. I just can’t keep the two straight! I always this gene flow= chance for some reason when that is not true.
By the way, I like your username :D</p>

<p>Oh sorry I forgot to explain the way I was looking at speciation. So in speciation, the members who were once part of the same population cannot breed with each other anymore. In gene flow, 2 DIFFERENT populations are interbreeding, so there is the addition of new alleles. The populations that are interbreeding can very well undergo speciation if that situation arises. I apologize for not being clear, I was talking about speciation in terms of breeding!!! Hope that helps.</p>

<p>Try to think of chance with genetic drift!!</p>

<p>Hahah thanks bud!</p>

<p>OMG thank you sooo much! I never thought of it that way! That’s so…logical haha. And don’t worry about it, most of the time I need to read an explanation like twice to understand. And your explanation was very good, I think I can keep that straight now :)</p>

<p>Gene flow is just the addition of new genes due to immigration.</p>

<p>Genetic drift is the change in allele frequencies due to chance. Small pops. will have genetic drift because smaller sample sizes are more subject to random variations in chance.</p>

<p>Gene flow is the fluctuation in the number of alleles in a population due to migration. I personally remember it because when organisms migrate they normally do so in packs. Then they are ‘going with the FLOW’ so you get gene FLOW</p>

<p>Genetic Drift is the fluctuation in the number of allele frequencies due to natural disasters, etc. For example floods or fires. From genetic drift you can have bottleneck, Founder’s effect, etc. You could remember it this way because ‘the GENETIC material is lost’ and u have GENETIC drift</p>