ShmoopTube

00:03

Here’s your shmoop du jour, brought to you by gene flow.

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It has nothing to do with how awesomely your skinny jeans fit. [Girls in dressing room]

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Gene flow does…what?

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And here are the potential answers…

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Gene flow is like dandelions being blown into your neighbor’s yard because you napped [Person napping on a hammock]

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instead of mowing the lawn like you promised.

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When genes migrate, stuff usually…happens.

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However, most DNA mutations occur naturally and not because of gene flow. [Man transforms into the Hulk]

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When a cell divides, it makes a copy of the DNA.

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It’s not entirely like “cut and paste”.

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More like “keep your fingers crossed” and hope for a perfect copy. [Girl crossing her fingers]

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Otherwise, you have a mutation.

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Gene flow is not the culprit here.

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So…

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Answer “A’ is wrong.

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How about “B”?

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Well, in the case of human organisms, we normally select mates on a non-random basis… based [Girl flirts with guy sat on a bench]

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instead on easily observable traits.

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Fortunately, as we mature, more thought will go into the non-random selection process.

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It’s all about the vibes.

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And not gene flow.

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“B” is incorrect.

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With natural selection, certain phenotypes are better able than others to contribute [Man bench pressing]

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their genes to the next generation.

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They’re more fit and uh…pumped up for action. [People working out in a gym]

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The end result is a gradual change in the gene frequencies of that population.

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None of which is caused by gene flow.

01:25

“C” is out.

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As for “D”, gene flow is the transfer of alleles from one population to [Alleles transfer from one circle to another]

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another.

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This transfer knocks the Hardy-Weinberg equilibrium out of whack, because it could change the

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allelic frequencies.

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And, when those frequencies are the least bit disrupted…well, prepare for some potentially

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hairy moments. [Man transforms into a caveman]

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“D” is definitely the correct answer.

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A word to the wise: you may want to avoid the…deep end of the gene pool… [Man jumps into deep end of a gene pool]

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