how does meiosis create genetic diversity for natural selection to operate?

Question

istim · Answer

Something about DNA I remember.

kira_yamato · Answer

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- As seen in this drawing, the homologous chromosomes have independent assortment. Hence if there are different alleles on the homologous chromosomes, there will be different alleles going into different gametes.
- There is also crossing over (not shown), causing homologous chromosomes to exchange parts of their DNA (and hence maybe different alleles of the same gene) with one another, causing more variations.
- Fertilization is random. Hence, there is about a 50% chance in this case to have a certain allele adding to the same egg. Multiply that by another 50% in the egg, you have 25% of getting a certain combination of one allele.