For natural selection to cause evolution, it must select for or against one or more of the genotypes for a trait. In the simple case of a trait that is determined by a single gene with two alleles, there are five combinations of genotypes that nature can select:

1. either homozygote (AA or aa but not both)
2. both homozygotes (AA and aa)
3. either homozygote and the heterozygote (AA and Aa or aa and Aa)
4. the heterozygote (Aa)
5. all alleles (AA, Aa, and aa).

In german cockroaches, curved wing (cv) is recessive to normal wing (cv+). bill, who is raising cockroaches in his dorm room, finds that the frequency of the gene for curved wings in his cockroach population is 0.6. in his friend joe’s apartment, the frequency of the gene for curved wings is 0.2. one day joe visits bill in his dorm room, and several cockroaches jump out of joe’s hair and join the population in bill’s room. bill estimates that, now, 10% of the cockroaches in his dorm room are individual roaches that jumped out of joe’s hair. what is the new frequency of curved wings among cockroaches in bill’s room? 0.69 0.4 0.5 0.31 0.20

Plz will mark! the diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere, b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify, d)anaerobic bacteria kept thriving with more oxygen