Other mechanisms of evolution 11.3

Student Self Assessment 1. I barely know what the subject is. I need significant help. 2. I think I’m starting to get it, but I need some clarification. I do make some mistakes. 3. I have a strong grasp of the subject. I make few mistakes. 4. I understand this as well as any other student in this classroom. I can help others.

Recall that a homologous structure is a feature that is similar in structure but appears different in different organisms. REMEMBER that homologous structures are similar in origin.

Recall that a vestigial structure is a structure or organ that is underdeveloped or unused. It once had a use in previous ancestor.

The movement of alleles (genes) from one population to another is called gene flow.

If I randomly pick out 50 marbles, I am likely to still have a high diversity of colors.

If I pick out only 6 marbles, I am less likely to have high diversity among the 6. Why?

Changes in how common a gene occurs within a population (allele frequency) is known as genetic drift. Genetic drift causes a loss of genetic diversity.

The bottleneck effect can lead to genetic drift The bottleneck effect can lead to genetic drift. It occurs when an event greatly reduces the size of a population. The Toba catastrophe of 70,000 BC is an example.

The founder effect occurs after a small number of organisms colonize a new area. Genetic drift causes a loss of genetic diversity.

Genetic drift can lead to a loss of genetic diversity. Why is this BAD???

The more genetic diversity within a species, the more likely that species will survive in a changing environment.

Student Self Assessment 1. I barely know what the subject is. I need significant help. 2. I think I’m starting to get it, but I need some clarification. I do make some mistakes. 3. I have a strong grasp of the subject. I make few mistakes. 4. I understand this as well as any other student in this classroom. I can help others.