Take notes - 1.What is the definition for natural selection given on page 463? 2.What do they mean by “No such thing as perfect” in Figure 16-11? 3.Look on page 460 and write down the conditions under which natural selection will occur. 4.What is meant by struggle for existence? 5.Why must a beneficial trait be “heritable” for it to drive evolution? 6.What are the three adaptations shown in the photos on page 461?

Individual Guided Reading Page What is the main point of the THINK ABOUT IT paragraph? 2.What do you think is meant by, “Variation is the raw material for natural selection?” 3.An organism’s genotype is the particular combination of ______ it carries. 4.What is meant by the phrase, “Natural Selection acts directly on phenotype, not genotype?” 5.(Page 483) In figure 17-2, what are the two alleles for fur color present in the mouse population? 6.How many brown alleles are present in the population? 7.How many black alleles are present? 8.Is a “gene pool” something that an individual would have or something that a population would have? 9.Read the last paragraph on 483 carefully. Explain in your own words what is meant by “Populations, not individuals evolve.”

3 Sources of Genetic Variation

Single-Gene Traits

Polygenic Traits

Individual Notes (Page 488) Using the example in Figure 17-6, explain how natural selection resulted in a change in allele frequency in the lizard population. (Page 489) Name and describe the three types of natural selection that act on polygenic traits.

Directional, stabilizing, or disruptive selection? Along the Florida coast, light-colored oysters are difficult for crabs to see because their shells are almost the same color as the limestone rocks. At the same time, dark- colored oysters are also difficult to see because they blend into the shadows cast by the rocks. In these areas, oysters that are intermediate in color are preyed upon most heavily by the crabs. Draw a graph depicting this type of evolution.

Directional, stabilizing, or disruptive selection? Mice living on the island of Ubba Dubba range in size from 4cm in length to 10cm in length. Their size is a polygenic trait. The average size in the 1920’s was 6cm. Today the average size is 9cm. Draw a graph of this type of evolution.

Directional, stabilizing, or disruptive selection? Robins typically lay a clutch of four eggs. Research has shown that when robins lay fewer than four eggs, there is a higher risk that none of the offspring will survive and reproduce as adults. Research also shows that when robins lay more than four eggs at a time, the babies tend to suffer malnourishment. Draw a graph of this type of evolution.

Genetic Equilibrium (Pg 491) 10,000 years ago Present

How could each of these change the genetic equilibrium of a population? 1.Natural selection: 2.Immigration/Emigration: 3.Mutations:

Small Population Size Can Change Equilibrium Too! Present

Genetic Drift Small populations only (small sample size) Random chance causes a shift in allele proportions.

Sexual Selection

Name 5 things that drive evolution

The Process of Speciation (Page 494) How does one species become two different species? What is reproductive isolation? (Page 495) What are the three kinds of isolation that lead to speciation? – Give an example of each

But how do the BIG leaps happen? (Page ) Read the section on Developmental Genes and Body Plans What is the significance of Hox genes in evolution?