1. CHAPTER 16 HIGHLIGHTS EVOLUTION OF POPULATIONS

2. GENES AND VARIATION When evolution is occurring in a population of organisms, the ______________ of alleles changes. What are alleles? (look at your glossary). The two main sources of genetic variation are _________ and __________ and these result from sexual reproduction. How does sexual reproduction promote genetic variation as opposed to asexual reproduction? (think about the process of meiosis) What determines the numbers of phenotypes for a given trait? What two processes can lead to inherited variation in population? What is a gene pool? How are allele frequencies related to gene pools? Refer to figure 16-2 on page 394. Which allele is dominant and which is recessive? COMPLETE THIS ANALYSIS BECAUSE I WILL CHECK THIS DURING THE NEXT NOTEBOOK CHECK!

3. EVOLUTION AS GENETIC CHANGE ____________________ on single-gene traits can lead to changes in allele frequencies and thus to evolution. Yeah, ok, but can you articulate an example of this concept? Think about the relationship between predator and prey. Which prey will have more fitness in their environment and which predator will have more fitness. _______________ can affect the distributions of phenotypes in any of three ways: directional selection, stabilizing selection, or disruptive selection. When individuals at one end of the curve have higher fitness than individuals in the middle or a the other end, this is ________________. When individuals near the center of the curve have higher fitness than individuals at either end of the curve, this is _________________. When individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle, this is ___________________.

4. EVOLUTION AS GENETIC CHANGE

7. In small populations, individuals that carry an allele may leave more ______________________ than other individuals by chance. Series of chance occurrences of this type can cause an allele to become ______________ in a population. What is the founder effect? Give an example of the founder effect as noted in your text. When Hardy-Weinberg conditions are met, the population will remain _________ unless one or more factors cause frequencies to change. When allele ___________ do not change, the population will not evolve. There are five conditions to maintain genetic equilibrium in a population from generation to generation and they are 1) ________ mating. 2) population must be _____________. 3) no movement into or out of the ____________. 4) no ___________. 5) no natural ___________.

8. Speciation Process The formation of new species is termed ______________. Factors such as natural selection and chance events (such as a volcano eruption or abrupt climate change) can change _________________ in a population. What is reproductive isolation? What are the three types of isolating mechanisms that are mentioned by your text? Refer to your text on page 406 Figure 16-13 and be able to articulate the changes that occur between species as a result of environmental variation. Speciation in the Galapagos finches occurred by founding of a _______________, geographic isolation, changes in the new population’s gene pool, ______________ and ecological competition. What is the take-home message from this chapter? What concept is most important in understanding biodiversity and the change in species over time?