Chapter 2 Outline
Diverse Methods of Reproduction Have Evolved
- Box 2.1: Biology of Sex: The Cellular Basis of Reproduction
Study questions: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8
Rival Theories Offer Explanations for Sexual Reproduction
- Sexual Reproduction May Limit Harmful Mutations
- Sexual Reproduction May Generate Beneficial Gene Combinations
- Future Research May Solve the Puzzle
- Box 2.2: Biology of Sex: The Paradox of Sexless Species
Study questions: 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20
Why Are There Two Sexes?
- Hermaphrodites Combine Male and Female Reproductive Functions
- Can There Be More Than Two Sexes?
- Why Are There Equal Numbers of Males and Females?
Study questions: 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28
Evolution Has Led to Diverse Methods of Sex Determination
- Sex May Be Determined by Chromosomes
- Sex May Be Determined by Temperature
Study questions: 29 | 30 | 31
Sexual Selection Produces Anatomical and Behavioral Differences between Males and Females
- Males and Females Follow Different Reproductive Strategies
- Males and Females Are Exposed to Different Reproductive Risks
- Males Often Compete for Access to Females
- Females Often Choose among Males
- Sometimes Males Make Significant Investments in Reproduction
- Box 2.3: Biology of Sex: When Males Get Pregnant
- If Males Invest, Sexual Selection May Work Differently
Study questions: 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47
Diverse Relationship Styles Have Evolved
- Social and Sexual Arrangements Are Not Necessarily the Same
- Male Promiscuity Offers Obvious Evolutionary Benefits
- Why Are Females Promiscuous?
- Female Promiscuity Leads to Adaptive Responses by Males
- Males May Copulate with Females by Force
Study questions: 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59
Sometimes, Helping Relatives Reproduce Is a Good Strategy
- Kin Selection Explains Some Altruistic Animal Behavior
- Box 2.4: Society, Values, and the Law: Does Sexual Morality have an Evolutionary Basis?—The Case of Incest
Study questions: 60 | 61 | 62 | 63 | 64 | 65 | 66
Sex May Acquire Other Functions beyond Reproduction
- Female and Male Bonobos Engage in Nonreproductive Sex
- Bonobos Use Sex for Conflict Resolution and Alliance Formation
Study questions: 67 | 68 | 69 | 70 | 71 | 72
