Lecture 7. Sexual Selection. Costs of sex Cost of meiosis Cost of producing males Cost of courtship and mating.

Slides:

Advertisements

Similar presentations

KEY CONCEPT Evolution occurs in patterns.

Advertisements

Gene flow is the movement of alleles between populations.

1) Why do males often compete for access to females more than females compete for access to males A) males invest less in reproduction B) access to females.

Announcements EXAM II next Wednesday (March 14th) Review Monday (March 12th) No Class Friday (March 16th)

Sexual Selection Elaborate traits, songs, dances, fights.

BIOE 109 Summer 2009 Lecture 9- Part I Sexual selection.

Sexual selection Sexual selection

Sexual Selection Christina Saremi PSYC141.

Sexual Selection - Recognized as a deviation from predictions offered by a strict selection model. In this case, there are different selective pressures.

Males and females evolved after sex IsogamyAnisogamy.

Sexual selection, a brief review Some basic principles. Some examples. Difference between sexual and natural selection. Sex role reversal. Video -Why Sex.

Sexual Selection. I.Motivation Sexual Dimorphism is Frequent.

Sexual Selection Variance in reproductive success

Sexual Selection Natural Selection: Individual Lifetime Reproductive Success Survival, Reproduction Tradeoff Greater Current Reproduction vs Survival (Future.

One last time: haplodiploidy reproduction 0.5 of genome from dad X 1.0 = of genome from mom X 0.5 = r = 0.75 Leafcutter ant queen + workers.

BIOE 109 Summer 2009 Lecture 7- Part I Linkage disequilibrium and the evolution of sex.

I. Evolution of Sex A. Asexual v. Sexual Reproduction B. Theories on the evolution of Sex 1) Unpredictable environment – Red Queen 2) Deleterious mutation.

Sexual Selection I A broad overview. Charles Darwin with his son William Erasmus in 1842 [picture omitted for copyright reasons]

Mating Games and Signalling

Sexual Selection in the Sea. Darwin’s postulates & evolution IF –Variation: phenotypic variation among individuals within population –Inheritance: some.

Sexual Selection (I). Costs of sex Cost of meiosis Cost of producing males Cost of courtship and mating.

Sexual Selection I A broad overview. Charles Darwin with his son William Erasmus in 1842.

Darwin’s Puzzle: Why are Males and Females Different?

KEY CONCEPT A population shares a common gene pool.

Set up Cornell Notes on pg. 23

Darwin’s Theory outline notes

Natural Selection Developed by Charles Darwin in 1859

Gene flow is the movement of alleles between populations.

KEY CONCEPT A population shares a common gene pool.

Behavioral Ecology Introduction Social behavior Sexual selection.

Natural Selection Problem

1 Social Relations Chapter 7. 2 Introduction Behavioral Ecology: Interactions between organisms and the environment mediated by behavior. Sociobiology:

1 Psychology 305A: Personality Psychology September 30 Lecture 7.

10.3 Theory of Natural Selection KEY CONCEPT Darwin proposed natural selection as a mechanism for evolution.

1.Behavior geneticists study the genetic basis of behavior and personality differences among people. 2.The more closely people are biologically related,

Mating Systems Conflict.

Sexual Selection NS: who SURVIVES SS: who REPRODUCES SS can explain some deleterious/costly characteristics that can’t be explained by NS Ornaments/Courtship.

1 Psychology 320: Psychology of Gender and Sex Differences Lecture 15.

Gene flow is the movement of alleles between populations.

1 How does sexual selection influence animal behavior? A (male) sage grouse.

11.3 Other Mechanisms of Evolution KEY CONCEPT Natural selection is not the only mechanism through which populations evolve.

Hosler: “Optical Allusions” another graphic novel exploring the evolution of eyes f.

Dancing with the Stars!. Sexual selection Intrasexual selection: most common is male-male competition Intersexual competition: most common is female choice.

11.3 Other Mechanisms of Evolution KEY CONCEPT Natural selection is not the only mechanism through which populations evolve.

Running with the Red Queen Why is there sexual reproduction?

Scales of Ecological Organization Organism Population Community Ecosystem Biosphere.

Evolution – Genetic Variation Within Populations  Key Concept:  A population shares a common gene pool.

Evolution of Populations

11.1 Genetic Variation Within Population KEY CONCEPT A population shares a common gene pool.

11.1 Genetic Variation Within Population KEY CONCEPT A population shares a common gene pool.

Sexual Selection - Recognized as a deviation from predictions offered by a strict selection model. In this case, there are different selective pressures.

11.1 Genetic Variation Within Population KEY CONCEPT A population shares a common gene pool.

Extra credit question Sexual selection theory predicts that ___________ pipefish should compete with each other for access to mates, and that ___________.

Evolution and its Effects on Ecology

NATURAL SELECTION AND ADAPTIVE EVOLUTION

Sexual Selection and Reproductive Behaviour

Sexual Reproduction Science 9, 2016.

The evolution of Populations

Puzzle of sexual dimorphism (differences in males and

Asexual and Sexual Reproduction

Evolution Evolution is the change in organisms over time.

“The sight of the peacock’s tail makes me sick.”

HMD Bio CH 11.1 KEY CONCEPT A population shares a common gene pool.

A review! In two sentences or fewer, explain what’s going on here.

By: James Schadenberg, MJ Pinheiro, Chad Gopaul and Amy Van Asseldonk

Natural Selection & Evolutionary Patterning

Unit 1: 1.7 Evolution - Selection

Population Evolution Chapter23.

Evolution & Sexual Selection

Presentation transcript:

Lecture 7. Sexual Selection

Costs of sex Cost of meiosis Cost of producing males Cost of courtship and mating

Benefits of sex Protection against mutations (Muller’s ratchet) Protection against environmental changes (Raffle hypothesis) Protection against biotic fluctuations (Red Queen hypothesis)

”Now here, you see, it takes all the running you can do to keep in the same place.” The Red Queen hypothesis

Why do male and female gametes differ in size? Geoffrey Parker et al.: divergent evolutionary selection favoured two types of gametes:  small and mobile (sperm)  sedentary and packed with nutrients (eggs)

Darwin (1871, p256): “We are, however, here concerned only with that kind of selection, which I have called sexual selection. This depends on the advantage which certain individuals have over other individuals of the same sex and species, in exclusive relation to reproduction.”

Sexual selection 1. More individuals are produced than manage to reproduce 2. Individuals differ in their ability to compete with others for mates or to attract members of the opposite sex  Result: the evolution of traits that enhance reproductive success while decreasing survivorship

What about these

Inrasexual Selection Members of one sex compete among themselves for access to members of the other sex Competition before mating Competition after mating Competition following conception

Bruce effect in rodents The pregnancy of a recently inseminated female is terminated upon exposure to an unfamiliar male

Male infanticide in langur monkeys.

Male infanticide in lions

Explain This ?

Intersexual Selection  Members of one sex (mostly males) ‘advertise’ that they are worthy of an investment.  Members of the other sex (usually females) choose among them.

Sexually selected “ornaments” of males Darwin argued that sexual selection via female choice was responsible for the evolution of male displays and plumage

The widowbird (Euplectes progne), a species the size of a blackbird that is endowed with a half-meter long tail Sexual selection for tail length in long-tailed widowbirds (Andersson 1982)

Mate-choice copying in the guppy (Poecilia reticulata ) One female’s choice of a mate affects another female’s choice

Male zebra finch

Fluctuating asymmetry: The extent of asymmetry in bilaterally symmetrical traits Sailfin Molly (Poecilia velifera)

Normal HighPerfect