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Introduction• ____________________: Study of social relations.– Interactions between organisms and the environment

mediated by behavior.

• ____________________: Branch of biology concerned with study of social relations.

• _____________: Number of offspring (genes) contributed by an individual to future generations.

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Introduction• Fundamental Question:– ?

– Female reproduction thought to be limited by …

– Male reproduction limited by …

http://www.youtube.com/watch?v=A-05Z-GsGfI

Birds of Paradise…

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Introduction

• – Exhibit both male and female function.

Which is the hermaphrodite?

http://xpress101.files.wordpress.com/2008/03/tulip-flash-pink.jpg http://scienceblogs.com/zooillogix/giant%20gippsland%20earthworm.jpg

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Mate Choice• – Differences in reproductive rates among

individuals as a result of differences in mating success.• _____________________: Individuals of one sex

compete among themselves for mates.

http://www.wildnatureimages.com/Ca%20to%20H/ELK-SPAR-JASPER-NP3..jpghttp://www.nrmsc.usgs.gov/files/images/BUBO%20mating%20ball.preview.jpg

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Mate Choice• _____________________: Individuals of one sex

consistently choose mates among members of opposite sex based on a particular trait.

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Mate Choice and Sexual Selection in Guppies• Given a choice, female guppies will mate

with…

– – Color characteristics that have been shown to

confer mating advantage:• • •

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Mate Choice and Sexual Selection in Guppies• Endler performed natural selection study to test

color pattern in guppies.– When freed from predation… WHAT HAPPENED?

• Kodric-Brown reported reproductive success was determined by a combination of male attractiveness and dominance status.– Observed attractive males tend to be …???

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Mate Choice Among Scorpionflies• Adult scorpionflies (genus Panorpa) feed on

dead arthropods in the forest understory.– Dead arthropod supplies are often limited.• Thornhill found that male Panorpa will take possession

of, and guard, dead arthropods.– Larger males are more successful.

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Nonrandom Mating Among Wild Radish

• Wild radish flowers have both male ( ) and female ( ) parts, but cannot self-pollinate.

• Marshall found _____________ mating in wild radish populations.

http://www.westernwildflower.com/Hikes/Pt.%20Reyes/Tomales%20Pt.%2007.07.05/Tomales%20pt%2007.07.05%20photos/sm%20Wild%20Radish1971.jpg

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Sociality• Evolution of sociality is generally accompanied

by:– – –

• Cooperation generally involves exchanges of resources or other forms of assistance.

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Sociality• Eusociality– More complex level of sociality.• Three major characteristics:

– – –

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Different-headed Smoothies(aka Heterocephalus glaber)

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Cooperative Breeders• Species living in groups often cooperate in

rearing offspring.– What benefit do helpers gain ?• Inclusive fitness:

– Inherited territory:

» Kin Selection

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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Green Woodhoopoes• Ligons found green woodhoopoes live in

territories defended by flocks of 2-16.– Only one pair breeds.• Exhibit strong ____________.• Scarcity of …

– Bulk of young tend to be helpers ranging from half to full siblings.•

http://www.biodiversityexplorer.org/birds/phoeniculidae/phoeniculus_purpureus.htm

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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African Lions• Packer and Pusey studied cooperation among

African lions in the Serengeti.– Prides of female lions include 3-6 adults, but may

contain as many as 18.• Many forms of cooperation.

–

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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African Lions• Males cooperate in territory defense.– Not always made up of close relatives.– Single males have no chance of claiming and defending

a pride.•

– Probability of siring young depends on rank within coalition.– Reproductive success more variable in groups of 3-4 than in groups

of 2.– Larger coalitions composed of relatives.

BIOL 3240 Plant and Animal Ecology – Sex & Social Relations

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BIOL 3240 Plant and Animal Ecology – Sex & Social Relations