Quiz concerns Evolution: change in allele frequencies from generation - - PowerPoint PPT Presentation

Evolution: change in allele frequencies from generation to generation Modern synthetic theory explains evolution as occurring in two stages: First stage: microevo processes = mutation, recombination, genetic drift, and gene flow produce and redistribute genetic variation Genetic drift: evolution due to chance Gene flow: evolution due to gene exchange between populations Second stage: macroevo processes like natural selection act on variation over geologic time causing speciation

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Quiz concerns

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Today: Anthropoids

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Last time: prosimians and tarsiers

monkeys, apes, humans

Traits distinguishing the anthropoids from prosimians...

• increased parental care
• more mutual grooming

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Anthropoids

• 85% of all primate species

Divided geographically: New World monkeys and Old World monkeys

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Monkeys

Where: Central and South America

• almost exclusively arboreal
• prehensile tail

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New World Monkeys

Tamarins and marmosets

• smallest monkeys
• claws (ancestral trait)
• twin births
• males more involved in infant care

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New World Monkeys (example)

Where: Africa to Southeast Asian islands

• sexual dimorphism
• females have swelling and redness during estrus

Divided into subfamilies: Cercopithecines Colobines

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Old World Monkeys (Cercopithecidae)

Baboons, mandrills, and macaques Where: Africa and Asia Diet: omnivorous Traits

• terrestrial baboons have ischial callosities

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Cercopithecines

Colobines Where: Africa and Asia Diet: folivorous Traits

• leaf-eating monkeys
• segmented stomachs

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Old World Monkeys: Colobines

Traits distinguishing them from monkeys Continued evolutionary trends:

• longer infant developmental periods
• more complex brains and behavior
• larger body size and brainier
• shortened trunk
• arms longer than legs
• no tail

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Hominoids: apes and humans

Where: tropic areas of southeast Asia Diet: omnivorous Brachiation: suspensory locomotion involving arm swinging Traits: adaptations to brachiation

• muscled shoulders
• long arms
• curved fingers

https://youtu.be/U3JhwjNfx_g

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Gibbons and siamangs

Where: forests of Borneo and Sumatra Diet: frugivorous Traits

• almost completely arboreal
• solitary

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Orangutans

Where: Africa (east/west lowland, and mtn gorillas) Diet: vegetarians Traits

• largest living primates
• sexual dimorphism

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Gorillas

Chimpanzees Where: equatorial Africa Diet: omnivorous plus other animals Traits

• knuckle-walking on ground
• brachiation in trees

Social: large fluid communities

• form lifelong attachments

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Hominoids

Bonobos Where: areas south of Zaire River Diet: omnivorous Traits

• copulate throughout estrus cycle
• female-centered communities
• female-female and male-male

sexual behaviors

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Hominoids

Homo sapiens Where: found everywhere in all climates Diet: omnivorous Traits

• only living bipeds
• brainsize increased enormously
• entirely dependent on culture

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Hominoids - humans