anthro lec final

primates as k selected species

• stable environment, predictable food supply

• high parental investment

• few offspring

• longer time btw births

• longer maturation/ lifespan

• bigger body size

alloparenting

non parent helps take care offspring

• trained experience w/ mothering —> more prepared when they have their own offspring

• provides for adoptive parenting if mother dies

• reinforces social bonds among adults

primate autonomic communication

• piloerection = hair stands on ends

• blushing, sweating

• displays (ritualized/ intentional behavior)

  • gorilla pounding chest, baboon displaying canines

• aggressive/ submissive behaviors

• gestures

broca’s area

speech production

• broca’s aphasia = inability to speak/ articulate words

wernicke’s area

speech language comprehension (coding/ decoding speech)

• wernicke’s aphasia = can produce speech but its nonsense

sociobiology

theoretical perspective to explain the behavior of animals

• altruism

• inclusive fitness

• infanticide

altruism

selfless behavior

• decreases individual’s fitness for the benefit of others

inclusive fitness

kin selection

• 50% DNA w/ parent, sibling, offspring

• 25% DNA w/ niece/ nephew

• 12.5% DNA w/ cousin

infanticide

male who takes over group will kill all the infants

• females then ovulate + male can pass on its DNA to next generation

ex: langurs

human classification

1. kingdom: animalia

2. phylum: chordata

3. class: mammalia

4. order: primates

5. family: hominids

6. genus: Homo

7. species: sapiens

chordata

• nerve cord

• gill slits at some point in development

• stiff, supporting cord spine

• vertebrates (spinal cord)

6 classes of animals

1. bony fishes

2. cartilaginous fishes

3. amphibians

4. reptiles

5. birds

6. mammals

homology/ homologous traits

characteristics shared btw 2 organisms based on descent from a common ancestor

• ex: 5 rays in mammals

primitive traits

a trait shared by a common ancestor

derived traits

a trait that is newly evolved in a species

• ex: horses going from 5 digits to 1 digit

analogy/ analogous traits

characteristics shared by 2 organisms based on FUNCTION, not by common ancestry

• ex: wing of bat vs wing of bird

what kind of traits to use when classifying orgaisms

homologous traits and SHARED derived traits

how to see evolutionary success

• # of habitats invaded

• # of species

• how long the species has survived on earth

• # of individuals

arthropods are most successful

precambrian era

3,000 million years ago

• evolution of life

• first microfossils

paleozoic age

570 million years ago —> cambrian explosion

• invertebrates (jellyfish, worms, trilobites) in water

• vertebrates evolve

• rise of amphibians (fish that left water) towards end of age

mesozoic age

225 million years ago —> age of reptiles

• water tight skin and amniote eggs (water tight egg)

• strong limbs to support being on land

• amazing adaptive radiation bc land was uninhabited —> took advantage of it

• DINOSAURS!!

  • theropods

• therapsids

• 65 mya = mass extinction of dinosaurs bc of meteor —> nuclear winter killing 75%, no bigger than 25 kg organisms survived

therapsids

mesozoic age: mammal like reptiles

• heterodonts

• led to mammals

therapods

mesozoic age: dinosaurs that led to birds

cenozoic age

66 million yrs ago to present day —> age of mammals

• monotremes: egg laying mammals; most primitive, incomplete homeothermic, lactation through pores

• marsupials: pouch mammals; births, immature creatures, and goes into pouches for more development

• Placental mammals: internalized egg, placenta

• Paleocene, Eocene, Oligocene

placental mammals

• Very successful all around earth

• Came from therapsids

• Rodents = most successful, 2/5 of all mammals

• Bats = second most successful, 925 species

homplasy

separate evolutionary development of similar traits that is NOT from common ancestors

• Includes analogies = homoplasies that are functional

• Parallel evolution

• Convergent evolution

Parallel evolution

not so differently related

• ex: OWM (gibbons: long armed fruit specialists) vs. NWM (spider monkey: long armed fruit specialist)

Convergent evolution

separate evolutionary development of similar structures in very unrelated species, distinctly related

• ex: marsupials vs placentals

How does a species form?

IMPORTANT: Geographic isolation

• phyletic gradualism

• Punctuated equilibrium

Phyletic gradualism

accumulation of differences in populations that overtime lead to a new species

Punctuated equilibrium

periods of stasis punctuated by speciation events

Paleocene

65-55 million years ago

• angiosperm radiation

• Plesiadapiformes dominate

plesiadapiformes

• primate like

• europe, china, north america

• posterior dentition = primate like, anterior dentition = very derived

• lacks post orbital bars

• laterally placed eyes

• claws instead nails

• part of eurachonta

eurachonta

• plesiadaiformes

• primates

• scandentia

• dermoptera

species most closely related to order primates

1. scandentia = tree shrews

2. dermoptera = flying lemurs/ colugos

3. chiroptera = bats

eocene

55-34 million years ago —> promisian radiation

• western US, europe, africa, asia

• eurprimates = true primates!

  • post orbital bar

  • Nails instead of claws

  • Grasping hands and feet

  • General dentition

• Adapids = lemur like, led to strepsirrhines

• omomyids = tarsier like, led to haplorrhines

oligocene

37-29 million years ago

• fayum in egypt —> preservation of fossils, seeds, bark, pollen

• first time we see primates in south america (rafted on land mass)

• fayum primates:

  1. oligopithecids

  2. parapithecids

  3. propliopithecids

• NWM and OWM split from apidiums

parapithecids

more primitive —> Apidium, 2-1-3-3 dental formula

• ancestor of NWM and OWM

propliopithecids

more derived —> aegyptopithecus, 2-1-2-3 dental formula, Y-5 molars

• ancestor of OWM, spider monkey like