Physical Anthropology Ch/wk5 (2/10)

Front 1

Phyletic Gradualism

Back 1

classic darwinian concept of evolution, slow changes over time

Front 2

Punctuated equilibrium

Back 2

Gould and Eldridge: based on fact that fossil record shows long periods of stasis. then catalytic event occurs to affect evolution: environmental problems, macromutational events (e.g. duplication of hox gene)

Front 3

Gould's adaptive landscape of evolution

Back 3

Main cause of speciation = cladogenesis by mutation or environmental changes, etc.Fitness scale is vertical, with greatest fitness found in deepest valleys. populations of organisms vary in stability/adaptive fitness (?)

Front 4

Cambrian period

Back 4

-600 million ya
- radiation of multicellular life-forms

Front 5

Devonian period

Back 5

-400 million ya
-first tetrapods

Front 6

Mesozoic period

Back 6

-65-250 million ya
-dinosaurs. In triassic period, first mammals.

Front 7

Cenozoic period

Back 7

-65 million ya thru today
-age of mammals

Front 8

Placoderms

Back 8

-first jawed fishes.
-No teeth, but jaws that can exert tremendous bite force
2 essential features for trajectory of vertebrate evolution:
1. jaws- expands diet, ecological niche, exposing them to different adaptive needs
2. Petral and pelvic paired fins, which will eventually develop into limbs

Front 9

evolutionary significance of first bony fishes

Back 9

1.Bones act as a mineral store
2.Functionally useful in muscular actions– levers for muscles.
3. Help with weight support (eventually useful for supporting weight out of the water)

Front 10

Lobe-finned fish:

Back 10

-have both gills and lungs
-strong large fins used for shuffling aroudn in shallow, murky water- almost like walking

Front 11

Tiktaalik roseae

Back 11

dates from middle to late Devonian. Possesses transitional features, linking it to transition from fish to first land-adapted vertebrates.

Front 12

Therapsids

Back 12

mammal-like reptiles in Paleozoic era. start of heterodont dentition- teeth have dif functions

Front 13

characteristics of early mammals

Back 13

very small, nocturnal and arboreal insectivores. endothermy, heterodonty.

Front 14

heterodonty

Back 14

dif teeth have dif functions. allows organisms to get more out of food source by crushing in teeth, and requires less energy for digestion. later, two sets of teeth over lifetime

Front 15

big changes in early mammal development

Back 15

-heterodonty
-inner eardrum (better hearing) bc of rearrangement of jaw
-larger brains
-reproductive: low birth no., mammary glands, postnatal infant dependency

Front 16

why mammals survived and dinosaurs didn't

Back 16

big asteroid about 65 mil years ago. mammals less affected by changes bc smaller (??), smarter, had endothermy (dust cloud made it cold)

Front 17

ancestral traits of primates

Back 17

-5-digit hand and foot
-collar bone
-lower bones of limbs permit inward rotation of hands and feet

Front 18

specialized/derived traits of mammals

Back 18

• Sensory systems
1. Forward directed eye orbits with stereoscopic, color vision.
2. Reduced olfactory sense.
3. Loss of vibrissa (whiskers) and development of sensitive finger tip pads (associated nails and loss of mammalian claws).
• Large brain size in relation to body size.

Front 19

important biological features of primates

Back 19

• Five digit hand and foot; necessary for our adaptation and tool use.
• Presence of tactile finger tip pads as a sensory system.
• Ability of the wrist and hand to rotate.
• Large brain.
• Emphasis on sense of vision.
• Generalized chewing dentition.

Front 20

important behavioral features of primates

Back 20

Behavioral features that are basic to who we are:
• daylight (diurnal) activity cycles.
• Social living.
• Diverse dietary habits.
• Intelligence and learned behavior.
• Small birth number and a prolonged childhood dependency.