Key steps in human evolution Flashcards Preview

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Flashcards in Key steps in human evolution Deck (36):
1

when did chimps and human diverge

5-6mya

2

what has occured to climate in homo evolution

6-4.5mya - stable and slightly warmer than today
4.5-1mya - increasingly unstable and fluctuations

3

when did the current ice age begin and the last glacial maximum

2.58mya
11.7kya

4

what are the period called before and after the last glacial maximum

before - Pleistocene
after- holocene

5

what are hominids

member of hominidae (great apes)

6

what are hominins

bipedal hominids
the lineage that leaads to homo sapiens

7

when did anatomically modern homo sap arise

200kya

8

what are premodern homo

pleistocene homo that lack modern human cranium and post cranial skeleton
inc N
H.heidelbergensis

9

what is the transitional homo

H.habilis (fingers could grasp)

10

what are the archaic Homo and when were they pressent

Australopithecus africanus (3-2.4mya)
Australopithecus afarensis (3.7-3mya )

11

what is some of the main difficulties in the field

rarity of fossils
what are en route to H.sap
homoplasy

12

why is there a rarity of fossils

up until 2mya on African plane - scavenged
low population and frequent bottlenecks

13

what is homoplasy

shared characteristics that aren't inherited from LCA

14

what is unusual about earth now

only one hominin
up until 13kya always at least two

15

what hominins were present 60kya

N
D
H.floresiensis

16

what is the earliest bipedal hominin

Ardipithecus ramidus
1.2m heght
4.4.mya

17

what interesting about A.ramidus fossil

opposoble thumbs - like Chimp - evidence spent time in trees
suggets transitional phase

18

what do A.afarensis fossils show about bipedalism

lucy - 3.6mya
same height as A.ramidus nut pelvis and muscle =
modern features = walk as we do
Laetoli footprint - suggets a gait and speed of walk sim
modern human

19

what are some eamples of theories for the evolution of bipedalism

hands free -but this not sel pressure
thermoreg on savanna - but A.ramidus in forest
incr energy efficiency - especially over long distance/pot competitive adv over other hominins
aquatic ape theory

20

what were the firt hominins to use tools

H. habilis
2.2mya

21

what is the first tool culture

olduwan
split flakes from surface of pebbles - scavenging meat not hunting

22

how is hommo tool use different from other animals

ability to improve/modify

23

what are the tools used by H.erectus

Achuelean tools
1.6mya -150kya little change
well balanced
some shaped for hand axes
for hunting
more sophisticated

24

what is speech and what does it require

ability for sound
anatomy inc low larynx/distorted tongue/large windpipe

25

what is language

system for communication

26

what do fossils of H.erectus show us about their ability for speech

similar windpipe to h.sap
threfore speech probs ev

27

what do N fossils suggest about their ability for speech

probs lacked lower larynx- less ability/limits no of sounds

28

what does cranial capactiy of hominins suggets about the evolution of language

in A.afarensis - 375-550cm^3
in H.habilis 650cm^3 and evidence of Broca area
after this all more than 1000cm^3

29

what is the problem with looking at brocas area on fossils

not human specific
not solely language role

30

what gene has genetics studied for the ev of language

FOXP2
assoc with diseases in which language affected

31

what subsitutions present in H.sap of FOXP2 and what hominins present in

T303N
N325S
both in N and some studies suggest in Erectus

32

what the effect of incr FOXP2 in zebra finch

incr dev of song = pot inv in reg song syst

33

what the phenotype shown by mouse with the FOXP2 homo subs

incr neuron growth in forebrain
altered patterns of ultrasonic vocalisations
incr dendrite length and synaptic plastcity
decr in dopamine conc

34

comparison of genes in human and chimp

incr nerual gene in homo

35

what evidence does tool use suggest about language

oldowan - tech stasis inconsitent with presence of language
pot a coev relationship would expect

36

what have studies on the social transmission of tool use shown

imporve when laguage to teach
not by imitation
suggest pot a sel for language