12 - Mammals 2/Human Evolution Flashcards
Delayed fertilization
sperm is retained in animal till they wake up. fertilization happens once they have more resources
What period did primates arise
cretaceous
65mya
- the big extinction of dinos
- nocturnal mammals emerged during the day
- tree animals that ate insects (archicebus achilles)
Primate characteristics (7)
- colour vision
- binocular vision and depth perception (eyes in front)
- center of gravity shifted over hindlimbs
- nails
- sensitive foot and hand pads for moving in trees
- friction ridges
- medial digits of hands and feet opposable
Primates suborders
Strepsirhini: 7 families include Lemurs, aye-aye, bush babies
Haplorhini: 6 families
Lemurs
5 digits
tail
Suborder haplorhini 6 families
- Tarsiidae (tarsiers)
- callitrichidae (marmosets and tamarins)
- cebidae (capuchin-like monkeys)
- cercopithecidae (mandrils, baboons, macaques)
- hylobatidae (gibbons, siamang)
- hominidae
Hominidae subfamilies
Ponginae: oranguatan
Homininae: has 2 tribes
Homininae tribes
Gorillini: gorilla
Hominini
First apes
25 mya
- highlands and savannahs created by geographical/climactic changes in eastern africa
- Apes became terrestrial: changed diet to grains, tubers, dead animals. upright posture+bipedal locomotion favoured (better for walking, looking for things like food/predators). Skull changes in human ancestors (face less protruding as brain enlarged, reduction in size of jaws, teeth and supraorbital ridges)
Homindae
family of suborder haplorhini
apes: gorilla, chimps, orangutan and humans
Homininae (subfamily) and Hominini (tribe)
Contains chimps and humans
Hominin
term used to refer to chimps and members of human lineage
Hominini
Used to refer only to human lineage without chimps
Panina
Subtribe designating the chimpanzee lineage
Hominina
Subtribe designating human lineage
Earliest hominins
- Sahelanthropus tchadensis (6mya)
- Australopithecus (3.9-2mya)
Sahelanthropus tchadensis
- 6 mya
- mixture of ape and hominin features
- close to human/chimp divergence
Australopithecus
- 3.9-2mya
- A. afarensis (lucy - 3mya), bipedal based on pelvis and leg structures
- A. africanus (3-2 mya)
Important step for humans
Tools and weapons
Lake Turkana
- not a single line of humans
- many species at one time
- found turkana boy, that was bigger than us but walked on 2 feet and used hands to carry things. Also made tools which could be taught
- good fossils because volcanic area
Evolution of hominins and advances
- H. habilis - 2.4 mya (“handy man”, stone tools)
- H. Erectus - 1.8 mya (tools, hunting and fire - turkana boy)
- H. Sapiens - 195 000 ya (sophisticated tools, hunting, engraving, art)
Fully modern humans present 30 000 ya
Cave paintings
- pass information without genetics, but through behaviour and culture
Culture
- system of nongenetic behaviours, symbols, beliefs, institutions and tech characteristic of a group that is transmitted through generations
- Predominantly human trait
- Cultural evolutions = when culture changes over time:
Not based on organic evolution: rather learning
Cultural evolution
- hunters and gatherers
- agricultural revolution
- industrial revolution
- genetic revolution
