Human Evolution

mammal characteristics

mammary glands, hair, endothermic, internal fertilization, differentiation of teeth

groups of mammals

monotremes, marsupials, eutherian

monotremes

eggs

marsupials

pouch

eutherian

complete developments in uterus

primate differences from mammals

fingers and toes are flexible, shoulder and hip joints have wide range of motion, eyes directed forward, large advanced brains, have one baby at a time

defining characteristic of primate

opposable thumbs

primate groups

prosimians, anthropoids

Differences between humans and our close relatives

hair, large complex brains, small teeth, upright posture, intricate behavior, tool making, language

hominoid

great apes and humans

hominin

more closely related to humans than chimps or gorillas

Hominids history

split from chimps, descended from trees, walked distances

3 genera of homonids

homo, australopithecus, ardipithecus

how identical are humans and chimps?

98.5%

Ardipithecus ramidus

hominin, walked upright, climbed trees, brain size small comapred to chimps, start of bipedalism

Australopithecus

Lucy found in Ethiopia, showed we evolved in Africa, fully bipedal

homo habilis

first to make stones - smarter

homo ergaster

size of modern humans, brain ½ size of humans

homo erectus

made large stone axes, used and created firs, first hominid to leave Africa to Europe

neanderthals

we didn’t evolve from them, only evolved in Europe and Asia, brain size around same as ours, buried their dead

homo sapiens

195,000 years ago, evolved in Africa, reduced size difference between sexes, large agriculture

Multiregional hypothesis

everyone evolved in Africa, homo erectus left Africa, homo sapiens evolved in many places

out of africa hypothesis

everyone evolved in Africa, homo erectus left Africa, homo sapiens only evolved in Africa

defining trait of humans

language

When did primates spit into monkeys and apes?

30 million years ago

When did hominids split from chimps?

6 million years ago

Who was Lucy? How old is she? What genus is she from? Where was she found?

First Australopithecus fossil to be found, 3.2 million years old, australopithecus afarensis, found in Ethiopia

When were tools first made?

2.5 million years ago

How are Neanderthals different from modern humans?

More robust, more prominent brows, protruding face

Why did Neanderthals go extinct?

homo sapiens replaced them

Did humans breed with Neanderthals?

yes

Why are larger brains good?

Capable of language, symbolic thought, artistic expression, and the ability to use and create tools

Why do we walk upright? What is the advantage?

freed hands for carrying and manipulating tools