Human Evolution

Question 1

hominids

Answer 1

differentiated ~20mya
tailless primates
mostly quadrupedal but could use hands, some bipedal movement
no breeding season, 8-9 months gestation
>97% genetic identity
capacity for language, cultures beyond family

Question 2

african apes

Answer 2

differentiated ~15 mya
large frontal sinuses
thin dental enamel

Question 3

hominins

Answer 3

~12 mya
lots of social qualities - playfulness, empathy, social hierarchy, group dynamics
tool use

Question 4

Homo

Answer 4

chimps and bonobos split off ~7mya
much more upright, bigger brain, specialized hands

Question 5

Sahelantrophus tchadensis

Answer 5

~7 mya
minimal age of the split from chimps and bonobos

Question 6

Orrorin tugenensis

Answer 6

~5-6 mya
probably a hominin

Question 7

ardipithecus ramidus

Answer 7

my beloved! ~4.4 mya
chimp brain, opposable big toe for climbing
small hominin canine teeth
the Eve of bipedalism

Question 8

Australopithecus africanus

Answer 8

looked like a chimp -protruding face, large canine teeth, long arms, small brain, but could climb and walk
~3.5 mya

Question 9

australopithecus africanus

Answer 9

possibly ~3.3 mya
brains started getting much bigger
possible originator of tool use

Question 10

homo habilis

Answer 10

~3 mya
big head
dexterous hands
tool use, flat face, short teeth
could climb but walked very similar to us

Question 11

homo erectus

Answer 11

likely had anatomy and behavior of modern humans
~1.9-0.2mya
smaller teeth, rounded skull and greater cranial capacity
first hominin to leave Africa, spreading into the middle east ~2mya
stone tools and fire

Question 12

neanderthals go extinct

Answer 12

~40 kya, after lots of introgression events, giving us a lot of neanderthal DNA

Question 13

Homo heidelbergensis

Answer 13

second wave out of Africa into Europe and Asia, around 600 kya

Question 14

Neanderthals

Answer 14

arose around 500 kya
brains slightly larger than ours
elaborate culture - art, stone tools, burial ceremonies
extinct ~40 kya

Question 15

Homo sapiens

Answer 15

left Africa around 60 kya
had lots of introgression events with Neanderthals
only about 2000 individuals gave rise to every human not living in Africa

Question 16

bipedalism

Answer 16

probably one of the first distinguishers of human ancestors
shorter, more dexterous arms
no opposable toes
pelvis and skill adapt for upright posture

Question 17

modern humans

Answer 17

big brains
helpless children and multiple dependent at once - we grow fast
not uniquely social or capable of language
lots of shared polymorphisms with apes, along with 98% of our coding DNA

Question 18

agriculture developed

Answer 18

around 11kya, independently all over the world - widespread by 7kya

Question 19

impacts of agriculture

Answer 19

lifestyle became sedentary
we began to grow exponentially, devastate habitats of other animals
health issues increase due to limitless calories with low nutrition
livestock and urbanization allow disease to spread

Question 20

contemporary human evolution

Answer 20

• men are evolving to be taller
• directional selection is favoring people with lower cholesterol
  very slight curves

Question 21

contemporary evolving QTL in humans

Answer 21

humans have 12 strong quantitative trait loci that have been seen as rapidly evolving
4 are related to our new diet - lactase persistence (allows us to digest lactose after weaning), amino acid absorption for farmers who got less of it in their diet