Lecture 17 Flashcards
1
Q
Uniquely Human Features
A
- large brains
- bipedal walking
- verbal symbolic speech
- music
- domestication of wolves and other animals
2
Q
Human Features Shared With Chimps
A
- self awareness
- use of tools
- making tools
- making weapons for hunting
- warfare
- complex social structures
3
Q
Ape–>Human size/proportion
A
- hips changed first, then foot then rib cage and skull
- variety of different things changing under variety of selective pressures at different times
- didn’t evolve because of our smarts, those came later
- upright walking came when we started to move away from forests, forests retreating and much of the ground is being replaced by dryer land ecosystems
4
Q
A. afarensis
A
- foragmen magnum that’s now in the base of the skull like ours because of how they walked (upright now)
- shows a lot of changes in anatomy
- pelvis and links to legs changes so they can walk upright (pelvis has to support vertical being)
- number of vertebrae changes as well as number of ribs
5
Q
Human vs. Ape Hip Girdle
A
- apes is longer and sticks out backward to support their locomotion
- humans is smaller and oriented so the human can walk upright
6
Q
Chimps vs. Humans
A
- femur is a straight line from hip articulation down to inside of kneecap
- human femur goes from inside hip articulation down to outside of kneecap (so it crosses over)
- chimps birth canal is smaller than humans because we have bigger brains to fit through
- human butt helps you stand upright-gives you stability; gut is upright and has to be supported by the pelvis so the butt helps with holding all this vertically
- humans developed to be able to run for a long
7
Q
Humans vs. Gorillas
A
- humans are the only primate with a chin
- humans teeth shaped in a parabola while gorillas shaped in a larger U
8
Q
Mosaic Evolution
A
-in bits that aren’t at the same time/place
9
Q
Piltdown Man
A
- made skull with human and ancient orangutan jaw
- fooled lots of people into thinking this was the most likely ancestor
10
Q
First Skull of A. africanus
A
- has endo cast of brain
- child skull
- fairly large brain
- teeth like ours
11
Q
H. ergaster (1)
A
-when this was discovered so are stone tools in the same strata
12
Q
H. erectus (1)
A
- individuals leave Africa and survive for a very long time
- last one died around 20,000 years ago in East Asia
- split with Neanderthals around 500,000 years ago (sister species)
- Neanderthals took care of each other and injuries had a culture
- at least two hybridization events that take place with these two ancient humans
13
Q
How many kinds humans living on earth at one time?
A
- 5
- Denisovians (only known via genome sequence from 43 kyr finger bone found in Denisova cave-Russia)
- H. neanderthalensis (genome also sequenced by Paabo lab)
- H. floriensis (possibly dwarfed H. erectus or older hominid-no DNA available) “Hobbits”
- H. erectus (slight chance that they survived this late in S. Asia)
- H. sapiens (rapidly leaving Africa at this time and meeting up with other hominids)
14
Q
What makes a human a human?
A
- speech
- gene required for human speech is FOXP2
15
Q
Weirdest Discovery Ever Made
A
- H. floresiensis
- called hobbits, didn’t ever get much bigger than a couple feet
- is it an australopithecine?
- a lot of species developed miniature variations of many that’s what this little guy is
16
Q
Body Size on Islands
A
-big animals get smaller and small animals get bigger
17
Q
Ardipithecus ramidus
A
- now our oldest well known ancestor
- likely split of humans and chimps 6-7 million years ago
- ape like skull
- brain ape sized
- teeth intermediate between ape and human
- walked upright-hip
- could climb well-foot still hand like
18
Q
H. hablils
A
- many features still similar to Australopithecus
- dates about 1-1.8 mya
- somewhat larger brain than Australopithecus
- small in stature
- post cranial skeleton not well known
19
Q
H. ergaster (2)
A
- early Homo
- post cranial skeleton much more like ours, larger skull than earlier hominids
- probable maker of first stone tools, 2.5 mya, and probable ancestor of H. erectus
20
Q
H. erectus (lots of info)
A
- appeared 1.8-1.7 mya
- closely related descendant of H. ergaster, but migrated from Africa into Eurasia as early as 1.8 mya-first hominid to adapt to cold conditions
- by about 700 kya gave rise to H. heidelbergensis, the ancestor to H. neanderthalensis and H. sapiens
- remarkably stable in morphology and apparently behavior for about 1 mya, although brain size increased
- brain size 800-900 cc earlier members and 1100 cc in latest
- pronounced supraorbital torus and prognathism
- dentition human, postcranium similar to humans, similar in size
- first human nose
- moderately arched basicranium-some ability to speak?
- stone tools limited and conservative use of fire (China)
- processed meat, likely hunter
- persisted in Asia to somewhere between 100 kya 20 kya
21
Q
Tools Australopithecus
A
- no trace oldest ca 2.5 million years oldowan tradition possible copper associated with H. habilis
- by ca 1.5 million years have much more sophisticated acheulean industry
22
Q
H. neanderthalensis
A
- middle East, western Asia, Europe-an ice age phenomenon (with a bad name in pop culture)
- brains size larger than ours (1200 to over 2000 cc)
- powerful skeletons-injuries like modern extreme athletes
- mid facial prognathism, an adaptation to serve cold
- very large supraorbital torus
- peculiar wear on incisors-behavioral indication
- brain asymmetry as in H. sapiens
- some interbreeding with humans indicated by genomic studies
- appear in Europe 130,000 years ago
- became extinct within a few thousand years from time of entry of H. sapiens into Europe
23
Q
Some indications of culture in Neanderthals
A
- buried dead
- no art of personal adornment as in modern humans, made clothing, spears and sophisticated stone tools
24
Q
Homo Sapiens
A
- Europeans and Asians-a bizarre evolutionary history revealed by genome sequencing of us, Neanderthals, and Denisovans
- H. sapiens expanding out of Africa and into Europe asia and southern asia and pacific
- meet and mate with neanderthals in europe
25
Q
Interbreeding
A
- all out of africa
- H.s. and Denisovans-in south Asia
- also traced in western pacific
- H.s. and H.n. intermingling occurred just out of Africa
26
Q
Genome Sequencing of Extinct Humans
A
- methods developed by Svante Paabo in Germany
- DNA isolated from bones in caves or other cool dry sites.
- DNA survives up to 100,000 years
- Fragments sequenced and aligned and compared to modern human genome
- they have nearly complete genomes of Neanderthals and Denisovans (from a single finger from Denisova Cave)
27
Q
Modern Humans-Record of Hybridization
A
- Africans-no Denisovan and no Neanderthal genes–highest diversity of modern humans
- Europeans and north Asians-4-6% neanderthal genes in their DNA, but not Denisovan
- Australian and New Guinea people–a few percent Denisovan genes in their DNA, as well as some Neanderthal genes
- molecular clock says Denisovans 1 myr diverged from us
28
Q
FOP2 Gene
A
- required for human speech
- differs in two bases from all apes
- these two bases are shared between modern humans and neanderthals
29
Q
An enhancer of the FZD9 gene in neocortex growth
A
- human version increases neocortex growth when expressed in mouse embryos
- the enhancer from chimp does not
30
Q
Unexpected Discoveries Still Happen
A
- H. floresiensis complete skull and skeleton of recent, tiny and primitive looking hominid
- possible explanations: Australopithecus, island miniaturized H. erectus, pathological H. sapiens
- DNA not preserved in hot wet environment
- hope for more fossils
