Exam Flashcards
(38 cards)
1
Q
What are the five forces of evolution?
A
Natural selection Random genetic drift Mutation Population mating structure Culture
2
Q
Natural selection details
A
- Since the environment can’t support unlimited population growth, not all individuals get to reproduce to their full potential
- some traits make it more likely that a species will survive
- but we interfere with that with things like IVF and modern medicine which means it’s not the same anymore hence the massive ⬆️ in population size
- environment adaptation = competition over food, water, mates and living space
3
Q
Genetic drift details
A
Changes in allele frequencies by chance
4
Q
Population mating structure details
A
- e.g. chimpanzees = patrilineal- when the females hit sexual maturity they leave the group and find another one this creates gene emmergration b/c they bring new genes to the new group
- mate preference = no consensus on how important it is e.g. giving food/grooming
5
Q
Mutation details
A
Error in copying the DNA
6
Q
Culture details
A
- The development of an ability from simple to complex
- e.g. nut cracking in chimpanzees - when the females move groups they adopt the new way the new group crack nuts
7
Q
What modern world advances will effect future evolution
A
- Social and religious attitudes towards population growth, birth control, abortion
- social attitudes about who to marry/not marry
- military culture
- domestication
- travel and transport improvements
- internet (e.g. online dating)
- genetic engineering
8
Q
We are currently in the Tertiary Period which is made up of 5 epochs, which are called?
A
Palaeocene epoch 65-54 ma Eocene 54-38 ma Oligocene 38-24 ma Miocene 24-5 ma Pliocene 5-1.8 ma (Anthropocene)
9
Q
Details of the Quaternary period
A
Beginning of the ice age - 1.8 ma
Includes the Holocene 11,000 ya -present
10
Q
What do these stand for? KNM WT ER OH D
A
KNM = Kenya National Museums WT = West (lake) Turkana ER = East Rudolf (former name for Lake Turkana) OH = Olduvai Gorge specimens D = Dmanisi specimens
11
Q
Details of the Olduvai Gorge (OH)
A
- in Northern Tanzania
- a steep sided ravine in the Great Rift Valley
- one of the most important palaeoanthropological sites in the world - excavated by the Leakeys
- homo habilis (1.9 ma)
- Paranthropus boisei (1.8 ma)
- homo erectus (1.2 ma)
- homo sapiens (17,000 ya)
12
Q
The Cradle of Human Kind details
A
- South Africa
- an area with many limestone caves
- Malapa cave - Australopithecus Sediba
- Paranthropus, homo habilis
- Rising Star cave - homo naledi
13
Q
Dmanisi cave details
A
- location Georgia
- 5 homo erectus skulls (1.8 ma) found but large morphology of skulls varies - not classified as different species because they are the same age and found in the same place
- oldest one outside of Africa
14
Q
4 characteristics of hominins
A
1) Increased brain size
2) Decrease tooth size
3) Bipedal
4) Increased tool use
15
Q
3 Ardipithecus groupings
A
1) Sahelanthropus
2) Orrorin
3) Ardipithecus kaddaba and ramidus
16
Q
What makes Ardipithecus group different from later hominins
A
They are the earliest Hominins who lack the features of later Hominins
17
Q
Sahelanthropus tchadensis details
A
- Ardipithecus group
- location = Chad
- found (small) Cranium , (large) jaw fragments, (large) teeth
- 7.6-6 ma
- small brain size
- oldest known hominin
- more downwardly orientated foramen magnum = suggested upright posture and locomotion
18
Q
Orrorin tugenensis details
A
- found in Kenya
- found arm + leg bones + teeth
- lived 6.1-5.8 ma
- unknown brain size
- Size and shape of femur suggests bipedalism
19
Q
Ardipithecus Kaddaba details
A
- found in Ethiopia
- jaw fragments found
- lived 5.8-5.2 ma
- Brain size unknown
- leg bone and foramen magnum suggest bipedalism
20
Q
Ardipithecus Ramidus details
A
- found in Ethiopia
- lived 4.4. ma (because it was found in two volcanic strata)
- has reduced canine size + presence of adaptations which could be bipedal (not habitually bipedal)
- very complete skeleton found
21
Q
Australopithecus group 5 species
A
- Australopithecus anamensis
- Australopithecus afarensis
- Australopithecus garhi
- Australopithecus africanus
- Australopithecus sediba
22
Q
What are the features of the australopithecus
A
1) bipedal
2) similarity structure to humans
3) Brain size similar to modern apes
23
Q
Australopithecus anamensis details
A
- found in Kenya
- 4.1-3.9 ma
- arm bone(chief specimen), ear canal piece, jaw joint found
- Brain size unknown
- lower leg bone (knee joint surface) indicates bipedalism
24
Q
Australopithecus afarensis “Lucy”
A
- Discovered Ethiopian Afar region
- most complete and well preserved A. Afarensis fossil
- 3.8-3.0 ma
- completeness = scientists could understand bipedalism in early humans
- Brain size ape like
- no evidence of toolmaking
- Habitat = woodland + open areas - known through isotope analysis
- diet soft fruit + leaves - but teeth adapted to eat hard foods as well
25
Australopithecus garhi details
- Central Ethiopian
- 2.5 ma
- Brain size 450 cm3 - no average because only one skull found
- Limb proportions = more human-like
26
Australopithecus africanus “Taung child”
- South Africa
- 3.0-2.0 ma
- Brain size ape like
- bipedal (Likely to be arboreally proficient)
- thicker teeth than A. Afarensis -suggests eating harder foods still
27
Australopithecus sediba details
- found in Malapa Cave, South Africa
- 2 ma
- Over 220 fragments from species found
- Wide range of features and post-cranially
- teeth, arm + leg length + narrow up a chest resemble Australopithecus
- Tooth traits + broad lower chest resemble Homo
28
Paranthropus group
- P. aethiopicus
-P. Boisei
-P. Robustus
(Also calls Australia)
29
Skull structure of Paranthropus in general
- Heavy chewing
- Large muscle attachments
- Large molars
- large jaws
30
Paranthropus aethiopicus details
- discovered Ethiopia + Kenya
- toothless lower jaw found (“black skull” because they of high levels of manganese)
- 2.5-2.3 ma
- Brian size 410 cm3
- skull + teeth adapted for eating tough foods
31
Paranthropus robustus details
- discovered Sough Africa
- found damaged skull + half jawbone
- 2-1 ma
- brain size 530 cm3 (slightly bigger than previous Paranthropus)
- considered a dead-end branch of the human family
- very robust jaw (masticatory features) which set it apart from Australopithecus & homo lineages
32
Paranthropus Boisei (“nutcracker man”)
- discovered Olduvai Gorge + Tanzania
- found many compleat skulls
- 2.3-1.3 ma
- brain size 400-550 cm3
- large chewing muscles
- “nutcracker man” b/c large posterior teeth + jaws made it look like vintage nutcracker
33
Homo group
- genus hominids includes modern Homo sapien + closely related species
- genus between 2.3-2.4 ma
- difference between early Australopiths + homo = increased cranial capacity in homo
- H. Habilis
- rudolfensis
- erectus
- heidelbergensis
- floresiensis
- naledi
- sapiens
34
Homo habilis (“handy man”
- Discovered Tanzania (most primitive homo)
- 2.4-1.4 ma
- brain size 510-687 cm3
- Large brain
- Smaller face and teeth
- “Handy man” = home-made tools found along with fossils
35
Homo erectus (“upright man”)
-Discovered in Java, Indonesia, Kenya
-“Java man“, “speaking man“ and “Turkana boy“
-1.8 ma - 50,000 ya
-Brain size = 600 -1200 cm³
-oldest known early human to have human-like posture (elongated legs, shorter arms compared to torso
-Ability to walk/run long distances (efficient bipedalism)
-generally considered the first species to leave Africa
-
36
Homo heidelbergensis
- discovered Germany
- found lower jaw (others found in Africa + Europe)
- 500,000-200-000ya
- Brain size 1274 cm³
- Big brained
- Big bodied
- sophisticated hunter
- Probably ancestor to Neanderthals and modern humans
37
Homo floresiensis (“the hobbit”)
- Discovered island of Florence, Indonesia
- “Hobbit“ Scholl, jaw and limb bones found
- 95,000 - 12,000 ya
- Brain size 400 cm³
- 3.5 feet tall
- Small body and brain
- Unknown if they are a species distinct from modern humans
- hypothesis e.g. Down’s syndrome, insular dwarfism or microcephaly
38
Homo sapiens
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