homonin evolution

Question 1

Sahelanthropus tchadensis

Answer 1

• first entry on chart
• transitional species
• 6-7 mya
• found in Chad
• Foramen magnum positioned to the rear of the skull
• Horizontally oriented basicranium
• Thick supra-orbital torus
• Long narrow brain case
• found by??

Question 2

human and apelike characteristics of Sahelanthropus tchadensis:

Answer 2

some human features: ???
apelike features:
-small brain, 
-projecting face, 
-sloped forehead and 
-large neck muscles.

Question 3

Ororrin tugenensis

Answer 3

• second entry on chart
• fount in Tugen Hills of Kenya
• 6 Ma
• Small teeth but thick enamel
• Femur suggests bipedality
• found by ??

Question 4

Ardipithecus Kadabba

Answer 4

• third entry on chart
• found in Ethiopia
• 5.6 million years ago
• Known only from teeth and fragments of skeletal bones
• Originally described as subspecies of Ardipithecus ramidus, now considered a possible ancestor of the latter (based on discovery of additional teeth).
• found by ??

Question 5

Ardipithecus ramidus

Answer 5

-fourth entry in chart
-found in Ethiopia
-had a small cranium
-Gracile limbs
-Bowl shaped pelvis
-4.4 Ma
-Basal foramen magnum
-Toe bone similar to later
bipedal hominins
- found by??

Question 6

Australopithecus anamensis

Answer 6

• fifth entry on chart
• Found at Alia Bay and Kanapoi, Kenya
• Mosaic of ape and human features
• Parallel tooth rows
• Hind limbs suggest bipedality
• 4.2 to 3.9 Ma
• found by???

Question 7

Australopithecus afarensis

Answer 7

• Gracile australopithecine
• 4.0 to 2.9 Ma
• Found in Hadar, Ethiopia, -Kenya and Tanzania
• The most well known hominin
• Clearly a biped
• Ape-like limb proportions
• Large sexual dimorphism
• Still some arboreal adaptations
• found by??

Question 8

Kenyanthropus platyops

Answer 8

-3.2 -3.5 Ma
-Western side of Lake Turkana basin in Kenya
-Tall cheek region and flat face
-Small teeth
-Mixture of ape and human traits
-Badly damaged skull
-Bipedal??
- found by ??
controversial fossil - very fragmented

Question 9

Australopithecus africanus

Answer 9

• Gracile australopithecine
• 3.2 – 2.1 Ma
• Southern Ape from Africa
• Australopithecus africanus
• Raymond Dart – first described species

Question 10

Paranthropus aethiopicus

Answer 10

• 2.5 Ma
• Earliest known robust australopithecine
• Eastern Africa (Turkana basin of northern Kenya, southern Ethiopia)
• Black skull
• Very few remains of this species have been found – still a mystery
• Strongly protruding face, large megadont teeth, and a -powerful jaw, and a well-developed sagittal crest

Question 11

Paranthropus robustus

Answer 11

found in South Africa

2-1.5 mya

Question 12

Paranthropus boisei

Answer 12

found in east Africa

lived 2.5-1 mya

Question 13

what does the term “Gracile australopithecines’ mean?

Answer 13

slighter build
prognathic face
smaller teeth
steeper forehead
smaller temporal fossa
longer snout
no crest
face sits below neurocranium
steeper forehead
incisor prognathism
less robust mandible
example: Australopithecus africanus

Question 14

what does the term robust australopithecines mean?

Answer 14

more robust
sagittal crest
massive teeth
larger temporal fossa
shorter snout
face is hafted, high on neurocranium
flatter forehead
flatter face
more robust madible

Question 15

Australopithecus garhi

Answer 15

• Found in middle Awash Ethiopia
• 2.5mya
• apelike face
• large teeth
• small brain
• associated with tool use - Olduwan type

Question 16

Australopithecus sediba

Answer 16

• 1.95-1.78 mya
• found in COHK Joburg
• mosaic of homo and aus traits
• Cranial capacity similar to that of Australopithecus, but jaw and teeth are gracile like those of early Homo
• found by Lee Burger

Question 17

Australopithecus sediba similarities with Homo

Answer 17

front of brain reorganized
projecting nose
smaller teeth and chewing muscles
hips are less flared and similar to humans
longer legs
precision grip

Question 18

Australopithecus sediba similarities with Australopiths

Answer 18

smaller brain size
long and high cheek bones
primitive molar cusps
small body size
longer upper limbs
primitive heel bone

Question 19

what were some of the earliest homo individuals found?

Answer 19

homo rudolfensis
homo habilis

found on the eastern shores of Lake Turkana
dated - 2.0-1.9 mya

Question 20

homo rudolfensis

Answer 20

more australopith face
larger brain
2.0-1.9 mya
Lake Turkana

Question 21

homo habilis

Answer 21

more australopith/smaller brain more human face
2.0-1.9 mya
Lake Turkana

Question 22

homo habilis shared traits with Aus afarensis

Answer 22

low body mass
teeth adapted to tough foods
Arboreal and terrestrial adaptation
development stages african apes

Question 23

homo habilis shared traits with erectus

Answer 23

stone tools

larger brain

Question 24

homo erectus

Answer 24

first hominin species to leave africa
major anatonical changes
brain size 1000cc
bipedalism is more modern
reduction in sexual dimorphism
association with well made stone tools - Acheulean hand axe
found by ??
found where??
lived 1.5 mya

Question 25

homo heidelbergensis

Answer 25

-800k-200kya -Africa and Europe, possibly Asia -mixture of sapiens and eretus features -massive brow ridge -forwardly projecting face -robust build -thick walled skull -larger brain capacity -Rear of cranium is more rounded -reduction in post canine tooth size found in Heidelberg germany found by ?? found in ??

Question 26

what is the Sima de los Huesos

Answer 26

13m shaft where many remains found 32 individuals dropped down ceremonially or disposing of dead one reddish handaxe

Question 27

Neanderthals

Answer 27

``` Neander valley - germany lived - 150k - 28kya -retromolar gap -occipital bun -projecting mid face -no chin -heavily built, short and stocky -bones are thicker ```

Question 28

adaptations for colder climates and the rules governing that

Answer 28

Bergman and Allen's rule - heat loss reduction - organisms that are shorter and ticker and more robust are built for shorter climates so that less heat is lost - animals in colder climates have shorter and stockier limbs

Question 29

homo sapiens

Answer 29

Reduced robusticity everything becomes smaller back teeth continue to reduce so do front teeth -cranial buttresses much less in evidence -loss of brow ridge -development of chin -sexual dimorphism reduces to modern levels -vertical forehead -canine fossa* -pyramidal mastoid process*

Question 30

what are the three theories of modern human origins?

Answer 30

complete replacement model regional continuity model partial replacement model

Question 31

explain the complete replacement model as a theory of modern human evolution

Answer 31

- developed by british paleontologists Christopher Stinger and Archeol. peter Andrews - proposes that anatomically modern populations - Sapiens replaced Heidelbergensis in Africa - migrated from Africa and completely replaced descendent populations of erectus in europe and Asia- they out competed them

Question 32

problem with the complete replacement model?

Answer 32

-doesnt account for the transition from heidelbergensis to sapiens anywhere else other than africa

Question 33

explain the partial replacement model as a theory of modern human evolution

Answer 33

- proposed by Bunter Brauer of the uni of Hamburg - Erectus moved out of africa and settled in the of the globed - eventually giving rise to heidelbergensis around 100kya - Thes H. sapiens moving into Eurasia, and hybridized with resident groups (non H. sapiens descendants of H. erectus) , eventually replacing them. - The disappearance of these archaic humans outside of Africa was due to hybridization (interbreeding and not complete replacement) and replacement.

Question 34

another name for the partial replacement model

Answer 34

the assimilation model

Question 35

explain the regional continuity model as a theory of modern human evolution

Answer 35

- Associated with paleoanthropologist Milford Wolpoff of the University of Michigan. - H. erectus moved from Africa to Eurasia around 2 mya and gave rise to H. heidelbergensis in the various regions. - Human populations in Europe, Asia, and Africa continued evolutionary development from H. heidelbergensis to anatomically modern humans. - No en mass migration of H. sapiens from Africa into the rest of the world. - However, limited gene flow between regions.

Question 36

what is the most accepted theory?

Answer 36

The out of africa hypothesis - replacement

Question 37

what are some predictions that come along with a replacement hypothesis?

Answer 37

- The oldest anatomically modern specimens will be in Africa - Transitional forms will be in Africa - Co-existence of ancient modern sapiens and archaic forms outside africa - archeological evidence for modernity should appear in africa first

Question 38

where was some evidence of modernity found in africa and when was this evidence from?

Answer 38

Blombos cave | 100k-70kya