Non-Human Primates

Question 1

When was the chimp human LCA

why are chimps useful

Answer 1

6-8mya

 Comparison with these helps see apomorphies (derived only in humans) and pleisomorphies (inherited from LCA)

Question 2

Why are dimorphic extant apes useful

Answer 2

o Extant primates can be used to quantify intra vs interspecific variation eg Harvati 2004 who used comparisons with great apes to see if Neanderthals are subset of sapiens
o Reconstructing LCA locomotion
 No modern analogue?

Question 3

What did Koops find regarding motivation for tool use

Answer 3

Whereas chimpanzees are renowned for their tool use, bonobos use few tools and none in foraging

Extrinsic opportunities did not explain the tool use difference, whereas intrinsic predispositions did. Chimpanzees manipulated and played more with objects than bonobos, despite similar levels of solitary and social play. Selection for increased intrinsic motivation to manipulate objects likely also played an important role in the evolution of hominin tool use.

Koops 2015

Question 4

What are extrinsic/ intrinsic motivations

Answer 4

extrinsic (ecological and social opportunities)

intrinsic (predispositions)

Question 5

What might explain the difference between chimp and bonobo tool use

Answer 5

intrinsic motivation

Bonobos pay more attention to social cues, whereas chimpanzees pay more attention to the action target object.

Together with our findings this suggests a trade-off between tool use motivation and social attention.

Question 6

Which primate group is abundant and often in association with ancient hominins

Answer 6

Abundant (e.g., 349 cercopithecid remains from the Sagantole Formation at
Gona)

Question 7

• How can cercopithecids help us to understand hominin evolution? (4)

Answer 7

• Biochronology: correlation of stratigraphic units using the fossil assemblages
contained within them (i.e., biostratigraphic markers).
→ dating primate/hominin-bearing sites.

Biogeography: geographic distribution of species and fossil remains.
→ faunal/primate/hominin dispersals. (eg (Strait and Wood, 1999)

• Ecomorphology: relationship ecological niche/morphological adaptations.
→ reconstruction of palaeoenvironments.

• Adaptations: cercopithecids are used to contextualize the adaptations and
evolutionary trends of hominins (‘control-group’).
→ identify selection pressure.
(o Is there a rationale for thinking human primates act differently
Monkeys control group to contextualise selection pressure
Eg same adaptations, diet ?)

Question 8

What hypothesis did Jolly propose in 1970

Answer 8

The ‘seed-eater hypothesis’ (Jolly, 1970, 2001):

opposability of the thumb and developed masticatory apparatus in Theropithecus and early hominins as an
evidence of adaptations to hard-object feeding.

• Convergence due to environmental changes and selection pressures during the Plio-Pleistocene?

Question 9

What is the seed eating hypothesis

Answer 9

systematic comparison between two species of baboon; one more adapted to open habitats than the other , and how the differences are mirrored in comparisons between hominids and chimpanzees.

In a nutshell, his basic argument is that Theropithecus are more adapted to open habitats and ‘seed eating’ than Papio

Question 10

Did hominins and cercopithecids occupy different ecological niches because of
competition?

Answer 10

Similar body mass, same environment, distinct ecological behaviours (Dunbar, 1983).

• Theropithecus became grazers while hominins consumed meat?

Question 11

• Is brain enlargement during the Plio-Pleistocene confined to hominins?

Answer 11

• Comparative analysis of the brain size of three contemporaneous eastern African primate genera: Paranthropus, Homo and Theropithecus.
• Significant brain size increase in hominins, not in cercopithecids: environmental changes cannot explain this trend.

Question 12

• How many fossil species at Sterkfontein Member 4?

Answer 12

• Qualitative study and metric analyses of craniodental material indicate the coexistence of three species at Sterkfontein: Parapapio broomi, Parapapio whitei
and Parapapio jonesi.

• Speciation event that could also be seen within Australopithecus? If there are many different species of cercopithecoids here then that suggests there was a speciation event and we should also separate hominin species found there

Question 13

• How many fossil baboon genera in South Africa?

Answer 13

• No clear morphometrical threshold between Parapapio/Papio.

• Evolutionary species including ancestors and descendants of a same lineage, as
in Australopithecus and Paranthropus?

Question 14

• How open was the habitat of southern African hominins?

Answer 14

• Ecomorphological analysis of cercopithecid postcranial remains from hominin bearing sites (Sterkfontein, Bolt’s Farm and Swartkrans).
• Paranthropus less arboreal than Australopithecus?

Question 15

How are monkeys useful in the question: How old are the southern African hominin-bearing sites?

Answer 15

• Identifying cercopithecid biomarkers that are found in eastern and southern Africa.
• Integrating southern African hominins into a chronological framework.

• Example: Gorgopithecus major is found is present in Olduvai Bed 1 (Tanzania)
at 1.8-1.63 Ma but also in Kromdraai A (South Africa).

Question 16

• Did hominins disperse at the same time and in the same direction as other
African primates?

Answer 16

• Hominins part of 4-7 Plio-Pleistocene faunal interchanges that involved
cercopithecids.

• Did Paranthropus robustus’ ancestors migrate from eastern to southern Africa
(monophyly vs paraphyly)?