Dietary tolerance and the advent of meat eating

Question 1

what is the general primate diet?

Answer 1

• mostly omnivores with generalised dentition
• have preferences
• most eat combinations of fruit, leaves and insects
• meat eaters - chimps, gorillas, baboons
• some are leaf specialists (colobine monkey)

Question 2

how are we as a species becoming more and more unhealthy?

Answer 2

generally - lack of exercise and increase in consumption of unhealthy foods with little nutritional value

Question 3

how are hominin diets reconstructed?

Answer 3

craniodental morphology
isotopic study
dental microwear analyses

Question 4

how do we reconstruct hominin diets using craniodental morphology

Answer 4

-head and teeth morphologies
- Morphological features such as thin/thick enamel, small/large teeth, tooth shape, muscle attachment site and size, overall cranial size and shape can give one an idea of what and early hominin species was designed to eat
–not always good as other factors may have also influenced food eaten - availability
-

Question 5

how do we reconstruct hominin diets using stable isotopes?

Answer 5

• “you are what you eat”
• stable isotopes of food stuffs can become incorporated into the growing teeth and bones
• these tissues then acquire isotopic composition related to that of the source food that can reveal much about the diets
• carbon isotopes are commonly used

Question 6

how do we reconstruct hominin diets by studying dental microwear?

Answer 6

-Mammals show a strong and consistent association between dental microwear
pattern and food fracture properties.

• Those that crush hard, brittle foods (e.g., nuts, bones) typically have occlusal microwear dominated by pits, whereas those that shear tough items (e.g., leaves, meat) more often show long, parallel striations on their wear surfaces.
• These pits and scratches are traces of actual chewing events; they record activities during a moment in the life of an individual, much like footprints.

Question 7

meat eating amongst primates?

Answer 7

• meat from vertebrates is rarely eaten by primates

- humans and chimps eat significant amounts of meat

Question 8

describe the start of meat eating in early hominins

Answer 8

• First dominated by large quantities of plant matter
• tooth morphology and dental microwear suggests harder foods eaten as well
• 2.6 mya expansion in diet - meat and marrow
• possible evidence of hominin butchered bones at 3.39 years but little evidence and evidence is disrupted

Question 9

what is some evidence for meat eating?

Answer 9

• butchery marks found on bones

- hominin teeth marks found on bones

Question 10

what are cut marks on animal bones caused by?

Answer 10

slicing of meat off bone

Question 11

what are percussion marks caused by?

Answer 11

pounding a bone with a large stone to break it open and extract the marrow inside

Question 12

where was the first evidence of meat eating found?

Answer 12

Gona, Ethiopia (2.6 mya), earliest documentation of stone tools

Question 13

describe the earliest well documented evidence of persistent hominin carnivort?

Answer 13

from in situ excavated fossil fauna occuring with large concentrations of stone tools

• 2.0 mya Kanjera Kenya

Question 14

evidence of consumption of aquatic animals?

Answer 14

evidence at Koobi Fora
foods: turtles, crocodiles and fish
about 1.95 mya

Question 15

which hominins were the first systematic consumers of meat?

Answer 15

• Aus africanus, aus garhi and paranthropus aethiopicus 2.6-2.5 mya
• africanus and aethiopicus = no butchered bones in sites = less likely
• garhi but only in homo do we see biological features often linked to meat eating

Question 16

why did hominins begin to eat meat and marrow?

Answer 16

• calorie dense with essential amino acids and micronutrients
• aquatic fauna provided nutrients required for brain growth
• Increasing the consumption of animal foods could have assisted hominins in increasing their body and brain size without losing mobility, agility, or sociality.

Question 17

describe the technological ‘feedback loop’

Answer 17

stone tools = meat could be processed and then consumed = brainsize increased = more complex tools = more meat could be processed and then consumed

Question 18

evidence for the first uses of fire

Answer 18

• origins of fire associated with the cooking of meat
• 790kya = burnt seeds, wood, flint
• earlier traces of fire = eastern and southern africa : not widely accepted - swartkrans, koobi and chesowania (sediment discoloration)

Question 19

how did hominins access meat and marrow?

Answer 19

hunting

scavenging

Question 20

explain hunting in the context of the early hominins

Answer 20

earliest evidence of hunting tech - 500kya - hand crafted spears
complex projectiles - 71kya

Question 21

when did the hunting of larger animals begin

Answer 21

• hunting big animals = advanced tech needed - started with heidelbergensis

Question 22

what is persistence hunting?

Answer 22

running down one’s prey

Question 23

type of hunting possible without advanced tech

Answer 23

persistence running - difficult to recognise in the archaeological record

Question 24

what are some hunting signatures?

Answer 24

cut marks, no carnivore gnaw marks

Question 25

explain scavenging in the context of early hominins

Answer 25

Given that the earliest evidence for the use of hunting technology is relatively recent, hominins probably obtained most of their meat, especially from larger animals, via scavenging carnivore kills.

Question 26

what are some signatures of scavenging?

Answer 26

cut marks over carnivore gnaw marks

Question 27

what are disadvantages of a carnivorous way of life?

Answer 27

competition with other and more powerful carnivores e.g. lions, leopards

Question 28

what was another result of looking for meat?

Answer 28

becoming the prey of other carnivores

- evidence: skulls with predator marks in them