Diet

Question 1

Are primates herbivores?

What is a key feature of primate diet

Answer 1

• Primate omnivory: large number of plant food and small number of animal resources.

Flexibility: switching to novel food sources.

Question 2

What is a food repertoire

Answer 2

preferred food and occasional food (fallback food during food shortage)

Question 3

What is hard food

What are USOs?

Answer 3

Hard food: food items resistant to plastic deformation (nuts and seeds). • Underground storage organ (USO): root, bulb, rhizome, storage of energy and water

Question 4

What does food quality refer to?

What are high quality foods?

What type of food do fallback foods tend to be

Answer 4

Food quality: nutrient density (high- or low-quality food)

meat, nuts and USOs.

low in energy foods

Question 5

What do the following refer to:
Foraging strategies

Food processing

Answer 5

Foraging strategies: how to obtain food. • Food processing: how to access food (e.g., oral processing, manual processing).

Question 6

What is Kleiber’s Law?

Answer 6

an animal’s metabolic rate scales to the 3⁄4 power of the animal’s mass.

therefore, there is an
allometric relationship body mass/BMR

Question 7

How is LHS related to food quality

Answer 7

Could be related to the r/K selection theory: predictable environments with
abundant food resources would favor K-selected species (large-bodied
individuals, long maturation, few offspring, long lifespan ≠ r-selected species)

Question 8

How would folivory be reflected in digestive anatomy

Answer 8

diet of leaves requires large intestines and fermentation

Question 9

What is the expensive tissue hypothesis briefly

who came up with it

why is diet related

Answer 9

The expensive tissue hypothesis (Aiello & Wheeler, 1995): less energy to the gut, more energy to the brain, same BMR. • Possible if easy-to-digest food consumed.

Question 10

Define ecological niche

Answer 10

Ecological niche: species interactions within an ecosystem (biotic and abiotic
factors).

Question 11

Give 2 different types of speciation

Answer 11

Sympatric speciation: competition for resources. • Ecological speciation: ecological factor (e.g., environmental change)
responsible of the formation of a new species as a result of adaptations to a
new ecological niche

Question 12

define sympatric speciation

Answer 12

Sympatric speciation occurs when there are no physical barriers preventing any members of a species from mating with another, and all members are in close proximity to one another. A new species, perhaps based on a different food source or characteristic, seems to develop spontaneously

Question 13

What does Paranthropus’ morphology suggest about its diet

Answer 13

Large, thickly enameled postcanine teeth, extended zygomatic bones and bony crests (powerful muscles of mastication).
• Craniodental features suggest that it could generate and dissipate high bite forces: consumption of hard food items (e.g., nuts, seeds, hard fruits)?

Question 14

Do dietary changes only have implication on the cranium (4)

Answer 14

No
• Locomotion and posture: feeding positions, access to resources
(ecomorphology).
• Home range area (habitats).
• Meat consumption: technological innovations.
• Social behaviour: conspecific care.

Question 15

Give an example of conspecific care in hominins

Answer 15

the edentulous specimen of early Homo (~1.7mya) from Dmanisi - Would require sharing of food etc from rest of group

advanced alveolar bone atrophy indicates substantial tooth loss several years before death as a result of ageing and/or pathology

Question 16

What does diet reveal about social behaviours (not edentulous Homo from Dmanisi)

Give key references

Answer 16

Parental care and ontogeny: age at weaning and integration of solid food.
• Extended growth and development: maternal energetical costs.
• Dietary stresses may cause extended period of weaning (Joannes-Boyau et al., 2019).
• The grandmother hypothesis: greater longevitiy, foraged food sharing (Hawkes et al., 1998)

Question 17

Give key features of dental morphological changes between folivores, hard-food-eaters, and frugivores

Answer 17

• Folivores: tall shearing crests.
• Hard-object feeder: low cusps and large teeth.
• Frugivores: intermediate, large basins.

Question 18

When did Australopithecines wean their young

Answer 18

extended baby consuming mother’s milk bc there is reduced food sources around - age of weaning directly related to environment

Question 19

What is dental topography

What parameters are used

Answer 19

Dental topography: aspects of tooth geometry. • Parameters: how much the tooth surface differs from a flat surface (RFI),
surface curvature (DNE), tooth complexity (OPC)…

Question 20

What is important about thick enamel

Answer 20

longer lifetime, resistant to abrasive and tough food

Question 21

What is important about enamel distribution

Answer 21

reflects the stress dissipation pattern.

Question 22

How does the ‘hardness’ of foods in a diet affect enamel distribution

Answer 22

soft - thin enamel with an even distribution
medium - thin enamel with an uneven distribution
hard- thick enamel with uneven distribution

Question 23

What is an enamel hypoplasia

Answer 23

surface defect of the tooth crown that is caused by a disturbance of enamel matrix secretion (lines, pits, grooves).

often caused by Physiological stress (nutritional stress or disease during the development. )

Question 24

What is the wear pattern of a tooth

Answer 24

Wear pattern: cumulative loss of enamel (and dentine) due to friction of hard(e.g., seeds) and abrasive (e.g., phytoliths in plants, minerals) food objects.
• Reflect feeding behaviour.

Question 25

Were enamel hypoplasias common in australopithecines?

Answer 25

yes - indicates periods of starvation and environmental stress

Question 26

How can we compare the feeding biomechanics of ancient hominins?

What has this revealed

Answer 26

Finite element analysis: simulation of a physical phenomenon using numerical
techniques

• Morphology of Paranthropus was very good at dissipating mechanical stress (much better than Australopithecus) - Smith (2015) showed this by comparing strain during molar biting in STS5 and OH5

Question 27

What is important about cut marks on bones

Answer 27

evidence of tool-assisted consumption of meat

o What aniimals are present in the assemblage - o Were they hunting younger animals bc its easier - revealing about subsistence strategies

Question 28

How can Isotopes be used to investigate fossil hominin diet

Answer 28

Carbon in tooth enamel: variations of carbon isotopes (δ13C) reflect isotopic composition of the plants and animal protein eaten.

• Strontium, barium and calcium: low Ba/Ca in carnivores, high Sr/Ca in grazers, related to the composition of the substrate.

Question 29

What can we infer about Ardi. ramidus’ diet

Answer 29

diet dominated by C3
food similar to extant chimpanzees (forest/woodland feeding).

Thin enamel in Ardipithecus ramidus: no hard objects consummed.

Question 30

How did A. anamensis’ diet relate to ramidus

How did this relate to Kenyanthropus’ diet?

Answer 30

Australopithecus anamensis, derived nearly all of its diet from C3 resources - similar to ramidus

ubsequently, by ca. 3.3 Ma, the later Kenyanthropus platyops had a very wide dietary range—from virtually a purely C3 resource-based diet to one dominated by C4 resources

Question 31

What did the diet of Homo look like 2mya and how did this relate to P boisei

Answer 31

65/35 ratio of C3- to C4-based resources, whereas P. boisei had a higher fraction of C4-based diet (ca. 25/75 ratio).

Homo sp. increased the fraction of C4-based resources in the diet through ca. 1.5 Ma, whereas P. boisei maintained its high dependency on C4-derived resources.

Question 32

Describe the Australopithecus teeth morphology

What did microwear analysis reveal

Answer 32

flat, blunt molars without shearing crests, suitable for processing hard brittle objects (nuts, fruits) and soft food, but no seeds or meat.
• Thick enamel: resits breakage during the consumption of hard objects.

• Microwear analyses indicate longer scratches and few pits: feeding on fruits and some abrasive material (phytoliths?)

increase in diet breadth, increased home range?

Question 33

What does Isotope analyses (13C, Sr/Ca and Ba/CA) of Australopithecus teeth indicate? (4)

Answer 33

high C4
consumers (nearly close to the grass eating baboons),

→ consumption of USOs,

→ variability, thus highly flexible and opportunistic diet that includes frugivory and hard food (adaptations to fallback foods?).

elemental signatures and hypoplasias indicate seasonal dietary stress

Question 34

What does boisei’s cranium suggest about its diet

Answer 34

Isotope analyses of Paranthropus teeth: 13C-enriched foods (80% of C4
foods in P. boisei).

• Feeding biomechanics in Paranthropus: high bite forces, face well suited to withstand those loads.

Question 35

Compare briefly diet of robustus and boisei (2)

Answer 35

→ isotopic analyses: no overlap, unique diet in P. boisei,

→ microwear analyses: P. boisei leaf based diet (more similar to baboons?) and no hard objects, P. robustus much similar to savanna generalists and hard object feeders.

Question 36

What is the e hypothesis of isotopic niche?

Answer 36

Was the Australopithecus broad diet split into Paranthropus and Homo with
lower diversity of food? (Balter et al., 2012) • Was the early Homo diet broad (i.e., omnivorous and opportunistic
preferences) and Paranthropus specialized on hard food?

Question 37

 Who was first hominin to eat meat?

Answer 37

Earliest evidence of tool-assisted consumption of meat: >3.4 Ma (Dikika) or at
least at 2.5 Ma (Gona). - maybe afarensis?

leaves question of when did diet Shift from intermittent to more frequent meat consumption and exploitation of megafauna

Question 38

What are the temporal trends in diet and morphology in hominin evolution (4)

Answer 38

Molar size increase: tough and abrasive diets.
• Small anterior teeth: no food preparation.
• Thick mandibular bodies: can resist extreme stresses.
• Early hominins: hard and soft foods, abrasive and nonabrasive food

Question 39

What does the isotope analysis suggest about the dietary shifts in hominin evolution

Answer 39

Two major dietary shifts: early hominins (broader diet) and Homo (high-quality
food).

• Isotope analyses: from C3 (Au. anamensis and Ardipithecus) to C3 /C4 (Au. afarensis) to C4 (Paranthropus) and C3 /C4 (Homo) diets in eastern Africa.

Related to environment that is changing?

Question 40

Why is hominin anterior dentition interesting

Answer 40

• Apes can use these anterior teeth to access different parts of the food – not needed when we can prep before entering mouth

Question 41

Give evidence australopiths may have eaten meat

Answer 41

lesions observed in the vertebral elements L4 andL5 of Australopithecus africanus Stw 431 seem to be more consistent with the pathological condition of early brucellosis

seen in modern zebra and impala

given chimps occasionally eat meat - not implausible

table carbon isotope analysis of A. africanus
from Makapansgat Limeworks, South Africa, that suggest a diet based not only on fruit and leaves, but also on large quantities of carbon-13-enriched foods such as grasses and sedges or animals that ate these plants, or both

Question 42

What is the benefit of decreased prognathism in Paranthropus

Answer 42

jaw has greater muscular advantage
BUT
comes at a cost of tooth surface area and the size
of objects that fit in the mouth.

P. boisei solves the problem of tooth area by increasing the relative size of the teeth.

Question 43

How does africanus differ from afarensis (3)

Answer 43

africanus has higher and shorter and rounder braincase, that rarely shows sagittal cresting and that never shows compound temporo-nuchal cresting.

The nasal aperture is bordered by prominent anterior pillars and the zygomatic bone shows bossing at the transition to the temporal process.

subnasal prognathism