The Modern Diet Flashcards
Explain the difference between Ancestral and modern diet
Ancestral = high protein, high fruit, low fat, high total energy, very low carb
Ancestral needed more energy to hunt and store
Modern diet = low protein, low fruit, high fat(trans), less total energy, high carb, low fibre
(Konner & Eaton, 2010)
(Jew et al., 2009)
What evidence can be used to assess the ancestral diet
Full of unknowns in this area….
Inferences from:
- modern foraging groups
- living primates
- Paleoanthropology
What can we learn from paleoanthropology
Morphology and form
- dental wear + structure
->Constitute majority of fossil record
-> The cusps in the teeth would show what kind of diet would be consumed
- sagittal crests/robustness of mandibles
-> point at the top of the head and were used for chewing tougher food such as meat ->diet required it
Evidence of behaviours
- bone markings
- evidence at sites (rodent remains/remnants of fire/tools)
Hominid
All great apes and humans
Homomin
Just human ancestors
What preferences do we have in the modern diet have?
- Sweet Food
Prefer sweet for as a sign of ripeness and safe to eat -> wouldn’t eat fruit if sour as a sign of poisin/unsafe to eat - High fat/energy food
- move away from subsistence to consumerism
Explain the Evolutionary Discordance Hypothesis
(Konner & Eaton, 2010)
- The human genome is adapted to dietary conditions that no longer exist
- Change has occurred too rapidly for adequate genetic adaptation
- The resulting mismatch may explain some common chronic diseases
- First proposed in 1985 by Konner & Eaton
- Has evolved to embrace under- as well as over-nutrition (genome-nutrition divergence; Eaton & Iannotti 2017)
Could we go back to the Palaeolithic diet?
- not easily
- not as feasible and practical as modern diet
- more food such as dairy, grain and legumes
- Environmental and resource constraints with the current world food system
(Eaton & Iannotti 2017)
Explain the Significance of Bipedalism
- 4 Million years ago
- using 2 legs for walking
- before bigger brains & stone tools
- free hands
Habitually Bipedal
-> Has the ability to walk on 2 legs and chooses to walk on 2 legs
-> Chimps/apes can walk on 2 legs but choose to mainly walk on their hands as well
What could bipedal mammals do?
- Carry
- Use weapons and tools
- Carry veg, infants and water
- Walk between trees with food
- Feeding from bushes
- Feeding on grass seeds
- Provisioning family
- Thermoregulation
- Looking over tall grass
- Aquatic life
Explain the importance of foraging and what food was mainly foraged
Animals
- More prevalent in non-human primates than non-primate species
E.g. wading sticks - gorillas, termiting - chimps, thrusting spears - Senegal chimps, leaf sponges - capuchins (Jurmain et al. 2014)
Human Ancestors
- Tool assisted foraging
Australopithecus: wooden digging sticks (?Paranthrapus)
Mainly ♀ & young children
- Usually tubers, rhizomes & perennial bulbs
↑ carb, ↓ protein, important for energy
if uncooked need digestion inhibitors deactivating (soaking, fermenting, eating with clay) - Also roots, flowers, fruits, young leaves
- supplemented with small/slow-moving animals (♀ & children) & ? larger hunted animals (♂)
- tree foraging difficult -> body size
Explain the use of tools among ancesters
- used in early homos
- unlikely in male hominins until H. erectus
- ♀ required tools for foraging
- ♂ didn’t require until more successful hunters
- boys remained with ♀ until mature (skill transfer?)
What is the link between big brain, tool use and meat consumption
Larger brains require a greater proportion of resting energy to function.
Modern humans could not have evolved such an energy hungry brain without having evolved the nutritional strategies to maintain it.
Cyclic link between the 3
- Further of tools development
- Better hunting strategies & improved diet
- Continued increases in brain size
Explain the difference between different hominins as hunters and what their diets mainly consisted of
- 250,000 years ago
European hominins: successful big game hunters
- 1st H. erectus may still have mostly scavenged (Jurmain et al. 2014)
- Neandertals
successful big game hunters
- H. sapiens
more diverse protein intake (fresh water fish & waterfowl)
Meat intake poss. dependent on latitude
- Tropical = 5-20% meat
- sub-Arctic & Arctic = 70% meat
Current best estimates suggest 35-65% animal flesh, incl. substantial marine sources, in diets of hunter-gatherer ancestors for at least last 200,000 years (Konner & Eaton, 2010)
Neanderthals
- Larger nose and lungs ->more oxygen
- More energy needed to survive
- Made tools out of flint and used to hunt
