Primate Energetics Flashcards
(41 cards)
When did homo sapiens arise?
300 kya
When did agriculture arise?
10 kya
What percentage of human history have we likely lived as hunter-gatherers?
95%
What is the ladder of progress?
Historical evolutionary models which depicted life as striving towards complexity, in which humans are the most complex/sophisticated
What was the historical view on hunter-gatherer societies?
1) They served as a bridge between animals and modern humans
2) They were animalistic and on the edge of starvation
Why was the historical view on hunter-gatherer societies wrong?
Hunter-gatherers were not struggling nor at the edge of starvation, rather they were very good at adapting to ecological challenges (doing so through cooperation)
How did views on hunter-gatherers change?
In the 1950s-60s, views changed with the release of “Original Affluent Society” by Marshall Sahlins
Who wrote the “Original Affluent Society”?
Marshall Sahlins
What did Marshall Sahlins claim in his work about hunter-gatherers?
Sahlins claimed that hunter-gatherers had an optimal lifestyle because they did not have many needs/wants, and therefore were easily satisfied
What evidence did Marshall Sahlins use to back up his claim of hunter-gatherers living an optimal life?
The data of Richard Lee, who studied Kung hunter-gatherers from Southern Africa
What did Richard Lee find about the Kung in Kalahari?
Conducted a time analysis and determined that the hunter-gatherer society only spend 15 hours foraging for food per week, indicating that they were not on the edge of starvation, nor did they struggle to survive
Why was Richard Lee’s data on hunter-gatherer work weeks inaccurate?
1) He did not account for time spent processing foods (to make them edible)
2) If he did, we would find that the average time spent working per week was 40-45 hours
What did John Maynard Keynes believe would happen by 2030?
He believed that due to advancing technology, humans would only be required to work 15 hours per week
What is the economic problem?
The struggle for subsistence, which is a problem for all of the biological kingdom
What did researchers find upon investigating time budgets of animals?
A large proportion of their active time is spent in inactivity
Why might animals exhibit laziness?
If an organism’s goal is to stay alive, one satisfactory strategy is to only initiate foraging when hungry, and rest once satisfied
What is unique about the “laziness” perceived in bees?
There are always a designated group of bees that do nothing in case other workers get lost or need help
What is one reason that primates have slow life histories?
Primates have lower TEE than non-primate animals (exhibit metabolic deceleration)
What is TEE?
Total Energy Expenditure (number of calories burned per day)
How is TEE measured?
Animals are given isotopically tagged water, in which the rate of decay can be measured in their urine
What is “breaking through the grey ceiling”
Humans seem to have solved the energetic problem, where they have higher reproductive output, larger brains, and more exceptional longevity compared to other primates (no evidence of tradeoffs)
How did humans “break through the grey ceiling”
Relative to other primates, humans have accelerated their metabolism
How was metabolic acceleration achieved in humans?
Through shifts in foraging behaviour (that is, shift toward higher quality, large package sized foods that were harder to gain)
Compare and contrast the foraging behaviour of chimpanzees/NHM and humans?
1) Other primates tend to eat food with low-nutrients but are more easily accessible, rarely spending more energy to go for bigger game
2) Humans tend to go for “large game” that is nutritionally dense but extremely difficult to obtain, rarely opting for lower-nutritional foods
