human diet in the past

Question 1

why do we talk about the human diet

Answer 1

obesity crisis and other health concerns
dietary fads
ethics of meat eating
we have to feed 9-11 billion people by 2050-2100
sustainability of the human diet

Question 2

what have been some major changes in our diet

Answer 2

great ape diet
hunting and gathering: 2.5 MYA
cooking food: 1.8-0.4 MYA
eating some grain: 100,000 YA
agriculture: 12,000 YA
domestication of cattle: 10,000 YA
processed food

Question 3

can mammals eat cellulose or lignin

Answer 3

no

Question 4

how do grazers and browsers make a living

Answer 4

bacteria
specialized digestive tracts
microbes

Question 5

what diet do tree-living primates follow

Answer 5

primarily herbivorous

Question 6

why are leaf-eaters more specialized

Answer 6

compartmentalized stomach

Question 7

what are some benefits of fruit

Answer 7

high quality
seasonally abundant
easily digested carb

Question 8

why are fruits so easy to digest

Answer 8

mutualism with primates
fruit in exchange for seed dispersal

Question 9

are fruits low or high in fibre and protein

Answer 9

low

Question 10

what do herbivores/omnivores supplement with fruit with for fibre and protein

Answer 10

insects, animal matter, and young leaves

Question 11

what is the digestive tract of primates and humans like

Answer 11

simple
acidic to bread down protein

Question 12

what does the small intestine do

Answer 12

it’s simple
absorbs nutrients and sugars

Question 13

what does the large intestine do

Answer 13

not huge
ferments whatever plant material is leftover
absorbs nutrients

Question 14

what diet does chimpanzee follow

Answer 14

herbivore-omnivore

Question 15

what % of a chimps diet is plant based

Answer 15

94%

Question 16

what kind of food do chimps eat

Answer 16

mainly fruit supplemented with young leaves and animal prey

Question 17

how much fibre do chimps ingest a day

Answer 17

110g

Question 18

how much fibre does the average american ingest a day

Answer 18

10g

Question 19

what kind of gut do humans have

Answer 19

generalized gut

Question 20

how do humans’ large intestines differ from those of living apes

Answer 20

humans’ are shorter
humans are less able to absorb nutrients from cellulose

Question 21

what does our ability to absorb less nutrients and cellulose than apes tell us about our diet

Answer 21

indicative of a switch to a more omnivorous diet than apes

Question 22

what changes in our physical state came with a switch from herbivory to omnivory

Answer 22

tool use increase
brain size increase
decrease in molar teeth size
jaws/skull became lighter
shift from grinding to biting and tearing of animal flesh

Question 23

when did we begin cooking food

Answer 23

1.8 million-40,000 BP

Question 24

why did we start pounding and heating food

Answer 24

predigests food

Question 25

do we absorb more energy from cooked food or raw food

Answer 25

cooked food

Question 26

how long do chimps spend chewing raw food a day

Answer 26

5 hours

Question 27

how long does it take humans to eat cooked food

Answer 27

1 hour

Question 28

what does the extra energy from cooked food help with

Answer 28

could devote to build bigger brains in neanderthals and sapiens

Question 29

what were neanderthal and early sapien diets like

Answer 29

hunters gatherers most protein from meat

Question 30

what do starch granules from plants on fossil teeth and tools suggest

Answer 30

eating grains and tuber for at least 10,000 years; before agriculture

Question 31

do animal bones or plant remains preserve better

Answer 31

animal bones

Question 32

who had better teeth than us and how was that discovered

Answer 32

old hunter gatherers found from fossils

Question 33

what did old hunter gatherers no eat

Answer 33

sweets or bread

Question 34

what did old hunter gatherers not do to their cereals

Answer 34

grind them

Question 35

until what age did HGs feed children breast milk and why

Answer 35

age 5 or 6 because there was no dairy milk or baby food

Question 36

what do the inuit eat and where do they get their calories from

Answer 36

they have few plant options >90% calories from seals, narwhal, and fish

Question 37

where do Gwi San in Kalahari get their calories from

Answer 37

70% of calories from carbohydrate-rich sugary melons and starchy roots

Question 38

where do the Hadza get their calories from

Answer 38

70% of their calories from plants

Question 39

when did we cultivate wheat and wild barely in fertile crescent

Answer 39

11,500 BP

Question 40

when did potatoes in south america and maize in mexico emerge

Answer 40

10,000 BP

Question 41

when did rice in china emerge

Answer 41

82,000 BP

Question 42

when did farming spread throughout europe

Answer 42

5000-8000 BP

Question 43

why did farming spread throughout europe

Answer 43

farmers dispersed from the crescent

Question 44

where do most of our calories come from

Answer 44

90% come from plants domesticated before 5500 BP

Question 45

how often did HGs have children

Answer 45

every 3.5-5 yrs

Question 46

how often did farmers have children

Answer 46

every 2.5 yrs

Question 47

what are pros of agriculture

Answer 47

plentiful and predictable food supply population explosion farmers outnumbered foragers

Question 48

what is are cons of agriculture

Answer 48

shift from diverse HG diet to a narrower diet of cultivated wheat, barley, oats, rice, or corn poorer diet tooth decay reduced stature shift in fatty acid intake (omega-6/omega-3 ratio from 3:1 to >12:1 now) less fish more grain

Question 49

what happened to farmers due to an agricultural diet

Answer 49

suffered from iron deficiency and developmental delays, and shrank in stature

Question 50

what are some effects of an agricultural diet

Answer 50

switch from meat and fish to high glycaemic index carbohydrates parasites and new infectious diseases - transferred from domestic animals diabetes

Question 51

how many people have type 2 diabetes

Answer 51

392 million unknown in HG societies

Question 52

what does amylase enzyme do

Answer 52

pre-digests starchy food - bread, rice, and potatoes

Question 53

how many copies of the amylase genes do neanderthals and denisovans have

Answer 53

2 copies

Question 54

how many copies of the amylase genes do modern humans have

Answer 54

10-20 copies

Question 55

what type of eaters have more copies of the amylase gene

Answer 55

starchy food eaters (hadza) have more copies than meat eaters (yakut or siberia)

Question 56

why or why don't people drink milk

Answer 56

environmental reasons digestive reasons cultural reasons evolutionary reasons

Question 57

what is lactose

Answer 57

the sugar in milk

Question 58

what is the default genetic state of adult mammals

Answer 58

lactose intolerance

Question 59

how do young mammals digest milk

Answer 59

lactase enzyme

Question 60

when is the lactase gene turned off in humans

Answer 60

age 5

Question 61

why is lactose tolerance an adaptation

Answer 61

no competition between babies and others for mother's milk

Question 62

what % of adult Palaeolithic HGs would be lactose intolerant

Answer 62

99%

Question 63

what causes the lactase gene to not switch off

Answer 63

a mutation

Question 64

when did cheese making start

Answer 64

7200 BP

Question 65

how fast did the mutation of the lactose gene spread

Answer 65

faster than skin colour

Question 66

is lactose tolerance dominant or recessive

Answer 66

dominant AA = LT Aa = LT aa = LI

Question 67

who was Iceman

Answer 67

a mummy 7200 BP in Swiss alps lactose intolerant

Question 68

who is the least lactose intolerant

Answer 68

northern europeans

Question 69

what % of humans are lactose intolerant today

Answer 69

70%

Question 70

where is the highest lactose intolerance

Answer 70

sub-saharan africa south east asia south america

Question 71

why is lactose intolerance high/moderate in southern europe but consume lots of dairy

Answer 71

warmer temperatures meant that bacteria did the job for them dairy foods - yogurt and fermented cheese - lactose has been broken down by bacteria before eating