Term
| Why do we care about the diet of early hominins? |
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Definition
• Diet allows us to put our ancestors in the context of their environment
• Many modern diet trends have been based on what our ancestors ate. Learn to eat what we evolved to eat. |
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Term
| What kind of evidence is there? How do we know what we need to eat? |
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Definition
• Fossil teeth!
o Durable parts of the digestive system
o Tooth size!
o Enamel thickness and structure
o Tooth shape
o Tooth chemistry -- stable isotopes
o Microwear on teeth
• Microwear analysis--evidence of diet for individuals as opposed to species level adaptations |
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Term
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Definition
more surface area for processing more low quality foods
and
increase prob. Of fracturing smaller or thinner items. |
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Term
| Why do we look at molar tooth size? |
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Definition
o Easy to measure
o Obvious variation btwn hominin species |
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Term
| Caveats of studying molar size |
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Definition
o Body mass estimates have huge error bars, so relative tooth size is a problem
o Tooth size does not consistently reflect diet in living primates (e.g. for new world monkeys, folivores have larger teeth than frugivores, but the opposite holds for old world monkeys) |
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Term
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Definition
large molar teeth compared with ardipithecus
thick molar enamel compared with ardipithecus
low occlusal relief, blunter teeth than chimps |
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Term
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Definition
extremely large molar teeth (megadont)
extremely thick molar enamel
extremely flat molars, even less relief than Australopithecus |
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Term
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Definition
reducing tooth size (especially H. erectus)
thinner enamel than australopiths
somewhat occlusal relief. Somewhere btwn gorillas and chimps. |
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Term
| Perks to enamel thickness |
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Definition
thick enamel for savannah living
•To prolong life in an abrasive environment.
•To strengthen the tooth to resist breakage given consumption hard, brittle foods. |
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Term
| advantages for checking enamel thickness |
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Definition
| • Obvious variation btwn hominin species |
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Term
| Disadvantages to studying enamel thickness |
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Definition
• Resistance to fracture relates to enamel dist. Not just avg. thickness
• Enamel strength also depends on enamel structure and chemistry
• Thin enamel can also be selected for (to increase sharpness at enamel-dentin junction) |
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Term
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Definition
o Sharper teeth with more occlusal relief more efficiently shear and slice tough foods
o Flatter, blunter teeth more efficiently crush hard, brittle foods without breaking |
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Term
| Adavantages for studying Occlusal Relief |
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Definition
o Obvious variation between hominin species
o Consistent relationship between form and function in living primates: tough leaf eaters have long crests while hard object feeders have flatter molars. Mixed feeders have intermediate. |
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Term
| Caveats of studying occlusal relief |
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Definition
o This measures potential for fracturing foods rather than a reflection of actual behaviors
o Functional adaptive morph reflects selection in ancestors. |
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Term
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Definition
| • Diet: at least some hard, brittle, and perhaps abrasive foods |
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Term
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Definition
| dominantly hard, brittle, and perhaps abrasive foods |
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Term
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Definition
| potentially more tough foods, less emphasis on hard-brittle items. Tools and cut marked bones show and much more broader diet, including meat |
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Term
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Definition
o Ex: just cause your car is capable of driving 100 mph, doesn’t mean you will use it that way.
o Gorillas will change their diets (they have the teeth and guts they need)
o Chimps wont do this cause they don’t have teeth or guts |
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Term
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Definition
• Specialists should often reject the resources they are phenotypically meant to eat.
• Gorillas want the fruits and not the leaves--even though they are built to eat leaves |
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Term
| The last supper phenomenon |
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Definition
o Microwear feature can be "overwritten" in a matter of days
microwear can help us evaluate whether morphology or fallback foods preferred. |
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