Cultural and biological adaptation Flashcards
(15 cards)
Adaptation
Evolution by natural selection of interrelated systems of phenotypes that fit a breeding population to its environment, at least in somewhat a resilient way so that the population persists over large numbers of generation despite inevitable fluctuations in that environment
What is language
System of communication consisting of sounds words and grammar.
Verbal - sounds, words, conversations
Non-verbal - Gestures, sign language, Writing
Anatomy of speech
Change air flow through larynx - sound production. Individual sounds modified by movement of lips, cheeks and tongues.
Hyoid bone
Why is speech hard to study through fossils
Larynx, lips, cheeks and tongue made from soft tissue. So is the connections with muscles. They degrade over time.
Evolution of spoken language theories
Language evolved from pre-linguistic systems in human ancestors
primates communicate through gestures and vocally.
As population grow they need to communicate ideas.
Space for larynx found
FOX2P gene found in homo sapiens and Neanderthals that related to muscles of face.
How can environment effect evolution
Challenges - temp, precipitation, productivity of area = resources.
Short term - reaction over lifespan
Long term - Adaptation over many generation
Phenotypes survive if they can withstand challenging periods.
Examples of human adaptation
Cold tolerance is low - subcutaneous fat
Origin near they equator making tolerance low.
Supplements of clothing, shelter and fire removes high need for more fat.
Heat adpation - sweat glands to produce water and acclimatize to heat.
Bergmann’s rule
Body size is large in cold climates and smaller in warm climates.
Organisms at higher altitudes should be larger and thicker than those present near equator.
Allen’s rule
Body shape and endotherms vary by temp.
Minimising exposed surface area to minimise heat loss in hot climates
Maximising exposed surface area to maximise heat loss in hot climates.
How does diet effect adaptation
Correct nutrients allow body to survive and fulfil genetic potential
More food sources = better chance of survival.
Promotes survival when environment changes.
Dietary transitions
Early environment was warm, wet and forested - mainly fruit and leaves.
2-3 Mya climate changes to become drier
Pre-homo lineages adapt to the open drier grasslands.
Lactose effect in children
Infants have lactase enzyme which breaks down lactose - generally switched off after weaning to save energy.
This leads to lactose intolerance, where unabsorbed lactose is metabolised by intestinal bacterial = causes cramps and stomach aches.
Lactase persistence
30% of human population express lactase enzyme into adulthood.
Lactase breaks down lactose
LP is a selected trait in European, African and Asian populations.
If you retain ability to make lactase then you retain ability to use dairy resources.
Dairy husbandry
Sheep/goats domesticated in Asia 11kya
Into Europe by Mediterranean
Early neolithic people were lactase non-persistent.
LP increase in bronze and iron ages.
Bitter taste perception
People perceive taste different due to farms of taste receptors on tongues.
PTC is the bitter taste molecule
