The impact of Environment on Speciation Flashcards
allopatric
geographicical barrier
peripatric
species on the periphery are isolated
parapatric
due to partial spacial isolation
hybrid zone
sympatric
no gene flow due to preference change
founder effect
migrant population does not represent parent population
Big Bird lineage parents
Geospiz Fortis
Geospiza conirostris
why do Big Bird offspring have to interbreed?
isolated because of their song
How long did Darwin spend in the Galapagos Islands?
5weeks
Big Bird is an example of speciation occuring over how many generations…?
three
increased melanin causes…
decreased vitamin D
ethiopa vs congo body shape
pygmy vs nilotic
Allen’s rule:
as latitude increases, humans become shorter to reduce SA
Biilliac Breadth increases as…
latitude increases
what climates where neanderthals found in?
cold climates
what climates were homo erectus found in?
warm climates
early environments likely to have been abundant in:
vitamin C
N-3 FA
iodine
B vitamins
essential vitamisn indicate early humans lived in environments with an abundance of…?
fruit (rain forest)
fish (river)
meat (Savannah)
Savannah hypothesis aims to explain what aspects of modern humans…
bipedalism
hairless
speech + intelligence
Waterside Hypothesis evidence:
spine and lower limbs in same plane
bipedal, naked, subcutanous fat
strong diving reflex
wrinkled fingertips in response to water
When does the diving reflex dissapear in newborns?
4 months
diving reflex:
HR decrease (Stronger in humans)
fish in waterside hypothesis:
more protein = less time hunting
grasping reflex dissapears at what age?
6 months
primates came from…
West Africa
When were humans in east africa?
3/4 million years ago
Congo Basin:
Rain and Swamp Forest
why does living in the congo basin support the waterside hypothesis?
swimming easier form of travel
salts, minerals, iodine-rich plants found…
Mbeli Bei
how do humans and primates differ?
primates arent fond of water
The effect of Water on Great Ape dispersal
congo divides banobos, and different chimpanzee populations = rivers do not divid ehuman species
importance of human follils being found with African animal fossils
African animals display wetland adaptations
need to surive in water would have promoted which modenr human trait…
bipedalism
limitation of waterside hypotheiss:
insufficent at explaining why fish heavily present in human diet
million year flood in congo:
ancestors forced to be near water, leading to adaptions
how can we explain importance of fish in diet?
drought periods cause fish to congregate in mud pools
why did ancestral humand leave wetland?
draughts persisted over floods
forced to migrate to East Africa
waterside hypothesis implies what?
already bipedal and hairless by the time we entered the savannah
when is speciation encouraged?
when gene flow is blocked
