EE39 Flashcards
1
Q
why are there more species in the tropics?
A
cradle - faster speciation - lower extinction, longer time higher carrying capacity more niches, larger niches larger land surface area.
2
Q
how much more energy does the tropics get annually compared to the poles?
A
2.5 x more
3
Q
what can you model species number by?
A
function of environmental variables
4
Q
where is mammalian species richness high?
A
where its warm, wet and mountainous and where north and south biomes join up
5
Q
what is the time for speciation hypothesis?
A
glaciation wiped high lattitudes clean
most tropical regions have been more stable
temperate speciation rates might now be high.
6
Q
what is niche conservatism?
A
the tendency of a species to retain aspect of their fundemental niche over time
7
Q
what does species richness show?
A
complex spatial patterns, not just longitudinal gradient
