Biol 243 - theme 3

What would Malthus’ idea of limited resources look like?

there must be pressure to force adaptation (ex competition for resources)

human populations grow faster than available resources, so “fittest” indiviuals survive

Curvier main thoughts?

some species survive while others go extinct, number of species were declining

• existence of fossilized bones from species that no longer exist

Lyell main thoughts?

The earth must be older than believed and undergoing change

• landforms form gradually from geological processes, not catastrophes

Lamarck main ideas?

Species change over time (transmutation)

• acquired traits can be inherited, lost through disuse

Wallace main ideas?

theory of natural selection independently of Darwin in 1858

spurred Darwin to publish his own work

Charles Darwin origin of species by means of natural selection ideas

Evolution in response to natural selection is inevitable if:

there is variation in a trait, variation is heritable

some variants survive and reproduce more than others

specific features of the environment can generate natural selection on a trait

Limited gene flow in terms of finches on Galapagos islands means:

birds rarely move between the mainland and the islands

What is adaptive radiation?

a process in which organisms diversify rapidly from an ancestral species into many new forms

Phenotypic variation to survival/reproduction cycle

Learning objectives

slay