Adaptive Radiation Flashcards Preview

ENVR 202 pt. 2 > Adaptive Radiation > Flashcards

Flashcards in Adaptive Radiation Deck (10):
1

Anagenesis

change from one species into an entirely different species

2

cladogenesis

species develops branching off from the original species, original species remains

3

Adaptive radiation

evolution of ecological and phenotypic diversity within a rapidly multiplying lineage- differentiation of a single ancestor into an array of species (one species to many)

4

Ecological opertunity

the invasion of unused ecological niches leads to rapid diversification

5

Key innovation

the acquisition of a novel adaptive trait that allows organisms to exploit previously unavailable niches

6

Ecological hypothesis

The massive worldwide vegetational shift to angiosperm dominance can be explained by positive feedbacks between angiosperms and their environment

7

The Slow seeding hypothesis

Because of slow growth rates because of inefficient transport systems and low leaf photosynthetic capacity, gymnosperm seedlings are weak competitors with angiosperms in productive habitats -> angiosperms did better

8

Biotic drive for adaptive radiation

coevolution can drive increased rates of evolutionary change- existence of genetic variation and each species as a selective force on the other

9

Escape and radiate hypothesis

organisms under constraint from other organisms will develop new defenses which allow them to escape constraints- evolutionary arms race

10

Positive reinforcement

they go back and forth, one adapts, the other adapts in response