Evo4 Flashcards
(15 cards)
What is an ecological niche?
An organism’s role in its environment — includes habitat, activity, resources, and interactions.
Why can’t two species occupy the same niche?
They would compete too much — one would outcompete the other.
What is a species?
A group of organisms that can interbreed and produce fertile offspring.
What is speciation?
The formation of a new species through evolution and isolation.
What are two pathways to speciation?
Transformation (one species becomes another) and divergence (a parent species gives rise to new species).
What types of barriers can lead to speciation?
Geographical (e.g., mountains, rivers) and biological (e.g., mating behaviours, pheromones).
What is pre-zygotic isolation?
Reproductive barriers that occur before fertilization (e.g., mating behavior).
What is post-zygotic isolation?
Barriers that occur after fertilization (e.g., hybrid infertility).
What is adaptive radiation?
Rapid diversification of one species into many, each adapted to different niches.
Example of adaptive radiation?
Darwin’s finches with different beak shapes on the Galápagos Islands.
What is gradualism?
Evolution occurs slowly over time with small changes.
What is punctuated equilibrium?
Long periods of stability interrupted by brief periods of rapid change.
Which evolutionary model is more widely accepted?
Punctuated equilibrium, due to fossil record evidence.
What is phylogeny?
An organism’s evolutionary history.
What is an ecotone?
A region where two ecosystems overlap — usually has high biodiversity.
