Speciation Flashcards
All 5 cards in this deck
What did Alfred Russel Wallace publish with Darwin in 1858, and what did it lead to?
Joint writings on evolution by natural selection, which prompted Darwin to publish On the Origin of Species in 1859.
What work is Alfred Russel Wallace best known for?
His work on warning colouration in animals and his theory of speciation.
What are the steps that give rise to a new species?
e.g. a population of snails split in two by a new river
- The populations become isolated — the snails on each side cannot interbreed.
- Natural selection acts on the variation in each population, selecting different characteristics in each environment.
- The populations become so different that they can no longer interbreed to produce fertile offspring — two species.
How can you tell that two isolated populations have become separate species?
They can no longer interbreed to produce fertile offspring.
True or false? Two isolated populations of the same species experience exactly the same selection pressures.
False. Their environments differ, so natural selection favours different characteristics in each population.