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Flashcards in B2f-natural Selection Deck (11)

What is Darwin's theory of evolution?

-organisms in a species show wide variation
-compete for limited resources
-best adapted will survive(survival of the fittest)
-inheritance of successful adaptations
(Pass on adaptations to offspring)


What are adaptations controlled by?

Can be passed on to next generation


What is speciation?

The development of a new species


What is evolution?

When groups of organisms change over time


How does reproductive isolation cause speciation?

Same species change
They cant interbreed to produce fertile offspring


How is reproductive isolation caused by geographic isolation?

-physical barrier divides population of species
-different mutations creates new features
-natural selection
-conditions on each side different
-individuals will have different features
-wont be able to breed together


Why was the theory of natural selection controversial at first?

-went against religious beliefs about how life on earth developed(didn't need a creator)
-darwin couldn't explain why new characteristics appeared or how they were inherited
-not enough evidence to convince other scientists
Not many other studies had been done


Why is the theory of natural selection now widely accepted?

It explains a wide range of observations
It has been discussed and tested by a wide rang of scientists


What was lamarcks theory?

-if a characteristic was used a lot then it would be more developed
-these acquired characteristics could be passed on to offspring


Why was lamarcks theory discredited?

It didn't have a genetic basis


How has the theory of natural selection developed?

-DNA discovered
-new adaptations arise because of mutations
-successful adaptations passed on in genes that parents contribute