Evolution Flashcards
Who suggested the theory of evolution by natural selection?
Charles Darwin
What is meant by acquired characteristics?
Characteristics which we develop during our lifetime
What are the key steps in natural selection?
Mutation of gene gives organism advantage to survival. This helps them breed and they pass this mutation on.
Why did people have issues with Darwin’s theory of natural selection?
It challenged the idea that God made all life on earth.
Many scientists were not convinced because they did not think there was sufficient evidence for the theory.
Which birds did Darwin observe to find evidence for evolution?
Finches on the Galapagos Islands
Why do organisms show a wide range of variation?
Because of differences in their genes.
How are fossils formed?
From hard parts of animals that are hard to decay.
Preservation because lack of conditions for decay.
Preserved traces of organisms.
Why is the fossil record incomplete?
The fossils may have been destroyed by Earth movements or other climatic conditions, or the fossils could not form due to unsuitable conditions.
Give some reasons a species may become extinct.
New diseases Environmental change New predators New competitors A catastrophic event Natural changes
How do populations become isolated?
Islands break away from the mainland, new rivers form, mountain ranges or craters separate them
What is meant by speciation?
The formation of a new species. Occurs when part of a species is separated from the rest and they both evolve so they can no longer interbreed. They are now separate species.
