Extinction And Speciation Flashcards
What are the 3 ways fossils are formed?
Gradual replacement by minerals, casts and impressions and preservation
What are fossils?
Remains of organisms in rocks from many years ago
What is speciation?
The development of new species
When does speciation occur?
When populations of the same species become so different that they can’t breed anymore to produce fertile offspring
What two things lead to speciation?
Isolation and natural selection
What is isolation?
It is when populations are separated by physical barriers and the conditions on each side will be different
How does natural selection happen due to isolation?
Because the climates are different the species will have different characteristics which will become more popular over time
Why does each population show variation?
There is a wide range of alleles
Why does extinction happen?
Species can’t evolve quick enough
What are some reasons for extinction because the species couldn’t adapt quick enough?
The environment changes, a new predator kills them all, a new disease kills them all, they can’t compete for food, a catastrophic event or a new species develops
