variation and evolution - evolution by natural selection

Question 1

what have all different species come from?

Answer 1

first life forms were very simple for example single cells. all species of living things have evolved from these simple life forms. this is called evolution by natural selection

Question 2

Why will every rabbit have a different combination of alleles?

Answer 2

they have all have different parents which they have inherited them from
example: some will have alleles for thicker fur, some for better eyesight and others for better hearing

Question 3

how does evolution by natural selection work?

Answer 3

if an environment becomes colder, for the example of rabbits. the ones that have inherited alleles for thicker fur are more likely to survive the colder temperatures than the rabbits with thinner fur so because rabbits with thicker fur can survive the colder temperatures, they are more likely to go on to reproduce. offspring will then inherit the alleles for thicker fur + these offspring more likely to survive + reproduce. over many generations, alleles for thicker fur will become more common among the population of rabbits. tend to have thicker fur than before

Question 4

what is evolution?

Answer 4

the change in the inherited characteristics of a population over time through a process of natural selection

Question 5

what can happen if 2 populations of 1 species become so different in phenotype?

Answer 5

no longer interbreed to produce fertile offspring. these 2 populations have become 2 separate species