evolution

Question 1

what is natural selection?

Answer 1

occurs when there are selection pressures on organisms. This could be a change in the environment, availability of food or new predators.

Question 2

what are the steps of natural selection?

Answer 2

1. species produce more offspring than the environment can environment can handle.
2. The best adapted individuals in a population survive
3. the survives reproduce and pass on favourable alleles with the selective advantage
4. the best allesles increase in frequency within the population because the best survives

Question 3

what is speciation?

Answer 3

is the process of a new species evolving.

Question 4

what is the process of speciation?

Answer 4

1. part of the population becomes isolated by an isolated barrier (geographical, ecological, behavior)
2. different mutations occur in each each sub population
3. natural selection selects different mutations in each group due to different selection pressures in each sub population
4. each sub population over a long period of time evolves until they become to genetically different that they are 2 different species and can no longer interbreed together.

IM a New Species

= isolation, mutation, natural selection

Question 5

what are the 3 types of barries that can lead to isolated, give examples.

Answer 5

geographical - rivers, oceans, mountains

ecological - ph, salinity (salt) , different habitats

behavioral - differences in mating behavior

Question 6

what do the terms geographical, ecological and behavioral mean?

Answer 6

geographical - location, where the organism lives

ecological - interaction, how the organisms interact with each other and the environment

behavioral - what they do and why they do it