Which is an example of class evidence?

a. the scientist excludes a suspect from a crime investigation after analyzing fingerprints on the murder weapon and those of the suspect.

b. the scientist reports that kerosene from acme organic products was the accelerant used in an arson.

c. the scientist establishes that the dna from an assault suspect was found on the victim.

d. the scientist matches the toolmark on a broken door in a burglary with a toolmark made from a crowbar in a suspect's car.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

b is the correct answer