Which of the following examples shows how scientists continue to investigate darwin’s idea that species change over time by natural selection?

a. ornithologists study the wing shape and flight patterns of birds.
b. archaeologists uncover, catalog, and compare fossils of marine life.
c. microbiologists examine the reproduction rates of bacteria.
d. ecologists obtain samples of tree trunks to determine the trees’ ages.

Transposon can cause mutations in genes at or near the site of transposon insertion. it is possible for these elements to transpose away from their original site, causing a reversion of the mutant phenotype. in some cases, however, even more severe phenotypes appear when these elements excise from this site, due to events at or near the mutant allele. what might be happening to the transposon or the nearby gene to create more severe mutations?