The molecular clock has limited usefulness for estimating divergence times among species in part due to the saturation of dna sequences. this occurs because

a. dna sequences are unable to revert back to previous allelic states.
b. the variation in the substitution rate between closely related lineages prevents accurate estimation of divergence time.
c. variation in population sizes among lineages changes the effect of genetic drift.
d. in highly diverged lineages, substitutions will occur at sites that have been substituted previously

Which type of bacterial reproduction is depicted in the diagram?

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Actual age your first developed of age well comparison age refers to absolute age true or false