AP BIOLOGY

Detailed explanation-1: -Most evolutionary biologists distinguish one species from another based on reproductivity: members of different species either won’t or can’t mate with one another, or, if they do, the resulting offspring are often sterile, unviable, or suffer some other sort of reduced fitness.

Detailed explanation-2: -Molecular similarities provide evidence for the shared ancestry of life. DNA sequence comparisons can show how different species are related. Biogeography, the study of the geographical distribution of organisms, provides information about how and when species may have evolved.

Detailed explanation-3: -DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can show how related species are. Biogeography. The global distribution of organisms and the unique features of island species reflect evolution and geological change.

Detailed explanation-4: -A dichotomous key is an important scientific tool, used to identify different organisms, based the organism’s observable traits. Dichotomous keys consist of a series of statements with two choices in each step that will lead users to the correct identification.