Organs or other bodily structures within different species which resemble each other and have the same functions, but which did not have a common ancestral origin and development. Instead, the parts arose via convergent evolution and are thus analogies. In general, they are also planktonic and very small. The obsolete theory that offspring can inherit physical or behavioral characteristics from a parent that the parent acquired during its life. For example, a giraffe which stretches its neck to reach leaves at the top of a tall tree and thus ends up with a slightly longer neck can pass on the long neck trait so that its offspring also have long necks and can stretch it even longer.
Parapatric speciation is intermediate between allopatric and sympatric speciation.
The evolutionary history of a particular taxonomic group, usually a species. Compare monophyletic and paraphyletic . In evolution , the process through which a group of species diverge from a single ancestral form. People with this trait may suffer milder symptoms of sickle-cell anemia, or may have no symptoms. Some scientists believe the trait actually provides an evolutionary advantage in tropical environments because the slightly altered shape of the blood cells causes a person to be more resistant to malaria .