Answer to Question #309717 in Zoology for Diana's

Question #309717

Why are derived characteristics more useful in establishing evolutionary relationships than are shared characteristics used to subgroups of mammals to illustrate answer

Expert's answer

characteristics more useful in establishing evolutionary relationships than are shared characteristics used to subgroups of mammals when similar similar physical features occur in organisms because of environmental constraints and not due to a close evolutionary relationship

homologous: when similar physical features and genomes stem from developmental similarities that are based on evolution
phylogeny: the evolutionary history of an organism
molecular systematics: molecular phylogenetics is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism’s evolutionary relationships
Organisms may be very closely related, even though they look quite different, due to a minor genetic change that caused a major morphological difference.
Unrelated organisms may appear very similar because both organisms developed common adaptations that evolved within similar environmental conditions.
To determine the phylogeny of an organism, scientists must determine whether a similarity is homologous or analogous.
The advancement of DNA technology, the area of molecular systematics, describes the use of information on the molecular level, including DNA analysis.

Key Terms

analogous: when similar similar physical features occur in organisms because of environmental constraints and not due to a close evolutionary relationship
homologous: when similar physical features and genomes stem from developmental similarities that are based on evolution
phylogeny: the evolutionary history of an organism
molecular systematics: molecular phylogenetics is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism’s evolutionary relationships