2018年5月8日 · symplesiomorphy The possession of a character state that is primitive (plesiomorphic) and shared between two or more taxa. Shared possession of a symplesiomorph character state is not evidence that the taxa in question are related.

For example, vertebrae are found in zebras, cheetahs, and orang-utans, but the common ancestor in which this trait first evolved is so distant that the trait is shared by many other animals. Therefore, possession of vertebrae sheds no light on the phylogenetic relations of these three species. See also symplesiomorphy.

A symplesiomorphy is a character common to the whole range, part of the species' shared legacy, although some may display it to a greater extent than others. Conversely, a synapomorphy is a character shared by only some of the species.

2018年6月11日 · Phylogeny Phylogeny is the inferred evolutionary history of a group of organisms (including microorganisms ). Paleontologists are interested in understanding life through time, not just at one time in the past or present, but over long periods of past t

2018年5月11日 · stereometry. Art or science of measuring solids. Branch of geometry dealing with solid figures. Stereometric therefore pertains to stereometry or solid geometry.