 | Term | Definition |
| |
common ancestor |
the first species that evolved the shared derived character state |
| |
convergent evolution (convergence) |
evolution of similar features independently in different evolutionary lineages, usually from different antecedent features of by different developmental pathways |
| |
homoplasy |
independed evolution of a similar or identical character state in two or more lineages; embraces convergence, parallel evolution, and evolutionary renewal |
| |
monophyletic group |
one in which all members are descended from a single common ancestor |
| |
node |
a branch point in the phylogenetic tree; represents the common ancestor |
| |
parsimony |
in systematics, the principle of invoking the minimal number of evolutionary changes to infer phylogenetic relationships |
| |
shared derivative character states |
indentifies a monophyletic group if and only if the character state is uniquely derived |
| |
sister group |
two groups that share the same common ancestor |
| |
synapomorphy |
a derived character state that is shared by two or more taxa and is postulated to have evolved in their common ancestor |
| |
anagenesis |
evolutionary change in traits in each descendant lines |
| |
cladistics |
pertaining to branching patterns; a cladistic classification classifies organisms on the basis of the historical sequences by which they have diverged from common ancestors |
| |
homology |
possession by two or more species of a character state derived, with/without modification, from their common ancestor |
| |
polyphynetic group |
a taxon consisting of unrelated lineages usually placed together due to convergent evolution |
| |
outgroups |
taxa closely related to, but outside, the monophyletic group |
| |
cladogenesis |
branching of a lineage into two or more descendant lines |
| |
paraphyletic group |
a monophyletic group in which some descendants of the common ancestor have been removed |
| |
phenetics |
classification based on degree of overall similarity between individuals |
| |
phenogram |
diagram representing the classification |
