Respuesta :
The answer is ancestor.
Common ancestor is an ancestral organism that two or more descendant lineages have in common. If organisms are not similar, but still have similar genes, that indicates that they share the common ancestor. The more basic the common genes are, their common ancestor is more close to the last universal common ancestor (LUCA).
In cladistic analysis, similar Gene's that appear in dissimilar organisms, indicate that they share a common ANCESTOR