Locate the branch representing the species of interest: Identify the branch on the tree that corresponds to the species you're investigating.
Examine the branch's status: Determine whether the branch leading to the species terminates or continues.
Extinct species: If the branch ends abruptly with no subsequent descendants, it suggests that the species is extinct.
Extant species: If the branch continues and gives rise to further descendants, the species is considered extant or still in existence.
Cross-reference with other evidence: It's essential to cross-reference the phylogenetic evidence with other sources, such as fossil records, historical documentation, and observations from the field. This comprehensive approach helps increase confidence in determining whether a species is extinct.
In summary, analyzing the phylogenetic tree, identifying the branch of interest, and cross-checking with other sources are key steps in determining if a species is extinct.