Final answer:
To draw a phylogenetic tree, start by selecting a group of organisms to study. Then, identify the common ancestors and their descendants by drawing lines between nearest relatives. Label each tip with the name of a species. To represent an extinct lineage, draw a short twig spurting out of the tree and then stopping, indicating a species that went extinct before evolving into new species. Label this twig with the name of the extinct group.
Step-by-step explanation:
To draw a phylogenetic tree, start by selecting a group of organisms to study. Then, identify the common ancestors and their descendants by drawing lines between nearest relatives. Label each tip with the name of a species. To represent an extinct lineage, draw a short twig spurting out of the tree and then stopping, indicating a species that went extinct before evolving into new species. Label this twig with the name of the extinct group.