Final answer:
Cladistics is a method used to distinguish between homologous ancestral and derived characteristics and understand relationships between groups of organisms. Scientists use combined morphologic and molecular data to construct phylogenetic trees that show evolutionary connections. Analyzing physical appearance and using molecular data are important for inferring evolutionary relatedness.
Step-by-step explanation:
Cladistics, or the use of cladograms, is a method of visually distinguishing between homologous ancestral and derived characteristics. Ancestral characteristics are found in the common ancestor of the species being classified, whereas derived characteristics are only found in the groups in question. By exclusively looking at derived characteristics, scientists can develop a clearer understanding of the relationships between the groups being studied.
Scientists use combined data based on evolutionary relationships from many sources, such as morphologic and molecular data, to put together the phylogeny of an organism. Phylogenetic trees are constructed using these data to show how species and taxon groups evolved from common ancestors.
For example, scientists can analyze physical appearance by comparing shared morphological characteristics to infer evolutionary relatedness between groups of organisms. They can also use molecular data for analysis by comparing shared genes or DNA sequences. However, it is important to consider reproductive strategies as well, as they can also influence evolutionary relationships.