Building Phylogenetic Trees from Molecular Data

Key points: Phylogenetic trees represent hypotheses about the evolutionary relationships among a group of organisms. A phylogenetic tree may be built using morphological (body shape), biochemical, behavioral, or molecular features of species or other groups. In building a tree, we organize species into nested groups based on shared derived traits (traits different from those of the group’s ancestor). The sequences of genes or proteins can be compared among species and used to build phylogenetic trees. Closely related species typically have few sequence differences, while less related species tend to have more. Introduction We’re all related—and I don’t just mean us humans, though that’s most definitely true! Instead, all living things on Earth can trace their descent back to a common ancestor. Any smaller group of species can also trace its ancestry back to common ancestor, often a much more recent one. Given that we can’t go back in time and see how species evolved, how can we figure out how they are related to one another? In this article, we’ll look at the basic methods and logic used to build phylogenetic trees, or trees that represent the evolutionary history and relationships of a group of organisms. #MolecularClock #GeneCkock #evolutionaryClock #PrincipleOfParsimony #phylogenicTree #outgroups #ingroup #Homology #Homoplasy #cladogram #Phylogram #domain #kingdom #phylum #Class #genus #ScientificNames #taxonomicHierarchy #species #phyliogeneticTree #Evolution #speciation #diagram #branchingInAPhylogeneticTree #Genetics #bilology #taxonomy #populationGenetics #hawaiiIslands #founderEffect #geneticDrift #geneticVariation #taxa #clade #Paraphyletic