When modelling common ancestor evolution, researchers use mathematical models and computer simulations. These often include simulations of physical processes such as cell growth, metabolism, and gene expression, as well as molecular processes such as mutation and evolutionary change over time. Using data and evidence from various sources, researchers can recreate different evolutionary paths and branch points, leading to new species and populations. Additionally, common ancestor evolution models may consider population genetics and inter- and intra-species behavior. By doing so, researchers can better understand how populations change over time and how characteristics within a species can vary based on their environment, biology, and other factors.