A change in an organism that improves its ability, and the ability of its offspring, to survive in an environment.
An ancestor shared by two or more descendant species.
A fossil of a body or body part of an organism.
The molecule that encodes genetic information. It is shaped like a double helix held together by bonds between base pairs.
The scientific theory for how groups of living things change over time.
A representation of how a specific taxonomic group evolved new species over time. All trees are hypotheses, and are based on comparison of living species, fossils, and genetic data.
Remains or traces of an organism turned to stone by geochemical processes.
The activity of a body part.
A specific sequence of DNA base pairs that controls the expression of one or more traits.
An evolutionary mechanism in which genes and traits in small populations increase in abundance over generations by chance, not because they impact an individual's ability to survive.
The passing on of genetic traits from parent to offspring.
A member of the family of primates that includes humans, their ancestors, and close relatives.
The name for our species: modern humans.
A change in a gene's structure that may be passed on to future generations.
An evolutionary mechanism whereby individuals tend to pass on heritable features that enable them to cope better with their environment to future generations. Over time, populations of individuals will exhibit more of the better-adapted features.