Primates may have evolved in the cold

ancestor: A predecessor. It could be a family forebear, such as a parent, grandparent or great-great-great grandparent. Or it could be a species, genus, family or other order of organisms from which some later one evolved. For instance, ancient dinosaurs are the ancestors of today’s birds. (antonym: descendant)

ape: A group of rather large primates, all of which lack a tail. They include gorillas, chimpanzees, bonobos, orangutans, gibbons and humans. Most people tend to group humans into their own separate subcategory owing to a number of special traits. These include a larger brain, greater mental abilities (including being able to talk) and their ability to walk on two legs.

biologist: A scientist involved in the study of living things.

climate: The weather conditions that typically exist in one area, in general, or over a long period.

colleague: Someone who works with another; a co-worker or team member.

common ancestor: Also known as shared ancestor. It’s an ancestor that two or more descendants have in common. Two siblings share a parent as a common ancestor. This also applies on the level of species and groups of organisms. Two or more species can share a common ancestor at the genus level. Two or more genera can share a common ancestor at the family level, and so on. Tigers and lions have a common ancestor, as do humans and Neandertals.

computer model: A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.

continent: (in geology) The huge land masses that sit upon tectonic plates. In modern times, there are six established geologic continents: North America, South America, Eurasia, Africa, Australia and Antarctica. In 2017, scientists also made the case for yet another: Zealandia.

density: The measure of how condensed some object is, found by dividing its mass by its volume.

evolutionary: An adjective that refers to changes that occur within a species over time as it adapts to its environment. Such evolutionary changes usually reflect genetic variation and natural selection, which leave a new type of organism better suited for its environment than its ancestors. The newer type is not necessarily more “advanced,” just better adapted to the conditions in which it developed.

evolutionary biologist: Someone who studies the adaptive processes that have led to the diversity of life on Earth. These scientists can study many different subjects, including the microbiology and genetics of living organisms, how species change to adapt, and the fossil record (to assess how various ancient species are related to each other and to modern-day relatives).

family: A taxonomic group consisting of at least one genus of organisms.

forest: An area of land covered mostly with trees and other woody plants.

fossil: Any preserved remains or traces of ancient life. There are many different types of fossils: The bones and other body parts of dinosaurs are called “body fossils.” Things like footprints are called “trace fossils.” Even specimens of dinosaur poop are fossils. The process of forming fossils is called fossilization.

lemur: Any of many primate species that tends to have a cat-shaped body and usually a long tail. They evolved in Africa long ago, then migrated to what is now Madagascar, before this island became separated from the east coast of Africa. Today, all wild lemurs (some 33 species of them) live only on the island of Madagascar.

model: A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes. Or an individual that is meant to display how something would work in or look on others.

primate: The order of mammals that includes humans, apes, monkeys and related animals (such as tarsiers, the Daubentonia and other lemurs).

Proceedings of the National Academy of Sciences: A prestigious journal publishing original scientific research, begun in 1914. The journal’s content spans the biological, physical and social sciences. Each of the more than 3,000 papers it publishes each year, now, are not only peer reviewed but also approved by a member of the U.S. National Academy of Sciences.

species: A group of similar organisms capable of producing offspring that can survive and reproduce.

tropics: The region near Earth’s equator. Temperatures here are generally warm to hot, year-round.