Human Evolution and Reproductive Isolation Flashcards

A collection of vocabulary terms covering human anatomical evolution, the Out of Africa Hypothesis, and mechanisms of reproductive isolation based on lecture notes.

Bipedalism

The ability to walk on two limbs or legs.

Cranial ridge

A ridge running across the top of the skull that served to attach large jaw muscles to the head.

Foramen magnum

The opening in the skull through which the spinal cord enters.

Hominids

A group of primates that contains all the African apes and includes humans and their ancestors (Family Hominidae).

Hominins

A subgroup of the hominids that includes only bipedal modern humans and their early human ancestors, such as Ardipithecus, Australopithecus, and Homo.

Prognathous

The protruding or projecting forward of the upper or lower jaw.

Opposable thumb

A thumb that can be placed opposite the fingers of the same hand to allow for power and precision grip.

Stereoscopic vision

A type of vision that allows for depth perception and 3D vision.

Homo sapiens

A species name meaning 'wise man' to which all humans living today belong.

Out of Africa Hypothesis

A hypothesis stating that modern humans originated in Africa and then spread to other parts of the world.

Sexual dimorphism

A condition where males and females of the same species are usually distinctly different in appearance.

Reproductive isolation

Mechanisms that restrict gene flow between species, preventing them from interbreeding and producing fertile offspring even if they mix.

Mitochondrial DNA (mtDNA) analysis

Genetic evidence showing that all modern humans evolved from a female ancestor that lived in Africa about $150,000$ years ago.

S-shaped spine

A characteristic of humans that allows the pelvis, leg, and feet to be directly under the abdomen, helping with the centre of gravity.

C-shaped spine

A characteristic of apes that differs from the S-shaped spine found in bipedal humans.

Homo habilis

Known as 'handyman,' this species was the first to make and use primitive stone tools.

Homo erectus

A human ancestor that utilized complex tools and was the first to control and manipulate fire.

Ardipithecus ramidus

An early hominin fossil found only in Africa, supporting the Out of Africa Hypothesis.

Australopithecus afarensis

A hominin species also known as 'Lucy,' whose fossils have only been discovered in Africa.

Human Pelvis

An anatomical structure that is short and wide to facilitate bipedalism and support upper body mass.

Quadrupeds

Organisms that use four limbs for locomotion, characterized by a foramen magnum at the back of the skull.

Dentition change

The evolutionary shift toward smaller canines, suggesting a decreased need to bite and tear and an increased need to grind and chew cooked food.

Cultural Evolution

The development of practices such as manufacturing pottery, practicing art, burying the dead, and developing artificial language, first seen in early Homo sapiens.