Origin and Migration of Modern Humans

Flashcards covering the origins of modern humans, their physical cranial features, genetic lineages (haplogroups), and the history of global migration patterns.

Homo erectus

The precursor to modern humans that evolved in Africa and expanded to Eurasia beginning about 1.8 million years ago.

Nariokotome

A 1.6 mya African Homo erectus subadult representing one of the many pulses of outward migration from Africa.

Anatomically Modern Humans (AMHs) Cranial Capacity

The brain volume of modern humans, which is usually more than $1350\,cc$.

Basicranium Flexion

The bending or flexure of the cranial base that is associated with an increasing brain size.

Foramen magnum

The large opening at the base of the skull which, in modern humans, faces straight 'down'.

Qafzeh

An archaeological site in Israel where a 100,000-year-old nearly modern human skull was found along with burned flints and a horse tooth.

Haplotype

A group of genes inherited together as a block from a single parent that shows a unique genetic pattern, typically based on mitochondrial DNA or Y chromosome DNA.

Haplogroup

A group of individuals sharing similar haplotypes and a common ancestor having the same single nucleotide polymorphism (SNP) mutations.

Mitochondrial DNA (mtDNA)

Genetic material located in the mitochondrion organelles that is inherited directly from the mother.

Y chromosome

Part of the nuclear DNA passed from father to son unchanged because it does not swap bits with the X chromosome.

Genetic markers

Mutations that serve as signposts defining different human lineages; the first appearance of one begins a new branch in the human family tree.

San Bushmen

A group in southern Africa believed to be direct descendants of the first evolved Homo sapiens over 100,000 years ago.

Mitochondrial Eve

The common ancestral female from whom markers in mtDNA have been charted back, living in Africa approximately 200,000 years ago.

Common male ancestor

The shared ancestor whose Y chromosome markers have been traced back to approximately 60,000 years ago.

Haplogroup L0

A genetic lineage found primarily in eastern and southern Africa, including populations such as the San Bushmen.

Haplogroup L3

A lineage that gave rise to all mtDNA diversity found outside of Africa after lineages began leaving the continent around 60,000 years ago.

Glacial maximum sea levels

A period around 40,000 years ago where sea levels were almost $125\,m$ ($400\,ft$) lower than today, exposing continental shelves.

Neolithic European gene pool

Only around 20 percent of this gene pool is of Neolithic origin, suggesting the DNA of Middle Eastern farmers was not as widely spread as their practice of agriculture.

M-173

A genetic marker originating around 30,000 years ago that is found at very high frequency in Western Europe, including Basques and Celts.

M-45

A genetic marker described as a 'stepping stone' on the way to M-173, indicating that Europeans are a subset of the Central Asian clan.

M-168

A genetic marker referred to as 'Eurasian Adam' associated with migration routes occurring 31,000 to 79,000 years ago.

Canine fossa

The hollowed cheeks noted as a feature of the anatomically modern human skull.

Mental foramen

A hole in the jaw usually located under the premolars in modern human skulls.