Human Ancestry and Genetics of Identity

Flashcards covering human evolution, ancestral species, molecular evolution methods, and genetic identity/forensics as per the the provided lecture notes.

Indigenous people

Groups whose ancestors lived in a region longer than any other group and have preserved unique cultures, languages, and traditions.

Khoisan people

A population living in the Kalahari Desert in southern Africa having some of the oldest genetic lineages and high genetic diversity.

Molecular clock

A technique using mutation rates in DNA sequences to estimate when two species shared a common ancestor.

Hominins

Humans and their ancestors that lived after the split from African apes approximately $6$ million years ago.

Homo sapiens sapiens

Modern humans who first appeared about $200,000$ years ago.

Ardipithecus

An early ancestor that lived about $4.4$ million years ago; capable of walking on two legs and climbing trees.

Australopithecus afarensis

A species known as "Lucy" that lived about $3.6$ million years ago, stood about $4$ feet tall, and walked upright.

Homo habilis

Meaning "handy human," this species was the first in the Homo genus to use advanced tools.

Homo erectus

A hominin that lived about $1.8$ million years ago; the first to use fire, have complex social groups, and migrate widely.

Neanderthals

Archaic humans who lived in Europe and western Asia, adapted to cold climates, and contributed $1-2\%$ of DNA to modern Europeans and Asians.

Introgression

The movement of gene variants from one species or subspecies into another.

Admixture

The mixing of DNA from different populations through reproduction.

Denisovans

A group related to Neanderthals discovered via DNA in Siberia; their DNA remains in populations in Papua New Guinea, Melanesia, and Australia.

Ötzi the Ice Man

A frozen individual found in the Alps from $5,200$ years ago with ancestry linked to Sardinia and Corsica.

Highly conserved genes

DNA sequences that change slowly over time and are usually essential for survival.

Mitochondrial DNA (mtDNA)

DNA passed from mother to child used to track maternal ancestry; it mutates quickly.

Y Chromosome DNA

DNA passed from father to son used to track paternal ancestry.

SNPs (Single Nucleotide Polymorphisms)

Single nucleotide differences in DNA sequences between individuals.

STRs (Short Tandem Repeats)

Short repeated DNA sequences ($2-10$ bases) used for identification; also known as microsatellites.

Haplogroups

Groups of linked DNA markers used to trace deep ancestry and inherited from a common ancestor.

Mitochondrial Eve

The most recent common female ancestor of all living humans, estimated to have lived $200,000$ years ago in Africa.

Bering Land Bridge

The route humans used to cross from Siberia to the Americas approximately $15,000-25,000$ years ago.

FOXP2 gene

A gene partly responsible for controlling speech, shared by both humans and Neanderthals.

AHI1 gene

A gene that helps control movement and coordination related to walking upright.

MYH16 mutation

A mutation that reduced jaw muscle size in humans, allowing for expansion of the skull and brain.

Synteny

The similar order of genes between different species.

Indels

Insertions and deletions of DNA segments.

Genetic marker

A DNA sequence used to represent a gene or trait, which does not necessarily encode proteins.

VNTRs (Variable Number Tandem Repeats)

Longer repeated DNA sequences ($10-80$ bases) used in older DNA profiling; also called minisatellites.

Capillary Electrophoresis

A modern DNA profiling method where STR regions are copied by PCR and detected by a laser as peaks on an electropherogram.

CODIS (Combined DNA Index System)

The FBI's DNA database system which compares $20$ STR locations.

Hardy-Weinberg Equation

A formula ($p^2 + 2pq + q^2 = 1$) used to calculate genotype frequencies for DNA evidence.

Product rule

A method used to determine the probability of a DNA match by multiplying the frequencies of multiple genetic markers.

Secondary transfer

The indirect transfer of DNA from one person to another.

DNA dragnet

A forensic approach involving the collection of DNA from many people in a specific area to find a suspect.

Centimorgan (cM)

A unit of measurement used to estimate the amount of shared DNA and the closeness of a relationship.

Haplotype

A group of linked genetic variants that are inherited together.