Population Genetics and Human Evolution. Chapter 19. Gradients of Genetic Variation in Human Populations. Prior to genomics, evolutionary biologists surveyed populations and cataloged differences in allele frequencies
Table 19-5, p. 428
Each circle in the center represents genetic variation within a population defined as a race. The variations overlap greatly as shown by the dark grey in the center. Few to no genetic differences belong to a single racial group.
Fig. 19-9, p. 429
Images from http://christpantokrator.blogspot.com/2011/06/human-evolution-diagrams.html
Evolution is not a linear morphing of one typeof organism into another – a common misunderstanding
Rather, evolution is branching from a shared ancestor
7 m.y.a. chimps and humans had a common ancestor
Fig. 19-10, p. 430
Estimates of the dates of origin and extinction of the three main groups of hominins (green, blue, and orange). The australopithecines split into two groups about 2.5 to 2.7 million years ago.
Time (millions of years ago)
Fig. 19-11, p. 430
The origin and spread of modern H. sapiens, reconstructed from genetic and fossil evidence.
European population Origin: 40,000 to 50,000 years ago
New World population Origin: 20,000 to 30,000 years ago
Asian population Origin: 50,000 to 70,000 years ago
Immigration from Africa About 137,000 years ago; 200 to 500 or more individuals
African populations Origin: 130,000 to 170,000 years ago Population: 23,000 to 45,000
Australo-Melanesian population Origin: 40,000 to 60,000 years ago
Fig. 19-13, p. 432
**Colors correspond to major continental regions.
Fig. 19-12, p. 431
–440,000 to 270,000 y. a. Split of ancestral human and Neanderthal populations
–41,000 y. a. Earliest modern humans in Europe
–195,000 y. a. Earliest known anatomically modern humans
–706,000 y. a. Coalescence of human and Neanderthal reference sequences
–28,000 y. a.
Most recent known Neanderthal remains
Genomic and fossil evidence has been used to estimate the time of divergence of human and Neanderthal lines relative to landmark events evolution. Genomic analyses trace evolution back much farther than fossils can.
Fig. 19-15, p. 434