Book Previews Diaspora & Origins

Diaspora Sophie Campbell

  • The patterns of migration. A set of metascapes based on a range of migration datasets.
  • Metascape Press
  • :a preview of work in process
  • :20 pages

Origins Sophie Campbell

  • A visual guide to the origins of cultures.
  • Metascape Press
  • :a preview of work in process
  • :26 pages

The story of the human species begins in Africa 300,000 years ago. Migrations moved humanity around that continent 170 – 130 thousand years ago. Sixty to eighty thousand years later humankind advanced beyond the land of its origin. Green corridors and land bridges opened as the climate changed and our species moved through these access ways into new homelands.

An initial exploratory wave clung to the southern coastline of Asia to exploit its intertidal abundance of food, developing sophisticated maritime technology that enabled people to get all the way to Australia and into Melanesia. Another group moved inland through Iraq and spread north into Europe and east into Asia.

Step by step humans found their way to every habitable land mass on our planet, ending the discovery phase at New Zealand less than a thousand years ago. On leaving Africa we encountered other hominid species that migrated out of Africa before us, assimilating them through interbreeding (Homo denisova and Homo neanderthalensis) and/or out-competing them to extinction. Clues of our passage can be read in the records of archeology, food transportation, linguistics, cultural practice. Migratory patterns are also stamped into our DNA.

The metascapes in this book are a collection of these patterns, designed to give the reader a sense of how intrinsic migration has been for our species.

footprints

Mitochondrial DNA Analysis

waves

Main Sequence Chronology

Compass

Maori Star Chart

plate 1

Admixture of the Japanese Haplogroup

plate 2

Admixture of the Indian Haplogroup

plate 3

Admixture of the Iranian Haplogroup

plate 4

Admixture of the French Haplogroup

plate 5

Admixture of the Spanish Haplogroup

plate 6

Admixture of the Irish Haplogroup

plate 7

Admixture of the Scottish Haplogroup

plate 8

Admixture of the Han Haplogroup

plate 9

Admixture of the Uyger Haplogroup

plate 10

Admixture of the SanKhomani Haplogroup

plate 11

Admixture of the Finnish Haplogroup

Data

The dataset analysed here consists of 1,490 individuals sampled from 95 world-wide groups with 2- 46 individuals per group. Each individual had genotypes at 474,491 genetic markers (Single- Nucleotide-Polymorphisms; SNPs) across all 22 non-sex chromosomes.

Modelling

A typical individual is broken into 30,000 pieces of information on his or her ancestry. Mixture modelling with the CHROMOPAINTER algorithm uses the palettes of different groups in order to help to characterise their admixture history.

Coancestry

Coancestry curves follow an exponential distribution with rate equal to number of generations ago that the admixture event occurred. An estimate is made using an exponential decay rate simultaneously to the full set of coancestry curves using standard statistical software. If there are two or more admixture times, then the coancestry curves are predicted theoretically to have a mixture of exponential decay rates.

Dating

Current literature assumes a generation corresponds to 28 years. Generations (G) convert to years (Y) using the following formula: Y = 1950 - 28 x (G+1). This formula fixes 1950 as the arbitrary birth-year for sampled individuals, which should not make a significant difference given the overall uncertainty in date inference.