An overview of human migrations

Published on June 30, 2015 Reviewed on July 21, 2024   39 min

Other Talks in the Series: Human Population Genetics II

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Hello, and welcome to this talk. I'm Mark Jobling, a professor in the Department of Genetics at the University of Leicester, UK. The purpose of this talk is to give you a broad overview of human migrations and to touch on a number of topics that will be covered in more depth elsewhere in the course. I hope to provide a taster, and to inspire your interest in human population genetics. There are 7 billion of us humans living in most of the habitable area of our planet, from hot deserts to icy tundra, from low-lying plains to high mountain plateaus and tiny, isolated islands to large cities with millions of cosmopolitan inhabitants. We show a lot of phenotypic diversity. This includes obvious differences, such as hair, skin, and eye color, height and body proportions, and less obvious ones involving dietary tolerances and disease susceptibilities. How can genetics contribute to understanding how this situation came about? Studying human population history charms with our natural interest in our origins, but it also has practical uses in understanding the distribution of disease alleles and the origins and significance of phenotypic differences.
The raw material we need for this genetic study of human migrations is genome variation data. As we'll see, this is now technically quite easy to obtain. We also need DNA samples from current human populations. Sometimes these can be more tricky. Thanks to technological advances, we can now also combine these with DNA from ancient human remains. Finally, we need models for mutation processes and models for demographic change in populations that allow us to do statistical and computational analysis and to interpret the data in a useful way.
During this talk I will go through some of these issues. I'll start by simply describing the human genome and genetic variation and say how diversity is distributed globally. I'll discuss the genetic evidence for a recent origin of modern humans in sub-Saharan Africa and describe the exciting finding that there was interbreeding between anatomically modern humans and archaic humans. During the occupation of new territories, genetic adaptations were important, and I will give some examples of these. Later migrations have had profound effects on particular parts of the world and I will summarize some of these, too. Finally, I will point to the importance of interdisciplinary work in this field. Geneticists cannot work alone.