Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Feb;103(1):1-46.
doi: 10.1257/aer.103.1.1.

The 'Out of Africa' Hypothesis, Human Genetic Diversity, and Comparative Economic Development

Quamrul Ashraf  1 , Oded Galor  2
Affiliations

The 'Out of Africa' Hypothesis, Human Genetic Diversity, and Comparative Economic Development

Quamrul Ashraf et al. Am Econ Rev. 2013 Feb.

Abstract

This research argues that deep-rooted factors, determined tens of thousands of years ago, had a significant effect on the course of economic development from the dawn of human civilization to the contemporary era. It advances and empirically establishes the hypothesis that, in the course of the exodus of Homo sapiens out of Africa, variation in migratory distance from the cradle of humankind to various settlements across the globe affected genetic diversity and has had a long-lasting effect on the pattern of comparative economic development that is not captured by geographical, institutional, and cultural factors. In particular, the level of genetic diversity within a society is found to have a hump-shaped effect on development outcomes in both the pre-colonial and the modern era, reflecting the trade-off between the beneficial and the detrimental effects of diversity on productivity. While the intermediate level of genetic diversity prevalent among Asian and European populations has been conducive for development, the high degree of diversity among African populations and the low degree of diversity among Native American populations have been a detrimental force in the development of these regions.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Expected Heterozygosity and Migratory Distance in the HGDP-CEPH Sample
Figure 2
Figure 2
The Hump-Shaped Effect of Diversity on Development
Figure 3
Figure 3
The 53 HGDP-CEPH Ethnic Groups and Migratory Paths from East Africa
Figure 4
Figure 4
Observed Genetic Diversity and Population Density in 1500 CE – The Unconditional Relationship
Figure 5
Figure 5
Predicted Genetic Diversity and Population Density in 1500 CE – The Unconditional Relationship
Figure 6
Figure 6
Predicted Genetic Diversity and Population Density in 1500 CE – Conditional on Transition Timing, Land Productivity, and Continental Fixed Effects
Figure 7
Figure 7
Adjusted Genetic Diversity and Income Per Capita in 2000 CE – The Unconditional Relationship
Figure 8
Figure 8
Adjusted Genetic Diversity and Income Per Capita in 2000 CE – Conditional on Transition Timing, Land Productivity, Institutional and Geographical Determinants, and Continental Fixed Effects
Figure A.1
Figure A.1
Predicted Genetic Diversity and Population Density in 1000 CE – Conditional on Transition Timing, Land Productivity, and Continental Fixed Effects
Figure A.2
Figure A.2
Predicted Genetic Diversity and Population Density in 1 CE – Conditional on Transition Timing, Land Productivity, and Continental Fixed Effects
Figure B.1
Figure B.1
Pairwise Fst Genetic and Migratory Distances in the HGDP-CEPH Sample
Figure C.1
Figure C.1
Observed Genetic Diversity and Population Density in 1500 CE – Cubic Spline vs. Quadratic Fit
Figure C.2
Figure C.2
Predicted Genetic Diversity and Population Density in 1500 CE – Cubic Spline vs. Quadratic Fit
Figure C.3
Figure C.3
The First- and Second-Order Partial Effects of Predicted Diversity on Population Density in 1500 CE – Conditional on Transition Timing, Land Productivity, and Continental Fixed Effects
Figure C.4
Figure C.4
Adjusted Genetic Diversity and Income Per Capita in 2000 CE – Cubic Spline vs. Quadratic Fit
Figure C.5
Figure C.5
The First- and Second-Order Partial Effects of Adjusted Diversity on Income Per Capita in 2000 CE – Conditional on Transition Timing, Land Productivity, Institutional and Geographical Determinants, and Continental Fixed Effects
Figure C.6
Figure C.6
Ancestry-Adjusted Migratory Distance and Some Mean Physiological Characteristics of Contemporary National Populations
Figure H.1
Figure H.1
Thermoregulation in Genetically Uniform vs. Diverse Honeybee Colonies (Source: Jones et al., 2004)
Figure H.2
Figure H.2
Comb Area Growth in Genetically Uniform vs. Diverse Honeybee Colonies (Source: Mattila and Seeley, 2007)
Figure H.3
Figure H.3
Foraging Rates in Genetically Uniform vs. Diverse Honeybee Colonies (Source: Mattila and Seeley, 2007)
Figure H.4
Figure H.4
Preferential Bias of Cooperation with Kin in the Long-Tailed Tit (Source: Russell and Hatchwell, 2001)
Figure H.5
Figure H.5
Kin Discrimination and the Indirect Fitness Benefit from Cooperation (Source: Griffin and West, 2003)
Figure H.6
Figure H.6
Weight Growth in Kin vs. Non-kin Groups of Cooperatively Feeding Spiders (Source: Schneider and Bilde, 2008)
Figure H.7
Figure H.7
Feeding Efficiency in Kin vs. Non-kin Groups of Cooperatively Feeding Spiders (Source: Schneider and Bilde, 2008)
See this image and copyright information in PMC

References

    1. Acemoglu Daron, Johnson Simon, Robinson James A. Institutions as a Fundamental Cause of Long-Run Growth. In: Aghion Philippe, Durlauf Steven N., editors. Handbook of Economic Growth, Vol IA. Elsevier North-Holland; Amsterdam, The Netherlands: 2005.
    1. Alesina Alberto, La Ferrara Eliana. Ethnic Diversity and Economic Performance. Journal of Economic Literature. 2005 Sep;43(3):762–800.
    1. Alesina Alberto, Devleeschauwer Arnaud, Easterly William, Kurlat Sergio, Wacziarg Romain. Fractionalization. Journal of Economic Growth. 2003 Jun;8(2):155–194.
    1. Ashraf Quamrul, Galor Oded. Dynamics and Stagnation in the Malthusian Epoch; Working Paper, Department of Economics, Williams College; 2010. - PubMed
    1. Ashraf Quamrul, Galor Oded, Özak Ömer. Isolation and Development. Journal of the European Economic Association. 2010 Apr-May;8(2-3):401–412.

Additional Works Cited

    1. Barro Robert J., Lee Jong-Wha. International Data on Educational Attainment: Updates and Implications. Oxford Economic Papers. 2001 Jul;53(3):541–563.
    1. Chandler Tertius. Four Thousand Years of Urban Growth: An Historical Census. The Edwin Mellen Press; Lewiston, NY: 1987.
    1. Darwin Charles. On the Origin of Species by Means of Natural Selection. John Murray; London, UK: 1859.
    1. Frankham Richard, Lees Kelly, Montgomery Margaret E., England Phillip R., Lowe Edwin H., Briscoe David A. Do Population Size Bottlenecks Reduce Evolutionary Potential? Animal Conservation. 1999 Nov;2(4):255–260.
    1. Griffin Ashleigh S., West Stuart A. Kin Discrimination and the Benefit of Helping in Cooperatively Breeding Vertebrates. Science. 2003 Oct;302(5645):634–636. - PubMed

LinkOut - more resources