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Autosomal STR analyses in native Amazonian tribes suggest a population structure driven by isolation by distance
Sidney E B Dos Santos1, Elzemar M Ribeiro-Rodrigues, Andrea K C Ribeiro-Dos-Santos
1Laboratório de Genética Humana e Médica, Departamento de Patologia, Centro de Ciências Biológicas, Universidade Federal do Paráa, Belém, Brazil.
Human Biology
|July 11, 2009
Summary
Genetic diversity in Amazonian native tribes is lower than in European or African populations, with variation explained by isolation by distance rather than geographic or linguistic barriers.
Area of Science:
- Population Genetics
- Anthropology
- Human Evolution
Background:
- Amazonian native populations exhibit unique genetic profiles.
- Understanding gene flow barriers is crucial for anthropological insights.
Purpose of the Study:
- Investigate genetic diversity and gene flow among Amazonian tribes.
- Determine the influence of geographic and linguistic factors on genetic structure.
- Explore anthropological explanations for observed genetic patterns.
Main Methods:
- Genotyping of eleven short tandem repeat loci in 526 individuals from ten Amazonian tribes.
- Analysis of molecular variance (AMOVA) and Bayesian Structure analysis.
- Geographic autocorrelation analysis to assess isolation by distance.
Main Results:
- Lower average heterozygosity (H) and number of alleles (N(A)) compared to non-Amazonian populations.
- High between-population genetic variation observed.
- No significant geographic or linguistic barriers to gene flow detected.
- Genetic structure explained by isolation by distance up to 300 km.
Conclusions:
- Genetic diversity in Amazonian tribes is shaped by isolation and distance, not major linguistic or geographic barriers.
- Recent contact with non-native populations may correlate with lower genetic diversity in some tribes.
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