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Updated: Jul 15, 2026
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Preparation and Gene Modification of Nonhuman Primate Hematopoietic Stem and Progenitor Cells
Published on: February 15, 2019
More genes underwent positive selection in chimpanzee evolution than in human evolution.
Margaret A Bakewell1, Peng Shi, Jianzhi Zhang
1Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Summary
Human evolution shows fewer positively selected genes than chimpanzee evolution, contrary to common belief. This suggests natural selection
Area of Science:
- Evolutionary Biology
- Genomics
- Comparative Genomics
Background:
- Human evolution is marked by significant phenotypic changes, leading to the assumption of greater positive Darwinian selection in humans compared to chimpanzees.
- Understanding the genetic basis of human and chimpanzee divergence is crucial for comprehending evolutionary adaptations.
Purpose of the Study:
- To quantitatively compare the number of genes that have undergone positive Darwinian selection in the human and chimpanzee lineages since their divergence.
- To investigate the factors influencing the efficacy of natural selection in humans and chimpanzees.
- To explore the functional and biological differences in genes under positive selection in both species.
Main Methods:
- Analysis of nearly 14,000 genes in humans and chimpanzees.
- Utilized a proper outgroup for accurate evolutionary comparisons.
- Employed rigorous methods to avoid sequencing errors and verify statistical analyses.
Main Results:
- The number of genes under positive selection is significantly lower in humans than in chimpanzees, despite a higher overall non-synonymous substitution rate in humans.
- Reduced efficacy of natural selection in humans, potentially due to a smaller long-term effective population size, explains these findings.
- Positively selected genes in humans and chimpanzees exhibit distinct molecular functions and biological processes, but these differences do not clearly align with assumed species-specific adaptations.
Conclusions:
- The study refutes the notion that enhanced Darwinian selection is the primary driver of human origins.
- Findings suggest a complex interplay between population size and selection efficacy in shaping evolutionary trajectories.
- The identified genes support links between human diseases and past adaptations but do not validate specific hypotheses on human origins like chromosomal speciation or widespread brain-gene acceleration.
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