Trends in Cell Biology
ReviewHuman evolution
Section snippets
Origins of human genetic variation
The questions of when and where our species originated might seem quite straightforward, but, in fact, the definition of the origin of a species is not trivial. However, from a molecular-genetic perspective, it is clear that the DNA sequences found in contemporary individuals have been passed down to them from previous generations. It is also clear that, in every generation, some DNA sequences are not passed on because some individuals have no children or the sequence fails to be transmitted
Ancient DNA
How does the picture of our ancestry described above fit with the picture of human origins provided by paleontology? Here, we run into the problem that, while geneticists specialize in studying the genes in people that exist today, which thus are bound to have had ancestors in the past, paleontologists study fossils that might not have descendants. A potentially valuable approach to resolve this problem would be to study DNA sequences from fossils, as this would allow direct inference of the
Human traits
The human gene pool is, in general, very mixed, whereas some phenotypic traits show a distribution that seems to vary with geography in a systematic way, such as skin colour, facial features, hair texture and aspects of the digestion of foods. One striking observation is that such traits are located at places where our bodies interact directly with the environment. Therefore, it is easy to imagine that selection could have shaped these differences in a relatively short time, particularly if
What makes us human?
A number of abilities set us apart from other species on this planet. Perhaps the most notable among these are cognitive skills, such as the use of a complex language, long-term planning and an advanced ability to give and receive instructions. These features, which together are generally used to define us as human, emerged in an ancestral species after our lineages diverged from its closest living relatives – the African apes. It would seem that the identification of the genetic differences
Concluding remarks
For the first of the three areas discussed here, the origins of genetic variation in humans, it is clear that many more worldwide studies of genetic variation at different loci are needed. This work is likely to be performed in the near future, not least because it will be of great importance for finding genes that are involved in complex traits. Hopefully, it will be performed in a coordinated way, such that the data will be compiled and compared rationally. However, an all-out sequencing
Acknowledgements
I am greatly indebted to T. Baumgärtel, I. Ebersberger, W. Enard, H. Kaessmann, A. Stone, M. Stoneking and L. Vigilant for comments on drafts of this manuscript. Our work is supported by the DFG, the MPG and the BMBF.
References (27)
Haplotype structure and population-genetics inferences from nucleotide-sequence variation in human lipoprotein lipase
Am. J. Hum. Genet.
(1998)Ancient DNA and the polymerase chain reaction: the emerging field of molecular archaeology
J. Biol. Chem.
(1989)Neandertal DNA sequences and the origin of modern humans
Cell
(1997)On the probability of Neanderthal ancestry
Am. J. Hum. Genet.
(1998)- et al.
Molecular definition of pericentric inversion breakpoints occurring during the evolution of humans and chimpanzees
Genomics
(1998) The genetical archaeology of the human genome
Nat. Genet.
(1996)- et al.
The role of the Y chromosome in human evolutionary studies
Evol. Anthropol.
(1996) Archaic African and Asian lineages in the genetic ancestry of modern humans
Am. J. Hum. Genet.
(1997)DNA sequence diversity in a 9.7 kb region of the human lipoprotein lipase gene
Nat. Genet.
(1998)- et al.
X chromosome evidence for ancient human histories
Proc. Natl. Acad. Sci. U. S. A.
(1999)
Sequence variation in the human angiotensin converting enzyme
Nat. Genet.
DNA sequence variation in a non-coding region of low recombination on the human X chromosome
Nat. Genet.
The molecular descent of the major histocompatibility complex
Annu. Rev. Immunol.
Cited by (26)
A Complete Neandertal Mitochondrial Genome Sequence Determined by High-Throughput Sequencing
2008, CellCitation Excerpt :A genome-wide analysis of human and Neandertal genes holds the promise to identify many such cases for nuclear genes. However, whereas the mtDNAs of extant humans are monophyletic with respect to Neandertals, this is not expected to be the case for most nuclear genes (Pääbo, 1999). This fact will be helpful for the identification of recent positive selection in humans.
The Derived FOXP2 Variant of Modern Humans Was Shared with Neandertals
2007, Current BiologyCitation Excerpt :The retrieval of nuclear DNA sequences from ancient remains by the polymerase chain reaction (PCR) is fraught with difficulty, primarily because most remains contain extremely low quantities of endogenous DNA. An additional problem when Neandertal remains are studied is that modern human DNA is a frequent contaminant of ancient remains and laboratory reagents [6] and that most human DNA sequences cannot be distinguished from Neandertal sequences [7]. Thus, in addition to designing six primers that in four combinations amplify the nucleotide positions 911 and 977 (Figure 1), we designed three types of controls in order to as far as possible ensure the authenticity of our results.
DNA sequence variation in a 3.7-kb noncoding sequence 5′ of the CYP1A2 gene: Implications for human population history and natural selection
2002, American Journal of Human GeneticsCitation Excerpt :Additional evidence for an African origin is provided by the geographical distribution of haplotypes: haplotypes found outside Africa are mostly a subset of those found within Africa. This pattern has been observed in a number of other studies (Tishkoff et al. 1996, 2000; Calafell et al. 1997; Hammer et al. 1997; Watson et al. 1997; Alonso and Armour 2001) and agrees with a scenario in which some African populations left the continent to populate the rest of the Old World (Jorde et al. 1998; Pääbo 1999; Yu et al. 2002). The linkage-disequilibrium patterns seen in this study are in agreement with a number of other studies that have found less linkage disequilibrium in African than in non-African populations (Tishkoff et al. 1996, 1998, 2000; K. K. Kidd et al. 1998; J. R. Kidd et al. 2000; Reich et al. 2001).
Genetic differences between humans and great apes
2001, Molecular Phylogenetics and EvolutionN-glycolylneuraminic acid deficiency in humans
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