Almost 20 years of Neanderthal palaeogenetics: adaptation, admixture, diversity, demography and extinction

Sánchez-Quinto, Federico; Lalueza-Fox, Carles

doi:10.1098/rstb.2013.0374

Cited by 43 publications

(25 citation statements)

References 71 publications

(129 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, polar bear alleles could conceivably be found in many locations across the brown bear range. This would resemble the findings from humans, where introgressed Neanderthal and Denisovan alleles have been dispersed across large distances (Sánchez‐Quinto & Lalueza‐Fox ).…”

Section: The Baseline Problem: How Can We Be Certain That the Admixtusupporting

confidence: 77%

Introgressive hybridization: brown bears as vectors for polar bear alleles

Hailer

2015

Molecular Ecology

View full text Add to dashboard Cite

The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach.

show abstract

Section: The Baseline Problem: How Can We Be Certain That the Admixtusupporting

confidence: 77%

Introgressive hybridization: brown bears as vectors for polar bear alleles

Hailer

2015

Molecular Ecology

View full text Add to dashboard Cite

show abstract

“…According to Suarez, prevalence of inbreeding is probably the main cause of high fluctuating asymmetry in Neanderthals. Recent evidence of low genetic variation in Neanderthals is consistent with this hypothesis [226,227]. Doyle and Johnson [228], however, compared dental asymmetry of Pueblo and Eskimo populations, in which inbreeding was not widespread, to that of Neanderthals.…”

Section: Fossil Hominidsmentioning

confidence: 59%

Fluctuating Asymmetry of Human Populations: A Review

Graham

Özener

2016

Symmetry

View full text Add to dashboard Cite

Fluctuating asymmetry, the random deviation from perfect symmetry, is a widely used population-level index of developmental instability, developmental noise, and robustness. It reflects a population's state of adaptation and genomic coadaptation. Here, we review the literature on fluctuating asymmetry of human populations. The most widely used bilateral traits include skeletal, dental, and facial dimensions; dermatoglyphic patterns and ridge counts; and facial shape. Each trait has its advantages and disadvantages, but results are most robust when multiple traits are combined into a composite index of fluctuating asymmetry (CFA). Both environmental (diet, climate, toxins) and genetic (aneuploidy, heterozygosity, inbreeding) stressors have been linked to population-level variation in fluctuating asymmetry. In general, these stressors increase average fluctuating asymmetry. Nevertheless, there have been many conflicting results, in part because (1) fluctuating asymmetry is a weak signal in a sea of noise; and (2) studies of human fluctuating asymmetry have not always followed best practices. The most serious concerns are insensitive asymmetry indices (correlation coefficient and coefficient of indetermination), inappropriate size scaling, unrecognized mixture distributions, inappropriate corrections for directional asymmetry, failure to use composite indices, and inattention to measurement error. Consequently, it is often difficult (or impossible) to compare results across traits, and across studies.

show abstract

“…The appearance of new taxa-speciation-and the extinction of existing ones are all significant transitions in human evolution, ones where microevolutionary processes accumulate sufficiently across geographically structured groups for independent lineages to evolve and die out. Recent findings through ancient DNA approaches have shown that there may, at least in the recent past, have been reproductive interactions between such lineages [63,64], but these are not the primary drivers of phenotypes and behaviours-indeed, they are identifiable because they are such brief events. The key finding is that speciation occurs throughout human evolution, and is not confined to specific periods, suggesting a complex and cumulative pattern of change.…”

Section: A Major Transition Is As Much About What Is Missing As What mentioning

confidence: 99%

Mosaic evolution and the pattern of transitions in the hominin lineage

Foley¹

2016

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

One contribution of 17 to a discussion meeting issue 'Major transitions in human evolution'.Subject Areas: evolution, palaeontology, behaviour Keywords: human evolution, mosaic evolution, major transitions, human evolutionary ecology, hominins, tempo and mode of evolution Humans are uniquely unique, in terms of the extreme differences between them and other living organisms, and the impact they are having on the biosphere. The evolution of humans can be seen, as has been proposed, as one of the major transitions in evolution, on a par with the origins of multicellular organisms or the eukaryotic cell (Maynard Smith & Szathmáry 1997 Major transitions in evolution). Major transitions require the evolution of greater complexity and the emergence of new evolutionary levels or processes. Does human evolution meet these conditions? I explore the diversity of evidence on the nature of transitions in human evolution. Four levels of transition are proposed-baseline, novel taxa, novel adaptive zones and major transitions-and the pattern of human evolution considered in the light of these. The primary conclusions are that changes in human evolution occur continuously and cumulatively; that novel taxa and the appearance of new adaptations are not clustered very tightly in particular periods, although there are three broad transitional phases (Pliocene, Plio-Pleistocene and later Quaternary). Each phase is distinctive, with the first based on ranging and energetics, the second on technology and niche expansion, and the third on cognition and cultural processes. I discuss whether this constitutes a 'major transition' in the context of the evolutionary processes more broadly; the role of behaviour in evolution; and the opportunity provided by the rich genetic, phenotypic (fossil morphology) and behavioural (archaeological) record to examine in detail major transitions and the microevolutionary patterns underlying macroevolutionary change. It is suggested that the evolution of the hominin lineage is consistent with a mosaic pattern of change.This article is part of the themed issue 'Major transitions in human evolution'.

show abstract

Almost 20 years of Neanderthal palaeogenetics: adaptation, admixture, diversity, demography and extinction

Cited by 43 publications

References 71 publications

Introgressive hybridization: brown bears as vectors for polar bear alleles

Introgressive hybridization: brown bears as vectors for polar bear alleles

Fluctuating Asymmetry of Human Populations: A Review

Mosaic evolution and the pattern of transitions in the hominin lineage

Contact Info

Product

Resources

About