scholarly journals The evolutionary history of Neandertal and Denisovan Y chromosomes

2020 ◽  
Author(s):  
Martin Petr ◽  
Mateja Hajdinjak ◽  
Qiaomei Fu ◽  
Elena Essel ◽  
Hélène Rougier ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Evolutionary History ◽  
Genetic Load ◽  
Modern Human ◽  
Gene Pools ◽  
Human History ◽  
Effective Population ◽  
Modern Humans ◽  
Y Chromosomes ◽  
History Of

AbstractAncient DNA has allowed the study of various aspects of human history in unprecedented detail. However, because the majority of archaic human specimens preserved well enough for genome sequencing have been female, comprehensive studies of Y chromosomes of Denisovans and Neandertals have not yet been possible. Here we present sequences of the first Denisovan Y chromosomes (Denisova 4 and Denisova 8), as well as the Y chromosomes of three late Neandertals (Spy 94a, Mezmaiskaya 2 and El Sidrón 1253). We find that the Denisovan Y chromosomes split around 700 thousand years ago (kya) from a lineage shared by Neandertal and modern human Y chromosomes, which diverged from each other around 370 kya. The phylogenetic relationships of archaic and modern human Y chromosomes therefore differ from population relationships inferred from their autosomal genomes, and mirror the relationships observed on the level of mitochondrial DNA. This provides strong evidence that gene flow from an early lineage related to modern humans resulted in the replacement of both the mitochondrial and Y chromosomal gene pools in late Neandertals. Although unlikely under neutrality, we show that this replacement is plausible if the low effective population size of Neandertals resulted in an increased genetic load in their Y chromosomes and mitochondrial DNA relative to modern humans.

scholarly journals The evolutionary history of Neanderthal and Denisovan Y chromosomes

Science ◽  
2020 ◽  
Vol 369 (6511) ◽  
pp. 1653-1656 ◽  
Author(s):  
Martin Petr ◽  
Mateja Hajdinjak ◽  
Qiaomei Fu ◽  
Elena Essel ◽  
Hélène Rougier ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Evolutionary History ◽  
Genetic Load ◽  
Modern Human ◽  
Gene Pools ◽  
Chromosomal Gene ◽  
Human History ◽  
Effective Population ◽  
Y Chromosomes ◽  
History Of

Ancient DNA has provided new insights into many aspects of human history. However, we lack comprehensive studies of the Y chromosomes of Denisovans and Neanderthals because the majority of specimens that have been sequenced to sufficient coverage are female. Sequencing Y chromosomes from two Denisovans and three Neanderthals shows that the Y chromosomes of Denisovans split around 700 thousand years ago from a lineage shared by Neanderthals and modern human Y chromosomes, which diverged from each other around 370 thousand years ago. The phylogenetic relationships of archaic and modern human Y chromosomes differ from the population relationships inferred from the autosomal genomes and mirror mitochondrial DNA phylogenies, indicating replacement of both the mitochondrial and Y chromosomal gene pools in late Neanderthals. This replacement is plausible if the low effective population size of Neanderthals resulted in an increased genetic load in Neanderthals relative to modern humans.

scholarly journals Model-based detection and analysis of introgressed Neanderthal ancestry in modern humans

2017 ◽  
Author(s):  
Matthias Steinrücken ◽  
Jeffrey P. Spence ◽  
John A. Kamm ◽  
Emilia Wieczorek ◽  
Yun S. Song
Keyword(s):  
Genetic Material ◽  
Genetic Load ◽  
Modern Human ◽  
Human Populations ◽  
Effective Population ◽  
Weak Selection ◽  
Modern Humans ◽  
High Coverage ◽  
Model Based ◽  
And Migration

AbstractGenetic evidence has revealed that the ancestors of modern human populations outside of Africa and their hominin sister groups, notably the Neanderthals, exchanged genetic material in the past. The distribution of these introgressed sequence-tracts along modern-day human genomes provides insight into the ancient structure and migration patterns of these archaic populations. Furthermore, it facilitates studying the selective processes that lead to the accumulation or depletion of introgressed genetic variation. Recent studies have developed methods to localize these introgressed regions, reporting long regions that are depleted of Neanderthal introgression and enriched in genes, suggesting negative selection against the Neanderthal variants. On the other hand, enriched Neanderthal ancestry in hair- and skin-related genes suggests that some introgressed variants facilitated adaptation to new environments. Here, we present a model-based method called diCal-admix and apply it to detect tracts of Neanderthal introgression in modern humans. We demonstrate its efficiency and accuracy through extensive simulations. We use our method to detect introgressed regions in modern human individuals from the 1000 Genomes Project, using a high coverage genome from a Neanderthal individual from the Altai mountains as reference. Our introgression detection results and findings concerning their functional implications are largely concordant with previous studies, and are consistent with weak selection against Neanderthal ancestry. We find some evidence that selection against Neanderthal ancestry was due to higher genetic load in Neanderthals, resulting from small effective population size, rather than Dobzhansky-Müller incompatibilities. Finally, we investigate the role of the X-chromosome in the divergence between Neanderthals and modern humans.

scholarly journals The evolutionary history of human spindle genes includes back-and-forth gene flow with Neandertals

2021 ◽  
Author(s):  
Stéphane Peyrégne ◽  
Janet Kelso ◽  
Benjamin Marco Peter ◽  
Svante Pääbo
Keyword(s):  
Gene Flow ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Modern Human ◽  
Modern Humans ◽  
Ancestral Gene ◽  
Cytoskeletal Structure ◽  
Spindle Apparatus ◽  
History Of ◽  
Segregation Of Chromosomes

Proteins associated with the spindle apparatus, a cytoskeletal structure that ensures the proper segregation of chromosomes during cell division, experienced an unusual number of amino acid substitutions in modern humans after the split from the ancestors of Neandertals and Denisovans. Here, we analyze the history of these substitutions and show that some of the genes in which they occur may have been targets of positive selection. We also find that the two changes in the kinetochore scaffold 1 (KNL1) protein, previously believed to be specific to modern humans, were present in some Neandertals. We show that the KNL1 gene of these Neandertals shared a common ancestor with present-day Africans about 200,000 years ago due to gene flow from the ancestors (or relatives) of modern humans into Neandertals. Subsequently, some non-Africans inherited this modern human-like gene variant from Neandertals, but none inherited the ancestral gene variants. These results add to the growing evidence of early contacts between modern humans and archaic groups in Eurasia and illustrate the intricate relationships among these groups.

scholarly journals Molecular evolutionary analysis of human primary microcephaly genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nashaiman Pervaiz ◽  
Hongen Kang ◽  
Yiming Bao ◽  
Amir Ali Abbasi
Keyword(s):  
Evolutionary History ◽  
Genetic Basis ◽  
Brain Size ◽  
Primate Species ◽  
Evolutionary Analysis ◽  
Australopithecus Afarensis ◽  
Primary Microcephaly ◽  
Modern Humans ◽  
History Of ◽  
The Brain

Abstract Background There has been a rapid increase in the brain size relative to body size during mammalian evolutionary history. In particular, the enlarged and globular brain is the most distinctive anatomical feature of modern humans that set us apart from other extinct and extant primate species. Genetic basis of large brain size in modern humans has largely remained enigmatic. Genes associated with the pathological reduction of brain size (primary microcephaly-MCPH) have the characteristics and functions to be considered ideal candidates to unravel the genetic basis of evolutionary enlargement of human brain size. For instance, the brain size of microcephaly patients is similar to the brain size of Pan troglodyte and the very early hominids like the Sahelanthropus tchadensis and Australopithecus afarensis. Results The present study investigates the molecular evolutionary history of subset of autosomal recessive primary microcephaly (MCPH) genes; CEP135, ZNF335, PHC1, SASS6, CDK6, MFSD2A, CIT, and KIF14 across 48 mammalian species. Codon based substitutions site analysis indicated that ZNF335, SASS6, CIT, and KIF14 have experienced positive selection in eutherian evolutionary history. Estimation of divergent selection pressure revealed that almost all of the MCPH genes analyzed in the present study have maintained their functions throughout the history of placental mammals. Contrary to our expectations, human-specific adoptive evolution was not detected for any of the MCPH genes analyzed in the present study. Conclusion Based on these data it can be inferred that protein-coding sequence of MCPH genes might not be the sole determinant of increase in relative brain size during primate evolutionary history.

scholarly journals Mitochondrial DNA Diversity of Modern, Ancient and Wild Sheep (Ovis gmelinii anatolica) from Turkey: New Insights on the Evolutionary History of Sheep

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e81952 ◽  
Author(s):  
Sevgin Demirci ◽  
Evren Koban Baştanlar ◽  
Nihan Dilşad Dağtaş ◽  
Evangelia Pişkin ◽  
Atilla Engin ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Evolutionary History ◽  
Dna Diversity ◽  
History Of ◽  
Wild Sheep

scholarly journals Phylogeography of the California Thrasher (Toxostoma Redivivum) Based on Nested-Clade Analysis of Mitochondrial-DNA Variation

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 346-361
Author(s):  
Erik A. Sgariglia ◽  
Kevin J. Burns
Keyword(s):  
Mitochondrial Dna ◽  
Range Expansion ◽  
Evolutionary History ◽  
Isolation By Distance ◽  
Nested Clade Analysis ◽  
Dna Variation ◽  
History Of ◽  
Past Fragmentation ◽  
Intraspecific Relationships ◽  
Geologic Data

Abstract Distribution of genealogical lineages within a species is likely the result of a complicated series of ecological and historical events. Nested-clade analysis is specifically designed as an objective phylogeographic approach for inferring evolutionary processes on a spatial and temporal scale for small subclades within a larger set of intraspecific relationships. Here, we use nested-clade analysis as well as other phylogeographic methods to investigate the evolutionary history of California Thrasher (Toxostoma redivivum) populations. Inferences resulting from nested clade analysis suggest a history that includes past fragmentation, range expansion, and isolation-by-distance. Along with root information, those inferences enable the construction of a biogeographic scenario for this species involving general southern ancestry, an early north–south division, northward range expansion, and a southward back-expansion into an already populated southern region. Isolation-by-distance is also identified, particularly in southern California, indicating that gene flow between localities does occur but is restricted. Many conclusions drawn from this study are concordant with geologic data as well as phylogeographic scenarios drawn for other codistributed California taxa.

scholarly journals Archaic mitochondrial DNA inserts in modern day nuclear genomes

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Robert Bücking ◽  
Murray P Cox ◽  
Georgi Hudjashov ◽  
Lauri Saag ◽  
Herawati Sudoyo ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Modern Human ◽  
Sub Saharan Africa ◽  
Next Generation Sequencing Data ◽  
Human Populations ◽  
Sequencing Data ◽  
Modern Humans ◽  
High Coverage ◽  
Nuclear Genomes

Abstract Background Traces of interbreeding of Neanderthals and Denisovans with modern humans in the form of archaic DNA have been detected in the genomes of present-day human populations outside sub-Saharan Africa. Up to now, only nuclear archaic DNA has been detected in modern humans; we therefore attempted to identify archaic mitochondrial DNA (mtDNA) residing in modern human nuclear genomes as nuclear inserts of mitochondrial DNA (NUMTs). Results We analysed 221 high-coverage genomes from Oceania and Indonesia using an approach which identifies reads that map both to the nuclear and mitochondrial DNA. We then classified reads according to the source of the mtDNA, and found one NUMT of Denisovan mtDNA origin, present in 15 analysed genomes; analysis of the flanking region suggests that this insertion is more likely to have happened in a Denisovan individual and introgressed into modern humans with the Denisovan nuclear DNA, rather than in a descendant of a Denisovan female and a modern human male. Conclusions Here we present our pipeline for detecting introgressed NUMTs in next generation sequencing data that can be used on genomes sequenced in the future. Further discovery of such archaic NUMTs in modern humans can be used to detect interbreeding between archaic and modern humans and can reveal new insights into the nature of such interbreeding events.

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