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Probability, Populations, Phylogenetics And Hominin Speciation, Niccolo Caldararo

Human Biology Open Access Pre-Prints

A number of recent articles have appeared on the hominin Denisova fossil remains. Many of them focus on attempts to produce DNA sequences from the extracted samples. Often these project mtDNA sequences from the fossil remains of a number of Neandertal fossils and the Denisovans in an attempt to understand the evolution of Mid Pleistocene human ancestors. These papers, introduce a number of problems in the interpretation of speciation in hominins. One concerns the degradation of the ancient DNA and its interpretation as authentic genetic information. Another concerns the idea of “species” versus that of “population” and the use of …

Neanderthal And Woolly Mammoth Molecular Resemblance: Genetic Similarities Might Underlie Cold Adaptation Suite, Meidad Kislev, Ran Barkai

Human Biology Open Access Pre-Prints

With the ongoing growth of gene-based research in recent decades, the possibility of examining changes that have taken place in structures over the course of evolution has become increasingly accessible. One intriguing subject at the forefront of evolutionary research is that of how environmental pressures affect species evolution through epigenetic adaptation. In this paper we present the available molecular components of adaptation to cold environments in two extinct mammals – the woolly mammoth and the Neanderthal. These two species co-existed in similar geographic and environmental European settings during the Middle and Upper Pleistocene and both were direct descendants of African …

Infectious Disease And The Diversification Of The Human Genome, Jessica F. Brinkworth

Human Biology Open Access Pre-Prints

The human immune system is under great pathogen-mediated selective pressure. A combination of divergent infectious disease pathogenesis across human populations, and the overrepresentation of “immune genes” in genomic regions with signatures of positive selection suggests that pathogens have significantly altered the human genome. However, important features of the human immune system can confound searches for and interpretations of signatures of pathogen-mediated evolution. Immune system redundancy, immune gene pleiotropy, host ability to acquire immunity and alter the immune repertoire of their offspring through “priming”, and host microbiome complicate evolutionary interpretations of host- pathogen interactions. The overall promiscuity and sensitivity of the …

Evolution And Otitis Media: A Review, And A Model To Explain High Prevalence In Indigenous Populations, Mahmood F. Bhutta

Human Biology Open Access Pre-Prints

Inflammation of the middle ear (otitis media) comprises a group of disorders that are highly prevalent in childhood, and indeed are amongst the most common disorders of childhood. Otitis media is also heritable, and has effects on fecundity. This means that otitis media is subject to evolution, yet the evolutionary selection forces that may determine susceptibility to otitis media have never been adequately explored.

Here I undertake a critical analysis of evolutionary forces that may determine susceptibility to middle ear inflammation. These forces include those determining function of the middle ear, those affecting host immunity, and those affecting colonization by, …

Low Mitochondrial Dna Diversity In An Ancient Population From China: Insight, Yu Dong, Chunxiang Li, Fengshi Luan, Zhenguang Li, Hongjie Li, Yinqiu Cui, Hui Zhou, Ripan S. Malhi

Human Biology Open Access Pre-Prints

To gain insight into the social organization of a population associated with the Dawenkou period, ancient DNA analysis of 18 individuals from human remains from Fujia site, Shandong Province, China was completed. Directly radiocarbon dated to 4800–4500 cal BP, the Fujia site is assumed to be associated with a transitional phase from matrilineal clans to patrilineal monogamous families. Our results reveal a low mitochondrial DNA diversity from the site and population. Combined with Y-chromosome data, the pattern observed at the Fujia site is most consistent with a matrilineal community. The patterns also suggest that the bond of marriage were de-emphasized …

A Homogenizing Process Of Selection Has Maintained An 'Ultra-Slow' Acetylation Nat2 Variant In Humans, Blandine Patillon, Pierre Luisi, Estella S. Poloni, Sotiria Boukouvala, Pierre Darlu, E. Genin, Audrey Sabbagh

Human Biology Open Access Pre-Prints

N-acetyltransferase 2 (NAT2) is an important enzyme involved in the metabolism of a wide spectrum of naturally occurring xenobiotics, including therapeutic drugs and common environmental carcinogens. Extensive polymorphism in NAT2 gives rise to a wide interindividual variation in acetylation capacity which influences individual susceptibility to various drug-induced adverse reactions and cancers. Striking patterns of geographic differentiation have been described for the main slow acetylation variants of the NAT2 gene, suggesting the action of natural selection at this locus. In the present study, we took advantage of the whole-genome sequence data available from the 1000 Genomes project to investigate the …

Celiac Disease As A Model For The Evolution Of Multifactorial Disease In Humans, Aaron Sams, John Hawks

Human Biology Open Access Pre-Prints

Celiac disease (CD) is a multifactorial chronic inflammatory condition that results in injury of the mucosal lining of the small intestine upon ingestion of wheat gluten and related proteins from barley and rye. Although the exact mechanisms leading to CD are not fully understood, the genetic basis of CD has been relatively well characterized. In this review we briefly review the history of discovery, clinical presentation, pathophysiology, and current understanding of the genetics underlying CD risk. Then, we discuss what is known about the current distribution and evolutionary history of genes underlying CD risk in light of other evolutionary models …

Using The Neandertal And Denisova Genetic Data To Understand The Common Mapt 17q21 Inversion In Modern Humans, Núria Setó-Salvia, Federico Sánchez-Quinto, Eudald Carbonell, Carlos Lorenzo, David Comas, Jordi Clarimón

Human Biology Open Access Pre-Prints

The polymorphic inversion on 17q21, that includes the MAPT gene, represents a unique locus in the human genome characterized by a large region with strong linkage disequilibrium. Two distinct haplotypes, H1 and H2, exist in modern humans, and H1 has been unequivocally related to several neurodegenerative disorders. Recent data indicates that recurrent inversions of this genomic region have occurred through primate evolution, with the H2 haplotype being the ancestral state. Neandertals harbored the H1 haplotype, however until now no data was available for the Denisova hominin. Neandertals and Denisovans are sister groups that share a common ancestor with modern humans. …

Human Alu Insertion Polymorphisms In North African Populations, Lotfi Cherni, Sabeh Frigi, Hajer Ennafaa, Nabil Mtiraoui, Touhami Mahjoub, Amel Benammar-Elgaaied

Human Biology Open Access Pre-Prints

Several features make Alu insertions a powerful tool used in population genetic studies: the polymorphic nature of many Alu insertions, the stability of an Alu insertion event and, furthermore, the ancestral state of an Alu insertion is known to be the absence of the Alu element at a particular locus and the presence of an Alu insertion at the site that forward mutational change. This study analyses seven Alu insertion polymorphisms in a sample of 297 individuals from the autochthonous population of Tunisia (Thala, Smar, Zarzis and Bou Salem) and Libya with the aim of studying their genetic structure with …

Primate Phylogenomics: Developing Numerous Nuclear Non-Coding, Non-Repetitive Markers For Ecological And Phylogenetic Applications And Analysis Of Evolutionary Rate Variation, Zuogang Peng, Navin Elango, Derek E. Wildman, Soojin V. Yi

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Genetic analyses are often limited by the availability of appropriate molecular markers. Markers from neutrally evolving genomic regions may be particularly useful for inferring evolutionary histories because they escape the constraints of natural selection. For the majority of taxa however, obtaining such markers is challenging. Advances in genomics have the potential to alleviate the shortage of neutral markers. Here we present a method to develop numerous markers from putatively neutral regions of primate genomes.

Results

We began with the available whole genome sequences of human, chimpanzee and macaque. Using computational methods, we identified a total of 280 potential …

Molecular Evolution Of The Cytochrome C Oxidase Subunit 5a Gene In Primates, Monica Uddin, Juan C. Opazo, Derek E. Wildman, Chet C. Sherwood, Patrick R. Hof, Morris Goodman, Lawrence I. Grossman

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Many electron transport chain (ETC) genes show accelerated rates of nonsynonymous nucleotide substitutions in anthropoid primate lineages, yet in non-anthropoid lineages the ETC proteins are typically highly conserved. Here, we test the hypothesis that COX5A, the ETC gene that encodes cytochrome c oxidase subunit 5A, shows a pattern of anthropoid-specific adaptive evolution, and investigate the distribution of this protein in catarrhine brains.

Results

In a dataset comprising 29 vertebrate taxa, including representatives from all major groups of primates, there is nearly 100% conservation of the COX5A amino acid sequence among extant, non-anthropoid placental mammals. The most recent common …