Project description:For a long time, Neanderthals were considered hunters of large mammals, whereas the diversification of the exploited faunal spectrum to include smaller taxa, including birds, was assumed to be specific to anatomically modern humans. In recent decades, archaeozoological analyses of faunal remains from layers associated with Middle Palaeolithic lithic industries have revealed traces of human manipulation of small taxa, indicating the exploitation of a wider range of animals than previously thought, including small or fast-moving animals such as molluscs, leporids and birds. These new data have challenged the view that Neanderthals did not exploit small animals, thereby narrowing the behavioral gap with anatomically modern humans. Nevertheless, the information currently available comes almost exclusively from southern Europe and the nature of Neanderthal small fauna exploitation in northern Europe remains largely unknown. The present study aims to fill this gap by applying archaeozoological methods, including detailed taphonomic and traceological analyses, to 118 bird remains recovered from levels containing Middle Palaeolithic industries at Scladina cave, southern Belgium. Analyses of proteomics were applied to clarify the taxonomic identity of two morphologically non-diagnostic elements. Compared to mammal remains, bird bones, most of which belong to the order Galliformes, are scarce at Scladina Cave. This is likely due to conservation bias. Traces of non-human predators or scavengers, suggest that mammalian carnivores are responsible for accumulating a considerable portion of the avian assemblage. In total, seven bird bones exhibit anthropogenic traces, and one element presents questionable traces. Various Galliformes and a cormorant were exploited likely for their meat, during MIS 5 and/or 6 and MIS 6. The terminal posterior phalanx (talon) of a raptor of the size of a pomarine eagle displays intense polishing that could be linked to human manipulation of this element (MIS 5 and/or 6), although in the absence of tool marks this remains hypothetical at this stage. On the radius of a Western capercaillie, two deep incisions may indicate bone working, and intense use-wear on one of the fractured ends indicates that the bone has been utilized, potentially on soft organic material (MIS 6). This study provides the first evidence of the exploitation of birds during the Middle Palaeolithic in Belgium and constitutes the only detailed archaeozoological analysis of bird material in northwestern Europe. The likely transformation and use of a bird bone is only the second example recovered from Neanderthal occupations. The novel taxa identified as Neanderthal prey highlight the plasticity of Neanderthal ecological behavior, adapting to different landscapes and climates and exploiting the full spectrum of locally available prey.
Project description:Male offspring resulting from interbreeding of genetically diverged populations are frequently infertile or subfertile due to failures in chromosome pairing. The resulting reproductive isolation of the two populations represents an early step in speciation. In inter-subspecific mouse hybrids, the binding of the histone methyltransferase PRDM9 to both chromosome homologues at matching positions is important for successful chromosome pairing. This mechanistic property underpins Prdm9’s role as an important speciation gene, the only one yet identified in vertebrates. Here we show that this behaviour holds true for more distant evolutionary relationships across the species barrier. By altering PRDM9’s binding pattern, we restore fertility in hybrids of distinct species.
Project description:Changes in gene expression are thought to underlie many of the phenotypic differences between species. However, large-scale analyses of gene expression evolution were until recently prevented by technological limitations. Here we report the sequencing of polyadenylated RNA from six organs across ten species that represent all major mammalian lineages (placentals, marsupials and monotremes) and birds (the evolutionary outgroup), with the goal of understanding the dynamics of mammalian transcriptome evolution. We show that the rate of gene expression evolution varies among organs, lineages and chromosomes, owing to differences in selective pressures: transcriptome change was slow in nervous tissues and rapid in testes, slower in rodents than in apes and monotremes, and rapid for the X chromosome right after its formation. Although gene expression evolution in mammals was strongly shaped by purifying selection, we identify numerous potentially selectively driven expression switches, which occurred at different rates across lineages and tissues and which probably contributed to the specific organ biology of various mammals. Our transcriptome data provide a valuable resource for functional and evolutionary analyses of mammalian genomes. To study mammalian transcriptome evolution at high resolution, we generated RNA-Seq data (∼3.2 billion Illumina Genome Analyser IIx reads of 76 base pairs) for the polyadenylated RNA fraction of brain (cerebral cortex or whole brain without cerebellum), cerebellum, heart, kidney, liver and testis (usually from one male and one female per somatic tissue and two males for testis) from nine mammalian species: placental mammals (great apes, including humans; rhesus macaque; mouse), marsupials (gray short-tailed opossum) and monotremes (platypus). Corresponding data (∼0.3 billion reads) were generated for a bird (red jungle fowl, a non-domesticated chicken) and used as an evolutionary outgroup.
Project description:Molecular phylogenomics investigates evolutionary relationships based on genomic data. However, despite genomic sequence conservation, changes in protein interactions can occur relatively rapidly and may cause strong functional diversification. To investigate such functional evolution, we here combine phylogenomics with interaction proteomics. We develop this concept by investigating the molecular evolution of the shelterin complex, which protects telomeres, across 16 vertebrate species from zebrafish to humans covering 450 million years of evolution. Our phylointeractomics screen discovers previously unknown telomere-associated proteins and reveals how homologous proteins undergo functional evolution. For instance, we show that TERF1 evolved as a telomere-binding protein in the common stem lineage of marsupial and placental mammals. Phylointeractomics is a versatile and scalable approach to investigate evolutionary changes in protein function and thus can provide experimental evidence for phylogenomic relationships.
Project description:One of the central issues in evolutionary developmental biology is how we can formulate the relationships between evolutionary and developmental processes. Two major models have been proposed: the 'funnel-like' model, in which the earliest embryo shows the most conserved morphological pattern, followed by diversifying later stages, and the 'hourglass' model, in which constraints are imposed to conserve organogenesis stages, which is called the phylotypic period. Here we perform a quantitative comparative transcriptome analysis of several model vertebrate embryos and show that the pharyngula stage is most conserved, whereas earlier and later stages are rather divergent. These results allow us to predict approximate developmental timetables between different species, and indicate that pharyngula embryos have the most conserved gene expression profiles, which may be the source of the basic body plan of vertebrates. This SuperSeries is composed of the SubSeries listed below.
Project description:<p>Residues from ancient artifacts can help identify which plant species were used for their psychoactive properties, providing important information regarding the deep-time co-evolutionary relationship between plants and humans. However, relying on the presence or absence of one or several biomarkers has limited the ability to confidently connect residues to particular plants. We describe a comprehensive metabolomics-based approach that can distinguish closely related species and provide greater confidence in species use determinations. An approximately 1430-year-old pipe from central Washington State not only contained nicotine, but also had strong evidence for the smoking of <em>Nicotiana quadrivalvis</em> and <em>Rhus glabra</em>, as opposed to several other species in this pre-contact pipe. Analysis of a post-contact pipe suggested use of different plants, including the introduced trade tobacco, <em>Nicotiana rustica</em>. Ancient residue metabolomics provides a new frontier in archaeo-chemistry, with greater precision to investigate the evolution of drug use and similar plant-human co-evolutionary dynamics.</p>
Project description:Birds have a sex chromosome system in which females are heterogametic (ZW) and males are homogametic (ZZ). The differentiation of avian sex chromosomes from ancestral autosomes entailed the loss of most genes from the W chromosome during evolution. However, to what extent mechanisms evolved that counterbalance the consequences of this extensive gene dosage reduction in female birds has remained unclear. Here we report functional in vivo and evolutionary analyses of a Z-chromosome-linked microRNA (miR-2954) with strongly male-biased expression that was previously proposed to play a key role in sex chromosome dosage compensation1. We knocked out miR-2954 in chicken, which resulted in early embryonic lethality of homozygous knockout males, likely due to the highly specific upregulation of dosage-sensitive Z-linked target genes of miR-2954. Our evolutionary gene expression analyses further revealed that these dosage-sensitive target genes have become upregulated on the single Z in female birds during evolution. Altogether, our work unveils a scenario where evolutionary pressures on females following W gene loss led to the evolution of transcriptional upregulation of dosage-sensitive genes on the Z not only in female but also in male birds. The resulting overabundance of transcripts in males resulting from the combined activity of two dosage-sensitive Z gene copies was in turn offset by the emergence of a highly targeted miR-2954-mediated transcript degradation mechanism during avian evolution. Our findings demonstrate that birds have evolved a unique sex chromosome dosage compensation system in which a microRNA has become essential for male survival.