Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

Structural elements are widespread across genomes, but their complexity and role in repeatedly driving local adaptation remain unclear. In this work, we use phased genome assemblies to show that adapt...

Abstract. Adaptive evolution can be described by an uphill walk in a fitness landscape. However, climbing the global peak in a multipeak landscape is impro

Fossils of Orrorin record the first convincing evidence of hominid terrestrial bipedalism in the Late Miocene, at about six million years ago. Bipedalism in the slightly older (7 Ma old) Sahelanthropus has recently been called into question. Here we present the first known hominine postcranial element from Azmaka (Bulgaria), a 7.2 Ma old nearly complete femur, which we tentatively attribute to cf. Graecopithecus. The Azmaka hominine represents a candidate for the ancestral form of positional behaviour from which bipedalism documented in later hominins evolved. The Azmaka femur lacks many of the specialised attributes of arboreal quadrupeds. At the same time the combination of locomotor features of this femur indicates a complex locomotor repertoire. Qualitative and quantitative morphological analyses demonstrate that the Azmaka femur combines certain attributes of terrestrial quadrupeds and bipeds and clusters mostly with early bipeds and partially with African apes. The morphology indicates a transitional form of bipedalism. The wooded-grassland savanna environment of the early Messinian locality of Azmaka suggests that terrestrial bipedalism likely evolved in a non-forested setting. The early Messinian age is critical to our understanding of mammalian palaeobiogeography and the intercontinental dispersals between Eurasia and Africa. We hypothesise that the descendants of the Azmaka hominine may have dispersed from Eurasia into Africa under the influence of climatic and environmental changes in the eastern Mediterranean. If such dispersal occurred, it may have been associated with subsequent re-occupation of more forested settings in both the ancestors of African apes and hominins.

The eyeball is not rigid and deforms during saccades. As a consequence, the saccade waveform recorded by an eye tracker may depend on which structure of the eye is used to estimate eyeball rotation. Here, we systematically describe and compare signals co-recorded from the retina, the cornea (corneal reflection, CR), the pupil, and the lens (fourth Purkinje reflection, P4) during saccades. We found that several commonly used parameters for saccade characterization differ systematically across the signals. For instance, saccades in the retinal signal had earlier onsets compared to saccades in the pupil and the P4 signals. The retinal signal had the smallest saccade amplitude and reached the peak saccade velocity earlier compared to the other signals. At the end of saccades, the retinal signal came to a stop faster than the other signals. We discuss possible explanations that may account for the relationship between the retinal signal and the other signals.

Abstract. Divergent natural selection caused by spatial environmental variation can lead to local adaptation and evolutionary divergence between population

<p>Read about &ldquo;Eco-Evolutionary Dynamics for Finite Populations and the Noise-Induced Reversal of Selection&rdquo; by Ananda Shikhara Bhat and Vishwesha Guttal (Jan&nbsp;2025)</p><br/>

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution