Ground nesting of soft eggs by extinct birds and a new parity mode switch hypothesis for the evolution of animal reproduction

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 17, 2024

ABSTRACT Nearshore ground nesting of soft eggs by extinct birds is demonstrated here, providing a new explanation for the abundance bird fossils in early Cretaceous lacustrine environments, where humidity conditions required egg incubation would have been present. This reinforces recent findings Archaeopteryx near Jurassic marine possibility that wings and elongated feathers developed primarily association with nest protection on only secondarily flight, origin flight from up. Notably, preceded rigid evolution, but both crocodiles, whose ancestors seem to antedated precursors, extant reproduce exclusively via hard-shelled eggs. Therefore, an order how reproduction could occurred lineage in-between two evolutionary moments In alternative commonly accepted convergent evolution viviparity eggshells, parity mode switch hypothesis presented here. It postulates existence, since rise animals, inherited ancestral between oviparity. evolved embrace oviparity after eggshells appeared evolution. Commitment particular or eggshell type may conditioned survival entire animal groups, especially during major extinction events, explaining, among others, all reproduced eggshells.

Language: Английский

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A synthetic review: natural history of amniote reproductive modes in light of comparative evolutionary genomics

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 19, 2024

There is a current lack of consensus on whether the ancestral parity mode was oviparity (egg-laying) or viviparity (live-birth) in amniotes and particularly squamates (snakes, lizards, amphisbaenids). How transitions between modes occur at genomic level has primary importance for how science conceptualises origin amniotes, highly variable Squamata. Synthesising literature from medicine, poultry science, reproductive biology, evolutionary I review genomics physiology five broad processes (here termed 'Main Five') expected to change during modes: eggshell formation, embryonic retention, placentation, calcium transport, maternal-fetal immune dynamics. Throughout, offer alternative perspectives testable hypotheses regarding proximate causes evolution squamates. If did evolve early history lepidosaurs, nucleation site hypothesis as explanation. The framework this can be extended infer their state. also provide mechanism may transition make predictions about directionality three species. After considering evidence differing amniote origins, that unifies (i) retention model (ii) traditional which describes egg an adaptation terrestrial environment. Additionally, contextualises within Medawar's paradigm. Medawar posited pregnancy could supported by immunosuppression, inertness, evasion, immunological barriers. demonstrate does not support gestation gravidity across most but adequate paradigm explain first tolerated internal fertilization delayed deposition. In context, thought barrier. serving barrier underpins eggshell, there should oviparous met with responses utero. Rare examples two species differentially express very few genes gravidity, suggestive absent reaction are skinks Lampropholis guichenoti Lerista bougainvillii. These serve good models original egg. Overall, grounds itself historical while offering modern perspective amniotes. encourage scientific community utilise resource comparative studies, embrace complexity system, thoughtfully consider frameworks proposed.

Language: Английский

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Parametric Design and Mechanical Characterization of a Selective Laser Sintering Additively Manufactured Biomimetic Ribbed Dome Inspired by the Chorion of Lepidopteran Eggs

Biomimetics, Journal Year: 2024, Volume and Issue: 10(1), P. 1 - 1

Published: Dec. 24, 2024

The current research aims to analyze the shape and structural features of eggs lepidoptera species Melitaea sp. (Lepidoptera, Nympalidae) develop design solutions through implementation a novel strategy biomimetic design. Scanning electron microscopy (SEM) analysis chorion reveals medial zone that forms an arachnoid grid resembling ribbed dome with convex longitudinal ribs concave transverse ring members. A parametric algorithm was created aid computer-aided (CAD) software Rhinoceros 3D Grasshopper3D in order abstract emulate biological model. series physical models were manufactured variations geometric parameters like number rings, their thickness, curvature. Selective laser sintering (SLS) technology Polyamide12 (nylon) material utilized for prototyping process. Quasi-static compression testing carried out conjunction finite element (FEA) investigate deformation patterns stress dispersion models. appears significantly dampen snap-through behavior is observed typical solid lattice domes, decreasing dynamic stresses developed during response preventing catastrophic failure structure. Increasing curvature segments further reduces phenomenon improves overall strength. However, excessive has negative effect on maximum sustained load. thickness rings also increases strength dome. increase rib radius leads more acute earlier failure. above results validated using respective analyses.

Language: Английский

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A Review: Comparative Genomics and Physiology of Parity Mode Evolution in Amniotes

Published: Nov. 18, 2022

Across amniotes, squamates represent the only clade with highly variable parity modes, oviparity (egg-laying) and viviparity (live-birth). Despite this, relatively little is known about how evolve at genomic physiological levels in squamates. Within context of interdisciplinary medical, poultry science, reproductive biology literature, I review genomics physiology reproduction across five broad processes expected to change during transitions between modes—eggshell formation, embryonic retention, placentation, calcium transport, maternal-fetal immune dynamics. This first time that dynamics considered modern medical where embryos are no longer conceptualized as analogs allografts. offer alternative perspectives holistic hypotheses on transcriptomic drivers mode Two new pathways through which early Lepidosaurs may have transitioned rapidly intermediate stages presented. Overall, illuminates biological plausibility labile modes some squamate lineages, constrained others. Future research should be open either possibility unless clade-specific evidence suggests otherwise. Rather than emphasizing feasibility direction, posit minor variations a shared process.

Language: Английский

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