Genomic predisposition is associated with the direction of sex chromosome evolution.

August 27, 2026| Source: Science (New York, N.Y.)

Sex chromosome evolution is among the most dynamic genomic innovations in vertebrates, yet why some lineages evolve XY while others evolve ZW remains unclear. Using chromosome-level genomes from 19 geckos, we found that gecko sex chromosomes originated independently from 16 ancestral chromosomes. Their origins are nonrandom in both time and direction. Five of 11 datable origins coincide near the Middle Miocene Climatic Transition (~10 million years ago). Ancestral gene content is associated with the direction of evolution, with testis-enriched regions tending to evolve into ZW and testis-depleted regions into XY, a pattern observed across multiple amniote sex chromosome origins. Geckos with genetic sex determination repeatedly evolve partial dosage balance through up-regulation in the heterogametic sex. Sex chromosome evolution thus follows constraints from ancestral genomic predisposition and environmental context.

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Nutrient legacies from elephant megacarcasses create coldspots of biodiversity and hotspots of ecosystem processes.

Terrestrial megafauna (animals >1,000 kg) have substantial impacts on ecosystems while alive; yet, we know little about the impacts of these ecosystem engineers after they die. Like whale carcasses in the ocean, terrestrial megacarcasses may leave ecological legacies via the nutrient pulses they create on the landscape. Here, we investigated the impact of elephant megacarcasses on savanna ecosystems in Kruger National Park, South Africa. To determine how elephant carcasses affect below- and a

EnvironmentOctober 20, 2026

Maternal ranging strategies facilitate offspring social play at energetic cost in the most solitary ape.

In most vertebrates, social play among peers is considered essential for behavioral development. Yet in solitary species bearing single offspring, opportunities for social play are inherently scarce. Whether mothers of such species actively facilitate play opportunities for their offspring, and at what cost, remains unknown. We used 15 y of behavioral and movement data (∼32,600 observation hours) from 31 wild Bornean orangutan ( Pongo pygmaeus wurmbii ) mother-offspring pairs to test whet

EnvironmentOctober 13, 2026

Continuous UV irradiation played an inconclusive role in selecting the canonical genetic alphabet.

An abundance of heterocyclic molecules analogous to canonical nucleobases (i.e., adenine, thymine, guanine, cytosine, and uracil) used as the genetic alphabet in DNA and RNA could have been present in various prebiotic environments on early Earth. However, extant biology generally uses the canonical nucleobases and nucleosides as the genetic alphabet, and not any number of possible noncanonical counterparts. Ultraviolet (UV) irradiation was likely abundant on the surface of the early Earth and h

EnvironmentOctober 13, 2026

Fault-controlled natural hydrogen reservoirs as underground hydrogen storage sites.

Underground hydrogen storage requires geological formations with demonstrated hydrogen containment, yet no conventional storage candidate (salt caverns, aquifers, or depleted hydrocarbon reservoirs) offers direct, prior evidence of H 2 -specific sealing. We propose that subcommercial natural hydrogen reservoirs, where H 2 has accumulated over geological timescales, can serve as precertified storage sites. This proposition is evaluated using the Bulqizë fault-controlled natural H 2 reservoir

EnvironmentOctober 13, 2026

Breaking trait scaling via the evolution and regulation of dimorphic decoupling in ants.

The evolution of allometry, changing how morphological traits scale to body size, has fueled adaptive radiations. In ants, allometry has facilitated the repeated evolution of a worker-soldier caste system. Here, we reveal an unexpected morphological pattern and its superorganismal regulation within the hyperdiverse genus Pheidole . We uncovered that antennal sizing between the small worker and the big soldier is identical, lacking intercaste scaling (antennae-body scaling is decoupled) yet retai