Researchers discovered the mechanism behind a decades-old evolutionary mystery—how “selfish chromosomes” cheat the rules of genetic inheritance. The study is the first to identify the Ovd gene acts as a quality control checkpoint during sperm development. Normally, Ovd detects and eliminates abnormal sperm cells. But selfish chromosomes exploit the system to kill competitors, boosting their chances of passing into the next generation. The findings reveal the biology behind segregation distortion, a phenomenon in which genes sway inheritance in their favor to beat the standard 50/50 odds predicted by Mendelian genetics.

Researchers from the University of Seville are participating in an international study that sheds new light on the genetic diversity of Andalusian society between the 8th and 11th centuries AD and reinforces the historical significance of the dolmen as a sacred space used throughout the ages

Researchers have long known that temperature can determine whether some reptiles develop as male or female, but this process is not well understood in lizards and snakes. A new study in leopard geckos offers the first detailed look at how this works in a squamate reptile. The researchers found that differences between males and females begin at the genetic level before any physical changes appear and identified the key developmental window when temperature decides sex.

Researchers studied wild Northern cardinals to see how everyday challenges shape the gut microbiome. Even brief disruptions, like short handling or rival interactions, triggered microbial changes linked to stress hormones, body condition and beak coloration. Birds with the largest microbial shifts also showed pronounced physiological and visual stress responses, highlighting the gut microbiome as a sensitive indicator of health. The study reveals how subtle, routine stressors influence internal biology, offering new insights into how wild animals maintain resilience and cope with environmental pressures.