Biological evolution is the heritable change in characteristics of biological populations over successive generations, driven by mechanisms such as mutation, recombination, genetic drift, gene flow, and natural and sexual selection. It operates through changes in allele frequencies within gene pools, constrained and shaped by developmental, physiological, and ecological contexts. Evolutionary processes generate adaptation, diversification, and extinction, producing hierarchical patterns from microevolutionary shifts within populations to macroevolutionary dynamics among lineages. At the molecular level, evolution involves sequence variation, genomic rearrangements, and changes in gene regulation, which collectively underlie phenotypic diversity and the emergence of complex biological organization.
A new comparative review, published in The Anatomical Record, examines factors that may lead to birth complications among humans and other mammals. The study suggests that fetal sex may play an important role in risky births ...
A new study led by researchers at the University of California, Santa Cruz, has overturned decades of assumptions about Miracinonyx trumani, the extinct predator popularly known as the American cheetah. By analyzing nuclear ...
Evolution
Sep 4, 2026
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About 200 million years ago, furry, little egg-laying creatures evolved the ability to feed their offspring with a secretion from special glands: milk. Their evolutionary journey continued, and by about 160 million years ...
Evolution
Sep 3, 2026
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Bacterial promoters are DNA sequences that recruit RNA polymerase to initiate transcription, primarily through two elements called −10 and −35. However, the contributions of these elements to promoter evolution and regulation ...
Cell & Microbiology
Sep 2, 2026
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Many animal species, ranging from peacocks and birds of paradise to some lizards, fish and beetles, display physical features or ornaments that can attract potential mates. These ornaments can include colorful plumage, elaborate ...
What did dinosaurs eat? Teeth provide important clues to understanding the ecology of dinosaurs, which became extinct approximately 66 million years ago. Their shape, structure and patterns of wear can help scientists reconstruct ...
Evolution
Aug 31, 2026
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A surprising discovery by Technion researchers sheds new light on the dynamics of evolution. Published in the Proceedings of the National Academy of Sciences, the study shows that when an organism has several evolutionary ...
Evolution
Aug 27, 2026
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The formation of complex terrestrial ecosystems was a significant innovation in the evolutionary history of life on Earth. This event signified the expansion of life beyond marine environments and marked the beginning of ...
Evolution
Aug 27, 2026
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How has offspring dependence on parents evolved over the course of evolution? Researchers at the University of Bayreuth, in collaboration with Kyoto University, Japan, have investigated one possible mechanism by studying ...
Evolution
Aug 27, 2026
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Why do humans rely on XY chromosomes to determine sex, while birds use ZW—and many reptiles use neither, letting temperature decide instead? Sex determination is remarkably diverse across the animal kingdom. In genotypic ...
Evolution
Aug 27, 2026
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