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Salamanders without lungs produce lungs as embryos despite having lost their lungs as adults over millions of years. The lungs of many vertebrates, including humans, are crucial. However, four extant amphibian clades now mostly breathe through their wet skin rather than their lungs. The developmental causes of lung loss in these clades are poorly understood. When the Plethodontidae, a dominant family of salamanders that are all lungless as adults, were examined, researchers from Harvard University's Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology found that they do develop lungs as embryos. This finding sheds light on the evolution of lung loss over millions of years. The journal Science Advances just published their findings. With about two-thirds of the diversity in the current salamander population, Plethodontidae is the salamander family with the greatest number of species. The skin and mucous membranes of the mouth and throat serve as the pr...

Princeton University geneticist Stephen Gaughran has confirmed that "Fernanda" is connected to a tortoise that was removed from Fernandina Island more than a century ago and that both of them are genetically different from all other Galápagos tortoises. A Galápagos species of tortoise that was previously believed to be extinct has been found to still be alive. The tortoise, named Fernanda after her native Fernandina Island, is the first of its kind to be found in more than a century. The Fernandina Island Galápagos giant tortoise, sometimes known as the "wonderful gigantic tortoise," was only ever found as a single individual. The finding of a female tortoise on Fernandina Island in 2019 provided the opportunity to determine whether the species is still extant. By sequencing the genomes of the living creature and the museum specimen and comparing them to the other 13 species of Galápagos giant tortoises, Stephen Gaughran from Princeton University proved that the two...