reproduction

140 years ago, an agate specimen from India was registered in the Mineralogy Collection at London’s Natural History Museum. Now, a team of researchers say the suspiciously spherical agate formed inside a 60-million-year-old dinosaur egg.Spiders Catapult From SexThe agatized egg likely belonged to atitanosaur, which were common in what is now India during the Cretaceous. (Earlier this year, nearly 100 titanosaur nests in India were comprehensively identified and documented.)Robin Hansen, a mineral curator at the museum,…

If you look at where wombats deposit their poo, you realize they must be able to perform some surprising acrobatics. It has always amazed me to see wombat scats on top of grass tussocks or logs, because I've always wondered how the stocky creatures must have maneuvered themselves to put it there.It turns out these sturdy marsupials also engage in a different kind of acrobatics: we recently received a video from Lyndell Giuliano and Andy Carnahan at Tomboye, New South Wales, who had filmed two wombats in the wild "doing…

Photo: Brent Hofacker (Shutterstock)Scientists in Spain have perhaps finally settled an important debate: Men really can be “growers or showers.” The team examined data from hundreds of men and found that their penises fell along a spectrum of added length during erection. The urologistsdidn’t uncover any factors associated with having either type of penis, though, and the largest proportion of men were somewhere in the middle.The research was conducted by urologists in Madrid, Spain. They were earnestly interested in…

Over time, they refined TDI-11861. In mice, the drug didn’t appear to interfere with sexual functioning or cause any side effects. And most importantly, the sperm were normal again a day later. Of course, there is a big caveat: Mice are not people. But humans also have the sAC enzyme, and in males, it’s also involved in sperm movement. Buck and Levin are reassured that the strategy might be safe in people by another team’s report from 2019, which described two infertile men with mutations in the gene that makes sAC. The…

Supergenes can also complicate the process of mating. In some species, supergenes create a breeding system that in effect has four sexes. Because of a supergene in the North American birds called white-throated sparrows, for example, there are two “morphs” with dissimilar coloration and behaviors. Not only do males have to find females, but they must find a partner from the opposing morph. Otherwise, offspring will die either from inheriting supergenes from both parents or from inheriting none. Only chicks that receive a…

Fifty years ago, the Supreme Court effectively legalized abortion with its Roe v. Wade decision. Seven months ago, the Court took those rights away. Since the decision in Dobbs v. Jackson, antiabortion legislators have pushed state-level laws that try to ban abortions at earlier and earlier points in pregnancy. With some of these laws, legislators want to make abortion illegal as soon as an embryo has detectable cardiac activity. These so-called “fetal heartbeat laws” and their underlying talking point that abortion…

Screenshot: @beingalibertarian / Instagram / GizmodoEggs used to be something you could rely on, a faithful stalwart, always there to boil or fry in moments when my wallet was light and more expensive kitchen staples like beef felt out of reach. Simpler times. Anyone’s who’s tried to make an omelette recently knows that egg prices are through the roof. In California, unfortunate shoppers have to shell out a stunning $7.37 for a dozen eggs on average, three times what they paid last year, according to the Washington Post.…

A team of paleontologists in India have given 256 fossilized dinosaur eggs a close look, in hopes of better understanding how some of the largest known dinosaurs bred and hatched.The eggs were found across 92 titanosaur nesting sites in India’s Narmada Valley, north and east of Mumbai, with the first clutches discovered in 2012. Now, researchers have published insights about the types of fossilized eggs found in these nests, along with inferences about the dinosaurs that laid them. The team’s research is published today…

Border and his colleagues are not the first to raise the possibility of spurious genetic correlations. When designing studies, geneticists can control for the effects of factors like parental traits and childhood environment by comparing people who have those things in common—that is, siblings. Earlier this year, statistical geneticist Laurence Howe and a team of researchers did just that. When Howe compared siblings with each other, he observed no genetic correlation between BMI and years of education. Somehow, it was…

Compared to a few decades ago, young people have surprisingly less access to high-quality, informative sex education. Typically, human sexuality programs have been the responsibility of middle or high schools, but like many things, sex is political, and sex education has been prey to the influences of religious dicta, fundamentalist morals, and a family values agenda. As a result, STIs have been at an all-time high for each of the past six years, including among older adults, who are often ignored because people presume…