sex determination

Some interesting new research. The paper is, unfortunately, behind a paywall but they made a video, so it is worth posting. Here's the press release for the paper: Scientists know that temperature determines sex in certain reptiles—alligators, lizards, turtles, and possibly dinosaurs. In many turtles, warm temperatures during incubation create females. Cold temperatures, males. But no one understands why. A recent study sheds further light on this question. The findings of researchers Kayla Bieser, assistant professor at Northland College, and Thane Wibbels, professor of reproductive biology…
tags: evolution, evolutionary biology, gynandromorph, bilateral gynandromorph bird, half-sider, mixed-sex chimaera, sex determination, molecular biology, genetics, developmental biology, endocrinology, birds, chicken, Gallus gallus, ornithology, researchblogging.org,peer-reviewed research, peer-reviewed paper, journal club Half-sider. Almost exactly one year ago, hundreds of American birders were thrilled by sightings and photographs of this remarkable Northern Cardinal, or Redbird, Cardinalis cardinalis, photographed in Warrenton, VA. Image: DW Maiden, 2 March 2009. I'll never forget the…
For humans and most other mammals, sex is a question is chromosomes. Two X chromsomes makes us female while an X and a Y makes us male. Birds use a similar but reversed system, where males are ZZ and females are ZW. But for reptiles, including crocodiles, turtles and many lizards, sex is determined not by genes, but by temperature.  In crocodiles, males hatch from eggs incubated at cooler temperatures while warmer conditions produce females. In turtles, it's the other way around, and lizards use a variety of criteria including some very complicated combinations of genes, temperature and…
tags: evolutionary biology, mate choice, sex determination, genetic compatibility, behavioral ecology, Gouldian Finch, Erythrura gouldiae, peer-reviewed paper The three color morphs of Gouldian finches, Erythrura gouldiae. Image: Sarah Pryke, Macquarie University. Gouldian finches, Erythrura gouldiae, are small cavity-nesting passerines that are endemic to open savannahs adjacent to mangrove swamps in northern Australia. These finches eat a variety of native grass seeds, but to meet the increased energetic and nutritional demands of rearing chicks, they primarily eat insects when breeding…