We've all heard about the birds and the bees. But apparently when it comes to birds, they have an unusual take on his and hers -- and the difference is genetic. Species with differentiated sex chromosomes (X and Y in humans, for example) get around the fact that males and females get different-sized portions of sex chromosome genes with a balancing act geneticists call dosage compensation. But research published today in the Journal of Biology shows that birds are extraordinary, because some bird genomes can live with an apparent overdose of sex-related genes.
Why Are Male Antlers And Horns So Large?:
Why are male ungulate antlers and horns so large? Darwin, when proposing his theory of evolution and sexual selection, suggested that the size of male ungulate antlers and horns may reflect male individual quality, and thereby be used by conspecifics as an honest signal of male sexual vigor, health, strength, hierarchical status, or ability to fight.
Neighbors Gone, Fruits Gone, Species Gone:
Neighbors gone, sex gone, fruits gone, species gone. This is the ultra-short conclusion of the findings in a study by Dennis Hansen, Heine Kiesbüy, and Christine Müller from Zurich University, and Carl Jones from the Mauritian Wildlife Foundation, who found that an endangered plant in Mauritius depends on a neighboring plant to provide a safe home for its pollinator, a day-active gecko.
Millions of times during their four-month lifespan, human red blood cells must squeeze through tiny capillaries to deliver their payload of oxygen and pick up waste carbon dioxide-functions essential to life. Now, for the first time, MIT researchers have developed a dynamic, molecular-level model that describes how the cells deform their normal disc shape to pass through vessels that are often much narrower than the cells themselves.
Scientist Develops New Mathematical Model To Study Disease Genetics And Evolution:
USC College computational biologist Peter Calabrese has developed a new model to simulate the evolution of so-called recombination hotspots in the genome. Published March 5 in the early online edition of the Proceedings of the National Academy of Sciences, the mathematical model and its associated software bring much-needed rigor to evolutionary investigations of how natural selection acts on individual genes, said Calabrese, a research assistant professor of biological sciences.
Biologists Produce Global Map Of Plant Biodiversity:
Biologists at the University of California, San Diego and the University of Bonn in Germany have produced a global map of estimated plant species richness. Covering several hundred thousand species, the scientists say their global map is the most extensive map of the distribution of biodiversity on Earth to date.
Some Caterpillers Just Don't Want To Grow Up:
An international project explores why it's an evolutionary advantage that only 25 percent of the caterpillars of Maculinea rebeli, a Lycaenid butterfly whose caterpillars live as parasites inside colonies of Myrmica ants, feeding on regurgitations from the nurse ants, complete development within one year. The rest are inactive and mature after two years. Intense competition and years where the ant colony avoids reinfection may be part of the explanation.
Fossil Discovery Marks Earliest Record Of Limbloss In Ancient Lizard:
It wouldn't have been the easiest way to get around. A University of Alberta paleontologist has helped discover the existence of a 95 million-year-old snakelike marine animal, a finding that provides not only the earliest example of limbloss in lizards but the first example of limbloss in an aquatic lizard.
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