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A Bug’s (Sex) Life: Diving Beetles Offer Clues About Sexual Selection

By Guest PostFebruary 6, 2012Nature, Sciencearizona desert, co evolution, dawn higginson, diving beetles, dytiscidae, epifluorescence image, Europe, evolution, evolutionary relationship, female, fertilization, great diving beetle, hygrotus sayi, invertebrate, kari segraves, kelly miller, larva, male, mammal, mollusk, reproductive organ, scott pitnick, sexual evolution, sexual selection, sexual trait, speciation, sperm evolution, sperm storage, spermatheca, syracuse university, thermonectus marmoratus, university of arizona

*Studies of diving beetles suggest sperm evolution may be driven by changes in female reproductive organs, challenging the paradigm of post-mating sexual selection being driven mostly by competition among sperm.*

Studying female reproductive tracts and sperm in diving beetles (Dytiscidae), researchers from the University of Arizona and Syracuse University have obtained a glimpse into a bizarre and amazing world of sperm that can take on a variety of forms – including joining together into conglomerates that navigate the twisted mazes of the female reproductive tract.

Analyses of the evolutionary relationships among diving beetles reveal that sperm form appears to follow function dictated by female reproductive organs. (more…)

New Species of Ancient Crocodile, Ancestor of Today’s Species, Discovered by MU Researcher

By Guest PostFebruary 1, 2012Nature, Scienceaegisuchus witmeri, age of the crocs, age of the dinosaurs, ancestor, casey holliday, crocodilians, fossilized skull, late cretaceous period, mesozoic era, modern crocodile, nick gardner, prehistoric crocodile, shieldcroc, species, thermo regulator

COLUMBIA, Mo. – A University of Missouri researcher has identified a new species of prehistoric crocodile. The extinct creature, nicknamed “Shieldcroc” due to a thick-skinned shield on its head, is an ancestor of today’s crocodiles. Its discovery provides scientists with additional information about the evolution of crocodiles and how scientists can gain insight into ways to protect the species’ environment and help prevent extinction. The discovery was published this week in the journal PLoS-ONE (Public Library of Science). (more…)

Moonlighting Enzyme Works Double Shift 24/7

By Guest PostFebruary 1, 2012Nature, Sciencearabidopsis, atp synthase, building block, chloroplast, david Kramer, energy, france, gamma, Germany, michigan state university, moonlighting enzyme, new function, nutrient, photosynthesis, plant enzyme, protein, root, root hair, subunit

EAST LANSING, Mich. — A team of researchers led by Michigan State University has discovered an overachieving plant enzyme that works both the day and night shifts.

The discovery, featured in the current issue of Proceedings of the National Academies of Science, shows that plants evolved a new function for this enzyme by changing merely one of its protein building blocks. (more…)

Severe Declines in Everglades Mammals Linked to Pythons

By Guest PostJanuary 31, 2012Environment, Natureafrican python, alex wolf, alligators, america, beni anaconda, boa constrictor, bobcat, burmese python, camp walker, christopher gillette, cottontail rabbits, dan kimball, deschauensee anaconda, ecological impact, ecosystem, everglades, everglades ecosystem, everglades national park, everglades python, fox, geographic pattern, green anaconda, invasive species, john willson, mammal decline, mammals, marcia mcnutt, marsh, michael dorcas, michael rochford, national park, opossums, prey, python, python predation, rabbits, raccoons, robert reed, spread of pythons, therese walters, U.S. Geological Survey, united states

HOMESTEAD, Fla. — Precipitous declines in formerly common mammals in Everglades National Park have been linked to the presence of invasive Burmese pythons, according to a study published on Jan. 30, 2012, in the Proceedings of the National Academy of Sciences.

The study, the first to document the ecological impacts of this invasive species, strongly supports that animal communities in this 1.5-million-acre park have been markedly altered by the introduction of pythons within 11 years of their establishment as an invasive species. Mid-sized mammals are the most dramatically affected. (more…)

Monogamous Birds….Peeping on the Neighbours!

By Guest PostJanuary 28, 2012Naturecolourful plumage, courtship dance, disease, dominique drullion, female, female zebra finche, frederique dubois, hypothesis, immunosuppressive effect, laboratory, male bird, male genetic quality, monogamous species, public information, reproduction period, sexual selection, social environment, song, testosterone, zebra finch

It is well documented that male birds seduce females using their songs, colourful plumage and courtship dances. These signals reflect male genetic quality and will be graded by the female to determine a male’s potential as a mate. The stronger the grade, the better the odds of being selected.

But this basic rule isn’t the only yardstick used by females. As surprising as it seems, birds know how to use data from their social environment to maximize their chances of reproduction. Frédérique Dubois, a professor at the Université de Montréal Department of Biological Sciences, has already demonstrated that female Zebra Finches will favour a male chosen by another female. Dubois refers to this as imitation and the use of “public information” in choosing a mate. (more…)

Turtles’ Mating Habits Protect Against Effects of Climate Change

By Guest PostJanuary 27, 2012Naturebaby turtles, climate change, green turtle, hatchling sex ratios, marine turtle, mating habits

The mating habits of marine turtle may help protect them against the effects of climate change, according to new research led by the University

Published on 25th January 2012 in Proceedings of the Royal Society B, the study shows how mating patterns of a population of endangered green turtles may be helping them deal with the fact that global warming is leading to a disproportionate number of females being born. (more…)

Predators Hunt for A Balanced Diet

By Guest PostJanuary 16, 2012Natureaarhus university, anchomenus dorsalis, ants, aphids, balance of nutrients, balanced diet, beetle larvae, butterfly larvae, calorie content, crickets, denmark, female beetles, food webs, fruit flies, garden insect, grasshoppers, ground beetle, kim jensen, massey university, moths, new zealand, nutritional value, offspring, omnivores, predators, predatory animals, slugs, university of exeter

Predators select their prey in order to eat a nutritionally balanced diet and give themselves the best chance of producing healthy offspring.

A University of Exeter and Oxford-led study published in Proceedings of the Royal Society B shows for the first time that predatory animals choose their food on the basis of its nutritional value, rather than just overall calorie content.

An international team of scientists from the Universities of Exeter and Oxford in the UK, University of Sydney (Australia), Aarhus University (Denmark) and Massey University (New Zealand) based their research on the ground beetle, Anchomenus dorsalis, a well-known garden insect that feasts on slugs, aphids, moths, beetle larvae and ants. (more…)

Tortoise Species Thought to Be Extinct Still Lives, Genetic Analysis Reveals

By Guest PostJanuary 10, 2012Naturec elephantopus, charles darwin, chelonoidis elephantopus, domed shaped shells, ecological integrity, floreana, floreana island, galapagos islands, genetic analysis, genetic database, giant tortoises, gisella caccone, hunting by whalers, hybrid offspring, isabela, isabela island, missing species, northern shore, northern tip of isabela island, probability, ryan garrick, saddle shaped, shells of tortoises, species, theory of natural selection, university of mississipi, volcanic slopes, volcano wolf, volcano wolf tortoises, voyage to the galapagos, yale university

Dozens of giant tortoises of a species believed extinct for 150 years may still be living at a remote location in the Galápagos Islands, a genetic analysis conducted by Yale University researchers reveals.

The analysis, published Jan. 9 in the journal Current Biology, suggests that direct descendants of at least 38 purebred individuals of Chelonoidis elephantopus live on the volcanic slopes of the northern shore of Isabela Island — 200 miles from their ancestral home of Floreana Island, where they disappeared after being hunted by whalers. (more…)

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