Bigger Is Fitter? Quantitative Genetic Decomposition of Selection Reveals an Adaptive Evolutionary Decline of Body Mass in a Wild Rodent Population. Abstract In natural populations, quantitative trait dynamics often do not appear to follow evolutionary predictions.
Despite abundant examples of natural selection acting on heritable traits, conclusive evidence for contemporary adaptive evolution remains rare for wild vertebrate populations, and phenotypic stasis seems to be the norm. This so-called “stasis paradox” highlights our inability to predict evolutionary change, which is especially concerning within the context of rapid anthropogenic environmental change. While the causes underlying the stasis paradox are hotly debated, comprehensive attempts aiming at a resolution are lacking. Here, we apply a quantitative genetic framework to individual-based long-term data for a wild rodent population and show that despite a positive association between body mass and fitness, there has been a genetic change towards lower body mass. Author Summary. Agrp neuron activity is required for alcohol-induced overeating : Nature Communications. Researchers rejuvenate aging mice with stem cell genes.
Stem cells can spawn other types of body cells, but they have another striking capability—they remain young.
Researchers have now harnessed this ability to boost the life spans of mice and refurbish some of their tissues. Although the approach won’t work in humans, it could lead to ways to keep our bodies vigorous even as we get older. “It’s a beautiful piece of work,” says genome scientist Howard Chang of Stanford University School of Medicine in Palo Alto, California, who wasn’t connected to the research. The study, he adds, reinforces the idea that “aging is not just a passive process. We can intervene to change the outcome.” DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis: The American Journal of Human Genetics. We combined data across studies in a large-scale epigenome-wide meta-analysis to evaluate the association between maternal smoking during pregnancy and DNA methylation in offspring.
The nose knows how to kill MRSA. Learn Science at Scitable. HIV virus is one of the most pressing health concerns facing the modern world.
Since the first reported case of HIV/AIDS in 1981, over 25 million people have died. Out of the millions of people infected each year with the HIV virus, a few have shown HIV/AIDS resistance. Tardigrade Protein Helps Human DNA Withstand Radiation. Eye of Science/Science Photo Library Water bears are renowned for their ability to withstand extreme conditions.
Tardigrades, or water bears, are pudgy, microscopic animals that look like a cross between a caterpillar and a naked mole rat. Disruption of an Evolutionarily Novel Synaptic Expression Pattern in Autism. Abstract Cognitive defects in autism spectrum disorder (ASD) include socialization and communication: key behavioral capacities that separate humans from other species.
Here, we analyze gene expression in the prefrontal cortex of 63 autism patients and control individuals, as well as 62 chimpanzees and macaques, from natal to adult age. We show that among all aberrant expression changes seen in ASD brains, a single aberrant expression pattern overrepresented in genes involved synaptic-related pathways is enriched in nucleotide variants linked to autism.
Furthermore, only this pattern contains an excess of developmental expression features unique to humans, thus resulting in the disruption of human-specific developmental programs in autism. Several members of the early growth response (EGR) transcription factor family can be implicated in regulation of this aberrant developmental change. Author Summary Academic Editor: David Penny, Massey University, NEW ZEALAND Introduction Results.
Fossil eukaryotes: Fungal origins? : Nature Ecology & Evolution. Buried lasers will sense Earth's spin and quakes doing the twist. The aluminum hatches are the only clue to what lies beneath.
Buried amid the corn and wheat fields of Fürstenfeldbruck, a sleepy monastery village 20 kilometers from Munich, Germany, is an inverted pyramid of concrete, steel pipes, and precision sensors, as deep as a three-story building. Last month, when lasers began coursing around the edges of the tetrahedron, Rotational Motions in Seismology (ROMY), as it is called, began its reign as the most sophisticated ring laser in the world, capable of sensing how Earth itself twists and turns.
Old Sticks in the Mud: Hazards of Lahars from Mount Rainier Volcano. Summary A thematic "big idea" for these exercises as related to geological processes is that volcanic debris flows (lahars) can flow long distances, bury and aggrade river valleys, and cause long-term stream disturbances and dramatic landscape changes.
The big idea related to sustainability is that humans are connected to Earth systems and thus, to nature. Several activities can be done individually or in sequence by students in one class over time. To prepare for these activities, the students will first read a US Geological Survey (USGS) overview about volcanic hazards and then USGS Fact Sheet 2008-3062 by Driedger and Scott (2008) which will help them answer a series of questions about Mount Rainier's hazards.
Gestión del riesgo en Manizales. Por Gonzalo Duque-Escobar * Temas asociados a la gestión integral del riesgo, de interés para la ecorregión cafetera de Colombia.
Anexo del “Manual de geología para ingenieros” .Aspectos geofísicos de los Andes de Colombia: Si bien los desastres suelen clasificarse por su origen en naturales y antrópicos, sus consecuencias reflejan la combinación de factores que evidencian la interacción del ser humano con la naturaleza. Si bien los desastres suelen clasificarse por su origen en naturales y antrópicos, sus consecuencias reflejan la combinación de factores que evidencian la interacción del ser humano con la naturaleza. Ver en: California prepares for earthquakes that could have 30 times more energy than San Andreas. The threat of a massive earthquake and tsunami have been looming over the Pacific Northwest for decades.
Now, experts are taking it seriously. Science Creative Quarterly.
In Obesity, a Micro-RNA Causes Metabolic Problems. Bacterial “immune system” used to engineer human DNA in human cells. Precisely engineering the genome of human cells remains largely in the realm of science fiction. It's possible, with the right virus, to get new or modified genes into cells. RNA-based vaccine could wipe out the flu forever. Researchers remove extra chromosome from Down’s syndrome cells. Could a gene therapy be next?
Genome Sequence of the Pea Aphid Acyrthosiphon pisum. Complete Mitochondrial Genome and Phylogeny of Pleistocene MammothMammuthus primigenius. Scientists Discover An Exoplanet So Massive They're Not Even Sure It's A Planet. You know we've found something new and interesting when scientists don't really know how to classify it. Using the Subaru Telescope an international team of astronomers has discovered a "super-Jupiter" so massive that it seems they're not quite sure whether to call it a planet or a low-mass brown dwarf (in other words, a star that failed to fire).
Located roughly 170 light-years from Earth, the host star is roughly 2.5 times more massive than the sun and its planet is about 13 times larger than Jupiter, making this the highest-mass star to ever host a directly imaged orbital companion--especially one of this size. Kappa Andromedae is part of what's known as the Columba stellar moving group, and at just 30 million years old it is relatively young (our Sun is estimated to be more like five billion hears old).
So the strange case of Kappa Andromedae and super-Jupiter Kappa And b gives astronomers some things to think about. Living the Sweet Life: How Does a Plant Pathogenic Fungus Acquire Sugar from Plants? Birds Do It, Bees Do It, but Candida albicans Does It Differently.