Genetics

There were no external injuries. The fossil — discovered in the region of Yakutia — has its skin, hair, hooves and tail preserved. Yakutia is also famous for having found woolly mammoth fossils in the permafrost. Scientists from Russia’s Northeast Federal University, who presented the discovery Thursday, said the foal is estimated to be 30,000 to 40,000 years old. They believe it was about two months old when it died.[name], “Ancient horse found perfectly preserved in permafrost” at CBC News, via Associated Press From Phys.org: Semyon Grigoryev, head of the Mammoth Museum in the regional capital of Yakutsk, was surprised to see the perfect state of the find. He noted it’s the best-preserved ancient foal found to date. More. Soil Read More ›

An anthropologist asks: Now go even further back in time to the 17th or 18th century. The number of folks on average living then who could have contributed to your genetic endowment is so large (more than 1,000), and their possible genetic contribution so small (about 0.098 percent for 10 generations back), it would be smoke and mirrors to assert claims about who they were in person. In fact, most of these people left no trace of themselves in your genome. In short, while it can be hard to get your head around the statistics involved, go back more than a few thousand years and you are genealogically related to almost everyone on Earth. Genetically speaking, however, very few of these Read More ›

From ScienceDaily: There are a couple of key features that make a turtle a turtle: its shell, for one, but also its toothless beak. A newly-discovered fossil turtle that lived 228 million years ago is shedding light on how modern turtles developed these traits. It had a beak, but while its body was Frisbee-shaped, its wide ribs hadn’t grown to form a shell like we see in turtles today. “This creature was over six feet long, it had a strange disc-like body and a long tail, and the anterior part of its jaws developed into this strange beak,” says Olivier Rieppel, a paleontologist at Chicago’s Field Museum and one of the authors of a new paper in Nature. “It probably Read More ›

From ScienceDaily: Scientists at the MDI Biological Laboratory and the University of Maine have discovered that genetic material in the cell that was previously thought to be “junk” because of its apparent lack of function likely plays a part in regulating genetic circuits responsible for regeneration in highly regenerative animals. … The discovery of these novel long noncoding RNAs and their role in regulating regeneration may lead to an answer to the paramount question that is being examined by scientists at the MDI Biological Laboratory: If highly regenerative animals such as zebrafish and salamanders can regenerate tissues and organs, why we can’t we? The answer could one day lead to the development of drugs to trigger humans’ dormant pathways for Read More ›

From ScienceDaily: A University of Montana researcher has discovered that mountain pine beetles may avoid certain trees within a population they normally would kill due to genetics in the trees. UM Professor Diana Six made the discovery after studying mature whitebark and lodgepole trees that were the age and size that mountain pine beetle prefer, but had somehow escaped attack during the recent outbreak. After DNA screening, survivor trees all contained a similar genetic makeup that was distinctly different from the general population that were mostly susceptible to the beetle. “Our findings suggest that survivorship is genetically based and, thus, heritable,” Six said, “which is what gives us hope.” In western North America, whitebark pine, a high elevation keystone species Read More ›

An interesting new paper on how the genetic code minimizes the impact of mistranslations: Statistical and biochemical studies of the standard genetic code (SGC) have found evidence that the impact of mistranslations is minimized in a way that erroneous codes are either synonymous or code for an amino acid with similar polarity as the originally coded amino acid. It could be quantified that the SGC is optimized to protect this specific chemical property as good as possible. In recent work, it has been speculated that the multilevel optimization of the genetic code stands in the wider context of overlapping codes. This work tries to follow the systematic approach on mistranslations and to extend those analyses to the general effect of Read More ›

Researchers Iranzo and Koonin ask: Typically, natural selection results in deletions of harmful genes, so the main question is, why hasn’t natural selection wiped out genetic parasites? They mean “transposons, plasmids, viruses” etc., that offer no benefit to the hosts. They offer a hypothesis: In a new study published in EPL, researchers Jaime Iranzo and Eugene V. Koonin at the National Institutes of Health in Bethesda, Maryland, have found that horizontal gene transfer may be one of the keys to understanding the persistence and spread of genetic parasites over evolutionary timescales. In horizontal gene transfer (HGT), genetic information is transferred to an organism by a variety of mechanisms other than the traditional parent-to-offspring process of transferring DNA. For example, an Read More ›

What? Doug Axe draws attention to a new paper at Evolution News and Science Today which suggests that “the genetic program for limb development predates limbs.” Abstract: Cephalopod mollusks evolved numerous anatomical innovations, including specialized arms and tentacles, but little is known about the developmental mechanisms underlying the evolution of cephalopod limbs. Here we report that all three axes of cuttlefish limbs are patterned by the same signaling networks that act in vertebrates and arthropods, although they evolved limbs independently. In cuttlefish limb buds, Hedgehog is expressed anteriorly. Posterior transplantation of Hedgehog-expressing cells induced mirror-image limb duplications. Bmp and Wnt signaling, which establishes dorsoventral polarity in vertebrate and arthropod limbs, is similarly polarized in cuttlefish. Inhibition of the dorsal Bmp signal Read More ›

… as the only way to save the species? From Bryan Walsh at Medium: “Our morality and our moral dispositions evolved to stop us from killing ourselves within our small group and to make sure that we cooperated with our small group,” says Savulescu, the Uehiro Professor of Practical Ethics at the University of Oxford. “But they didn’t evolve to provide benefits to strangers or to deal with large numbers of individuals at risk. All those features mean we’re particularly badly placed to deal with large statistical threats like the use of biological weapons or global collective action problems like climate change.” Essentially Savulescu believes that we “lack the moral capacities to deal with the sort of world we’ve created Read More ›

From ScienceDaily: “A paper published in 2002 (Enard et al., Nature 418, 869-872) claimed there was a selective sweep relatively recently in human evolutionary history that could largely account for our linguistic abilities and even help explain how modern humans were able to flourish so rapidly in Africa within the last 50-100,000 years,” says senior author Brenna Henn, a population geneticist at Stony Brook University and UC Davis. “I was immediately interested in dating the selective sweep and re-analyzing FOXP2 with larger and more diverse datasets, especially in more African populations.” Henn says that when the original 2002 work was done, the researchers did not have access to the modern sequencing technology that now provides data on whole genomes, so Read More ›

From ScienceDaily: Researchers have developed new techniques to track the mobilization of jumping genes. They found that during a particular period of egg development, a group of jumping-genes called retrotransposons hijacks special cells called nurse cells that nurture the developing eggs. These jumping genes use nurse cells to produce invasive material (copies of themselves called virus-like particles) that move into a nearby egg and then mobilize into the egg’s DNA driving evolution, and causing disease. … Carnegie co-author Zhao Zhang explained: “We were very surprised that the these jumping genes barely moved in stem cells that produce developing egg cells, possibly because the stem cells would only have two copies of the genome for these jumping genes to use. Instead, Read More ›

From ScienceDaily: The reproductive history of the unisexual, ladies-only salamander species is full of evolutionary surprises. In a new study, a team of researchers at The Ohio State University traced the animals’ genetic history back 3.4 million years and found some head-scratching details — primarily that they seem to have gone for millions of years without any DNA contributions from male salamanders and still have managed to persist. For some time, it has been assumed that they steal other species’ sperm, “which the males of sexual species deposit on leaves and twigs and the like. When this happens, it stimulates egg production and the borrowed species’ genetic information is sometimes incorporated into the genome of the unisexual salamanders, a process Read More ›

From Mark Fischetti at Scientific American: Bipolar disorder, for example, was more similar to schizophrenia than to major depression even though clinicians may link bipolar disorder and depression, based on their symptoms. These insights could possibly reveal new treatments, says neurogeneticist Daniel Geschwind of the University of California, Los Angeles, one of the investigators. More. It’s becoming increasingly evident (see the stories below) that a great deal of what we need to know about a person (or any life form) is not in their genes. See also: At PLOS: “Genes – way weirder than you thought” Bale monkeys more closely related to sister species than same species in different locationsThe “biological species concept” is yet another textbook dead zone. Girl Read More ›

From Mike Klymkowsky at PLOS: Through his studies on peas, Gregor Mendel was the first to clearly identify some of the rules for the behavior of these inheritable factors using highly stereotyped, and essentially discontinuous traits – a pea was either yellow or green, wrinkled or smooth. Such traits, while they exist in other organisms, are in fact rare – an example of how the scientific exploration of exceptional situations can help understand general processes, but the downside is the promulgation of the idea that genes and traits are somehow discontinuous – that a trait is yes/no, displayed by an organism or not – in contrast to the realities that the link between the two is complex, a reality rarely Read More ›

The “biological species concept” is yet another textbook dead zone. From ScienceDaily: Dr Addisu Mekonnen and colleagues at The University of Oslo, Norway, looked at the genetic diversity of the two populations of Bale monkeys. Analysis of mitochondrial DNA suggested strong genetic differences between the Bale monkeys who lived in continuous forests or fragmented forests. The researchers found that the populations of Bale monkeys were so different from each other that the Bale monkeys from fragmented forests were more similar to vervets and grivets than Bale monkeys from continuous forests. Dr Addisu Mekonnen, corresponding author of the study, explains: “Remarkably, our phylogenetic analysis showed that Bale monkeys in fragmented forests are more closely related to their sister species, vervets and Read More ›