Double X Science - It's In Your Genes

Search Results for: label/species bottleneck

  • Biology Xplainer: Evolution and how it happens

    …he population will change over time. It will be adapted to its environment. It will evolve. Other mechanisms of evolution A pigeon depicted in Charles Darwin’sVariation of Animals and PlantsUnder Domestication, 1868. U.S.public domain image, via Wikimedia. When Darwin presented his idea of natural selection, he knew he had an audience to win over. He pointed out that people select features of organisms all the time and breed the…

    Authored by on January 29, 2012

  • Circumcision shuffles the penis ecosystem

    groups — that is, in both men who were circumcised and men who were not (or at least, not yet). At the start of the trial, the authors measured 150,000 bacteria (16S ribosomal RNA copies) per swab in the control arm and 200,000 bacteria in the interventional arm. A year later, they found 57,000 copies on the uncircumcised men, compared to 38,000 on the circumcised ones. That difference, they say, is significant (albeit with a p value of 0.0…

    Authored by on April 16, 2013

  • Biology Explainer: The big 4 building blocks of life–carbohydrates, fats, proteins, and nucleic acids

    …molecules themselves break down into a surprisingly small number of building blocks. The proteins that make up all of the living things on this planet and ensure their appropriate structure and smooth function consist of only 20 different kinds of building blocks. Nucleic acids, specifically DNA, are even more basic: only four different kinds of molecules provide the materials to build the countless different genetic codes that translate into all…

    Authored by on June 8, 2012

  • That deadly, imported, meningitis-toting snail? Isn’t.

    …y wolf snails in Hawaii. Note to humans: These kinds of efforts are always a disaster. No. Introducing. Species. [Image credit: Rosy wolf snail, by Dylan Parker, via Wikimedia Commons, Creative Commons Attribution Share-Alike 2.0 license. Originally posted to Flickr by photographer Dylan Parker.] Here’s a children’s book that one of our knowledgeable readers has recommended, all about the rosy wolf snail. It’s “big, strong…

    Authored by on May 9, 2013

  • Of Mint, Mollusks, and Mojitos

    I finished assembling the requested cheddar cheese and cracker sandwiches and made sure to follow the precise directions for filling the sippy cups: half apple juice, half water, one ice cube, and a slice of lemon (don’t ask, my kids are high maintenance).  Saturday afternoon was upon us and it was clear that we all needed a little downtime.  So I set the girls up for a picnic on the family room floor, engaged Netflix, and laid out their snack. …

    Authored by on June 25, 2012

  • Thanks, Mom, for not eating me

    …he’s so cute, I could just eat him up!” No, grandma. Just … no. Happy Mother’s Day! Supporting Literature J. Bartlett,  Filial cannibalism in burying beetles, Behavioral Ecology and Sociobiology, Vol. 21, No. 3 (1987), pp. 179-183 [PDF] Hope Klug and Michael B. Bonsall, When to Care for, Abandon, or Eat Your Offspring: The Evolution of Parental Care and Filial Cannibalism, The American Naturalist, Vol. 170, No. 6 (Decembe…

    Authored by on May 13, 2013

  • DXS Op-Ed: How birth control can save the world

    …over the last 50 years, reaching 7 the billion mark in March of this year.  This is an astounding statistic since it took until 1804 – around 50,000 years – to reach our first billion.  World Population: 1800 – 2100 (Wikimedia Commons) What makes these numbers really scary is the concept of carrying capacity, which is an ecological term used to describe the maximum number of individual members of a species that a certain habita…

    Authored by on May 2, 2012

  • Why blueberries won’t turn you blue and other blueberry facts

    …of blueberry nutrition includes it as a source of sugar. One cup (148 g) of blueberries contains about 15 g of sugar and 4 g of fiber, a single gram of protein, and half a gram of fat. If you are counting carbs, this cup has 21 g of them. That one cup of blueberries averages about 85 calories, which is approximately the same as a medium apple or orange. While almost all the vitamins and minerals nutrition gurus like to report on are present to s…

    Authored by on September 3, 2012

  • After Newtown missteps, journalists get guidelines

    …almost twice as likely to say that they don’t want to live or work near a person with mental illness if they read an article about a person with mental illness involved in a mass shooting, according to a study published March 20 in the American Journal of Psychiatry. Interestingly, this tendency is the same even if the article avoids any mention of mental illness. This may be because this link between violence and mental illness is deeply engrain…

    Authored by on March 27, 2013

  • Tracing the taming of the turkey

    …be an important feature of native culture in what is now the southwestern U.S. Evidence from bones and fossilized excrement—coprolites—from archaeological digs in the area show that the turkey’s importance goes back at least 2000 years there, as well.  In addition, analysis of the mitochondrial DNA—which passes only from mother to offspring and accumulates mutations at a slow, predictable rate—yielded two unexpected finds. First, these birds di…

    Authored by on November 21, 2012

Page 1 of 512345