Tag Archives | Genetics

New Research on “Junk” DNA Raises Questions on Eve of Crucial Court Hearing

Picture: Flickr, Peter Alfred Hess (CC)

It seems that new discoveries about DNA, and our own human genome in particular, are coming more rapidly today. More things seem to exist on a scale of genetic variance, and it was recently found that our so-called “junk DNA” is full of important ramifications for genetic disorders and random mutations that determine our evolutionary fate.

But in a more immediate sense, DNA research may raise dire questions and have important bearing on current legal arguments, such as the Ninth Circuit‘s Haskell v. Harris, a case challenging California’s warrantless DNA collection program.

Via Jennifer Lynch at the Electronic Frontier Foundation:

EFF asked the court to consider ground-breaking new research that confirms for the first time that over 80% of our DNA that was once thought to have no function, actually plays a critical role in controlling how our cells, tissue and organs behave.

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Today’s Environment Can Influence Behavior Generations Later

He's Coming!

Photo: An-d (CC)

Via ScienceDaily:

Researchers at The University of Texas at Austin and Washington State University have seen an increased reaction to stress in animals whose ancestors were exposed to an environmental compound generations earlier.

The findings, published in the latest Proceedings of the National Academy of Sciences, put a new twist on the notions of nature and nurture, with broad implications for how certain behavioral tendencies might be inherited. The researchers—David Crews at Texas, Michael Skinner at Washington State and colleagues—exposed gestating female rats to vinclozolin, a popular fruit and vegetable fungicide known to disrupt hormones and have effects across generations of animals. The researchers then put the rats’ third generation of offspring through a variety of behavioral tests and found they were more anxious, more sensitive to stress, and had greater activity in stress-related regions of the brain than descendants of unexposed rats.

“We are now in the third human generation since the start of the chemical revolution, since humans have been exposed to these kinds of toxins,” says Crews.

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Has Human Evolution Stopped?

possan (CC)

possan (CC)

We’re screwing with our own nature as well as that of many other species and the Earth itself, with unpredictable consequences. Matt Ridley offers his opinion on what that might mean in the Wall Street Journal:

If you write about genetics and evolution, one of the commonest questions you are likely to be asked at public events is whether human evolution has stopped. It is a surprisingly hard question to answer.

I’m tempted to give a flippant response, borrowed from the biologist Richard Dawkins: Since any human trait that increases the number of babies is likely to gain ground through natural selection, we can say with some confidence that incompetence in the use of contraceptives is probably on the rise (though only if those unintended babies themselves thrive enough to breed in turn).

More seriously, infertility treatment is almost certainly leading to an increase in some kinds of infertility.

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The Evolution Paradigm Shift

Evolution 21 CenturySuzan Mazur interviews James Shapiro, author of Evolution: A View from the 21st Century, for Counterpunch:

Suzan Mazur: I went through the book over the weekend. It’s very thoughtful the way you’ve put it together. Would you describe your theory, which involves cells speaking to one another — cognitively, informationally. You say in reality the “gene” is “not a definite entity” — it’s “hypothetical in nature.”

James Shapiro: There are three components there.

(1) As I say in the book, cells do not act blindly. We know from physiology and biochemistry and molecular biology that cells are full of receptors. They monitor what goes on outside. They monitor what goes on inside. And they’re continually taking in that information and using it to adjust their actions, their biochemistry, their metabolism, the cell cycle, etc. so that things come out right. That’s why I use the word cognitive to apply to cells, meaning they do things based on knowledge of what’s happening around them and inside of them.

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Natural Selection Driving Human Evolution As Late as the 19th Century

Writes ScienceNow via WIRED Science:

In a world where we’ve tamed our environment and largely protected ourselves from the vagaries of nature, we may think we’re immune to the forces of natural selection. But a new study finds that the process that drives evolution was still shaping us as recently as the 19th century.

The finding comes from an analysis of the birth, death, and marital records of 5,923 people born between 1760 and 1849 in four farming or fishing villages in Finland. Researchers led by evolutionary biologist Alexandre Courtiol of the Institute for Advanced Study Berlin picked this time period because agriculture was well established by then and there were strict rules against divorce and extramarital affairs. The team looked at four aspects of life that affect survival and reproduction, key signposts of natural selection: Who lived beyond age 15, who got married and who didn’t, how many marriages each person had (second marriages were possible only if a spouse died), and how many children were born in each marriage.

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Antibiotic Resistance Genes Accumulating in Lake Geneva Via Wastewater Treatment Plants

Lake Geneva

Photo: Christopher Down (CC)

Via ScienceDaily:

Large quantities of antibiotic-resistant bacteria enter the environment via municipal — and especially hospital — wastewater streams. Although wastewater treatment plants reduce the total number of bacteria, the most hazardous — multiresistant — strains appear to withstand or even to be promoted by treatment processes. This was demonstrated by Eawag researchers in a study carried out in Lake Geneva, near Lausanne.

Treated wastewater from the city of Lausanne — around 90,000 m3 per day — is released into Vidy Bay (Lake Geneva); the discharge point is located 700 m offshore, at a depth of 30 m. The Lausanne region does not have a pharmaceutical industry or intensive animal production. However, the Lausanne treatment plant receives wastewater not only from the region’s 214,000 inhabitants and a number of smaller healthcare centres, but also from a major healthcare facility — the University Hospital of Canton Vaud (CHUV).

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The Inbred Appalachian Family With Blue Skin

bluefamilyA real-life blue-blooded family exists, ironically, in the impoverished hills of Kentucky. As they have mingled with the broader population, the number of blue children has dwindled, sadly. Via Daily Mail:

Dating back to the early 1800s, an isolated family in eastern Kentucky started producing children who were blue. As a result of a coincidental meeting of recessive genes, intermarriage and inbreeding, members of the Fugate family were born with a rare condition that made them visibly discoloured. Looking at the portrait, they appear to have been either Photoshopped, but science proves that the condition is in fact real.

It began when Martin Fugate, a French orphan, settled on the banks of eastern Kentucky’s Troublesome Creek to claim a land grant in the early 19th century. He married a red-haired American named Elizabeth Smith – who had a very pale complexion – and their union formed a genetic mutation that resulted in their descendants being born with blue skin.

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Icelanders Avoid Inbreeding Through Online Incest Database

Ingólfr ArnarsonSo says Samantha Grossman in TIME:

Nowadays, some light Internet stalking is as common a pre-date ritual as showering or putting on a clean shirt. But for Icelanders, that online screening process can include running a date’s name through an incest database.

Sound ridiculous? Consider this: when you live in an isolated nation with a population roughly the size of Pittsburgh, accidentally lusting after a cousin is an all-too-real possibility. But a search engine called Íslendingabók (the Book of Icelanders) allows users to plug in their own name alongside that of a prospective mate, determining any familial overlap. The site claims to track 1,200 years of genealogical information about the island’s inhabitants. Anyone with an Icelandic ID number — that is, citizens and legal residents — is accounted for, the New York Daily News reports.

Not only can the site rule out courtships that might be a bit too close for comfort, but also it helps users determine if they share family ties with any famous Icelanders.

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Rare Mutation Leaves People Without Fingerprints

No PrintsThis would be a useful trait for the aspiring supervillian. Natalie Villacorta wrote recently in Science:

In 2007, a Swiss woman in her late 20s had an unusually hard time crossing the U.S. border. Customs agents could not confirm her identity. The woman’s passport picture matched her face just fine, but when the agents scanned her hands, they discovered something shocking: she had no fingerprints.

The woman, it turns out, had an extremely rare condition known as adermatoglyphia. Peter Itin, a dermatologist at the University Hospital Basel in Switzerland, has dubbed it the “immigration delay disease” because sufferers have such a hard time entering foreign countries. In addition to smooth fingertips, they also produce less hand sweat than the average person. Yet scientists know very little about what causes the condition.

Since nine members of the woman’s extended family also lacked fingerprints, Itin and his colleagues, including Eli Sprecher, a dermatologist at the Tel Aviv Sourasky Medical Center in Israel, suspected that the cause might be genetic.

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All Non-African People Are Part Neanderthal

Neanderthal child

Reconstruction of a Neanderthal child.

Interesting article from Alasdair Wilkins on io9.com:

The evidence has been mounting for years that early humans and Neanderthals interbred, but now it’s pretty much a certainty. Part of the X chromosome found in people from outside Africa originally comes from our Neanderthal cousins.

It’s kind of amazing to think that, as recently as just a few years ago, the scientific consensus was that humans and Neanderthals were completely separate species and probably didn’t interbreed. Since then, a ton of new evidence has come to light to change that position, and now new research from Damian Labuda of the University of Montreal more or less completes this big reversal.

Neanderthals, one of the last extant hominid species other than our own, left Africa somewhere between 400,000 and 800,000 years ago and settled mostly in Europe until they went extinct 30,000 years ago. Early modern humans left Africa about 80,000 to 50,000 years ago, meaning they overlapped with Neanderthals in time and place for at least 20,000 years.

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