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New Evidence Links the Collapse of Aztec Society to a Deadly Salmonella Outbreak

A new pathogen can have devastating consequences in genetically homogenous populations.


When Spanish forces arrived in Mexico in 1519, the native population was estimated to be around 25 million. A century later, there were only around 1 million left, following several devastating outbreaks of disease brought in from overseas.

Despite plenty of speculation, the diseases that contributed to the collapse of Aztec society remain unconfirmed. But now scientists have presented the first DNA evidence of a bacterial species from one of the worst epidemics — and it suggests that a deadly outbreak of salmonella might have been involved.

The downfall of Aztec society has been the source of plenty of fascination, and it’s generally believed that a variety of factors were involved — mainly the arrival of Spanish forces, followed by several outbreaks of European diseases among the native population.

Want more crop variety? Researchers propose using CRISPR to accelerate plant domestication

The more crops we cultivate, the less chance our food supply wil get wiped out by a disease.


Out of the more than 300,000 plant species in existence, only three species—rice, wheat, and maize—account for most of the plant matter that humans consume, partly because in the history of agriculture, mutations arose that made these crops the easiest to harvest. But with CRISPR technology, we don’t have to wait for nature to help us domesticate plants, argue researchers at the University of Copenhagen. In a Review published March 2 in Trends in Plant Science, they describe how gene editing could make, for example, wild legumes, quinoa, or amaranth, which are already sustainable and nutritious, more farmable.

“In theory, you can now take those traits that have been selected for over thousands of years of crop domestication—such as reduced bitterness and those that facilitate easy harvest—and induce those mutations in plants that have never been cultivated,” says senior author Michael Palmgren, a botanist who heads an interdisciplinary think tank called “Plants for a Changing World” at the University of Copenhagen.

The approach has already been successful in accelerating domestication of undervalued crops using less precise methods. For example, researchers used chemical mutagenesis to induce in weeping rice grass, an Australian wild relative of domestic rice, to make it more likely to hold onto its seeds after ripening. And in wild field cress, a type of weedy grass, scientists silenced genes with RNA interference involved with , resulting in improved seed oil quality.

4 Ways this revolutionary gene-editing tool could change the world

The woolly mammoth has been extinct for more than 4000 years. Now scientists are talking about bringing it back with the help of a powerful gene-editing technique called CRISPR-Cas9.

But CRISPR’s promise extends far beyond the possibility to resurrect extinct animals. It may also have the potential to boost crop yields and create alternatives fuel sources, protect us from insect-borne scourges like malaria and Zika, and even cure cancer.

Forget Mammoths, We Could Bring Dinosaurs and Neanderthals Back to Life

Dangerous thought.


The scientific world was set ablaze of late as discussions ramped up about the resurrection of the wholly mammoth. I know what you’re thinking: Jurassic Park. Well, not quite — but maybe not that far off, either. Dr. Michio Kaku, professor of theoretical physics at the City College of New York, wonders: what if we could clone the Neanderthal, or a dinosaur, based solely off their genomes?

George Church, geneticist and director of Harvard University’s Church Labs, believes that we can clone a Neanderthal in our lifetime. So much so that he thinks all we need is “one extremely adventurous human female.” While he doesn’t advocate for the project to be attempted straight away, he does encourage discussion on the matter. Church believes that with current stem cell technology and our completed sequence of the Neanderthal genome, we are equipped with the potential to clone a Neanderthal.

The Neanderthals went extinct tens of thousands of years ago, so cloning one from recovered DNA would be impressive enough of a feat — but what about something from 65 million years ago? Dr. Kaku addresses this, admitting that cloning a dinosaur won’t be as easy as cloning a Neanderthal or a mammoth (which wouldn’t very “easy” to begin with) — but that doesn’t mean it’s impossible.

US approves 3 types of genetically engineered potatoes

BOISE, Idaho (AP) — Three types of potatoes genetically engineered to resist the pathogen that caused the Irish potato famine are safe for the environment and safe to eat, federal officials have announced.

The approval by the U.S. Environmental Protection Agency and the U.S. Food and Drug Administration late last week gives Idaho-based J.R. Simplot Company permission to plant the potatoes this spring and sell them in the fall.

The company said the potatoes contain only potato genes, and that the resistance to late blight, the disease that caused the Irish potato famine, comes from an Argentine variety of potato that naturally produced a defense.

The Long-Shot Bid to Put Crispr in the Hands of the People

Last week, the US Patent and Trademarks Office ruled on the most-watched patent proceeding of the 21st century: the fight for Crispr-Cas9. The decision was supposed to declare ownership of the rights to the revolutionary gene editing technique. But instead, the patent judge granted sorta-victories to each of the rival parties—a team from UC Berkeley and another with members from both MIT and Harvard University’s Broad Institute. That’s great for those groups (and their spin-off, for-profit gene editing companies with exclusive licenses). But it leaves things a bit murkier for anyone else who wants to turn a buck with gene editing.

The Crispr discoverers now have some authority over who gets to use Crispr, and for what. And while exclusive licenses aren’t rare in biotech, the scope of these do stand out: They cover all the 20,000-plus genes in the human genome. So this week, legal experts are sending a formal request to the Department of Health and Human Services. They want the federal government to step in and bring Crispr back to the people.

Crispr is new, but patent laws governing genetic engineering date back decades. In 1980, shortly after the Supreme Court ruled that genetically engineered microbes were patentable, Congress passed something called the Bayh-Doyle Act. The law gives permission for universities to patent—and license—anything their researchers invented with public funds, making it easier to put those inventions back in the hands of citizens.

Playing favorites: Brain cells prefer one parent’s gene over the other’s

Well, in my immediate family; we get science, math, and futurists talents from my dad. And, there does seem to be a pattern in my immediate family with this; not sure about others. Would love to know though.


SALT LAKE CITY — Most kids say they love their mom and dad equally, but there are times when even the best prefers one parent over the other. The same can be said for how the body’s cells treat our DNA instructions. It has long been thought that each copy — one inherited from mom and one from dad — is treated the same. A new study from scientists at the University of Utah School of Medicine shows that it is not uncommon for cells in the brain to preferentially activate one copy over the other. The finding breaks basic tenants of classic genetics and suggests new ways in which genetic mutations might cause brain disorders.

In at least one region of the newborn mouse brain, the new research shows, inequality seems to be the norm. About 85 percent of genes in the dorsal raphe nucleus, known for secreting the mood-controlling chemical serotonin, differentially activate their maternal and paternal gene copies. Ten days later in the juvenile brain, the landscape shifts, with both copies being activated equally for all but 10 percent of genes.

More than an oddity of the brain, the disparity also takes place at other sites in the body, including liver and muscle. It also occurs in humans.

OCD-like behavior linked to genetic mutation, study finds

Got OCD; check your genes for a mutation.


A new Northwestern Medicine study found evidence suggesting how neural dysfunction in a certain region of the brain can lead to obsessive and repetitive behaviors much like obsessive-compulsive disorder (OCD).

Both in humans and in mice, there is a circuit in the brain called the corticostriatal connection that regulates habitual and repetitive actions. The study found certain synaptic receptors are important for the development of this brain circuit. If these receptors are eliminated in mice, they exhibit obsessive behavior, such as over-grooming.

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