The world’s crops face a vast army of enemies, from fungi to bacteria to parasitic animals. Farmers have deployed pesticides to protect their plants, but diseases continue to ruin a sizable portion of our food supply.

Some scientists are now investigating another potential defense, one already lurking beneath our feet. The complex microbial world in the soil may protect plants much like our immune system protects our bodies.

Scientists have known about so-called “suppressive soils” for decades. In 1931, a Canadian scientist named A. W. Henry discovered the spores of the common root rot, a fungus that strikes wheat crops, in a range of soil samples. But try as he might, he could almost never get the spores to grow.

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Scientists digging in the Liang Bua cave on the Indonesian island of Flores years ago found a tiny humanlike skull, then a pelvis, jaw and other bones, all between 60,000 and 100,000 years old.

The fossils, the scientists concluded, belonged to individuals who stood just three feet tall — an unknown species, related to modern humans, that they called Homo floresiensis or, more casually, the hobbits.

On Wednesday, researchers reported that they had discovered still older remains on the island, including teeth, a piece of a jaw and 149 stone tools dating back 700,000 years.

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Just a few years ago, Crispr was a cipher — something that sounded to most ears like a device for keeping lettuce fresh. Today, Crispr-Cas9 is widely known as a powerful way to edit genes. Scientists are deploying it in promising experiments, and a number of companies are already using it to develop drugs to treat conditions ranging from cancer to sickle-cell anemia.

Yet there is still a lot of misunderstanding around it. Crispr describes a series of DNA sequences discovered in microbes, part of a system to defend against attacking viruses.

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The history of African-Americans has been shaped in part by two great journeys.

The first brought hundreds of thousands of Africans to the southern United States as slaves. The second, the Great Migration, began around 1910 and sent six million African-Americans from the South to New York, Chicago and other cities across the country.

In a study published on Friday, a team of geneticists sought evidence for this history in the DNA of living African-Americans. The findings, published in PLOS Genetics, provide a map of African-American genetic diversity, shedding light on both their history and their health.

Continue reading “Tales of African-American History Found in DNA” →