Author: Lori Jia

Air Pollution, Evolution, and the Fate of Billions of Humans

Posted on by Lori Jia

The New York Times, January 13, 2020

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The threat of air pollution grabs our attention when we see it — for example, the tendrils of smoke of Australian brush fires, now visible from space, or the poisonous soup of smog that descends on cities like New Delhi in the winter.

But polluted air also harms billions of people on a continuing basis. Outdoors, we breathe in toxins delivered by car traffic, coal-fired plants and oil refineries. Indoor fires for heat and cooking taint the air for billions of people in poor countries. Over a billion people add toxins to their lungs by smoking cigarettes — and more recently, by vaping.

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Once, America Had Its Own Parrot

Posted on by Lori Jia

The New York Times, December 20, 2019

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When European settlers arrived in North America, they were stunned to discover a gorgeous parrot.

The face of the Carolina parakeet was red; its head was yellow, its wings green. Measuring a foot or more from beak to tail, the parakeets thrived in noisy flocks from the Atlantic Coast to what is now Oklahoma.

“I have seen branches of trees as completely covered by them as they could possibly be,” John James Audubon wrote in 1830. When the parrots landed on a farmer’s field, “they present to the eye the same effect as if a brilliantly coloured carpet had been thrown over them.”

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Fractured Forests Are Endangering Wildlife, Scientists Find

Posted on by Lori Jia

The New York Times, December 5, 2019

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Around the world, humans are fracturing vast forests. Highways snake through the Amazon’s rain forests, and Indonesia plans an ambitious transportation grid in Borneo, through some of the largest untouched expanses of tropical forests.

If you were to parachute at random into any of the planet’s forests, you’d probably land a mile or less from its edge, according to a recent study.

Conservation biologists have intensely debated the dangers that the fracturing of woodlands poses to animals. While many studies have shown that extinctions are more common in fragmented environments, others haven’t documented much effect.

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Is This the First Fossil of an Embryo?

Posted on by Lori Jia

The New York Times, November 27, 2019

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A creature called Caveasphaera lived in China 609 million years ago, and it left behind fossils that resemble tiny grains of sand. But as innocuous as those fossils appear, they may speak volumes about our own evolutionary history.

Under a microscope, the fossils turn out to be clusters of hundreds or thousands of cells. Were they on their way to developing into adult bodies? On Wednesday, a team of researchers published a study on hundreds of new Caveasphaera fossils, using high-powered X-ray beams to create three-dimensional images of the cells. They argue that these remains are embryos of early animals or their close relatives.

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Scientists Are Just Beginning to Understand Mysterious DNA Circles Common in Cancer Cells

Posted on by Lori Jia

The New York Times, November 20, 2019

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There’s no image in biology more iconic than our chromosomes — all 23 pairs of DNA bundles arrayed in a genetic lineup. But in a surprising number of cases, this picture leaves out something very important.

In some cells, extra circles of DNA float alongside the regular chromosomes. Scientists first noticed this so-called extrachromosomal DNA five decades ago. But for years they weren’t exactly sure what to make of it.

New research is now focusing on those mysterious loops. They are surprisingly common in cancer cells and play a bigger role in many types of cancers than was previously recognized.

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