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.

Continue reading “Fractured Forests Are Endangering Wildlife, Scientists Find” →

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.

Continue reading “Is This the First Fossil of an Embryo?” →

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.

Continue reading “Scientists Are Just Beginning to Understand Mysterious DNA Circles Common in Cancer Cells” →