Christening the Earliest Members of Our Genus

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The New York Times, October 24, 2013

Link

Around 1.8 million years ago, human evolution passed a milestone. Our ancestors before then were little more than bipedal apes. Those so-called hominids had chimpanzee-size bodies and brains, and they still had adaptations in their limbs for climbing trees. But the fossils of hominids from 1.8 to 1.5 million years ago are different. They had bigger brains, flatter faces and upright bodies better suited to walking.

Their geography changed, too. While earlier hominid fossils have only been found in Africa, the newer ones also turn up at sites stretching across Asia, from the Republic of Georgia all the way to Indonesia.

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Snowfallization

Posted on by Carl Zimmer

This post was originally published in “Download the Universe,” a multi-author blog about science ebooks edited by Carl Zimmer.

Sea Change. By Steve Ringman and Craig Welch. Published by Seattle Times.

The Course of Their Lives. By Mark Johnson and Rick Wood. Published by Milwaukee Journal-Sentinel. 

Reviewed by Carl Zimmer

October 24, 2013

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Naming Our Ancestors: My New Column for the New York Times

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FIVE 1.8 MILLION-YEAR-OLD SKULLS FROM DMANISI, GEORGIA. IMAGE COURTESY OF M. PONCE DE LEÓN AND CH. ZOLLIKOFER, UNIVERSITY OF ZURICH, SWITZERLAND

Last week, scientists published a study of five 1.8 million-year-old hominid fossils. They may reveal profound lessons about a crucial chapter in our evolution: how our ancestors changed from bipedal apes to a more human-like lineage–in other words, the emergence of our genus, Homo. So what name do we give these skulls? What species do they belong to? It’s no simple matter naming our hominid ancestors, and that difficulty tells us something intriguing about their biology. And that’s the subject of my “Matter” column this week in the New York Times. Check it out.

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How Many Cells Are In Your Body?

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E.M.UNIT, ROYAL FREE HOSPITAL SCHOOL OF MEDICINE/WELLCOME TRUST PHOTO LIBRARY/CREATIVE COMMONS

A simple question deserves a simple answer. How many cells are in your body?

Unfortunately, your cells can’t fill out census forms, so they can’t tell you themselves. And while it’s easy enough to look through a microscope and count off certain types of cells, this method isn’t practical either. Some types of cells are easy to spot, while others–such as tangled neurons–weave themselves up into obscurity. Even if you could count ten cells each second, it would take you tens of thousands of years to finish counting. Plus, there would be certain logistical problems you’d encounter along the way to counting all the cells in your body–for example, chopping your own body up into tiny patches for microscopic viewing.

For now, the best we can hope for is a study published recenty in Annals of Human Biology, entitled, with admirable clarity, “An Estimation of the Number of Cells in the Human Body.”

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Genomes From Birth: My New Piece for Slate

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PHOTO BY BRIDGIT COILA VIA CREATIVE COMMONS

Genetic testing for individual disorders was once the brave new world, but now it’s a familiar routine of having a baby. But what about looking over a baby’s entire genome? As the price for sequencing DNA crashes, it’s becoming a real possibility. At Slate, I write a new study in which the genomes of 240 babies will be sequenced, and researchers will see whether how that avalanche of data affects their medical care. Check it out.

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