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Although scientists may not have come close to cataloging all the different kinds of life on the planet, genetics pioneer Craig Venter is pressing ahead with his plans to create biology version 2.0. Venter is at the forefront of the new field of synthetic biology, in which scientists try to create all new organisms out of their component genetic parts: “We’re moving from reading the genetic code to writing it” [Pittsburgh Post-Gazette], Venter has said. Now, he and his colleagues have taken the next step towards synthetic life.

In a study published in Science, the researchers explain how they took the genome from the bacterium Mycoplasma mycoides and transferred it to a yeast cell, where established genetic engineering techniques allow for easier tinkering. After altering the genome in several key ways, they transplanted it into the hollowed out shell of a different bacterial species, Mycoplasma capricolum. The breakthrough came when the altered genome “booted up” and began instructing its host bacterium to produce colonies of M. mycoides. 

That success will help researchers overcome a stubborn obstacle that has prevented the creation of a made-from-scratch life form. Last year, Venter’s team created a synthetic bacterial genome by stitching together pieces of synthesized DNA. To build a synthetic organism, however, researchers will have to transplant that synthetic genome into a cell and have it successfully reboot the cell. But that last step has proved problematic. The synthetic genome was assembled in yeast, which means it lacked some of the molecular markings characteristic of bacteria. Researchers discovered that without those markings, the host bacterium viewed the transplanted genome as a foreign invader and destroyed it [Technology Review]. In the new study, the researchers added chemical markings called methyl tags to the M. mycoides genome while it was in the yeast cell, permitting the genome to sneak past the host bacterium’s defenses.

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Forensic science, often used to produce evidence for criminal trials using such techniques as fingerprint analysis, is “badly fragmented” and unreliable in the U.S., according to a report by the National Academy of Sciences. Crime laboratories around the country are grossly underfunded, lack a scientific foundation and are compromised by critical delays in analyzing physical evidence…. The report calls into question the scientific merit of virtually every commonly used forensic method, including analysis of fingerprints, hair, fibers, blood spatters, [and] ballistics [The New York Times].

According to the report “no forensic method”—with the notable exception of DNA analysis—”has been rigorously shown able to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.” Of particular concern is the use of comparative forensic methods like hair or fingerprint analysis to match a piece of evidence to a particular person, weapon, or place [New Scientist].

DNA was excluded from the criticism because “the chances of a false positive are minuscule, but also because the likelihood of such errors is quantifiable. Studies have been conducted on the amount of genetic variation among individuals, so an examiner can state in numerical terms the chances that a declared match is wrong.” Other forensic techniques, however, have not been studied to determine how many sources might share similar features, or to quantify the level of uncertainty in any measurement made.

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For the first time, scientists have sequenced the mitochondrial DNA of a Neanderthal. Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, analyzed the genetic material from a 38,000-year-old leg bone found in Croatia and published their findings today in Cell.

The mitochondria are only passed down the female line, so can be used to trace the species back to an ancestral “Eve”, the mother of all Neanderthals. The team analysed the DNA of 13 genes from the Neanderthal mitochondria and found they were distinctly different to modern humans, suggesting Neanderthals never, or rarely, interbred with early humans. The genetic material shows that a Neanderthal “Eve” lived around 660,000 years ago, when the species last shared a common ancestor with humans [Guardian].

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A clump of hair that lay frozen in the Greenland tundra for 4,000 years has yielded DNA from the earliest Arctic residents, and offers clues to their origins.

Researchers have long wondered who those rugged settlers were, and where they came from. Were they part of a massive migration that swept through all of North America, or were they a separate tribe that eventually gave rise to Greenland’s present-day Eskimos?

Until now, no ancient human remains had been found in that harsh climate to allow researchers to study the genetics of those “Paleo-Eskimos.” But the new discovery sheds some light on the people, and suggests that neither of the earlier theories is correct; in fact, they were a distinct tribe that journeyed all the way from Siberia to Greenland, but didn’t stick around to populate the frozen north.

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