Tracking history before DNA


F.Chen et al./Nature

Over the past two decades, DNA retrieved from ancient fossils has transformed scientists’ understanding of human evolution. Analysis of the similarities and differences in the DNA of different hominin groups has allowed researchers to map out the tangled family tree in a way that was previously not possible. And genetic material has led to some major finds, such as the discovery of Denisovans in the first place…

Ancient DNA has also left geographical blind spots. DNA degrades faster in warm environments, so although a 100,000-year-old specimen found in a cold Siberian cave might still harbour genetic material, a fossil that has spent that long in the heat of Africa or southeast Asia generally will not. As a result, little is known about the genetics of even relatively recent hominins from these regions, such as H. floresiensis…

Now researchers are hoping that protein analysis might begin to fill in some of those blanks. The idea is not new: as early as the 1950s, researchers had reported finding amino acids in fossils. But for a long time, the technology needed to sequence ancient proteins just didn’t exist … That changed in the 2000s, after researchers realized that mass spectrometry — a technique used to study modern proteins — could also be applied to ancient proteins. Mass spectrometry essentially involves breaking down proteins into their constituent peptides (short chains of amino acids) and analysing their masses to deduce their chemical make-up.

RTFA. Fascinating as paleontology can always be. Learning the where and when of how we got to here and now. True science never walks away from a problem because it’s difficult. Even when it takes generations to resolve.

Making a video on gun violence in Philadelphia can get you killed

A man working on a video about gun violence was shot and killed in Philadelphia, police said … “This 55-year-old male was working for a production company. They were inside of a private residence. They were interviewing and filming some family members whose children were victims of gun violence in the last two to three years,” Police Chief Inspector Scott Small said.

The man went out to his van to get more equipment and police said he was shot multiple times. Production equipment and two cellphones were found on the sidewalk … The man was taken to a hospital, where he died.

Though police didn’t initially identify the victim, his name was published a day or two later. Anthony Merriett Jr.