DNA
Central principle of biology challenged? Human cells write RNA sequences into DNA
Human cells write RNA sequences into DNA
Rob Sheldon: Biologists’ use of the term “half-life” shows just how tenuous many of their propositions really are
Recently, our physics color commentator Rob Sheldon took issue with the use of the term “half-life” to describe the survival of DNA in fossils. He says the term has a specific meaning with respect to radioactive decay that just does not apply to other events in nature. In the biology paper at issue, with “half-life” in the name, the authors explain and use the concept in connection with radiocarbon dating: Abstract: Claims of extreme survival of DNA have emphasized the need for reliable models of DNA degradation through time. By analysing mitochondrial DNA (mtDNA) from 158 radiocarbon-dated bones of the extinct New Zealand moa, we confirm empirically a long-hypothesized exponential decay relationship. The average DNA half-life within this geographically constrained Read More ›
A zoologist on that microbe that copies its DNA in a way “unknown to science”
Does DNA really have a “half life”? Physicist Rob Sheldon is skeptical
At New Scientist: “single-celled organism that lacks most of the molecular equipment needed to kick-start DNA replication”
New form of human DNA found – a four-stranded knot
DNA may be the computer of the future — because, of course, life is designed
Archaea microbes have genes like flexible slinkies
They were only discovered in 1977 and they get more unusual all the time: Microbes called archaea package their genetic material into flexible shapes that flop open in unusual ways, Howard Hughes Medical Institute (HHMI) Investigator Karolin Luger reports March 2, 2021, in the journal eLife. “Very much to our surprise, we found that these structures can undergo all sorts of gymnastics,” says Luger, a biochemist at the University of Colorado Boulder. Like DNA in the nucleus of human cells, archaeal DNA coils around proteins like string wrapped around a yo-yo. But there’s another twist, the team found. Those coils of DNA can also spread 90 degrees apart—a phenomenon scientists hadn’t seen before. Such bends in the springlike structures could Read More ›