After fifty years of research, scientists have finally unraveled the molecular mechanics of the bacterial flagellar motor. This sophisticated biological machine allows single-celled bacteria to swim toward nutrients or tumble randomly to find new directions. Recent breakthroughs using cryo-electron microscopy have revealed how protein stators act as turnstiles, driven by a constant influx of protons known as the proton motive force. This mechanism converts entropic energy into kinetic rotation, providing a fundamental look at the physical forces that power cellular life.
This editorial discusses how genomic studies are being used to understand the origins of language in humans. Researchers are attempting to pinpoint the earliest divergence in modern human populations, specifically between the Khoisan people of southern Africa and the rest, to establish a lower bound for when linguistic capacity developed – at least 135,000 years ago. The article highlights the difficulty in reconstructing very old languages, pointing out that many early languages are "known unknowables," lost to time. It acknowledges the distinction between linguistic capacity and fully formed language, suggesting the former may have predated the latter.
A new study challenges the traditional theory about the Jomon people of Japan, suggesting a single founding migration rather than multiple waves. The research, based on mitochondrial DNA analysis, indicates that regional diversity arose from internal division and local evolution within the archipelago.
Researchers have developed a new method to reconstruct the genetic code of ancient organisms, potentially allowing them to study life forms that existed before LUCA (Last Universal Common Ancestor). This involves creating 'progenitors' – simplified genetic systems that mimic the characteristics of early life, and then evolving them in the lab to observe how complexity arises.
A new mathematical model suggests that Neanderthals didn't go extinct due to inferiority, but rather were absorbed through interbreeding with migrating Homo sapiens populations, leading to their genetic dilution over time.
DNA from a Neanderthal bone fragment in Crimea, dated to around 45,900-45,300 years ago, reveals genetic links between European and Siberian Neanderthals and suggests a migration corridor along 55°N.
Nobel Prize winner Svante Pääbo discusses his work in paleogenetics, including sequencing the Neanderthal genome, discovering the Denisovans, and his theories on why Homo sapiens survived while Neanderthals went extinct, attributing it to our larger population size.
Geneticist David Reich explains how analyses made possible by technological advances show human history to be one of mixing, movement, and displacement.
The article discusses the existence of over 20 early human species that coexisted with Homo sapiens, their potential reasons for extinction (climate change, competition, interbreeding), and the current understanding of human evolution.
The article details a study suggesting that rapid shifts in gene regulation, rather than changes in protein-coding genes, likely drove the evolution of human intelligence. Researchers identified two key regulatory "saltations" – sudden changes – unique to humans that impact areas like memory, learning, social behavior, and emotional depth.
