Human evolutionary history is rich with the interbreeding of divergent populations. Most humans outside of Africa trace about 2% of their genomes to admixture from Neanderthals, which occurred 50–60 thousand years ago¹. Here we examine the effect of this event using 14.4 million putative archaic chromosome fragments that were detected in fully phased whole-genome sequences from 27,566 Icelanders, corresponding to a range of 56,388–112,709 unique archaic fragments that cover 38.0–48.2% of the callable genome. On the basis of the similarity with known archaic genomes, we assign 84.5% of fragments to an Altai or Vindija Neanderthal origin and 3.3% to Denisovan origin; 12.2% of fragments are of unknown origin. We find that Icelanders have more Denisovan-like fragments than expected through incomplete lineage sorting. This is best explained by Denisovan gene flow, either into ancestors of the introgressing Neanderthals or directly into humans. A within-individual, paired comparison of archaic fragments with syntenic non-archaic fragments revealed that, although the overall rate of mutation was similar in humans and Neanderthals during the 500 thousand years that their lineages were separate, there were differences in the relative frequencies of mutation types—perhaps due to different generation intervals for males and females. Finally, we assessed 271 phenotypes, report 5 associations driven by variants in archaic fragments and show that the majority of previously reported associations are better explained by non-archaic variants.

For a few years now, scientists at Washington University have been working on techniques to turn stem cells into pancreatic beta cells as a way of addressing insulin shortages in diabetics. After some promising recent strides, the team is now reporting another exciting breakthrough, combining this technique with the CRISPR gene-editing tool to reverse the disease in mice.

The pancreas contains what are known as beta cells, which secrete insulin as a way of tempering spikes in blood-sugar levels. But in those with diabetes, these beta cells either die off or don’t function as they should, which means sufferers have to rely on diet and or regular insulin injections to manage their blood-sugar levels instead.

One of the ways scientists are working to replenish these stocks of pancreatic beta cells is by making them out of human stem cells, which are versatile, blank slate-like cells that can mature into almost any type of cell in the human body. The Washington University team has operated at the vanguard of this technology with a number of key breakthroughs, most recently with a cell implantation technique that “functionally cured” mice with diabetes.

The common view of heredity is that all information passed down from one generation to the next is stored in an organism’s DNA. But Antony Jose, associate professor of cell biology and molecular genetics at the University of Maryland, disagrees.

In two new papers, Jose argues that DNA is just the ingredient list, not the set of instructions used to build and maintain a living organism. The instructions, he says, are much more complicated, and they’re stored in the molecules that regulate a cell’s DNA and other functioning systems.

Jose outlined a new theoretical framework for heredity, which was developed through 20 years of research on genetics and epigenetics, in peer-reviewed papers in the Journal of the Royal Society Interface and the journal BioEssays. Both papers were published on April 22, 2020.