Elements heavier than zinc are synthesized through the rapid (r) and slow (s) neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of trends in chemical abundances in old Milky Way halo stars suggested that these elements are produced continually, in sites such as core-collapse supernovae. But evidence from the...
Tag Archives: Ancient
R-process enrichment from a single event in an ancient dwarf galaxy
Elements heavier than zinc are synthesized through the rapid (r) and slow (s) neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of trends in chemical abundances in old Milky Way halo stars suggested that these elements are produced continually, in sites such as core-collapse supernovae. But evidence from the...
Ancient gene flow from early modern humans into Eastern Neanderthals
It has been shown that Neanderthals contributed genetically to modern humans outside Africa 47,000–65,000 years ago. Here we analyse the genomes of a Neanderthal and a Denisovan from the Altai Mountains in Siberia together with the sequences of chromosome 21 of two Neanderthals from Spain and Croatia. We find that a population that diverged early from other modern humans in Africa contributed genetically to...
Sex! Brains! Ancient mysteries! This year’s Weird Science Awards have ’em all
When the calendar turns, it’s time to reflect on the biggest sensations of the past year: Time’s Person of the Year, AP’s Top News Story, Hollywood’s Oscar picks — and, of course, the Weirdies. The Weirdies? Since 2008, my annual Weird...