MI weekly selection #89
Ancient star holds evidence of one of its earliest ancestors
Traces of one of the universe’s first stars may have been found in the chemical signature of another ancient star that gobbled up material from the earlier star’s supernova. SDS J0018-0939, a star found in the halo around the Milky Way about 1,000 light-years from Earth, is about 13 billion years old and its chemical composition suggests it absorbed material from the supernova of an even older star that may have been 200 times the size of our sun.
Hummingbirds evolved ability to taste sweets
Hummingbirds’ taste receptors have evolved to be able to detect sweets, according to a study in Science. Researchers have long wondered why hummingbirds were drawn to sweet nectar when their genes don’t have codes to develop sweet taste receptors, but a team of biologists have found that the birds’ ability to detect umami switched over millions of years of genetic mutations to an ability to suss out sweets.
Overabundance of synapses linked to autism
The brains of children with autism have too many synapses, which are usually pruned away by the brain as the child grows in adolescence, according to a study published in Neuron. Researchers suggest that something stops the pruning process, leaving some areas of the brain with an overabundance of synapses causing stimuli overload. The study could help explain how autism develops and lead to possible treatments.
Neanderthals died out earlier than thought
Research suggests that Neanderthals died out much earlier than previously thought, and humans may have played a role in their demise. Researchers reevaluated artifacts from 40 European sites during the period when humans came to Europe and Neanderthals disappeared, using improved dating techniques to reach their conclusions.
Genetically altered pig hearts still beating after year in baboon hosts
Genetically engineered pig hearts grafted into baboons have survived more than a year. Scientists tested several genetic modifications, but the most successful were those that added the human thrombomodulin gene, which prevents clotting. The next step will be to replace a baboon’s heart with the pig heart to see if they can sustain life there.