Your brain on viral content\u00a0<\/p>\n
Gerdes, Patricia; Karlsson, Ofelia; Garza, Raquel; Atacho, Diahann A. M. et al. \u201cRetroviral insertions contributed to the divergence of human and chimpanzee brains.\u201d Science Advances.<\/a><\/p>\n A virus that infected chimpanzees millions of years ago shaped the divergence of human and chimp brain development, shedding light on how our own species came to be more cognitively complex than our closest living relatives, according to a new study.\u00a0<\/p>\n Retroviruses are infectious agents that can invade the genomes of their hosts and insert copies of their own genetic material, producing long-term evolutionary effects. Researchers have now discovered a family of these endogenous retroviruses called PTERV1\u2014which are abundant in chimpanzees, but absent in humans\u2014that influence brain development.\u00a0\u00a0\u00a0<\/p>\n \u201cAmong primates, the human brain stands out as the largest and most complex due in part to an increase in cortical neurons and increase in synaptic connectivity,\u201d said a team led by researchers from Lund University. \u201cWith a size roughly three times that of our closest living evolutionary relative, the chimpanzee, it has unique cognitive capabilities.\u201d<\/p>\n \u201cThe underlying genetic divergences responsible for these differences are still poorly understood,\u201d the researchers continued, noting that their new findings \u201creveal a mechanism by which endogenous retroviral insertions contributed to human-chimpanzee brain divergence.\u201d<\/p>\n The team discovered the mechanism using human and chimpanzee brain organoids, which are miniature clusters of neurons grown from stem cells that can model some aspects of brain development. The results revealed chimpanzee-specific PTERV1 insertions on chromosome 19 that silences a gene called LINC00662. In contrast, this gene is active during human brain development, and affects neuronal maturation, development, and outgrowth.\u00a0\u00a0<\/p>\n \u201cThese PTERV1 insertions are thought to have originated from infections that occurred in the ancestors of African apes about 5 to 7 million years ago,\u201d said the team. \u201cPTERV1 elements are found in chimpanzees, bonobos, and gorillas\u2026Notably, the absence of PTERV1 insertions from the human genome suggests that either the human and chimpanzee lineages did not occupy the same habitat at the time or that germline-competent cells of the human ancestor were resistant to this infection.\u201d<\/p>\n \u201cIn summary, this study describes how retroviral insertions contributed to the functional divergence of the human and chimpanzee brain, providing a mechanism by which retroviral infections influenced primate brain speciation,\u201d they added.<\/p>\n In other words, early humans appear to have dodged consequential pandemics that widely infected our primate brethren simply because they had a random immunity to it, or roamed different ranges. While retroviruses are far from the only factor in our cognitive development, it\u2019s still eerie to think that our human brain\u2014that brilliant lump you are using to read these words\u2014is shaped by dumb luck.<\/p>\n In other news\u2026<\/p>\n Another brain to crow about<\/p>\n Schmidbauer, Philipp and Nieder, Andreas. \u201cUltrarapid decision-making in an avian brain.\u201d Science.<\/a><\/p>\n Speaking of interspecies brain-offs, it seems the birds have got us beat\u2014at least when it comes to snap decisions. Scientists have discovered that carrion crows (Corvus corone) can make ultrafast choices in \u201capproximately 235 milliseconds on average, which is roughly twice as fast as has been observed in monkeys or humans and without sacrificing accuracy,\u201d according to a new study.<\/p>\n A pair of researchers observed two crows performing a common discrimination task in which dots on a screen move left, right, up, or down. The crows selected the predominant direction by pecking a target circle on a touchscreen, after which they were rewarded with promptly dispensed treats. The crows performed the task dozens of times at extremely high speeds, achieving an overall choice accuracy of 75 percent (crow 1) and 73 percent (crow 2).<\/p>\n \u201cHaving diverged from mammals more than 360 million years ago, birds evolved a distinct nuclear pallium\u201d\u2014a part of the vertebrate forebrain\u2014\u201dthat lacks the layered neocortex yet retains key organizational and computational principles characteristic of mammalian brains,\u201d said study authors Philipp Schmidbauer and Andreas Nieder of the University of T\u00fcbingen.\u00a0\u00a0\u00a0<\/p>\n \u201cThese findings highlight the extraordinary efficiency of avian decisionmaking circuitry, possibly shaped by evolutionary pressures for rapid visuomotor control,\u201d the team added.<\/p>\n So if anyone ever calls you a birdbrain, the correct response is \u201cthanks.\u201d\u00a0<\/p>\n \ud83c\udf18<\/p>\n Subscribe<\/a> to 404 Media to get The Abstract<\/a>, our newsletter about the most exciting and mind-boggling science news and studies of the week. Who is this sarcopha-guy?<\/p>\n Rodwell, Warwick. \u201cWestminster Abbey\u2019s Roman Sarcophagus and its Afterlife.\u201d Journal of the British Archaeological Association.<\/a><\/p>\n Archaeologists may have finally discovered the mysterious identity of an ancient skeleton buried in a Roman-era sarcophagus that was first unearthed on the grounds of Westminster Abbey more than 200 years ago.\u00a0<\/p>\n Despite an inscription on the sarcophagus identifying the occupant as Valerius Amandinus\u2014a wealthy Londoner who lived between 300 to 400 AD\u2014the bones likely belong to a medieval monk named \u00c6lfwig, born centuries later in the year 993.\u00a0<\/p>\n \u201cThe burial was of a male, probably in his late forties, and was radiocarbon dated to around the turn of the 11th century,\u201d said study author Rodwell Warwick of Westminster Abbey. \u201cThe corpse had been laid in a timber coffin and covered with lime; it was then placed inside the sarcophagus. It is argued that this was the prestigious burial of Abbot \u00c6lfwig.\u201d<\/p>\n The sarcophagus was exhumed and moved to a northern courtyard during King Henry III\u2019s reconstruction of the abbey in the mid-1200s, where it laid for about six centuries. On Easter Monday 1820, the coffin was \u201cwantonly broke by workmen\u201d according to a note from an unknown contemporary archivist. Any grave goods were likely plundered by this crew and the sarcophagus was hastily put back together and reburied with the bones all jumbled up inside. It was then re-discovered in 1869 with a note that the burial \u201c\u2018had been subjected to violence by a previous examination.\u201d<\/p>\n It turns out anything is recyclable\u2014even sarcophagi. The discovery that this Roman coffin at some point took on another tenant now raises the new question of how the earthly remains of Valerius Amandinus got evicted and where they ultimately wound up.\u00a0<\/p>\n \u201cThe Starry Night\u201d\u2014of July 22, 1889?<\/p>\nSketches of gorilla, chimp, and human skulls. Image: kaiwei zhang<\/p>\n
Crow acing the test. Image: Andreas Nieder<\/p>\n
Interior of the sarcophagus, as found upon opening in 2016. Image: Rodwell, Warwick<\/a>, 2026.<\/p>\n