Human-caused fire transformed prehistoric California

+ forensic DNA analysis in Maui; orcas and otters fight back US Edition - Today's top story: A changing climate, growing human populations and widespread fires contributed to the last major extinction event − can we prevent another? [View in browser]( US Edition | 18 August 2023 [The Conversation] [The Conversation]( Top headlines - [The legal argument for disqualifying Trump from office]( - [Why a carbon tax on income, not consumption, could be more equitable]( - [Think you can get 8 for 8 in this week’s news quiz? Give it a go]( Lead story Fifty thousand years ago, North America looked quite different. Glaciers covered much of the landscape, and large mammals like mastodons, giant sloths, big cats and dire wolves roamed. Over several thousand years, humans had made it to North America, too, and lived alongside many of these mammals. But as the climate started to warm, the glaciers receded and human populations expanded. These mammals started dying out – to the scale of a major extinction event. New research suggests that there was more than just a warming climate and human expansion at play. A study of fossil records at the La Brea Tar Pits in Los Angeles released yesterday shows that at the time these mammals were dying off, widespread fire had also started changing the landscape. Emily Lindsey and Lisa Martinez from UCLA and Regan Dunn from USC break down how fires – many of which humans likely started – [transformed this region and led to ecosystem collapse](. They also warn that some of these factors – a warming climate, human-caused wildfires – parallel what scientists see today. [ [Get our Understanding AI series – four emails delivered over the course of a week, with experts explaining this confusing topic.]( ] Mary Magnuson Assistant Science Editor The fossil deposits at the La Brea Tar Pits in Los Angeles have well-preserved remains of many prehistoric animals that got stuck in natural asphalt seeps over the past 60,000 years. Cullen Townsend, courtesy of NHMLAC [A changing climate, growing human populations and widespread fires contributed to the last major extinction event − can we prevent another?]( Emily Lindsey, University of California, Los Angeles; Lisa N. Martinez, University of California, Los Angeles; Regan E. Dunn, USC Dornsife College of Letters, Arts and Sciences New findings from the La Brea Tar Pits in southern California suggest human-caused wildfires in the region, along with a warming climate, led to the loss of most of the area’s large mammals. 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Scientists and volunteer divers are racing to save these valuable creatures. - [A carbon tax on investment income could be more fair and make it less profitable to pollute – a new analysis shows why]( Jared Starr, UMass Amherst Taxing consumption that contributes to climate change hits the poor the hardest, while overlooking the huge profits tied to greenhouse gas emissions. Trending on site - [Oppenheimer often used Sanskrit verses, and the Bhagavad Gita was special for him − but not in the way Christopher Nolan’s film depicts it]( - [As the mental health crisis in children and teens worsens, the dire shortage of mental health providers is preventing young people from getting the help they need]( - [Montana kids win historic climate lawsuit – here’s why it could set a powerful precedent]( The Conversation Quiz 🧠- Here’s the first question of [this week’s edition:]( Sixteen young people from Montana won their lawsuit against the state on Aug. 14. 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