Ancient microbial life used arsenic to thrive in a world without oxygen

Today, most life on Earth is supported by oxygen. But ancient microbial mats existed for a billion years before oxygen was present in the atmosphere. So what did life use instead? Source: https://earthsky.org/earth/ancient-microbial-life-arsenic…

Leonardo da Vinci saw a whale fossil that opened his mind to deep time

Renaissance-era polymath Leonardo da Vinci may have seen a whale fossil in his youth, prompting him to speculate that Earth was enormously old Source: https://www.newscientist.com/article/2250424-leonardo-da-vinci-saw-a-whale-fossil-that-opened-his-mind-to-deep-time/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home…