You know about fossils, but what other secrets are lurking in the ground beneath our feet? Hosted by: Hank Green ---------- Support SciShow by becoming a patron on Patreon: www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters—we couldn't make SciShow without them! Shout out to Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Patrick Merrithew, Charles Southerland, Fatima Iqbal, Benny, Kyle Anderson, Tim Curwick, Scott Satovsky Jr, Philippe von Bergen, Bella Nash, Bryce Daifuku, Chris Peters, Patrick D. Ashmore, Charles George, Bader AlGhamdi ---------- Looking for SciShow elsewhere on the internet? Facebook: www.facebook.com/scishow Twitter: www.twitter.com/scishow Tumblr: scishow.tumblr.com Instagram: instagram.com/thescishow ---------- Sources: rstb.royalsocietypublishing.org/content/370/1660/20130383#ref-83 www.nature.com/nature/journal/v506/n7486/full/nature12921.html www.pnas.org/content/106/52/22352.full#sec-8 rspb.royalsocietypublishing.org/content/272/1558/3?ijkey=f67bc26c8446905e2bffbb24fb7d9fd04da75f3d&keytype2=tf_ipsecsha www.ncbi.nlm.nih.gov/pmc/articles/PMC140122/ www.sciencedirect.com/science/article/pii/S1164556303000335 www.sciencedirect.com/science/article/pii/016770128790025X science.sciencemag.org/content/300/5620/791 academic.oup.com/mbe/article/24/4/982/1012556/Ancient-DNA-Chronology-within-Sediment-Deposits?ijkey=bc3552daa5b361e4213c0fb839987c51d731a0c4&keytype2=tf_ipsecsha science.sciencemag.org/content/347/6225/998.full?sid=a8020087-b772-4cc8-a69b-65ad52f2cfbc elifesciences.org/content/4/e10005 www.nature.com/nature/journal/v477/n7365/abs/nature10388.html Images: commons.wikimedia.org/wiki/File:Greenland_eastcoast.jpg commons.wikimedia.org/wiki/File:EscherichiaColi_NIAID.jpg commons.wikimedia.org/wiki/File:PCR_tubes.png commons.wikimedia.org/wiki/File:Quebrada_de_Cafayate,_Salta_(Argentina).jpg commons.wikimedia.org/wiki/File:Wheat_harvest.jpg www.nasa.gov/feature/jpl/mars-rock-ingredient-stew-seen-as-plus-for-habitability