A conversation with Forrest Bishop about the Pleistocene Murders - a whodunnit theory that seeks the cause of the megafaunal extinction that rocked the planet during the most recent period of glaciations - from 2.5 million years ago to about 10,000 years ago. While most theories - including a recent paper from Tel Aviv university point the finger at increasing populations of hungry humans, Forrest proposes that this ignores a crucial, global change that occurred over the course of the Pleistocene: a global decrease in carbon dioxide levels. In the Pleistocene Murders, he proposes that falling carbon dioxide levels led to the dominance of c4 plants - those who can flourish at relatively low partial pressures of CO2. This evolutionary advantage allowed grasslands to dominate the globe... which, in turn, led to a decrease in the caloric content of the trophic foundation of the world's ecosystems. It's an excellent story that binds together geology, chemistry, and biology... and even a little bit of spirit, as humans have an emergent role on the planet that we get to at the very end of the conversation Support the podcast by becoming a Patron @DemystifySci ªº¬˚∆≤≥≤≥ https://www.patreon.com/demystifysci ≤≥≤≥∆˚¬ºª Pleistocene Murders Blog: http://www.castaliahouse.com/otherscience-stories-the-pleistocene-murders-part-1/ ªº¬˚∆≤≥≤≥ Join the mailing list https://bit.ly/3v3kz2S​ ≤≥≤≥∆˚¬ºª Check our main channel, @DemystifyingScience for in depth-investigations: https://youtu.be/1OCL5Lq8m6s PODCAST INFO: Blog: http://demystifyingscience.com/blog Apple Podcasts: https://apple.co/3uhn7J1 Spotify: https://spoti.fi/39IDJBD RSS: https://anchor.fm/s/2be66934/podcast/rss Donate: https://bit.ly/3wkPqaD Swag: https://bit.ly/2PXdC2y SOCIAL: - Twitter: https://twitter.com/demystifysci - Facebook: https://www.facebook.com/groups/demystifyingscience - Instagram: https://www.instagram.com/demystifysci/ More details Forrest would like for you to know: "Atmospheric CO2 reached about 417 ppm last May, 2020. Now it's off a ppm or two due to all your plants eating it up. https://www.co2.earth https://www.esrl.noaa.gov/gmd/ccgg/trends/monthly.html As the level rises, C3 plants (your flowers, vegetables, trees) are becoming more competitive over C4 plants (corn, most grass, sugar, weeds, tumbleweed). A crossover was back at 400 ppm. Explanation- http://forrestbishop.mysite.com/Megafaunal.html Sign 1/10. Blackout. Look at shadows of trees and bushes. Are they completely black? Then the plant is intercepting every ray of sunlight. Did they used to do this, years and decades ago? Sign 2/10. Old tree, New Branch. Are older, mostly deciduous, trees now sprouting new branches lower down on their trunks, more than they used to? Sign 3/10. Wall of green. Rows of trees along roads that have grown together to block the Sun, from the ground up, along with all the little stuff in front of the trees. Dark as a cave inside. Sign 4/10. Giant rings. We cut down a Redwood that was well over 5’ diameter DBH. It was 45 yo, so 1.5”/yr diameter increase. Have you seen such giant growth rings on trees? Sign 5/10. Arboreal Reconquista. Have you seen grasslands that are being invaded and taken over by new trees? In Idaho and Wisconsin, at least, the state is actively trying to counter this. https://da.wikipedia.org/wiki/Hede Sign 6/10. Pop Up. Do you know of any ranch/range land where bushes, etc. are popping up where only grass grew before? Said to be happening in the American SW. Sign 7/10. Exploding Stumps. When a tree is cut down, it can sprout “suckers”. Seen any suckers exploding out of stumps lately? Not little stuff, massive new growth. Sign 8/10. Speedy Tips. The new tips on the conifer branches grow to a certain size each year, pretty uniformly. Have these new tips been increasing in size lately? Sign 9/10. Oddballs. Are new kinds of plants popping up here and there that didn't used to grow here and there? They might be existing types, hybrids, or something else. Sign 10/10. Before-After. Do you have any sets of new and old pictures of a natural, untouched landscape, both taken from the same point of view? The old ones are preferably several decades old."