Geography 2156B Lecture Notes - Lecture 2: Habitat Destruction, Neolithic, River Dolphin

• School: Western University
• Department: Geography
• Course: Geography 2156B
• Professor: Tony Weis

Document Summary

The 6th extinction spasm (cid:862)(cid:271)iologi(cid:272)al di(cid:448)ersit(cid:455) is i(cid:374) the (cid:373)idst of its (cid:1010)th great (cid:272)risis, this ti(cid:373)e pre(cid:272)ipitated e(cid:374)tirel(cid:455) (cid:271)(cid:455) (cid:373)a(cid:374)(cid:863) . The cambrian explosion: pivotal moment of fast-moving evolution in a short period of time, 540 million years ago rise of most major animal phyla. Extinction spasms (cid:858)(cid:271)a(cid:272)kgrou(cid:374)d rate(cid:859) (cid:894)at (cid:449)hi(cid:272)h spe(cid:272)ies e(cid:448)ol(cid:448)e a(cid:374)d die off, lo(cid:374)g slo(cid:449) pro(cid:272)ess(cid:895) (cid:448)s (cid:858)spas(cid:373)(cid:859) (cid:894)rapid pa(cid:272)e in relatively short period: dramatic shifts in the nature of life on earth. Great herbivores of asia and americas: hunted to extinction. Mesozoic era (cid:858)age of eptiles(cid:859: 252-66 million years ago, period of warm temperature, no ice, (cid:862)hothouse earth(cid:863, +3-(cid:1008) c a(cid:271)o(cid:448)e prese(cid:374)t, ** most famous extinction spasm ** Cretaceous-paleogene extinction spasm: end of dinosaurs, dramatically changed climate conditions. The pleistocene epoch: 2. 6 million 12,000 years ago. The holocene covers the last 11,500 years: geological epoch in which agricultural arised, gather-hunterers at very low density relatively warm earth conditions relatively stable earth climate.