BIOLOGY 1B Lecture Notes - Lecture 27: Microfungi, Human Impact On The Environment, Carbon Cycle
Document Summary
When you get into cenozoic (era), it breaks into epochs, like pleistocene (began (cid:1006). 8 (cid:373)illio(cid:374) (cid:455)ea(cid:396)s ago ea(cid:396)liest hu(cid:373)a(cid:374)s at that ti(cid:373)e too, (cid:271)ut that"s (cid:374)ot (cid:449)h(cid:455) it"s there) and goes to 12,000 years ago (agricultural revolution) Hypothesis that humans may have been responsible for megafaunal extinctions due to overhunting. Start with high levels of birth and death; with modernization, the death rate declines first (hygiene, medicine, healthcare, etc. ); birth rates don"t decline right away; birth rates drop later; after a long time (education, professional opportunities, tv, etc. ), both birth and death rates are low; birth rates can even drop below death rates (top heavy structure pyramid) Nit(cid:396)oge(cid:374) (cid:272)(cid:455)(cid:272)le (cid:374)it(cid:396)oge(cid:374) fi(cid:454)atio(cid:374) a(cid:374)d de(cid:374)it(cid:396)ification; humans have learned how to fix nitrogen ourselves. Phospho(cid:396)us (cid:272)(cid:455)(cid:272)le the(cid:396)e"s so(cid:373)e phospho(cid:396)us i(cid:374) at(cid:373)osphe(cid:396)e (cid:271)ut it is (cid:373)ai(cid:374)l(cid:455) a terrestrial phenomenon; erosion is natural mechanism for making phosphorus available to ecosystems. Atmospheric cells that drive global wind patterns.
