Describe how phytochrome acts in plant photoperiodism.
Chapter 20: Human Global Ecology The History of the Human Environmental Impact A turning point in the environmental history of humans – the emergence of agriculture and animal husbandry 8,000 years ago The human population increased Our impact was concentrated into much smaller space Scale of Human Impact Varies Pollution o Point sources – discrete, local sources of pollution E.g., power plant, car exhaust, sewage treatment plant Easier to regulate Regulations could shift the scale of the effects (e.g., taller smoke stacks long distance impacts) o Nonpoint sources – releases of pollution across a broad area Agricultura