文档介绍：The Biosphere and Animal Distribution Chapter 37 Earth Environment - Overview ? Water has physical properties critical to life on earth. ? The steady supply of sunlight maintains a suitable range of temperatures for life metabolism. ? Living matter requires a supply of major and minor elements available on earth. ? The earth ’ s gravity is strong enough to hold an extensive gaseous atmosphere. ? The environment is modified anisms. ? Organisms are adapted by evolution to the environment . ? The earth is an open system with a continuous supply of energy. ? Building materials for e from producers and are cycled through consumers. ? Life is part of a cycle of life-death-decay- recycling. Earth Environment Earth Environment ? The primitive earth of billion years ago had a reducing atmosphere of ammonia, methane, and water and was fit for pre- biotic synthesis of early living forms. ? This early atmosphere would be fatal to today ’s organisms. ? The appearance of free oxygen in the atmosphere is an example of the reciprocity of life and the earth. ? anisms produce changes in their environment and must adapt and evolve. Biosphere ? The biosphere is the thin outer layer of the earth capable of supporting life. ? Includes living organisms as well as the physical environments. Biosphere - Subdivisions ? Lithosphere – rocky material of the earth ’ s outer shell. ? Source of mineral elements required for life. ? Hydrosphere – water on or near the earth ’ s surface. ? Atmosphere – the ponent of the biosphere. ? Atmospheric oxygen is produced by photosynthesis. Greenhouse Effect ? Materials in the atmosphere, such as CO 2 and water vapor retain heat, raising atmospheric temperature. ? Greenhouse effect ? Burning fossil fuels increases CO 2 in the atmosphere. Greenhouse Effect ? The greenhouse effect provides conditions essential for life on Earth. ? Humans are increasing this effect. ? Increased temperatures could lead to a rise in