October 1, 2009 Report A 4.4-million year old fossil, discovered in Africa has opened a window onto humans' "early evolutionary steps," according to scientists.
Carmakers are looking to alternative fuels such as ethanol, natural gas and hydrogen to improve fuel economy, decrease greenhouse gas emissions and transition from foreign to domestically produced fuels. In this in-depth report, learn about the science and politics of alternative fuels, and explore how your car's fuel costs and emissions stack up to similar alternative fuel vehicles.