Lucy was found by Donald Johanson and Tom Gray on November 24, 1974, at the site of Hadar in Ethiopia. They had taken a Land Rover out that day to map in another locality. After a long, hot morning of mapping and surveying for fossils, they decided to head back to the vehicle.
Alkanes are an example of saturated compounds. An unsaturated compound is a chemical compound that contains carbon-carbon double bonds or triple bonds, such as those found in alkenes or alkynes, respectively. Saturated and unsaturated compounds need not consist only of a carbon atom chain.
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. Where double bonds are formed, hydrogen atoms are eliminated.