Homo erectus lived about 1.8 million years ago. Homo erectus had a brain as large as the smallest modern adult brain, but had notably different features, such as large brow ridges, a slightly protruding face, and no chin. Both Homo sapiens and Homo erectus are members of the same species. A scientist and his students are studying the rapid decline of a species. Individuals with traits best suited to the environment have the potential to leave the largest number of offspring.
Cells are highly organized.
Living organisms are capable of utilizing energy. Populations can undergo evolutionary adaptation. The body of the organism must maintain homeostasis. Hydrogen has 1 neutron. Hydrogen has 2 protons.