Aforensic scientist finds a single skin cell from saliva on a cigarette butt left in a room where a murder has just occurred. what process might he or she utilized to accumulate enough dna to determine who left the cigarette at the scene of the crime?
a. genetic engineering
b. gene therapy
c. gel electrophoresis
d. polymerase chain reaction

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.