A team of biology student's performed an experiment to test the effects of four different solutions on a de-shelled, raw chicken egg. Each raw unbroken chicken egg of the same size was placed in each of four different solutions. Twenty four hours later the following
results were
obtained. Using the data in the table above and your knowledge of science, what is the independent variable in the experiment?

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.