if you stay in a cave with no light, you still maintain a 24-hour cycle of waking and sleeping. why?

"acknowledging a right to benefit from the presence of animals requires government action to ensure human access to animals in a number of different spheres," writes jessica pierce, ph.d., in psychology today. the pragmatic meaning of the term "right" in this statement is

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Many organizations release indexes used to measure the development of the world's countries. as we learned in this lesson, these indexes measure many factors, from life expectancy to happiness. in your opinion, what are the three most important factors we can use to determine how developed a country might be? explain your answers in a few sentences.