The size of humans steadily increased because they ate more. why did they eat more?

If you have a difficult time knowing where your hand is without looking at it you may be having a problem with your what ?

Me with these questions image attached

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.