How does the rate of mid-ocean ridge spreading affect the level of CO2 in the atmosphere?

How can you approximate the number of calories required to keep you in energy balance?

How does secondary succession differ from primary succession?

Homo heidelbergensis was a tall, muscular hunter, who used both tools and weapons. because h. heidelbergensis was not a gatherer/forager, but ate a varied diet including meat and fish, we would expect to see what anatomical changes?