If we produced by mitosis then everyone would be the same. The would be no genetic differentiation. Because in meiosis, germ cells cross over and create zygotes with unique dna.
Mutualism is a relationship between two species in which both species benefit. Certain species of bacteria in your intestines form a mutualistic relationship with you.
Pollution plays a huge factor. With factories in demand, more and more substances are being released into Earth's atmosphere, resulting in higher temperatures.
