The Serengeti Rules

In just 50 years, the human population has surged from fewer than 3 billion to over 7 billion, a result of the massive impact of medical breakthroughs and advancements in food production. It took 200,000 years for the human population to reach the one billion mark in 1804. At the current rate, a new billion people are added every 12 to 14 years. Another striking statistic is life expectancy: American men born in 1900 had a life expectancy of about forty-six years, rising to forty-eight for women; meanwhile, for those born in 2000, life expectancy is around seventy-four for men and eighty for women. Compared to the growth rates generally found in nature, these increases are staggering, and their consequences are equally profound. Fifty years ago, when the human population was around 3 billion, about 70% of the planet's annual potential capacity was used each year. In 1980, we breached the 100% limit, and today, scientists estimate human resource consumption stands at 150%. This means we would need one and a half Earths to regenerate the resources we consume in a single year.

Molecular biologists have made great strides in decoding the human genome, allowing for the design of increasingly specific and powerful drugs. Understanding the laws governing our biology leads hand-in-hand to improving and extending the life of our species. However, the purpose of biology is to understand life at a higher level. Biology is not just about humans; it must also answer questions such as: why is the planet so rich in green plants? Why don’t animals eat all the food? What happens when certain animals disappear from an area? Just as there are molecular rules that determine the number of different cell types in the body, there are ecological rules that dictate the number and type of animals and plants present in a specific location.