Now that you're ROFL after seeing the obese man, have you ever wondered why we survived all these years? Charles Darwin's theory of evolution is based on the whole premise of "survival of the fittest". And do you call that fit? The point is its not fit as in gym/healthy, but fittest could be interpreted in a lot of ways - the species that survives is the one that is fittest for the circumstances.
Why should the human animal survive and prosper all these years when there are stronger animals out there? And we are so far ahead in the evolutionary game that we control the survival/extinction of the rest of the species. They are under our mercy, or atleast getting the mercy of the subset of homo sapiens who are members of PeTA or WWF. I have sometimes wondered while walking on the streets, why we humans built those huge buildings and live comfortably. Why not Tigers, Rats, Dogs or Ants?
Reproduction alone is not the answer because rats multiply faster. The next obvious answer would be Sixth sense. But billions of humans living alone with their sixth sense could not have dominated the earth the way we have dominated today. There's an element of collectivism that helped us unite in some way and survive so far. We still don't have as much collectivism as Ants, who could have easily been here instead of us. Imagine zillions of ants walking the face of earth, slowly and steadily building huge ant mounds and industries, which is easily possible. But their collectivism was not enough to beat us. If only they were carnivorous and fed on humans, they wouldn't be the object of fancy of every child playing in the park or backyard. Or they would not have become a cute decorating item on your coffee table.
Humans have both collectivism and individualism. The individualism makes some humans aspire to greatness, like a Wright brothers or Newton or Shakespeare or Einstein or Da Vinci, which help us like turbochargers in the evolutionary game. But the important element that made sure we didn't re-invent the wheel or re-invent the fire in evolutionary terms, was the transmission of knowledge from one generation to another. And the tools that helped us are language, books and internet, and not to forget schools and colleges and universities.
Intellect was the key in later years, but that still could not have helped early humans beat a lion in catching a deer. There could have been no "Teach yourself How to catch a deer in 21 days without being eaten by a Lion" in those days. Humans were not completely carnivores, and that solves half your food problems, because flesh rots faster than vegetables and they didn't have refrigerators in those days.
Can you think of any animal that doesn't have an external dependency on food? Even cows need grass. And if you have been to a park with monkeys, even they depend on the snack food you feed them, in additon to the fruits and nuts on the trees. That's where it all started. Imagine humans feeding monkeys in a park. Flashback 50 billion years. Only there are no humans to feed the monkeys, because the humans have not yet evolved from the monkeys. The monkeys jump around trees, grab fruits and vegetables and sometimes eat in groups. Some monkeys are more advanced than the others and fed on meat. As evolutionary rumours in erstwhile People magazine "Primates" go, one monkey-man dropped his food in the sea, discovered that salt added taste to his otherwise raw meat. Another monkey-man dropped his food in the fire and heating was born. Monkey man one meets Monkey man two and cooking was born. Salt evolved into garam masala, schezuan sauce and numerous other spicy tastemakers. And heating evolved into Firestoves, Kerosene stoves, Gas cylinders, Ovens, Microwaves and Magnetic Induction cookers.
And the external dependency of humans on food was gone. Now they no longer needed to hunt for food. They can store and cook their own food, which no other animal can even today. Now when everybody has to hunt for food everyday, humans can happily cook and feed on 3 sumptuous meals a day, and have other things to think about than where the next meal is coming from. They thought of agriculture, industries, science, philosophy, wars, computers and a lot of other things.
After depending on restaurants for a long time for food, I recently discovered this freedom from external dependency after learning to cook using the magnetic induction cooker i recently bought and the numerous packed and ready to cook foods available. I felt like the Neanderthal man walking on earth feeling sorry for the Lions and Tigers who'll never learn how to cook.