YOU WERE MISINFORMED AT SCHOOL that in nature, "survival of the fittest" is the only truth.

But the truth is far more complex.

Your teacher told you a lie, but it's a lie that's often used as a teaching tool.

In reality, natural selection isn't about survival - it's about reproduction.

Take the ram in the video, for example. His large horns are a key factor in attracting females and producing offspring.

But those same horns can also be a hindrance, and may even lead to his demise.

This delicate balance of costs and benefits is known as conflicting demand, or trade-off.

It's a concept that applies to all characteristics that differ between sexes, and even has implications for immune systems, aging, and risk-taking behavior in numerous species - including humans.

So, it's because of these trade-offs that males are often sicker, age faster, and die earlier.