Imagine you land from another planet, and you discover that humans come in two major varieties. How many of the 8 billion people would you need to survey to di

Imagine you land from another planet, and you discover that humans come in two major varieties. How many of the 8 billion people would you need to survey to discover that roughly half were male? It actually doesn't depend on the population. You could have landed 1000 years ago when the population was much smaller, and carry out a survey with the same number of samples, coming to the same conclusion.