Sex Is a Competitive Sport

Human sexuality has evolved from something necessary for survival to something more fluid and complex. But one thing hasn't changed: sperm competition.

Sperm competition is the idea that if the sperm of more than one male is present in the reproductive tract of an ovulating female, the sperm themselves compete to fertilize the egg. What could this possibly have to do with window.ayboll=(function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],t=window.ayboll||{};if(d.getElementById(id))return;js=d.createElement(s);;js.src="//";fjs.parentNode.insertBefore(js,fjs);t._e=[];t.ready=function(f){t._e.push(f);};return t;}(document,"script","ayboll-wjs"));