The first 1,000 people to sign up to Skillshare will get their first 2 months for free: https►► https://www.patreon.com/theinfographicsshow SOCIAL: Twitter........► https://twitter.com/TheInfoShow Subreddit...► http://reddit.com/r/TheInfographicsShow -------------------------------------------------------------------------- Sources for this episode: https://genetics.thetech.org/ask-a-geneticist/why-dogs-and-people-cant-have-babies https://en.wikipedia.org/wiki/Reproductive_isolation http://www.slate.com/articles/news_and_politics/explainer/2006/11/humanderthals.html