Why Bird Penises Are So Weird

To learn more about this topic, start your googling with these keywords: Sex chromosome: A chromosome involved in determining the sex of an individual. Cloaca: A posterior orifice that serves as the only exit for the gastrointestinal, urinary and genital tracts. Mutation: An alteration in the DNA sequence that makes up a gene. Sexually-selected Trait: A trait based on a mutation that confers a reproductive advantage. BMP4: A protein whose presence halts the growth of bird penises in the egg. MinuteEarth is produced by Neptune Studios LLC https://neptunestudios.info If you like what we do, you can help us! - Become our patron: https://patreon.com/MinuteEarth   - Buy our merch: http://dftba.com/minuteearth   - Buy our book: https://minuteearth.com/books - Sign up to our newsletter: http://news.minuteearth.com   - Share with your friends and family - Leave us a comment (we read them!) Learn more about your ad choices. Visit megaphone.fm/adchoices