• Question: What came first, the egg or the chicken?

    Asked by AndreaYngsLdzm to Stewart, Miriam, Marton, Laura, Kathryn, David on 9 Nov 2018.
    • Photo: David Ho

      David Ho answered on 9 Nov 2018:

      According to the theory of evolution, it was the egg! Broadly speaking, every time an animal reproduces, it’s offspring are a tiny bit different from the parent. Over time, these tiny differences build up and eventually cause different species to evolve (there’s a lot more to this, see for example here: https://science.howstuffworks.com/life/evolution/evolution1.htm).

      So a long time ago there were no chickens, but there were dinosaurs (which laid eggs). Over billions of years, some dinosaurs came to look more like chickens, and eventually we got to something that was very like a chicken, but not quite. That thing laid an egg, and out hatched the first ever chicken!

      Of course there would be a lot of argument about exactly what would be counted as the first chicken, and you couldn’t really point to an exact animal and say “that was the first chicken”. But there was definitely a time when there were no chickens, only eggs, and the first ever chickens definitely hatched from eggs!

    • Photo: Miriam Hogg

      Miriam Hogg answered on 9 Nov 2018:

      The Egg!
      Reptiles and other amphibious animals were using eggs to grow their young for millions of years before chickens came along! (Even dinosaurs laid eggs)

    • Photo: Stewart Martin-Haugh

      Stewart Martin-Haugh answered on 10 Nov 2018:

      Evolution tells us that organisms change with each generation. At some point, something that was not quite a chicken laid an egg containing a baby chicken.

      One way that organisms end up changing is if cosmic rays (particles from space) hit their DNA and cause it to change. The atmosphere protects us from a lot of cosmic rays (too many would be harmful) but some of them still get through.

      In fact there are cosmic rays passing through you right now!