• Question: What came first the chicken or the egg??? haha!! :)

    Asked by madsmith98 to Anil, Blanka, Cees, Emma, Mike on 24 Jun 2012. This question was also asked by farheen2904, whchloep, whmegandnath, whdavandbeat.
    • Photo: Emma Trantham

      Emma Trantham answered on 24 Jun 2012:

      LOL! Is it cheating to say the dinosaur?!

      Chickens (and all birds) are believed to have evolved from a group of dinosaurs called theropod dinosaurs.

      Birds, along with all other living organisms, evolve through changes in their DNA (the genes that make a chicken a chicken etc.). This is usually a very slow and gradual process.

      Let’s say for the sake of argument that we have the first chicken. It’s the first bird to have the exact DNA combination that makes a chicken a chicken. Technically this DNA combination was first brought about when DNA in the egg cell from its non-chicken mother, combined with DNA in the sperm cell from its non-chicken father, to form a single cell that we call a zygote. This zygote is what is housed within the egg shell and so technically you could say the egg came first… ( http://sciencebasedlife.wordpress.com/2012/03/10/which-came-first-the-chicken-or-the-egg-evolution-has-the-answer/ is a nice description of the process)

    • Photo: Blanka Sengerova

      Blanka Sengerova answered on 24 Jun 2012:

      The chicken and egg question is probably mostly a philosophical musing on the problem of a circular reference (occasionally spreadsheets will complain about a circular reference!) which happens when A is required for B to happen but B is also required for A to happen, i.e. something impossible.

      But I do like Emma’s explanation, thank you!

      As she says, the chicken and egg will have both evolved over time from a pre-chicken type of bird (ultimately a flying dinosaur) by very gradual modification of the DNA, the material that provides the instruction for making both chicken and egg. The DNA modification (of chicken and egg) happens in parallel but since most mutations that are transferred to the next generation happen at the stage when reproductive cells are formed (eggs and sperm) this would suggest that the egg would be first to have the modified DNA and then give rise to a modified chick.

      But that still doesn’t answer whether the flying dinosaur came before or after its egg, right? What do you think?