The Evolution of Corn

Posted by Siamang on: 10.29.2007 /

Here’s a science post.

It’s a great little blog post about where corn came from. People talk a lot about the evolution of animals. I think sometimes we forget that plants have a rich and amazing evolutionary history as well.
teosintevscorn.jpg

For many years, the origin of corn was a mystery. Like most known crops, it was domesticated 6000-10,000 years ago. But unlike other crops, its wild ancestor was unknown until relatively recently. Why this odd gap in our knowledge? Well, it turns out that corn is shockingly different — in form, or morphology — from its closest wild relative, which is a grass called teosinte, still native to southwestern Mexico.

Here we have the evidence that corn evolved from a grass called teosinte. It’s a wonderful discovery, because the ancestor of corn is still alive. We can look at the grass and the corn at the genetic level and see where one evolved into the other.

6 Responses to "The Evolution of Corn"

  • Comment by: Ir (Helen)

    1 10/29/07 9:27 AM | Comment Link |

    I’m glad I get to eat A and not B. B doesn’t look as appetizing.

  • Comment by: Karen

    2 10/29/07 10:01 AM | Comment Link |

    That is so cool. When you think about it, though, the stalk of corn really does look something like a hugely magnified grass stalk! Thanks.

  • Comment by: Ir (Helen)

    3 10/29/07 1:29 PM | Comment Link |

    I’m glad it evolved a thicker stalk to go with the heavier ear…that was pretty essential.

  • Comment by: Siamang

    4 10/29/07 2:09 PM | Comment Link |

    I’m glad it evolved a thicker stalk to go with the heavier ear…that was pretty essential.

    It may have been the same mutation. One thing that isn’t intuitively obvious about genetics is that one allele can control growth in many different ways.

    Think of someone with the genetic variance to be tall… like really tall, basketball player tall.

    Well, it’s not like they have one gene making their left leg long, and a different gene making their right leg long.. oh yeah, and a different one for each arm as well, and then another for their torso… and if they didn’t have all those genes they’d be a mixed-up half giant half dwarf.

    Body parts aren’t made seperately, all mix and match like an assembly line.

    I don’t know for a fact, but I strongly suspect that stalk size and ear size may have been controlled by the same group of genes.

  • Comment by: cautious

    5 10/30/07 9:14 PM | Comment Link |

    I don’t know for a fact, but I strongly suspect that stalk size and ear size may have been controlled by the same group of genes.

    From what little I know about genetics, I think the answer to this one is yes. Humans have been able to breed tiny dogs quite easily; there wasn’t a need to change one organ system or “part” of the dog at a time. Basically (and perhaps a bit over-simplistically) a few genes control growth: if they’re active for a longer time than normal, the organism is bigger than normal, if they’re active for a shorter time than normal, the organism is smaller than normal.

  • Comment by: Julie

    6 11/4/07 6:03 PM | Comment Link |

    Teosinte does not look like it would taste good popped with butter on it.