16 December 2013

"Hedge apples" may "remember" the megafauna


An interesting post today at American Forests muses about the "hedge apple"/"Osage orange"/"monkeyball" (Maclura pomifera):
Consider the fruit of the Osage-orange, named after the Osage Indians associated with its range. In the fall, Osage-orange trees hang heavy with bright green, bumpy spheres the size of softballs, full of seeds and an unpalatable milky latex. They soon fall to the ground, where they rot, unused, unless a child decides to test their ballistic properties.

Trees that make such fleshy fruits do so to entice animals to eat them, along with the seeds they contain. The seeds pass through the animal and are deposited, with natural fertilizer, away from the shade and roots of the parent tree where they are more likely to germinate. But no native animal eats Osage-orange fruits. So, what are they for? The same question could be asked of the large seed pods of the honeylocust and the Kentucky coffeetree...

In terms of evolutionary time, the difference between 13,000 years ago and now is like the difference between Friday, December 31, 1999 and Saturday, January 1, 2000. We may assign those two days to different centuries or millennia, but they are still part of the same week. Likewise, all the animals and plants of 13,000 years ago belong just as much in the present. In fact, they still live in the present, with just one major exception: most of the big and fierce animals are now gone...

Now let’s return to the forlorn fruit of the Osage orange. Nothing today eats it. Once it drops from the tree, all of them on a given tree practically in unison, the only way it moves is to roll downhill or float in flood waters. Why would you evolve such an over-engineered, energetically expensive fruit if gravity and water are your only dispersers, and you like to grow on higher ground? You wouldn’t. Unless you expected it to be eaten by mammoths or ground-sloths...

It’s true that such adaptations are now anachronistic; they have lost their relevance. But the trees have been slow to catch on; a natural consequence of the pace of evolution. For a tree that lives, say, 250 years, 13,000 years represents only 52 generations. In an evolutionary sense, the trees don’t yet realize that the megafauna are gone.
More at the link, and a big hat tip to Quigley's Cabinet for the via.

9 comments:

  1. I believe the same is true for why no other extant animals eat mango and avocados. Thanks to extinct megafauna, we can now enjoy these giant delicious fruits. Not sure how likely it is for some other animal to come around and help out the Osage orange (or others) in the next hundred thousand years.

    ReplyDelete
    Replies
    1. There are animals that eat mangos and avocados, but they're large fruits which probably were eaten by megafauna as a target group, since the smaller animals don't cart them far.

      Except humans. So avocados and mangos are not at all threatened, they found an animal to pick up the slack.

      Delete
  2. the first time i ever saw an osage orange was on the day i went to visit the grave of stonewall jackson's arm.

    so kind of surreal all around.

    they hurt when the fall on you, but they smell pretty.

    ReplyDelete
  3. My Michigan squirrels eat osage oranges. I collect them in November to feed them all winter. They must first freeze and then thaw, and then I roll them out into the yard, and the squirrels go crazy for them. It's fun to watch a squirrel try to carry one up a tree in its teeth, because often the weight is too great and he falls down. When they eat them on the ground they shred them furiously into yellow piles, eating some select portion of them.

    ReplyDelete
  4. The seeds are edible, but its a huge mess and waste of time. Squirrels seem to like them (as reported above).

    ReplyDelete
  5. Once a year, we gather some up, and strategically place them on paper plates around our house (usually down beside the toilet, or on top of our refrigerator, etc). Common wisdom is that they ward off spiders. I'm not sure if this works, but as they rot, they don't give off a smell noticeable to humans.

    ReplyDelete
    Replies
    1. I'm just curious - how do they "evolve" after you bring them in? Do they disintegrate into a gooey slime, or (more likely I suppose) desiccate into a dry shriveled mass? Or other?

      Delete
  6. We had hedge apples along the fencerow of our pasture when I was growing up and some of our horses liked to eat them.

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...