Question: Why do we have eyelashes?

Keywords:

  1. Well it may be that it’s just accidental. Evolutionary junk. Something from our past that has stuck.

    Or it has a use. The use is that it makes us have more kids – long term. That’s the definition of evolutionary success. We have more kids who then have more kids.

    OK, so let’s think. How can eyelashes allow me to have more kids. That seems weird.

    There’s a chance that my having eyelashes makes me more attractive. I think that’s probably true, but that’s an effect, rather than a cause. I think women will find me more attractive if I have eyelashes because we’ve evolved to find eyelashes more attractive. That’s a “circular argument”.

    So maybe there’s something more, you know, *practical*.

    How about this: eyelashes stop things falling into my eye. If I squint, I can stop dust and stuff going into my eye. That means I can, generally, see better.

    That would give me an advantage. If I was being hunted, or if I was hunting food, seeing clearly in times of stress (like being chased, or closing in on a mammoth) would help. I want to keep focussed and not have to stop and say “Oooh – wait, I’ve got something in my eye!”.

    That’s probably it. They give us some small advantage that allows us to survive a bit better and have more kids.

    Now it’s entirely possible that this advantage is *now* no use. I don’t hunt mammoths. I don’t get hunted on a regular basis. It could be now that I’m just seen as more attractive because I have eyelashes. So something that used to have a functional role has a cosmetic one. It’s stuck, and to get rid of them would require quite a lot of genetic change, but there’s no real pressure to get rid of them, so we don’t. No pressure = no change.

    0

  2. Eyelashes keep dust out of our eyes. That’s why they evolved.

    0

  3. Eyelashes help protect the eye from stuff getting into them. They are really sensitive to being touched and this tells us that something is near the eye and we should probably close our eyelids to keep the junk out of it.

    0

  4. That’s right. Eyelashes help keep dust out of your eyes. Camels have really long eyelashes and these help keep sand out of the camel’s eyes in a dust storm.

    Eyelashes also help to keep your eyes closed when you’re asleep. Eyelashes interlock with each other when you close your eyes and mean that your eyes can stay closed without having to use muscles too much. I know this because my little sister once went to bed with chewing gum in her mouth. Somehow during the night, it ended up caught in her eyelashes and we had to pull it out, ripping out most of her eyelashes in one eye. She had trouble keeping that eye shut when she went to bed. Luckily they grow back fast!

    0

Comments