10 Worst Evolutionary Designs

JamJam writes "Besides my beer gut, which I'm sure has some purpose, Wired is running a story on the 10 Worst Evolutionary Designs. Ranging from baby giraffes being dropped 5-foot during birth to Goliath bird-eating spiders that practically explode when they fall from trees."

Comments

Spartan Giraffes

[Knave75]

Perhaps the great fall is a way to cull the weak giraffes. Those that do not survive the 5 foot drop would never have been successful in the wild. Ditto for the slow-evolving shark siblings. If your brother eats you in the womb and you do not adequately defend yourself, then you simply did not deserve to live.

Seriously though, evolution does not provide traits that are advantageous, it simply removes those that are disadvantageous, relative to other traits. That is a subtle but important difference. Eating your brothers and sisters in-utero sounds pretty gross, but unless it hurts the reproductive rate of those who carry that gene, there is no reason to weed it out.

Re:Spartan Giraffes

[v1]

"...evolution does not provide traits that are advantageous, ..."
Yes it does.

Possibly more correct to say that evolution continuously offers random features which may or may not be advantageous, and the features which are detrimental to its survival tend to be removed from the gene pool.

OP is correct in saying that evolution in itself doesn't provide anything specifically helpful. It does encourage traits that happen to be beneficial though. Evolution is not the process of trying improvements, that's what heterosexual reproduction is for. The purpose of evolution is to improve on the survival of the accidentally better designs.

There are an insane number of good examples, but I'll toss out a good one now. Sickle Cell Anemia. Sucks if you have it, has a variety of nasty side effects and no visible benefit. Except if you live in say, Nicaragua, and are exposed to malaria-bearing mosquitoes all the time. Something about the cell shape defies the virus, SCA sufferers are immune to malaria. So the SCA expression there is very very high because although it grants a disadvantage, it also grants an advantage. Interesting thing about SCA is you only need one gene to have immunity, and require both to get the nasty side effects. But it's advantageous enough to be kept.

It's fun, but don't draw conclusions from it.

[Anonymous Coward]

Oh isn't this a great parlour game! Did you know that the retina is backwards, which is why we have a blind spot? How horrible, how inefficient!

These types of things are all very fun to discuss. But please oh PLEASE do not draw any inferences from them. They don't mean ANYTHING, from a philosophical or theological perspective.

(Example) The vagus nerve in giraffe's neck is as long and ungainly as it is because of the way it develops in the fetus. To make it more efficient in the adult would require a change in the course of fetal development. And depending on how you change the course of fetal development, other things need to change, too. This is a very large and complex system of interconnected dependencies. To look at one isolated phenotypic feature and say, "Hey, I could have designed that better!" bespeaks of a total lack of knowledge about what all is involved in development.

I will say for the record that I believe in evolution, not intelligent design. But whenever I heard people "on my side" using examples like this as "evidence" for NOT intelligent design it frustrates me. You have absolutely no idea the entire bredth of changes -- on every level, from genetics to protein synthesis to overall development -- that would be required to make whatever "inefficient design" work better. It isn't as simple as looking at the adult and saying "this nerve should go here, instead!"

So, that's my little rant. Examples like these are fun. They're entertaining. They're cute.

They are "evidence" of absolutely nothing.

Re:Old

[spire3661]

MY thoughts precisely. It is REALLY hard to make a list of bad evolution using SUCCESSFUL examples. Regardless of the weirdness of the design, it WORKS over the other designs that were submitted over the eons.