When evolution gets weird...

[WillParkinson]

http://www.iflscience.com/plants-and-animals/heres-what-it-looks-when-evolution-gets-weird

We’ve all heard examples of evolutionary perfection: The cheetah’s sleek, long-legged body, built for speed on the African savanna, or the parrot’s tough, ridged beak, ideally shaped for cracking open nuts. These adaptations may make us marvel at nature’s inventiveness and engineering skill. But you know what I love more than these shining examples of evolution? The less elegant creatures—the ones that survive despite being awkward, ugly, slime-covered, or completely absurd.

I collect these evolutionary oddities on my blog, WTF, Evolution?, and in the new book of the same name. In captions, I try to imagine: If there had been a thought process behind these organisms, what would it have been?

In reality, of course, evolution doesn’t think. It doesn’t sit down and plan out the best course for an organism to take. Instead, mutations happen at random, the useful ones stick, and over time they become adaptations that help the animal survive in its environment. But they’re not necessarily the features you’d choose if you were designing something from scratch.

[Scootaloo]

1. Awww, these critters just look goofy to the human eye

Which is ironic, becuse the human eye is one of the best examples of how evolution is only concerned with function, rather than elegance.

1) Our sensory cells face the wrong way. Light has to bounce off the back of our eye to reach them.

2) But wait, the sensory cells themselves are in the way - along with a nice spiderweb of blood vessels and nerves that supply them.

3) not to mention the blind spot caused by the hole where all these blood vessels and ocular nerves come into the eye.

4) Those sensory cells themselves? Recent re-adaptation for seeing color. We have good color vision for mammals... but seeing as most mammals see the world in murky shades of brown, yellow, and brownish-yellowish-blue, that's not saying an awful lot. Compared to birds and reptiles, we're missing 1/4 of the light spectrum. Compared to most invertebrates, we might as well be colorblind. You think that apple is red? That's cute.

5) What actually reaches our brain is a blurry, semi-pixellated blob of light that is given shape only by movement. It's also upside-down and backwards to reality, due to the refractory effect of our lens (we could go on for days about the joke that thing is) and the reflection off our retina. It goes into our brain, which then takes that information and constructs a CGI model that is a roughly 85% accurate depiction of what is really going on.

6) Also, the eyeball of land vertebrates has a lot of evolutionary kludges needed in order for the damn thing to even work out of the water. As usual, evolution used the least effort possible with the cheapest materials.

Compare the human eye to say, the squid. Squid eyes are tetrachromatic, for starters. They perceive colors in the spectrum we literally can't imagine. They plug right into the squid's brain from the back - there is no lattice of blood and nerve conduits poking into the squid eye and spidering across the seeing surface. Since it lives underwater, the squid never had to evolve all the oddball patches and fixes to make those eyes work in dry air.

Creationists like to claim that the human eye is too fine-tuned, too complex to have "just evolved." Yet... so many of them wear glasses. Why is that?

[tclambert]

2. Yeah, but the way sex works with Octopi is just sad.

The male gets to mate once, then he dies. The female then spends her remaining days caring for the eggs, and usually starves to death.

We definitely got the better of that deal.

Not sure exactly how it works with squids, though Wikipedia says, "deep water squid have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessile barnacles." (And now I have a case of sessile barnacle envy.)

[Odin2005]

9. If you stare at a clear blue sky you can see the white blood cells in your retinal blood vessels.

It's really unnerving.

And speaking of tetrachromacy, the common ancestor of all land vertebrates and bony fish was a tertrachromat, but we mammals were reduced to dichromacy when our shrew-like ancestors became nocturnal burrowers. Then our primate ancestors evolved trichromacy.

In fact, the higher primates are the only mammals that have color vision better than dichromacy.

[Warpy]

3. While I also appreciate the less attractive creatures

I don't think mutations are particularly random. I think DNA is "smarter" than that, for want of a better word, different sections switched on and off to respond to environmental stress, something that seems to have been confirmed in experiments with fruit flies, where severe stress produced many groups of genes suddenly switched on.

How else could we explain bacteria living at extreme depths in caves, drawing energy from acids or tube worms around deep sea volcanic vents, or anything that lives in deep water, for that matter? It seems that where there is an environment that doesn't incinerate DNA and RNA, life will adapt to it.

ETA: fruit flies, http://www.evolutionnews.org/2014/03/not_so_simple_f083491.html

[Thor_MN]

5. DNA is neither smart nor stupid.

The DNA that creates the most/best offspring wins. The successful changes accumulate, the unsuccessful changes disappear. If environmental stress ramped up to the point that groups of changes are needed for success, then groups of changes will occur, they are simply the successful changes.

You answered your own question, without invoking some sort of unexplained "DNA intelligence". Life will adapt to conditions that don't out right kill it.

[AverageJoe90]

4. Evolution is indeed weird sometimes.

For example, pandas are neither apes, monkeys, or any other primate.....nor are they related to us humans, either.....but they, too, have opposable thumbs. Convergent evolution, anyone? And speaking of us humans, we aren't that closely related to pigs at all, but porcine organs can still work as transplants for humans under the right conditions. Isn't that crazy?

And let's not get started on what is perhaps Australia's most unique animal.....the platypus.

[JayhawkSD]

6. Just FYI about the Cheetah

The real elegance of the Cheetah is not so much the way it is engineered for speed, which it certainly is, but the way it is engineered to make high speed changes of direction while at speed without losing any momentum. Running animals mostly slow down quite a lot while changing direction, and the Cheetah is unique in its ability to make sharp changes in direction virtually without losing any speed at all.

[Spitfire of ATJ]

7. A Lovecraft birthday balloon!!!....

[hunter]

8. Watch out for this spider...