Examples of bad "design" in humans

[robinson]

Really? That's interesting.

Ha! That is a line from a movie. About Bugz. It isn't true!

More than four legs would reduce speed and agility.

 

[gumboot]

I find that statement utterly strange. First, what is "best"?

Most effective at addressing whatever specific problem the feature was allegedly designed to address.

 

[gumboot]

How come there are no mammals with more than 4 limbs? It seems like an extra hand would confer massive evolutionary advantage...

This is precisely what I'm talking about - it's about "good enough", not "best".

No mammals have more than four limbs because mammals evolved after the establishment of the four-limb group. There's also no six limb birds or reptiles or amphibians. All of us have exactly four limbs.

Another thing to bear in mind is that evolution isn't so much about the "end product" (there is no end product - something IDists don't get) but the process.

Having five hands might be great, but in order for an organism to get to five hands it needs to get through the process first of surviving with five limbs that aren't hands. A fifth leg wouldn't be an advantage, in fact it would tend to get in the way.

 

[robinson]

What's that vitamin we can't create? Is it A? It's something animals can create, but humans can't.

Vitamin C is the most common. But there are others.

The reason for losing the ability to synthesize Vitamin C has been discovered to have evolutionary advantages.

Just realized I better expand on that.

Halliwell and Gutteridge suggest that because gulonolactone produces hydrogen peroxide as a result of Vit C synthesis, getting C from the diet lowers oxidative stress. The success of primates that lost the ability to create their own C is a testament to the success of this change.

 

[six7s]

Design, particularly if God's involved, is about "best".

I find that statement utterly strange. First, what is "best"? Longest life? A life free of pain? Lots of hot monkey sex action? Lots of kids? A good mind? Physical strength? Best is such a nebulous term it could be meaningless if regards to a discussion of design, in regards to humans.

I guess yaweh's design plan would be along these lines:

Sycophant V1.0

• Analysis:
  • something in my image suited to groveling worship of me at my imaginary feet
• Design:
  • knees for subservient kneeling
  • tongues for uttering woo praise crap
  • hands for clasping
  • frontal lobotomy for credibility
• Implementation:
  • rush job (who the frick is gonna bitch at me!?!)
• Testing:
  • yeah, whatever... whenever (see above)

Observing the duckbilled platypus

As distinct from all the other platypuses

it is damn good. Damn good.

Like New York, New York?

 

[volatile]

This is precisely what I'm talking about - it's about "good enough", not "best".

No mammals have more than four limbs because mammals evolved after the establishment of the four-limb group. There's also no six limb birds or reptiles or amphibians. All of us have exactly four limbs.

Another thing to bear in mind is that evolution isn't so much about the "end product" (there is no end product - something IDists don't get) but the process.

Oh, of course.

Having five hands might be great, but in order for an organism to get to five hands it needs to get through the process first of surviving with five limbs that aren't hands. A fifth leg wouldn't be an advantage, in fact it would tend to get in the way.

Well, that's not a hurdle that cannot be overcome - obviously insects managed to evolve more than four limbs. And I think in principle there's no clear reason why ape tails didn't evolve into a 'true' extra limb. But then, as we all know, the process of evolution is no slave to reason.

 

[Mashuna]

Could I have a spare liver and heart please? I like the two lungs and kidneys, I just don't think it goes quite far enough.

 

[gumboot]

Well, that's not a hurdle that cannot be overcome - obviously insects managed to evolve more than four limbs. And I think in principle there's no clear reason why ape tails didn't evolve into a 'true' extra limb. But then, as we all know, the process of evolution is no slave to reason.

I wonder if it's originally an efficiency thing - the animals that have more than four limbs are very small, and as a result they have to manage terrain that is - relative to them - incredibly uneven. Because they're small and don't have an internal skeleton they can utilise things like hydraulic blood pressure to control their limbs.

However in large animals like mammals, the terrain is much flatter relatively speaking, so stability isn't as important. They have heavy internal bones they need to move, and they're too big to utilise blood pressure to control limbs, so they have to develop muscles, but muscles burn a lot of energy - and add a lot of mass.

I suspect a human with, say, an extra pair of arms, would have to consume a much greater amount of food in order to provide enough energy to keep those extra limbs going. Unless those limbs enabled the animal to gather at least the extra energy required to run those limbs in excess of what its 4-limb competition could gather, the 6-limb beastie would die out. I can't see how those extra limbs would give an animal that substantial an advantage at the environmental scale of big animals.

Bear in mind that things like monkey tails evolved after the four-limb model was established - so the monkey tail is an animal evolving a fifth limb - it just hasn't been around anywhere near as long as the other four. I wouldn't be surprised if in a few million years or whatever (assuming we haven't wiped them all out) the monkey tail had advanced along the track to becoming another hand like appendage.

The elephant trunk is another good example - it has already evolved to the point of having two "fingers" so it's further along than the monkey tail.

 

[volatile]

Bear in mind that things like monkey tails evolved after the four-limb model was established - so the monkey tail is an animal evolving a fifth limb - it just hasn't been around anywhere near as long as the other four.

Aaaah... really? I did not know that. I'd always assumed tailed apes lost the tail as they evolved into humans (hence our residual tailbone / coxyx).

 

[a_unique_person]

I think the design of one of my appendages was way too small. Where's the intelligence in that?

 

[asmodean]

I find that statement utterly strange. First, what is "best"? Longest life? A life free of pain? Lots of hot monkey sex action? Lots of kids? A good mind? Physical strength? Best is such a nebulous term it could be meaningless if regards to a discussion of design, in regards to humans.

Second, design in reality is not about "best", it is often about "cheapest", "fastest" or "most profit". Even things like bridges and tunnels, in which you might think design is really really important, sometimes design is terrible.

So what yoy say is that God .. the intelligent deigner, sorry-. is constrained by time, money and access to components? God has a Pointy Haired boss who rather see a product hit a strict deadline than make the best possible product? God is outsouring, or wokrking as a consultant? use lowest-bid services?

See, these constraints might make sense when it comes to companies anmd their products but, IMO, not when talking about a supposed omni-max God and his designs.

 

[Blue Mountain]

Could I have a spare liver and heart please? I like the two lungs and kidneys, I just don't think it goes quite far enough.

And as a type I diabetic, a backup pancreas would have been useful. It's only been within the last 80 years that we've discovered how to synthesize insulin. Otherwise I'd be dead by now.

I consider myself lucky--diabetes is relatively easy to control. Parkinson's disease is much worse. Even with medication, it progresses and becomes increasingly more difficult to control.

 

[Delvo]

Humans are much more likely to choke than other animals. I was reminded of this the other day by someone choking to death whilst participating in a cake eating contest.

...which, like with some of the muscles that got stretched and wrapped around in strange ways, is something that we changed for the worse fairly recently, by cranking our heads "down" for our vertical stance and moving throat parts to allow speech.

The knee.

I see this complaint offered a lot, but the knee is really not a flawed trait for what it's meant for. It just gets damaged because people try to use it for things it isn't meant for (highly self-abusive sports, and walking on hard flat unyielding surfaces). It's the same thing that also creates problems for our ankles and lower backs: not manufacturing or design flaw, but misuse by owner. Get shoes that are adapted to make it more like you're walking on natural ground again (such as by MBT or Brooks), and don't abuse yourself with sports craziness, and your knees & ankles & back will be fine... maybe not forever, but for as long as the rest of you.

This raises an interesting point. Most of the comments (including mine) so far focus on macro-level designs such as the eyes, the spinal column, etc. But how many crappy designs exist at the cellular and chemical levels that nobody would know about unless they were a specialist in a relevant discipline?

Here's one. Muscle fibers contract because some long, skinny molecules lying parallel to slightly different long, skinny molecules can grab them and pull them for a bit, then let go and grab the next part, and so on, like a person climbing a ladder or rope. But unlinking and then linking to the next molecular linking site takes energy, both for the release and for the pull. So every little molecular "head" on a myelin chain keeps flapping back and forth while the fiber flexes. This is fine so far. But where it gets weird is that, once the muscle has contracted as far as it can or as far as we want it to, the flapping continues. (Either the myelin head repeatedly links and unlinks the same attachment site instead of moving on to the next, or some fibers are contracting while others are relaxing at any given time.) Why not simply not-release? It would save on the chemical resources we use for the release, prevent fatigue in stationary muscles for an indefinite amount of time while still holding the weight, and possibly allow more weight to be held. Sometimes our muscles really do lock in place like that because the "release" chemicals don't get there for some reason, and that's called a "cramp", and that's bad. But putting it under our control to turn it on and off would be good.

There could be a self-preservational element to it: a muscle that's locked in place might be damaged if something were to come along and force it to stretch out to the relaxed length again, or the fact that it doesn't budge could mean that the same accident harms a tendon or bone instead. As it is, that same kind of accident would merely cause the muscle to return to its relaxed length because it's retaining the ability to move either way while it flexes. But how often does that particular kind of accident happen? That's like carrying a couch and having someone or something heavy fall on top of the couch.

As distinct from all the other platypuses

Yes.

http://en.wikipedia.org/wiki/Ambrosia_beetle

(It's the bugs' old name, changed since then, but that bug is the reason why the platypus's scientific name couldn't be platypus at the time it was named, even though "platypus" SOUNDS like a scientific name.)

Well, that's not a hurdle that cannot be overcome - obviously insects managed to evolve more than four limbs.

The general rule is that the more exposed an animal is to gravity, the fewer legs it has, and the less exposed it is to gravity, the more it can have. The two main things that expose an animal to more gravity are being very big, and coming out of the water and onto land, so the limb count tends to go down when a lineage colonizes land, and does so more strongly in the larger sizes, OR only lineages which already have few limbs manage to make either of those changes very successfully. This evolutionary trend appears in multiple separate evolutionary lineages. The way it works is that handling a lot of weight calls for bigger limbs, and bigger limbs would get in each other's way if there were more, whereas lighter or buoyant animals can get away with smaller limbs, in which case having more of them gives the animal more traction.

 

[Delvo]

Aaaah... really? I did not know that. I'd always assumed tailed apes lost the tail as they evolved into humans (hence our residual tailbone / coxyx).

Vertebrates have had tails since before they became vertebrates, but the tails have usually not been prehensile. What's more recent, evolved in primates but not their ancestors or cousins, is making the tail prehensile, putting it to a use that tails weren't used for before.

 

[Ryan O'Dine]

I've skimmed the thread, and see a scarcity of neurological shortcomings. We may be the smartest creature on the planet, but our system for remembering things is a jumbled mess when you examine it up close.

The fact that so many of us believe in an intelligent designer despite the wealth of knowledge to the contrary shows how defective our native reasoning abilities are.

The gift of perceiving patterns often fools us but good.

Our use of language is wonderful, but the languages themselves suffer from much ambiguity, as any JREF thread will attest (see loglan^WP for a made-up language supposedly without ambiguity... which no one can seem to learn.)

And don't even get me started on the emotions. (Or I'll get really, really angry.)

 

[Cainkane1]

The intelligent design crowd says humans are far too advanced to have evolved, and therefore must have been designed, and that thus implies a designer. While there are a couple of logical fallacies in that conclusion, I'm more interested in the assertion that humans are designed.

Off the top of my head, I can think of two parts of the human body that do not seem to be well designed at all:

• The spinal column: On a recent episode of The Skeptic's Guide to the Universe, Dr. Steven Novella noted that the spinal column works quite well for quadrupeds, where it is normally horizontal. However, stand it upright (as we humans have it), and there are some problems, notably slipped discs and lower back pain.
• The punchline to an old joke: Who would run a septic line through a recreational zone?

What other example of bad design can others think of here?

You forgot to include scholiosis and kyphosis of the spine.

 

[quarky]

I'd like to see humans evolve into siamese octuplets, with a sort of radial symmetry. The shared brain would be in the center of the mass. We would live on beaches, in shallow, clear, warm water. We would hunt for food at the water's edge, rolling along on our many appendages, with one or more of our nostrils always being above water. Our multible hands would pluck various shellfish and shrimp from the water. We wouldn't be able to over-populate because we'd all be pretty much forced to live in the type of enviornment now favored by multi-millionaires.

 

[phantomb]

Well, the phrase "bad design" is just a made up idea, that nature "designs" anything, like there is some supernatural force at work. Explaining why we are the way we are is more fun to me, than imagining somebody designed us, and did a bad idea. Unless you count the humor of groin shots, in which case it can be fun to imagine a bearded old guy laughing his arse off upstairs at our misfortune.

Yes the phrase "bad design" is just a made up idea, but then again, nobody in this thread is supporting the proposition that there was an intelligent designer. This thread is about pointing out examples of things that we would consider to have been poorly designed if there was such a designer, so I find it odd that you have been responding as though we are all denying evolutionary explanations for our examples.

 

[Eos of the Eons]

Giraffes and other mammals hide their pregnancies so well that predators can't even see if they've gained a pound. Humans on the other hand, ugh. Most of us females never get our figures back, and are jealous of those that do.

 

[rwguinn]

I've skimmed the thread, and see a scarcity of neurological shortcomings. We may be the smartest creature on the planet, but our system for remembering things is a jumbled mess when you examine it up close.....

Absolutely untrue.
I rember quite well that I once had working knees...

ETA: Hmmmm.
But I can't seem to remember how to spell remember, so maybe you have a point..