Examples of bad "design" in humans

[gumboot]

Ah but this is generaly only a short term solution, as you become much more suseptable to enviromental change.

Hence why large rapid climate changes cause mass extinctions. There's good evidence that the "wipe the slate clean" sort of scope of extinction has occurred before. A sort of real version of Noah's Ark, minus the Ark.

But humans have dominated many of those enviroments for a long time.

We haven't though. Sure, a long time by the standards of mankind, but not on an evolutionary scale. What's truly extraordinary about humans is how little time we've been dominating our environment. Which follows. The moment we could seriously dominate our environment we immediately began to dominate all environments. So that in the space of a mere tens of thousands of years we went from a bunch of hunters struggling to survive in Africa along with all the other animals to building cities across the globe.

Ah you seemed to be ignoreing that point.

I was trying my best to stick to my original topic.

Depends on what you mean by excels. Yes one person will likely not be in the olympic ratings of multiple unrelated competitions. But a human could be pretty good at a range of activities that outstrip any other animal.

Indeed.

This is no more relevant that saying that the same horse would not win a mile long race and a pulling competition. It is true but not particularly relevant to the general capabilities of the horse.

Which is why I tried to highlight the stupidity of bringing up the Olympics. Highlighting the achievements of the top 0.0001% of highly specialised humans is not particularly relevant to the general capabilities of man.

I don't know about that. Variation in humans vs say variation in Canis Farmiliaris(the dog) does not seem that great.

Dogs have been purposefully bred by humans to create variation though. Domestic dogs are a good example (in other animals) that you can get a huge scope of variation if you can bring the animal outside the natural selection model and put it in a stable controlled non-competitive environment. It's worth pointing out that all domestic dogs descend from wolves in what is now China.

No I do not agree with that by and large.

Actually that should read "median" not "average".

It's a standard statistical model. You can have one population that has good performance, but a low level of scatter. They'll have a high median but a less impressive maximum.

Against that you can have another population with a scatter of performance right across the scale but the majority at the lower end and a tailing peak towards the upper end. They can have a much lower median but a much more impressive maximum.

If you compare maximum value for each population you'll get one on top. If you compare median you'll get the other.

Take, for example, a bite force comparison between polar bears and humans.

An average adult polar bear has a similar bite force to an average human adult - it's slightly stronger. However while the bite force variance in adult polar bears is very small, in humans it's quite large. If you take the strongest bite force for a human and a polar bear, the human will win by a considerable margin (humans have been known to produce a bite force as high as 1,000lb/sq in when grinding their teeth during their sleep).

(Actually I'll cite a Polar Bear's bite force as an excellent example of flawed design - their main source of food is seals, but it takes a Polar Bear about 45 minutes to chew through a baby seal's skin)

 

[gumboot]

One would assume that if these structures are ineffective there would be no selection pressure to retain them, but if they are detrimental there would be selection pressure to eliminate them.

This is, in a way, what the thread is about.

Evolution only requires an animal to survive long enough to pass on its genetic code. Traits that only become detrimental after the individual has finished breeding won't get eliminated.

What you'll find, for example, is that humans are in one way de-evolving because traits that were once quickly fatal now persist thanks to advancements in medicine and the variety of support that society offers. So there's probably some traits that cropped up post-civilisation that were throwbacks to earlier failed traits, but when they popped up again they weren't eliminated and have been passed on.

 

[ponderingturtle]

Hence why large rapid climate changes cause mass extinctions. There's good evidence that the "wipe the slate clean" sort of scope of extinction has occurred before. A sort of real version of Noah's Ark, minus the Ark.

But some species are more suseptable to extinction than others.

The Brown Rat for example is very sucessful as a generalist

We haven't though. Sure, a long time by the standards of mankind, but not on an evolutionary scale. What's truly extraordinary about humans is how little time we've been dominating our environment. Which follows. The moment we could seriously dominate our environment we immediately began to dominate all environments. So that in the space of a mere tens of thousands of years we went from a bunch of hunters struggling to survive in Africa along with all the other animals to building cities across the globe.

Anatomicaly modern humans have not been around for long enough.

I do not see lots of evidence that neolithic peoples had to run and hide from preditors as a way of life. In some situations sure, but they could also hunt those preditors if they wanted to. THey do seem to be at the top of the food chain.

 

[Delvo]

By and large humans are poor sprinters but good distance runners. There are numerous reasons for that(we can jog for one, giving use more flexible gates than quadropeds)

Can you define how the jogging gait is different from both walking and running/sprinting? I tend to think of it as essentially the same thing as sprinting/running, just at a lower intensity, but talking about it as a way of covering long distances efficiently (using little energy) makes it sound more like walking... but in either of those two cases, it would be like one and unlike the other, not distinct from BOTH.

Well the obvious one is freedom to use our hands. I counter that with the six limb model, so I don't buy that as an obvious benefit.

Another is the running one. I counter this with other considerations for our running ability such as ability to cool our selves and breath through our mouth. Yet there's an argument for our morphology playing a role, so I'll tentatively buy that one too

Vertical alignment minimizes the skin surface's exposure to sunlight in the middle of the day, maximizes the skin surface's exposure to lateral air flow for cooling, and puts the sensory organs high, all without making the body especially massive overall... and that last bit alone minimizes the volume-surface ratio, the amount of food required, and the incentive for predators to bother with us.

 

[ponderingturtle]

Can you define how the jogging gait is different from both walking and running/sprinting? I tend to think of it as essentially the same thing as sprinting/running, just at a lower intensity, but talking about it as a way of covering long distances efficiently (using little energy) makes it sound more like walking... but in either of those two cases, it would be like one and unlike the other, not distinct from BOTH.

That is the point. Animals can't run slower.

A horse has a number of fixed gates, it can not really slow one down it has to shift gates.

 

[gumboot]

A horse has a number of fixed gates, it can not really slow one down it has to shift gates.

Actually I've seen this as an argument for why horses are more efficient "movers" than people. Humans very quickly increase our heart rate and energy burning rate with only a minor increase in speed because the jump from walking to jogging is huge. In terms of expended energy we don't really benefit much from jogging slower.

In contrast a horse has 27 distinct gaits, all of different speeds, and all requiring different levels of energy, so it can adjust to whatever gait is best suited to the speed it wants to go.

Then at the total opposite end of the spectrum you have the Red Kangaroo that has only one gait (two if you count it's appallingly bad tripodal crawl), and once its hopping it can go from quite slow to very fast (5 or 6 km/h up to around 60km/h with very little change in energy burned or heart rate increase.

I find it fascinating that the natural world produces multiple vastly different solutions to the same basic problem. That's what's so cool about evolution.

 

[robinson]

This logic goes both ways:

Dump a human runner in the middle of Interstae traffic with a Kangaroo and let's see who reaches the shoulder first.

Dump a Spider Monkey and a human gymnast in a pole vault contest and lets see who can make the vault without falling.

Dump a antelope and a human sprinter into a Marathon and let's see who gets to the finish line first.

Drop a human into the ocean with a dolphin, turn a Killer whale lose, and let's see who gets away.

Put a top MMA fighter into a Silver Back's territory and let's see who comes out top.

See?

 

[gumboot]

But some species are more suseptable to extinction than others.

Quite true. Mammals, for example. Hence why we are are on top.

I do not see lots of evidence that neolithic peoples had to run and hide from preditors as a way of life. In some situations sure, but they could also hunt those preditors if they wanted to. THey do seem to be at the top of the food chain.

Well I think you could make a pretty good argument that human domination of the night time is a very recent achievement. Behaviour of early man seems to indicate we ran and hid when the sun went down. But even then our earliest efforts at dominating our environment were only after the last ice age so a mere 12,000 years ago. The speed of our domination after that was blistering - the Neolithic period began about 12,000 years ago and within 2,000 years our first town - Jericho - had protective stone walls, a population of 2,000 to 3,000, and a very large central tower. 3,000 years after that we'd already achieved the multi-city Sumer Civilisation. That's a degree of expansion that's just phenomenal.

I guess I'm thinking of "dominating your environment" as a lot more than "top of food chain". Lions, for example, are the super predator of their ecosystem, but they're still fighting a constant battle of survival (even without taking into account human impact). I certainly wouldn't say they dominate their environment.

In terms of dominating landscape, I'd put pre-Neolithic humans not much above any super predator today - certainly top of the food chain but hardly ruling all that they surveyed. What's remarkable is that in the space of 5,000 years we went from that to building multiple inter-linked cities with year-round agriculture, writing and all the other basic trappings of modern society.

I don't know about you, but that just blows my mind.

 

[Frozenwolf150]

Something I wanted to add, just to be fair:

Examples of bad "design" in humans

Edible.

While humans are technically edible, the same would go for any living thing on the planet. There is something that can prey on everything. However the fact is that when it comes to humans, most predators will turn up their noses at human flesh unless nothing else is available. From a predator's standpoint, humans aren't really worth eating. There is little meat on our bodies relative to our size, making us an inefficient food source. Humans tend to fight back, run away, and retaliate against any predatory threat. We have a tendency to hunt the very animals known to be dangerous to humans, to the point where many species are driven into endangerment. There is usually an ample supply of slower, dumber, and more substantial animals around for any predator to feed on regardless.

 

[gumboot]

This logic goes both ways:

See?

Er... I already made that point quite some time ago. I honestly don't know why people keep repeating it.

 

[gumboot]

Something I wanted to add, just to be fair:


While humans are technically edible, the same would go for any living thing on the planet.

Lots of animals and plants specifically evolved (or were specifically designed) to not be edible. If we were designed, and our designer intended for us not to be eaten, you have to ask why they didn't make us inedible... fill us with poison or something.

Maybe it was so we could eat each other if things got desperate.

If we were designed to be edible I'd be asking why our designer didn't make us unbelievably delicious to every carnivore out there.

Seems we're just moderately edible, which seems like a half-assed design to me.

Maybe it does come back to cannibalism after all. The 10 Commandments didn't say anything about eating your neighbour's wife, just coveting her.

 

[Blue Mountain]

Lots of animals and plants specifically evolved (or were specifically designed) to not be edible. If we were designed, and our designer intended for us not to be eaten, you have to ask why they didn't make us inedible... fill us with poison or something.

If we were designed to be edible I'd be asking why our designer didn't make us unbelievably delicious to every carnivore out there.

If we want to consider the relative tastiness of humans as a design (as opposed to evolved) feature, it might be useful to approach the problem from the point of view of a game designer. A very important aspect of any game--be it sporting, board, computer, or role-playing--is balance. So it could be argued that making humans scrumptious would be bad because it would unbalance the game in favour of the humans' enemies, while making them deadly poisonous would be unfair in the other direction.

Anyway, I'd prefer not to expand the topic into "what about the world makes you think it could not have been designed in advance?" Let's concentrate on the human body (and the mind, too, since I didn't specifically exclude that in the OP.)

 

[ponderingturtle]

Well I think you could make a pretty good argument that human domination of the night time is a very recent achievement. Behaviour of early man seems to indicate we ran and hid when the sun went down. But even then our earliest efforts at dominating our environment were only after the last ice age so a mere 12,000 years ago. The speed of our domination after that was blistering - the Neolithic period began about 12,000 years ago and within 2,000 years our first town - Jericho - had protective stone walls, a population of 2,000 to 3,000, and a very large central tower. 3,000 years after that we'd already achieved the multi-city Sumer Civilisation. That's a degree of expansion that's just phenomenal.

Depends. In that comment I was refering to man as being the apex predator of its enviroment.

I guess I'm thinking of "dominating your environment" as a lot more than "top of food chain". Lions, for example, are the super predator of their ecosystem, but they're still fighting a constant battle of survival (even without taking into account human impact). I certainly wouldn't say they dominate their environment.

I see how the phrase was imprecise and lead to interpretations that I did not have in mind.

But men have hunted lions with spears for thousands of years. I was thinking more in terms of animal to animal domination, not changing the enviroment to suit them(which humans are one of the few if not only one able to really do on any scale (and humans often mess things up for themselves as well))

In terms of dominating landscape, I'd put pre-Neolithic humans not much above any super predator today - certainly top of the food chain but hardly ruling all that they surveyed. What's remarkable is that in the space of 5,000 years we went from that to building multiple inter-linked cities with year-round agriculture, writing and all the other basic trappings of modern society.

I don't know about you, but that just blows my mind.

But that is the point, man is naturaly an apex predator, and in many ways the apex land preditor of the past 100,000 years.

So those who where talking about mans relative weakness, where missing that point.

 

[Frozenwolf150]

Lots of animals and plants specifically evolved (or were specifically designed) to not be edible. If we were designed, and our designer intended for us not to be eaten, you have to ask why they didn't make us inedible... fill us with poison or something.

True, but as I pointed out, humans certainly have adaptations that would render us relatively inedible. We might not have sharp quills or poisonous blood, but we make for a fairly inefficient source of food, and we do have the ability to create and use weapons. From a predator's standpoint, humans just are not worth it to chase after, fight to subdue, and then risk having them band together for a retaliatory hunt.

That and I'm pretty sure humans don't taste very good to begin with.

Maybe it was so we could eat each other if things got desperate.

If we were designed to be edible I'd be asking why our designer didn't make us unbelievably delicious to every carnivore out there.

Seems we're just moderately edible, which seems like a half-assed design to me.

Maybe it does come back to cannibalism after all. The 10 Commandments didn't say anything about eating your neighbour's wife, just coveting her.

There's a joke in there that would probably be NSFW.

But the obvious reason to avoid cannibalism, as I'm sure most people know, is because it increases the risk of foodborne diseases. Same species, same host, easy route for infection.

 

[rocketdodger]

"Bear Vs Man With Gun" and "Bear Vs Man" are not the same thing.

I just don't understand the point of your arguments in this thread. You seem to be asserting nothing more than "if you take a human and subtract their brain, they can't compete with many other animals in many endeavors."

Uhhh... ok, sure... but who cares?

 

[six7s]

Modern humans can't survive in a "wilderness" climate

I think you're conflating the term modern to encompass both 'currrent genetic version' and 'urban/i-pod dependent/etc'

we've lost that survival instinct

The how come we ain't extinct yet?

knowledge for surviving that environment is no longer commonly taught

Indeed... cos most of us don't live in 'that' environment

However, many humans today DO survive in wilderness environments

For starters without clothes we'd die of exposure in winter pretty much anywhere except along the tropics

So? A few billion of us die? It ain't the end of the whirled

In the tropics we'd probably die of heat exhaustion or dehydration.

As you point out, the key factor in avoidable deaths from heat exhaustion or dehydration is ignorance, not genetics: smart (environmentally savvy) people can and do live in arid places (e.g. the Australian outback), those accustomed to basking around the shallow end of the gene pool don't

Just cos 'most people don't have fundamental survival skills' does not mean those skills have been lost from the gene pool

 

[JoeTheJuggler]

OK that one I have to agree with. It is right up there with soft exposed reproductive organs hanging out at just the right level for a swift knee to the family jewels. If there is a God, he has a sick twisted sense of humor, and must really laugh it up each time somebody gets a groin shot.

They need a reduced temperature to produce sperm.

However, I don't see any reason why an omnipotent Designer couldn't figure out how to have well protected testicles that can still work just fine at core body temperature.

Similarly, I don't see why any of the other reasons why the other issues people have put forth couldn't be resolved by an omnipotent Designer. The objections you raise are all the constraints that face real-world, non-Designed biology. The trade-offs you mention are trade-offs that face forms that arise by evolution. There's no reason they have to be an issue for an Intelligently Designed creature.

As pointed out, for example, a Designer could certainly make eating and breathing two separate systems altogether rather than sharing parts (with its potential for choking).

 

[Unalienable]

And if I were criticizing human bodies ... as though they were machines somebody intended to put on the market, I would have two main points to make -- one of which I have surely made by now in my story: "The brain is much too big to be practical." The other would be: "Something is always going wrong with our teeth. They don't last anything like a lifetime, usually. What chain of events in evolution should we thank for our mouthfuls of rotting crockery?"

-- Kurt Vonnegut
Galapagos (1985)

 

[six7s]

Competition for resources (space and energy) with an exponentially increasing population means something has gotta give...

It's time to say bye bye Grandpops, you've outlived your usefulness... now go and starve, quietly if you can, in the corner

 

[GreyICE]

ok

Done. Without something to force the animal in a straight line, they won't even race.

Done. Without someone to physically direct the animal to the weights, they won't lift anything at all.

Which apparently is the same thing as performing on the rings or parallel bars? What are you smoking?

Dolphins could probably figure out how to race each other in a straight line, so I won't argue that one.

Apparently you have seen cranes doing triple lutz's and monkeys doing twists while vaulting. I haven't seen that. Maybe I am just ignorant?

Well, ignorant is one word. Being a dick is three more. Unless you're seriously suggesting the only thing that animals do on their own is stand perfectly still and wait to starve to death.

And yes, monkies could easily do every single thing a human does on parallel bars, probably with the bars twice as far apart. The fact that they haven't is immaterial. Are you stronger than Bill Kazmaier because you can lift 9,037 Yu Gi Oh cards and Bill Kazmaier has never lifted a Yu Gi Oh card in his life?

Their physical capacities outstrip ours. It's as simple as that. We are not the fastest animals, we are not the best endurance runners, we are not the strongest, the most agile, or the best at running. And why would we be? Millions of years of evolution was selecting for those traits in other animals. Our selection headed more towards 'cranial capacity,' 'social structure,' and 'manual dexterity.' That was a hell of a lot more useful in our climate than brute force, incredible agility or speed. After all, five humans (working together socially) can find a way (using their cranium) to catch and kill the fastest prey animal alive (and it probably involves manual dexterity). I know that there's a religious attachment to the concept that humans are a good design, but frankly, we're not. We're just good enough that we can survive long enough to reproduce.

P.S. And probably, the most frequent game we 'chased' was Rabbits. There have been many many small animal skeletons found in most prehistoric settlements. Prehistoric humans probably spent more time weaving together snares that caught a rabbit-sized creature than they did on giant mammoth hunts in the blistering cold where they chased the mammoth for weeks (on the other hand, only one of these makes good Hollywood. And it's not a bunch of manly, primal cave men sitting around in a circle weaving together strands of dried grass and vines to form snares).