I wonder why the human body is so badly designed?

[LJ17xx]

However the human race came about, why are we so unprepared for life? Our bodies aren't equipped. So many illnesses, mental health disorders, too many ways to die!

The human body is totally fit for purpose but we don't use it appropriately.

Also, we are designed to survive as a species, not necessarily as individuals (although there is the concept of 'the selfish gene').

Evolution requires us to live to sexual maturity and pass on our genes. Generation by generation. That’s it.

We do this. And then some.

I always felt that marsupials have if sussed : deliver a teeny-tiny baby, then suckle in in a pouch, allowing for skull/brain growth outside of the womb - no need for painful deliveries by either method....

Many animal young are born much more capable than human young, can walk within minutes of being born etc etc, are equipped with instinct, but they do not have the same ability to learn.

Perfectly I wouldn’t call it a huge evolutionary success when many young women die, and many are left with horrific injuries in the developing world.
If men had their penises shredded and were left maimed, with many dying in the developing world to birth children, there would be money poured in to help correct Mother Nature and her big mistake. I doubt the Americans would be funding nasa if most males could face the prospect of death or injuries at some time in life to carry on the species.

Because medical advances have altered the course of nature through natural selection.

Certainly in regards to childbirth:
In years gone by, most large babies (and / or their mums) wouldn't have survived childbirth. Medical interventions nowadays mean they do, and often go on to have big babies because themselves (due to a genetic disposition for larger babies) and so on...
If left to natural selection, only smaller babies would survive and go on to produce smaller offspring of their own.

I always wonder about life expectation 100 years ago and infant mortality. When they work out the average life expectation wouldn't infant mortality rates massively reduce it, so what I mean is if you managed to live to maturity was you life expectation significantly different to now?

Sorry off topic it is just something I always think about when people talk about the changes in life expectancy.

a) We weren't designed b) We live much longer than we used to c) We don't treat our bodies as we should. They hold up pretty well, considering.

My body cleanses itself with my liver and kidneys, I wish my house would clean itself.
I find it amazing I grew two humans. But the exit felt badly designed, but I read somewhere that it squeezes the amniotic fluid out of the baby.

I often say designed when I mean evolved. I think the production of a human at all is extraordinary and inevitably involves compromises (e.g brain size vs risk of death on child birth) but if one were Designing we would have wider hips, or perhaps not give birth through our pelvis, or our brain would not be entirely located within our skulls.

Humans can be both amazing and flawed. A well designed human (from the POV of someone who doesn’t want to age and die, rather than specifically from the POV of humanity not dying out) might have telomerase throughout adulthood to prevent aging, or teeth that can be replaced if they are lost. Even from a point of view of evolution, it’s not evolutionarily ideal to have so many people who are short/long sighted - I would be an exceedingly poor gatherer without glasses. We have a limited ability to burn fat to make heat - if we had more brown fat people might be less likely to feel cold all the time (but it would increase our overall required calorie intake - but for me, In a country of plenty) that would be a good thing.

None of the above mean that humans (and indeed so many living things) aren’t extraordinary, but all show non-ideal “design”.

I'd agree that we are poorly designed. The holes for breathing and for food intake are way too close together. Don't get me started on the holes for pleasure and for waste removal

I wonder too how much we’ve fucked with natural selection.

Before medicine became so advanced, even 50 years ago, those with attributes that didn’t give a survival advantage, died.

But now we have caesarians, for example. So many women who would have died in childbirth now survive, and pass those genes on to their children. So is it skewing the population- where years ago the population of women who birthed easily would increase as those who couldn’t died...

Same with childhood cancers, diseases like cf and diabetes. These children now survive to possibly pass on their genes..

So have we reached a tipping point where we are making the overall population sicker, or less suited to a healthy life, now it’s no longer “survival of the fittest”?

*etymology
Yes, that's similar to what I was getting at

*reallyanotherone

A very interesting point

I do sometimes think perhaps a poor design for childbirth is a way of controlling the population in a Hunter/gatherer primal society.
Whilst the young males would be off full of testosterone and impulsivity and lose their lives hunting or fighting with rivals....

Totally agree. If I had my way the trachea & oesophagus would be nowhere near each other, babies would be grown in tanks, it would be impossible for a rectum (or anything else down there) to fall out and appendices would no longer exist. Shoulders are a bit silly too. And don't even get me started on testicles! However it's not all bad...having 2 kidneys is a good thing. Brains are quite funky. And what's not to love about being able to touch your nose with your tongue?!

Peacheachpearplum I've thought that about life expectancy too.

Certainly when tracing my family tree I've found it very unusual for my ancestors to die before 60 odd and many were 70, 80 and even 90. And I've got back to 1540 on multiple branches. We weren't well off either! But there was high infant mortality so overall the average life expectancy of my family was lower in the past even if those who survived to breed lived reasonable lengths of time.

The reproductive system in women could be better! Periods for 40+ years! I hate them.

Cross post:
*Even from a point of view of evolution, it’s not evolutionarily ideal to have so many people who are short/long sighted - I would be an exceedingly poor gatherer without glasses.

None of the above mean that humans (and indeed so many living things) aren’t extraordinary, but all show non-ideal “design”.*

Additional examples to my point above- Short or long sighted is no longer an evolutionary disadvantage, once we invented glasses. So we are driving a non ideal “design” by “fixing” problems that once meant we may not survive. Had we not invented glasses, would a bigger percentage of the population have perfect vision?

It’s mostly not our bodies at fault though is it? We have made a really artificial insustaining environment to love in, and our bodies can’t cope. Too much pollution, stress, synthetic chemicals. Our bodies thrive best with the things we evolved with over millennia, it’s all the stuff we’ve thrown at it in the last few hundred years that cause most of the problems.

Perfectly I wouldn’t call it a huge evolutionary success when many young women die, and many are left with horrific injuries in the developing world.
If men had their penises shredded and were left maimed, with many dying in the developing world to birth children, there would be money poured in to help correct Mother Nature and her big mistake. I doubt the Americans would be funding nasa if most males could face the prospect of death or injuries at some time in life to carry on the species.

I take your point and don't disagree with it, but it's more of a feminist one, rather than evolutionary, isn't it?

really I tend to agree with you in that I can’t see how it can improve survival, but that is the price of civilised society - no one wants eugenics.

LJ I thought that you meant designed in the colloquial sense! :)

Once sugar came on the scene I think it would be a good idea if we grew a new full set of teeth in our thirties or forties when we’ve learned to look after them.

I bet before people studied and looked at screens for long hours fewer people wore glasses. Certainly in China eye exercises are now part of the school day. Isn't there some research that being outside a lot prevents short sightedness?

Because we evolved, if we were designed lots of things would be better.

We also evolved to stalk game in the African savanna, not to live in cities.

We aren’t designed.

That means that while we are amazing, wondrous products of evolution we also have a few quirks.

Evolution does not work to an end goal - it’s really important to understand that. Evolution works by the thing that’s evolving having variation in the population, and then a ‘pressure’ being applied by the environment that thing is in. So my dish of bacteria may have varying resistance to an antibiotic - if I add the antibiotic to the dish the ones that survive and reproduce are the ones that have some degree of resistance.

So for humans we have all sorts of interesting bits and bobs that reflect the fact that at one point or any other they were useful. A vestigial appendix for example.

We haven’t fucked with natural selection in a way because the modern world IS out world - again evolution doesn’t have a goal - it works in the moment. So there’s a pressure for women to have wider pelvises driven by foetal heads and childbirth survival and countering that is a pressure for them to be narrower so we can walk efficiently. There’s no design or intent behind it. How we evolve in the future will depend on what our environment is like - any new pathogens for example. Or the collapse of modern civilisation. Remember that reproduction is a big part of selection - if a trait hits past the reproductive years or has little effect on reproduction there is not the same pressure to spread as one that would kill you before childbirth. So we could expect a gene that confers resistance to a terrible plague to spread faster and more widely than one that gets rid of our wisdom teeth.

The question about glasses above is an interesting one and the answer is yes and no :)

Yes if we still needed brilliant vision to avoid predation then those with very poor eyesight would be disadvantaged. But short sight isn’t just inbuilt it’s environmental too and depending on things like daylight exposure during the younger years. We would expect the proportion of short sighted people to drop in a post apocalyptic world just because of that. Most slightly short or long sighted people would be OK and so there wouldn’t be massive selection pressure on it.