Anything about the human body

Apr 2017
647
Lemuria
#31
From the perspective of the long-term survival of species, evolution favors diversity. A type ideally suited to one environment may be poorly suited to survive if the environment changes (see Jonathan Weiner's "Beak of the Finch"). So it seems risky to me to deliberately move humanity toward idealized types, whether through breeding or genetic engineering. We don't know what the future has in store or what traits might be needed.

One example is a gene that's identified with obesity. In the U.S. today, the gene is debilitating but it's also a gene that helps people survive in times of famine. Purging it from the human genome might spell doom in some situations. Maybe it's just what the species needs to survive a big asteroid hit.

Culturally people tend to idealize tall, buffed, athletic types but those types really aren't all that well suited for survival in, say, desert conditions. The !Kung people of the Kalahari might represent a more practical ideal to strive for.

Also, I'm wary of "intelligence" enhancements. I have this suspicion that human intelligence lives near the borderlands of stability ("What on earth would give a person that idea?"), that our big mammalian brains represent a near maximum complexity before the structure becomes inherently unstable (see Philip K. Dick).

You have a good understanding of genetics and I agree with you.

I'm against genetic engineering because it is a form of bio-hazard and a corruption of the gene pool that can be irreparable and devastating.


Selective breeding is less intrusive and you can choose from a set of ideals. Some people would probably prefer to be tall and slender rather than muscular. Others would prefer to be normal or even short. But the common ideal is to reach the peak of human intelligence naturally and with technological interface without genetic modification.

Now this can reduce the diversity of a population. But this can be countered by keeping reservoir populations (may be even entire planetary population in reserve if that civilization is a space faring one). Usually a portion of the population will refuse to adopt new technology and want to live natural lives. Some will be dead set against ETHICAL eugenics. This is alright. You can make a pact with them. In exchange of taking their most talented, they would live free of interference for most part until they themselves start adopting technology again. Of course the initial seeding population will not tell the next generation of their origin. They will only have the basic keystone technology to start with and the initial pact.



This is how I see humanity should evolve, the entire galaxy peopled with a powerful league of humans of various species.
 
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Mar 2017
855
Colorado
#32
Suppose the woman in your family is pregnant, early stage. They take some amniotic fluid and discover cystic fibrosis. Before they started lung transplants, average life expectancy was 30 yrs. Will you be able to afford a lung transplant in 30 yrs?

"... but we can fix this with some genetic splicing!"

Of course you do it.

Like any technology, it has multiple uses. The same technology that can make a baby healthy is exactly the same as the one that can give a baby movie star looks, genius intelligence, and a professional athlete's body ... theoretically ... to those who can pay.

I don't have any conclusion here. It's just an observation that decisions about genetic tinkering are complex ... technically & morally.

BTW:
I completely agree that genetic diversity is the only reason evolution works at all. That "thrifty gene" is present in many ethnic groups that periodically survived starvation (Pima Indians are the usual example). It is believed that the gene to allow digestion of lactose became prominent in European peoples who suffered crop loss when they turned to raw dairy because there were few choices: individuals without that gene just died. I believe most people in Asia are lactose-intolerant, because they weren't subjects of that particular natural selection.
https://www.uu.se/en/news-media/news/article/?id=3154&typ=artikel
In the same way sickle cell anemia provides some resistance to malaria on the African continent, at one time all Mediterranean races had the gene for thalassemia ... which has a similar affect (Julius Caesar had one of the three forms of malaria at the time, he got it around 17 and died at 66, and it wasn't malaria that killed him).
 
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VHS

Ad Honorem
Dec 2015
4,281
Brassicaland
#33
Suppose the woman in your family is pregnant, early stage. They take some amniotic fluid and discover cystic fibrosis. Before they started lung transplants, average life expectancy was 30 yrs. Will you be able to afford a lung transplant in 30 yrs?

"... but we can fix this with some genetic splicing!"

Of course you do it.

Like any technology, it has multiple uses. The same technology that can make a baby healthy is exactly the same as the one that can give a baby movie star looks, genius intelligence, and a professional athlete's body ... theoretically ... to those who can pay.

I don't have any conclusion here. It's just an observation that decisions about genetic tinkering are complex ... technically & morally.

BTW:
I completely agree that genetic diversity is the only reason evolution works at all. That "thrifty gene" is present in many ethnic groups that periodically survived starvation (Pima Indians are the usual example). It is believed that the gene to allow digestion of lactose became prominent in European peoples who suffered crop loss when they turned to raw dairy because there were few choices: individuals without that gene just died. I believe most people in Asia are lactose-intolerant, because they weren't subjects of that particular natural selection.
https://www.uu.se/en/news-media/news/article/?id=3154&typ=artikel
In the same way sickle cell anemia provides some resistance to malaria on the African continent, at one time all Mediterranean races had the gene for thalassemia ... which has a similar affect (Julius Caesar had one of the three forms of malaria at the time, he got it around 17 and died at 66, and it wasn't malaria that killed him).
Since Liu Cixin's Micro-Age (微紀元)(microscopic humans) is hard (or almost impossible) to realize, will these thrifty genes be helpful in saving earth's limited resources?
We probably can eat substantially less than what we do currently.
Should we edit for other forms of genetic issues, such as Down's Syndrome, some forms of autistic spectrum disorder, or others?
 
Mar 2017
855
Colorado
#34
.. will these thrifty genes be helpful in saving earth's limited resources?
The thrifty gene works like this: it's turns any spare calories into fat.

In modern society, the Pima's are almost uniformly unhealthily obese. They don't experience periods of famine. Scientists started investigating when they noticed Pimas resistant to weight loss on the same diets that made other people thin.

In times where food is available, they just pack on pounds .. almost miraculously. When food is scarce, they live off the stored fat. This is a very unhealthy way to get through life, and yet it's let them survive ... like others with the gene.

If you think about it, nothing is saved. They don't eat "less" food. They pack on fat, but they typically must eat much more than they need ... as deposits for the future.

A Pima Indian caught in the feast/starve cycle may actually eat more food than someone eating a survival diet all the time. There's also a behavioral aspect. It's not clear if this is genetic or just a practical response: when they get really big, they don't move around much. This is serious: they've videotaped their lives. Part of the puzzle is them actually lowering their metabolic rates.
 
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VHS

Ad Honorem
Dec 2015
4,281
Brassicaland
#35
The thrifty gene works like this: it's turns any spare calories into fat.

In modern society, the Pima's are almost uniformly unhealthily obese. They don't experience periods of famine. Scientists started investigating when they noticed Pimas ballooning on the same diets that kept other people thin.

In times where food is available, they just pack on pounds .. almost miraculously. When food is scarce, they live off the stored fat. This is a very unhealthy way to get through life, and yet it's let them survive ... like others with the gene.

If you think about it, nothing is saved. They don't eat "less" food. Considering that energy is lost with every conversion, they actually eat "more" food ... when it's available. They eat food, just like us it's converted to something they can use. The excess is converted to fat, but the conversion itself takes energy. When they need the fat, the metabolic conversion also loses energy in order to get it to a form they can use.

A Pima Indian caught in the feast/starve cycle actually eats more food than someone eating a survival diet all the time.
Some genes might be useful in the past may not be desirable today.
Some suggest that if humans "become small" (not the microscopic level), we may use more resources than we do currently.
 

VHS

Ad Honorem
Dec 2015
4,281
Brassicaland
#36
Let's discuss the human eyes here:
After learning that many daytime birds have way superior eyes to humans, I am a firm believer of evolution rather than the so-called "intelligent design".
For example, birds don't have blood vessels in their retinas (way less vision issues here); they see with much higher acuity and way more colours than humans do.
(Owls don't see colours as good as daytime birds; then, most of us would choose the eyesight of daytime birds anytime.)
Kiwis are almost blind; then, they are nocturnal birds, too.
 
Mar 2017
855
Colorado
#37
Let's discuss the human eyes here:
After learning that many daytime birds have way superior eyes to humans, I am a firm believer of evolution rather than the so-called "intelligent design".
For example, birds don't have blood vessels in their retinas (way less vision issues here); they see with much higher acuity and way more colours than humans do.
(Owls don't see colours as good as daytime birds; then, most of us would choose the eyesight of daytime birds anytime.)
Kiwis are almost blind; then, they are nocturnal birds, too.
Intelligent design has a whole convoluted explanation of "non-evolution of the eye."

There isn't one kind of eye. There are quite a few varieties (you've pointed out just one). Light goes through a lens and hits sensitive light receptor cells. That's about the limit of commonality. Consider dragonfly compound eyes. They are nothing like mammal eyes or bird eyes ... which are pretty different from chameleon eyes ... and tuatara pineal eyes.


Despite the widely different kinds, their histories are all well documented in the fossil record. Eyes first appeared around ~540 MYA.
 

Corvidius

Ad Honorem
Jul 2017
2,332
Crows nest
#39
With dinosaurs there is also the factor of them having 80 chromosomes compared to our 23. This gives far greater scope for evolution to adapt rapidly to changes in the environment. That's why there are 10,000+ species of maniraptorans and about 5,500 species of mammal. I used that terminology to show that as far as mammals go, what we have is the totality of mammals ranging in diversity from the shrew to the blue whale. Birds, while being the only surviving dinosaurs, are not the totality of dinosaurs, with birds only representing one small group, the maniraptora. An equivalent situation for mammals would be if all of them were a variety of feline. The point here is that birds are extraordinarily successful and they do what they do better than we do what we do, and here I mean humans specifically as nobody would say that a dolphin is not a superb example of how evolution can adapt an animal to it's environment.

I think our intelligence has, so far, worked against our physical limitations. By that I mean that we are built for walking long distances, not building Great Pyramids, Great Walls or anything else that requires heavy lifting and the strain it puts on the vertebrae and the lumbar muscles and knee and other joints. We have crippled ourselves, and not just by heavy labor, but in other ways, like sitting on a chair, risking DVT, peering at a monitor, which is not good for our eyes, and risking repetitive strain injury or even carpal tunnel syndrome as our fingers tap away.
 
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Mar 2017
855
Colorado
#40
One should consider how walking up-right had on the use of tools and on sexual behavior.
Of all the animal species in the world, why is human birth so life threatening to both the mother and child? Even elephants with a ~100lb baby don't have that much trouble.

I read an anthropology paper that discussed a woman's hips as being a compromise between giving birth and walking upright. There ARE no other mammals that routinely walk on two legs to compare to. Basically, the hips narrowed (making birth tighter) to support a walk ... rather than a waddle. Look at apes who temporarily walk on two legs. <Forgive me if this is a repost within this thread>

There was also a book published in the 70's called "The Naked Ape." My recollection is that it's "pseudo-science" at the start of the"socio-biology" ... fad? It describes a notion that a woman's enlarged breasts (compared to other apes) are meant to draw the male around to frontal intercourse, as a reminder of buttocks: the concept of "socio" biology is that societal/relationship pressures push adaptation. There's a complicated explanation of how face-to-face was important for bonding ... or some such. Since apes occasionally use this posture, I think this interpretation is highly suspect.

As for tools? Opposable thumbs and two free arms allowed humans to master their environment. There are many, many animals from apes to birds that use tools: none of them can throw a spear, or make & lift bricks ... or make elegant, painted Grecian pottery just for fun.

For a long time, Neanderthals were interpreted as stupid, hulking also rans. Then they found tools, and jewelry, and flutes. Whoopsy!!
 
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