OK, I hope my question doesn’t get misunderstood, I can see how that could happen.
Just a product of overthinking.
Idea is that we can live fairly easily even with some diseases/disorders which could be-life threatening. Many of these are hereditary.
Since modern medicine increases our survival capabilities, the “weaker” individuals can also survive and have offsprings that could potentially inherit these weaknesses, and as this continues it could perhaps leave nearly all people suffering from such conditions further into future.
Does that sound like a realistic scenario? (Assuming we don’t destroy ourselves along with the environment first…)
Pretty much everyone here either misunderstands how evolution works, or is willfully ignoring it to push their viewpoint.
Humans at this point have very little evolutionary pressure from natural selection. We aren’t getting weaker, shorter, taller, or anything like that from natural selection because those traits aren’t killing people.
The main driving factors for human evolution are sexual selection, random mutation, and genetic drift. There are still some poorer areas disease may still play a not insignificant part, but even that is fairly minimal since people largely live to reproductive age.
Human evolution has been fairly stagnant for quite a while. The differences most people would notice are from changes in diet, environment, and other external forces. For natural selection to pressure evolution we would need to have a significant portion of the population sure before they are able to reproduce.
Pretty much everyone here either misunderstands how evolution works, or is willfully ignoring it to push their viewpoint.
Yes! Finally someone else who knows how…
Humans at this point have very little evolutionary pressure from natural selection.
Oh come on! Such a strong start but then you fell on your face. Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It never lets up. It’s more about reproduction than staying alive. Natural selection is happening every time someone reproduces more than someone else.
Natural selection isn’t the only thing at play though. That solely refers to the organism best adapted to the environment being more likely to survive and produce offspring. Essentially everyone in our population survives to be able to produce offspring.
Sexual selection plays a much bigger part now. That isn’t someone being the most adapted to the environment, it’s someone being the most attractive to a mate. There are plenty of adaptations across nature that are maladaptive to survival, but are selected for regardless.
Then there are random mutations and genetic drift. Those happen in every population. That is more just a matter of chance.
We have found ways to adapt to our environment outside of evolution. So we no longer have a significant natural selection process.
Sexual selection is a subcategory of natural selection
No. This is a result of thinking of natural selection as working towards an “absolute” better and away from an “absolute” weaker, as opposed to pushing in directions that are entirely defined by the situation.
Natural selection is this: in populations that make copies of themselves, and have mistakes in their copies, those mistakes that better fit the situation the copies find themselves in are more likely to be represented in that population later down the line.
Note that I didn’t say, at any point, the phrase “SuRvIVaL oF ThE FiTtEsT.” Those four words have done great harm in creating a perception that there’s some absolute understanding of what’s permanently, definitely, forever better, and natural selection was pushing us towards that. But no such thing is going on: a human may have been born smarter than everyone alive and with genes allowing them to live forever, but who died as a baby when Pompeii went off - too bad they didn’t have lava protection. Evolution is only an observation that, statistically, mutations in reproduction that better fit the scenario a given population is in tend to stick around more than those that don’t - and guess what? That’s still happening, even to humans - it’s just that with medical science, we’re gaining more control of the scenario our population exists in.
Now, can we do things with medical science - or science in general - that hurts people? Sure, there’s plenty of class action lawsuits where people sued because someone claimed their medicine was good and it turned out to be bad. But if you’re asking “are we losing out on some ‘absolute better’ because we gained more control of the world we reproduce in,” no, there is no “absolute” better. There’s only “what’s helpful in the current situation,” and medicine lets us change the situation instead being forced to deal with a given situation, dying, and hoping one of our sibling mutated copies can cope.
Survival of the fittest doesn’t mean what you think it means. Fitness, in the evolutionary sense, is a quantitative representation of individual reproductive success. So yes, the fittest of us do survive in the sense that their genes are passed on far more often than those that are less fit. For example, the overweight, nearsighted, diabetic car salesman with a lethal peanut allergy that has 16 children is more fit than most people on the planet.
The more varied the sample of individuals you can afford to keep alive in your population, the more chances you have that a subset of them will be able to withstand random changes in the fitness function. If the environment changes abruptly, you will have a hard time adapting as a species if you only ever supported people “within the norm”. What happens in those cases is called extinction.
Hmm, that’s an interesting question. I’m not an evolutionary biologist but I am a biologist (more specifically, a microbiogist).
The crux of the misunderstanding, I think, is that the definition of what counts as advantageous or “good” has changed over time. Very rapidly, in fact. The reason many diseases are still around today is because many genetic diseases offered a very real advantage in the past. The example that is often given is malaria and sickle cell anemia. Sickle cell anemia gives resistance to malaria, which is why it’s so prevalent in populations that historically have high incidence of malaria.
Natural selection doesn’t improve anything, it just makes animals more fit for their exact, immediate situation. That also means that it is very possible (and in fact, very likely) that the traits that we today associate with health will become disadvantageous in the future.
If we remember that natural selection isn’t trying to push humanity towards any goal, enlightenment, or good health, it becomes easier to acknowledge and accept that we can and should interfere with natural selection
the traits that we today associate with health will become disadvantageous in the future.
Yeah I can think of a few, like aging. 10000 years from now kids will be saying, “wow, those poor unevolved savages lived such short lives and only really got to enjoy the first little bit of it before they started falling apart. They even had genetic engineering at the time! Imagine how many people would be alive today if they hadn’t been so scared to edit their genes to prevent aging.” Then their teacher would come over and explain that it wasn’t so easy at the time. There were still so many other problems they had to solve and related genes that need to be modified to avoid undesirable consequences, and let’s get back on topic: how many planets fall under the rule of the galactic empire including our own planet Urth?
Oh boy, a population genetics question in the wild.
In technical terms what you are asking is:
When a selection pressure is removed for a deleterious allele, what happens to the allelic frequency on the population?
The answer: they remain stable in the population, unchanging from when the selection pressure was removed. Every generation will have the same ratio of affected individuals as the previous one
Look up Hardy-Weinberg Equilibrium for more info.
I would argue that modern medicine prevents non-selective deaths. We try and keep everyone alive, not just the idiots.
I expect gene editing soon to become so cheap that everyone starts customising their children, resulting in a situation analogous to where dogs are now: extreme variability improving the chances for survival by making sure we have the needed people for any situation except gamma ray burst which requires backups far from Earth.
I’ve been working on a sci Fi show where humans have this but they also have the ability to change their current physiology by infecting themselves with modified strains of cancer that slowly replaces you’re body with one you downloaded off the Internet this technology has also sorta obsoleted medicine because if you have a broken leg or infected with a fatel desese so long as the injury doesn’t affect your brain you can just replace your entire body by infecting yourself with genetically modified cancer
Call me when evolution figures out how to deal with guns and automotive accidents, which likely represent the largest selection factors on modern humans.
i always thought that it was the greater volume of humans, the greater the genetic diversity
There’s barely any pressure to extinguish “bad” traits, though.
If you’re the idiot who eats every berry you can find, cavemen can’t save you and your genes disappear. Modern medicine can and will save you, so you can create offspring and the berryeaters keep their proud heritage alive.
Now, what is considered “good” or “bad” is of course highly debatable, but currently we have effectively no survival pressure, the only selection is how many children you get.
But that if that “idiot” does propagate, but so does everyone else, no skin off the species back. If the selective pressure returns, well then the others keep going.
If genetic research gets to a point where we can beat any mutations, then probably not.
Also, a point I don’t see others mentioning, is religious people often tend to have more children, and whilst religion isn’t actually hereditary, children often do have more likelihood to follow the same religion as their parents, the population is likely to tend to more extremist religious people, unless the rate of conversion away from those religions drastically increases.
Hopefully the inbreeding within those weirdo groups helps fix that.
Yes, but I’d argue that capital has a more profound impact than “modern medicine”.
There is a massive MASSIVE selection pressure against reproduction for if you can afford kids or not.
You can look around the world and see countries with amazing health outcomes, beyond anything our ancestors even a few generations back could have dreamed of…
… And yet these countries no longer even have children at a replacement rate.
I’m not saying medicine isn’t a factor… Just saying that in terms of evolutionary pressure, capitalism is even greater a pressure.
if you can afford kids or not.
To amend that, if you are responsible and think you can’t afford kids and have the restraint and planning to select not to have children… there are plenty of people that can’t afford as many children as they have.
In fact of those that can “afford” kids easily, they are still more likely to stay at one or two.
A quite different approach: modern medical practice uses a whole lot of medicine, which ultimately ends up in (waste) water, and becomes an environmental problem, including a health hazard to humans. https://www.sciencedirect.com/science/article/pii/S2772427122000390
I’m sure you’ll be asking your first responder this question while he or she is in the middle of performing CPR on you, and calling for an AED, right? You’re not regretting the discovery of 30-2, are you?
- You did misunderstand the point of this question.
- Yes, I’d prefer not being resuscitated. If I am finally dead, let it stay that way.
I don’t think I misunderstood. You see dropping dead as your prize for losing in some type of social Darwin competition. You don’t see medical advances and life saving measures as being part of our evolution, as a species, to better survive? No offense, but regardless of how you feel about being resuscitated, some paramedic, or other first responder is still going to try to save your life. They can’t exactly stop the process and ask you for your opinion if you have no pulse, dude.
Bro you did not understand anything he asked about
First of all, it isn’t “bro”. Secondly, I’m trying to make a point that valuing the mental capabilities of people is worth mentioning, when the OP seems to dwell on the physical worth of a human. Part of the evolutionary process is long-term problem solving skills, isn’t it? We create ways to resuscitate people, cures for diseases, and solutions for other medical problems. OP insists that gives us weaker people that continue living in our society? Weaker in what regard? If all cancer is suddenly cured, then which people are weaker? I knew a girl that had an intellectual disability, but was fairly physically fit. She could run well, and walked and talked as well as most people. Would you want to encourage her to have children, while discouraging some woman with breast cancer from having children?
I think I understood OP fairly well. I just question if he wants to limit procreation amongst the disabled. Remember that Hitler wanted to do that.
You need to read a genetics textbook and then some evolutionary biology so you understand OPs question.
Yeah, I guess college biology textbooks and Charles Darwin’s origin of species weren’t enough for me. I shouldn’t try to stop OP’s hint at arguing against letting people with physical disabilities breed.
They never said nor implied that
There are already lots of great answers, I would like to point out that Natural Selection doesn’t care about the individual at all, it cares about the population, e.g. internal gestation, do you think any individual enjoys carrying a baby inside them? Preventing them from doing anything during the gestation period, being an easier prey to predators, etc… Unfortunately for the individual, creatures that carry their unborn babies inside them are less likely to abandon them even temporarily while seeking food, they’re also more easily kept warm, so for the species as a whole it’s better that there be internal gestation.
In short more individuals = better, imagine you have two populations, one with only 10 strong individuals, and one with 100 individuals of which only 10 are strong, which do you think is more likely to survive? And that is even assuming a strong/weak deterministic position, which is not the case for anything.
