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.
In this age of contraception, it’s more a matter of wanting to reproduce (and how often) rather than merely being able to. I can’t shake off the impression that less educated people are reproducing at a way higher pace, producing many offspring of which in before times many would not have reached reproduction themselves, but now they do.
You should watch the movie Idiocraty.
I’ve seen it. And less educated/poor doesn’t mean genetically less intelligent. And even if it did, all that means is a change in the average gene distribution. A large enough portion of every population still reproduces that we are unlikely to dead end any major gene variations. So we still maintain a diverse gene pool, and if something happens to make natural selection play a role, we still have enough variation to adapt to changes.
I think the point Idiocracy was trying to convey had less to do with the genetics of the stupid people breeding, and more so the downward spiral of intelligence due to policy societal and governmental changes. Dumb people, make dumb policy choices, including with regard to education. To me, it stands to reason that the downward slope of intelligence is percitpitated on how effective governmental policy is and how well education is distributed.
Agreed. Plus it is a satire. It was making a point. It wasn’t required to be factually accurate through the entire movie.
My disagreement was that there was any evolutionary downward pressure on human capability. We can do increasingly dumber things without it being a genetic change. Propaganda, indoctrination, and selective access to information can play a huge role in how people develop and ultimately behave.
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
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.
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.
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
If genetic research gets to a point where we can beat any mutations, then probably not.
Same question rephrased: Can seat belts be a threat to humanity long-term by greatly reducing the effects of natural selection? After all, stronger individuals are more likely to survive car crashes.
What about wood stoves? Surely the fittest individuals are able to handle the cold?
We removed ourselves from “natural selection” a long time ago.
And yet, we have not, for these inventions are the Adaptations developed by other humans for the purpose of the propagation of genetics similar to their own
I think we’re in a more similar position to birds of paradise. Several species of birds that live in the south Pacific/Indian ocean islands/Australia kind of region, where the weather isn’t particularly harsh, their food is abundant and there are no natural predators, so natural selection has given way to mate selection. Male birds of paradise are fancy as fuck with brightly colored burlesque plumage not because it’s any help surviving their environment, but because the girl birds think it’s sexy.
I think our genus is in a similar position, but got there via a different route. Once the upright walking, hands having, brain thinking ape got dexterous and smart enough to build fire and cook food, there was a sort of bootstrapping period of becoming smart enough to do engineering, at which point we arrive at anatomically modern humans, and from there most physical changes have basically been “because it’s sexy.” Men have deeper voices because it turns women on. Women have permanent boobs because it turns men on, etc. People from Asia have distinctively shaped eyelids…is there some environmental pressure in Asia that doesn’t exist in Europe or Africa, or is it because that eye shape became fashionable to ancient Asians?
And now we’ve arrived in a time where we have a functioning understanding of how genetics work, and the ability to manipulate those genetics at industrial scales. Seriously I think we departed the “it was cold so the ones with thicker fur were more likely to survive to fuck another day” phase of existence at some point, with the invention of writing at the latest.
I don’t think so.
For one, natural selection selects the “fittest”, but what the “fittest” means, changes over time.
Also, there’s lots of other factors that you may have overlooked, such as sexual selection probably playing a bigger factor.
Sexual selection usually takes care of problems like this. People with antisocial tendencies find it extremely difficult to find partners.
Unfortunately, not when they have money.
No. Human evolution is driven primarily by mate selection.
I would say that the greater the population (in part thanks to medicine) the greater the chances of beneficial mutations occurring and entering the collective gene pool. I see medicine as a safety net. I’m sure it’s more complicated than that, but that’s my professional take on it, as a musician.
Natural selection led to our intelligence to be able to made medicine in the first place.
Oh cool, it’s time to find out how much of a burden on humanity I am and whether I should have been left to die. Just hypothetically of course, I wouldn’t want anyone to misunderstand. I always enjoy this question with my morning coffee.
realistically industrialization and guns have a far larger impact on human evolution rn than healthcare.
Exactly, and yet the question is never “is agriculture a long-term threat to humanity?”. It’s always the people with medical issues who are acceptable first choices as society’s sacrificial MacGuffin, long before we question any technology that benefits the person who is “just asking questions”.
It’s like we didn’t already do Social Darwinism the first time. Super frustrating.
Agriculture has proven itself to be a boon to humanity. It’s our passion for excess that will kill us.
As has medicine and most other technologies. And yet… the question is never asked about the long term threats posed by people who aren’t personally hunting and tracking and foraging.
Maybe you should skip these threads in the future. Don’t you think it’s important for people to understand this concept? Not everyone knows everything. Educate.
And miss out on the reminder that my existence is precarious and dependent on the good-will of the able-bodied? Nah, that’s head-in-sand stuff. I prefer to remind everyone of what this line of questioning has led to in the past and the human consequences of discussing the rights of a group of people in the abstract.
Yes. Not educating is the way to go. That always works out well!
I think we’ve already demolished natural selection over here, modern medicine being the least of concern. Idiocracy was supposed to be humor, not foretelling.
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?
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
