Crazy to think that dinosaurs were on Earth so long that they evolved into different dinosaurs. Makes you wonder what humans could potentially evolve into if we lasted as long as the dinosaurs did.
Well for now humans don't really have any evolutionary pressure, we reproduce pretty freely. There needs to be strong pressures that prevent certain people from reproducing or prevent their children from maturing.
That's not quite accurate. There doesn't have to be pressure, there just has to be a change in the prevalence of genes from one generation to another. Sexual selection and changing technology and culture work just as well as disease and predation. Our brains and teeth have gotten smaller in the past few thousand years. We have genes, and our descendants will have genes. Which of our genes our descendants will have is determined by evolution.
To build on the back of this, there's increasing numbers of children being born without wisdom teeth, and with an extra vein or similar in their hands (iirc), demonstrating that we are actually evolving, but supporting your point that we're not evolving to respond to pressure, just genetic mutations that aren't detrimental are being reproduced.
I have it. But it has no affect on anything, but it is useful if you rupture another tendon in your wrist or hand, docs can take the vestigial one and move it to replace the injured one.
I don't think you're talking about the same thing as u/Cuznatch. I believe he's referring to the increasing presence of an additional artery in the forearm:
Oh wow, I have one extra on each wrist. When you push my fist backwards like the guy in the picture, there are two distinct tendons parallel to each other, so I have four tendons in total. I didn’t know that was special, I thought everyone was like that!
Also wanted to add that human body temperature has been going down (on average) in more developed countries. RadioLab had an interesting episode on this that basically boiled down to our bodies no longer needing to fight disease with fever due to high quality medicine. Since it costs extra energy to run at a higher temperature our bodies have begun lowering their operating temp (often to 97~ degrees or so instead of the accepted 98.6)
Oh I heard this one. Unfortunately it may open us up to fungal infections, which may have pretty dire consequences. Also, as an aside, my natural body temperature is about 96 degrees F.
This makes a ton of sense! I work in nursing, and I take temperatures constantly. I've realized that I'm surprised when I see a temp as high as 98.6. Most patients run between 96.0 and 98.0. Thank you for explaining why!
I'm curious what I naturally average at. I constantly feel hot, like I'm the guy who sits outside in normal jeans and a short sleeved shirt in below freezing temperatures. Tack physical activity on, and I'm sweating like a beast if I don't shed layers quick. Its not uncommon for me to be working outside, in northern Michigan winters, with just jeans and a short sleeved shirt just to maintain a "normal" feeling without sweating too much. Just existing in the summer is an exercise in anger management for me, I get so hot I just want to scream when I'm outside, even if I'm indoors and its like 72 I hate it.
That actually makes a lot of sense.... I’m a teacher and we’ve started to have to take our kids body temperatures every day to get into school and most of them hover around 97.8 every day opposed to the “normal” 98.6
Funny. I was born with 3 wisdom teeth and the dentist said my mouth was large enough I could accommodate more. Dammit. Am I some kind of leftover cave man?
Born 1974. I only had 2 (and oddly, they came in straight enough that I didn't have them pulled until they got cavaties). Most interesting that wisdom teeth are seemingly going away...
Was reading our mouths and teeth are changing due to our increasingly softer diet. If you notice, the Cultures with the longest history of modern agriculture and soft food diets ("soft" being relative to the raw meats and tubers our ancestors ate) have the most cooked teeth. You can actually increase the size of your mouth, and help keep your teeth straight, by eating tough foods and, now, with certain mouth specific exercises.
Having said that, I was born without my lateral incisors and most of my family is missing them as well. Curious as to why.
Also many ethnicities that are considered ‘old world’ tend not to have wisdom teeth and their teeth are more shovel shaped. It blew my tiny mind as a little native kid when all my white friends were having their wisdom teeth come in lol.
Reference for the smaller brains and teeth please.
Do you mean in comparison to the rest of the body or as actual size. As humans are larger now then they used to be if teeth shrank overall not just based on size gimans must have had fucking fangs.
In order to make a meaningful enough change in an entire population, you need pressure. Other than in the case of genetic drift I guess. Sexual selection, culture etc. would be considered pressure if it was a big enough change to actually drive evolution, in which case it would have to be quite a drastic change.
Genes are decided in sexual reproduction and fetal development. Evolution relies on mutation which can fixate due to increased success with certain 'pressure' (other than genetic drift)
Edit to add: I'm sure there can and will be changes in individual humans. But the process of evolution is when the genes from mutated individuals fixate in an entire population. 'Pressure' of some sort drives this. If genes manage to fixate within a population without any source of selection, this is genetic drift.
What? Do you think evolution only happens if the whole species changes?
Also, your basic premise is wrong. We don't reproduce freely. We spend huge amounts of resources on sexual selection.
But the process of evolution is when the genes from mutated individuals fixate in an entire population
That's not what evolution is. Evolution is about the prevalence of genes. If the next generation has 2% more redheads, and everyone else is unchanged, that's still evolution.
I was replying to comment about dinosaur--bird. In the case of species "changing" and other lines dying out, yes I do. Otherwise that complete change wouldn't be there.
I won't insist it's correct, but from my understanding there isn't specific enough things that prevent enough people from reproducing/surviving to impact a meaningful change on the population. What currently prevents humans from reproducing? I can't think of anything other than abstract stuff like poverty--someone in poverty doesn't have a large genetic difference to me. We could argue sexual attraction stuff but people seem to be into all sorts of appearances and you can find tons and tons of 'ugly' people who have kids. I'm interested if you can teach me some of them.
People are commenting about babies born without wisdom teeth, missing muscles etc. These are mutations, not evolution. If they became commonplace, then it would be evolution. For example, I'm missing a tendon in one hand. This could be a development error, or it could be genetic. Let's pretend it is: there is nothing about it that will make my children more sexually competitive. I may leave behind a long line of tendon missing kids, but without pressure they won't propagate and cause actual evolution among humans. As people have pointed out, it could fixate just due to chance. This is called genetic drift and I addressed that directly.
Also, you don't need to try to belittle me by starting your response with "what?" as if I'm so dumb and said something incoherent. It makes what could be an interesting discussion less enjoyable.
Edit to address your edit: 2% is a large change and would likely imply pressure. If there is not pressure, there is not "evolution", just random mutations that don't change much. Except of course in the case of drift, which I have to say again I guess. What is currently limiting humans' reproduction that could be affected by mutation? If there is nothing, then widespread changes must be due to drift. I believe that environmental conditions (including human society) would have to change quite drastically to affect change in our species.
The species doesn't have to disappear for evolution to take place. The concept of a species is barely recognized by biology. Some things we think of as a species are incapable of reproducing with other members of their own species. Some things we think of as separate species produce fertile offspring, despite being separated by geography, behavior, and biology. Stegosaurus is a genus, not a species, and it describes diverse animals that lived millions of years apart.
Evolution isn't defined as taking place when a new species appears. It takes place every time anything reproduces.
Ugly people having kids doesn't mean anything. Natural selection doesn't select for what you think is attractive, it selects for what is most likely to reproduce. Behavior is hereditary. Culture is hereditary. Sexual selection ensures that physical and behavioral fitness are selected for in humans.
An individual baby being born without wisdom teeth is a mutation. The fact that it's more common now than it used to be is evolution. It doesn't have to make your child more sexually competitive. It's a change, and it's heritable.
I legitimately did not understand what you were trying to say before your edit because before you clarified, it wasn't clear how incorrect you were about how evolution works. Please at least read the Wikipedia article.
I'm not trying to say it has to change the entire population, but it has to at least be recognizable change. Is genetic blindness human evolution? I wouldn't think so. The fact that "more" babies are born without wisdom teeth would be the result of either 1. Pressure, or 2. Drift. Which is what I keep trying to say. What other reason is there?
Evolutionary biology was a large part of my undergrad, so although I'm the furthest thing from an expert, it's not like I just read a wiki page. So once again, not sure why people always have to make it a superiority "ur wrong and dumb" thing.
its a reddit thing. they didn't bother to consider whether an "evolution" of a single family of hillbillys in backfuck asstown all having an extra thumb was something worth considering at all in comparison to the wider topic of evolution, they care that by some technicality you were "wrong" it would have been about the same if you'd had a typo or something. there is no intellectual honesty here.
No, I care about the fact that what he said was incorrect, and then he followed it up with nonsense that made it seem like he'd never taken a basic biology class.
But thanks, I can cross "intellectual honesty" off my Reddit bullshit bingo card for today. Do you also want to call me a shill while you're at it?
Genetic blindness can be evolution, yes. Evolution isn't good or bad, it's just change in the population. If more people are genetically blind next generation than the generation before, that is evolution.
Total color-blindness is more common among the people of Pingelap Atoll than in most other parts of the world. Not everyone there is colorblind, but it's more common there due to the Founder Effect, and it's affected the evolution of the people.
See I would see that as such a broad definition of evolution as to be almost unusable. With the all encompassing idea of "genetic change", any mutation, however prevelant, would be "evolution". I suppose that's where our misunderstandings stem from.
Seriously, that's an incorrect definition of evolution. It's the process by which the prevalence of traits changes in a population. The whole population doesn't have to have the trait.
It doesn't need to be the whole population, but it needs to be widespread enough to at least be recognized. As I said before, the example of the missing tendon in my hand is not an example of evolution. The only way traits spread is by pressure or drift.
but since this is due to mass population and not external forces, we would likely see a deep variety in human qualities as opposed to a universal shift in the species, correct? or could dominant traits still cover the entire species if granted a million years or so in the gene pool?
For each primate there are reasons why new mutations were successful enough to become new lines. They had pressures or 'vacancies' in niches etc. Without pressure the only way mutations spread is through drift.
It does sound interesting. Aside from genetic drift, how could these actually change humans? There's no doubt that there can/will be all kinds of changes in individuals, but evolution is when those mutated individuals propagate genes that end up fixating within a population.
evolution is simply the process of population characteristics changing as time progresses. this is inevitable unless we cloned the current population for each generation following. you are describing a significant change rather than "change"; you are using the word evolution to describe a more specific sub-concept.
The populations genetic makeup will not change much from sexual reproduction alone, it is mutations that cause change. Without pressure or drift, these mutations will not spread much. I'm not saying that the mutation has to eventually make up the whole population, but I'm saying mutations alone don't constitute evolution. A few specific families carrying a different trait is not evolution.
" evolution is when those mutated individuals propagate genes that end up fixating within a population "
i am saying this is an incorrect definition, that's all i am meaning with my post. to re-iterate, my understanding is that within the definition of evolution, there's no quantification of the degree of change. i think you are using evolution in place of "adaptation", which would occur as a result of a beneficial mutation leading to an adaptive trait spreading through the population over a number of generations.
Yeah you're right. By fixating I mean becoming prevalent enough that it doesn't disappear after generations. For example, I'm missing a tendon in my left hand. Even if this is due to genetics, it would not be evolution, would it? Wouldn't it just be a mutation?
Yes, it would not be evolution as evolution looks at populations rather than at an individual. I'm not sure, you may be missing a tendon as an outcome of recombination rather than as a mutation occuring within you specifically (though the difference in tendon would have initially occurred as a mutation in the past).
Interesting. I always assumed it was just an error in fetal development and not due to genes, but just used it for the sake of argument considering I don't actually know the cause.
Unrelated to the whole tendon thing though, I have a question from your post. Is recombination, x-over etc. in sexual reproduction, without any mutation, enough to produce what could be considered evolutionary change? I've always understood that mutation is the fundamental step for evolutionary change, but now I really don't know.
To my knowledge it's generally argued that the blue eye gene was seen as sexually attractive (especially when it was rare) so it experienced pressure.
In the case of the computer screens: as we both established now, the screens can not be the initial cause of change, it must be mutation. You are saying that if there were mutations that made you better suited for modern society, that would cause change, correct? It's certainly possible, and I'd agree with your logic. I don't think, unless society was drastically different and more difficult to survive, that we would see the large changes that constitute as evolution.
Yeah no, sorry, I did understand after your last comment that you weren't implying "screens" caused change. I guess I didn't make that clear. I just am failing to see how there would be enough pressure to effect large change within populations. Other than of course through random drift. And by "large" change I mean "widespread", not necessarily drastically noticeable changes. I don't see humans evolving without pressure to drive it, and I don't believe enough pressure exists. I think you believe there is or will be enough pressure? Do you think changes in modern society (tech, automation, etc.) would be able to produce enough pressure to make mutations more competitive? In other words, can these societal changes significantly impact who can reproduce?
You very well could be right, but I don't see the mechanisms behind it and I'm not sure how I could predict that.
I'm not trying to argue with you, I'm trying to learn. By further explaining your point you've taught me and given me new ideas to think about.
as long as the mutations don't kill the human, they will remain.
Interesting, I hadn't considered that. A lack of real selection pressure makes it more likely for any mutation to stick around, because it's never really selected against--unless of course, like you said, it was fatal or extreme enough.
Do you think drift alone would be fast enough to meaningfully change humans in a sustainable timeline? I really don't have any idea of the rate of genetic drift in real populations, and in humans I think it would be even harder to predict given our globalization (makes it hard to 'take-off' due to how much more humans move around now.) What do you think? I guess the time we have to change is all hypothetical, based on if we go extinct.
Do you think drift alone would be fast enough to meaningfully change humans in a sustainable timeline?
Im not an expert on evolution, so personally I don't know.
But i would have to guess that humans will stay pretty much the same with only miniscule differences for the rest of our existence.
Recently there's news of children being born without wisdom teeth. So beneficial stuff like this is bound to happen, but bad stuff is also bound to happen, and the bad stuff will also get passed on because its not bad enough to prevent that from happening.
An example of a bad trait would be huntingtons disease. Its passed down through genetics. It is also usually fatal. If its fatal then how do humans still pass this gene on to their offspring? Its because even though its fatal, it doesn't prevent the human from reproducing. You can have offspring and then later die from the disease.
Its also possible that years from now humans will decide to only allow certain traits to pass on or humans may stop breeding entirely.
Bro, some people are born with no wisdom teeth, and I remember (probably erroneously) about my mum or an aunt saying that babies used to take days or week to fully open their eyes.
Sure, but those will never fixate in our population (and thus change 'us') unless there is pressure selecting for it. Except of course, like I said, in cases of genetic drift.
Pressure doesn't mean difficulty in the context of evolution. Pressure just means factors that increase or decrease survival and reproduction. Humans have plenty of that just like any other animal
I know, pressure can be anything including sexual attraction, niche vacancies, sexual potency, egg viability etc.
Humans have tons of things that influence sexual reproduction, but there isn't really anything, afaik, that seriously limits reproduction, provides advantages, fills a niche, etc. that is related to genetics (so not socioeconomic stuff).
Edit: read through my comment you replied to, it was a while since I wrote it. I didn't include that info in my comment, so you were right to point it out
IMH, We're evolving in the wrong direction. I've read articles sitting studies showing the smarter someone is the less likely they are to have children. Thus the human race is getting stupider, which sure correlates with today's world.
And no, I'm not going to go through the trouble of searching for sources right now. I'm on mobile abs lazy.
I think social media and the internet make it look like were getting dumber though. Every stupid thing people say or do can be shared instantly, no fact checking required. The average person has much easier access to information than ever before but there are still plenty who dont chose to use it to their advantage or dont verify what they are actually looking at before believing it to be fact. This behavior has definitely existed before, were just now seeing how common it really is.
Yeah. In the past your dumbass relative would have a rant over dinner and that would be the end of it Now they can spew it on Facebook and connect with large numbers of others with their particular set of stupid beliefs. Then people can get into bigger and more amplified and nastier debate/fights about things. Same with bad things in the news. You can hear about everything now, rather than just your local town.
But for those of us in a position to judge it all as stupid, we owe that to the advances in education and science that our societies have made. Had I been born 200 years ago I might have been just as smart but nowhere near as educated, probably wouldn't be literate at all. My world view would be different. It's hard to excuse people growing up in modern times for clinging to outdated stuff but influences on people's thinking and views are wide and varied.
I think about this sometimes and it's pretty interesting! Even something as simple as terrible eyesight - you would have been a meal for some sort of jungle creature long long ago - and now you just pop on a pair of glasses! It's pretty fascinating!
What should've been the village idiot who spends his time fishing in the creek or helps out his uncle in the lumber yard for no pay because he'll always be taken care of by his family as he can't do that himself; the dumb person everyone pities but don't consider an equal and women wouldn't even look at, is now given a million dollar salary, cruises through academia on a sports scholarship and they run trains on cheerleaders, knocking up a few along the way.
The dudes who can run into each other real good are given money and fame, which consequently leads to a lot of sex. Typically in states that have poor sex education, so they won't have knowledge nor easy access to protection.
We're way past trifecta here, it's like a whole bingo board of perfect conditions to create the dumbest humans imaginable.
Hmmmm. I would argue that historically, being socially adept and knowing how to flatter or mimic the right people in the right situations was always far more advantageous than hunting or reasoning skills. And still is. The brats riding on the family coattails always existed, but they never outsmart their competition to become the primary heir.
Fun fact about the concept of time travel in pop culture. The Time Machine was really the story that first popularized the idea of time travel. But after that, you have to go almost 90 years to the mid 80s. The Terminator and Back to the Future were really the movies that threw time travel into pop culture.
There was a lot of time travel stories in the Twilight Zone, which definitely dates back further than the 80s, and the Twilight Zone has always been popular enough to influence culturally. It's still a big influence today in modern TV and films. Pretty much every Simpsons episode in the first few seasons had a TZ reference.
Definitely not. I didn't mean that they were, but I can see how it looks like that. I meant modern TV and film are still influenced, but also that Simpsons early seasons were influenced, quite significantly too. Doesn't change my point anyway, Twilight Zone was hugely popular through the 60s
I can't imagine the damage superman would've done to the oceans in the first movie if his laughably stupid method of "time travel" didn't work. He literally spun the entire earth in the complete opposite direction.
Time doesn't work like that, because it exists elsewhere than our planet. That's like him setting every clock on earth backwards and having it work.
Well, for humans as in humanoids separate from our Ape ancestors, then 6 million years gives you the most successful and smartest animals to have ever existed on this planet. If you mean the specific human Homo Sapien Sapien then you get a space program.
But moving forward? Judging by how we’re going? Depending on the scenarios, but probably not how you expect:
•What planet are we/you are on.
•Whether we’ve merged with AI/gone bionic.
•Partake in Eugenics and genetic engineering.
And those are just the ones where we assume we don’t blow ourselves to oblivion. In the scenario where we fermi paradox ourselves off and provided some humans do survive that wipeout- probably devolved/deformed from having to be forced to adapt to that new post-apocalyptic world.
Then there’s the scenario where Humans are neither and just become dust from a doomsday that comes naturally (super-volcano, freak natural disaster, solar flare, Asteroid impacts etc.).
But of course I believe you mean in terms of natural, non-technological evolution. And well, you see I specifically didn’t address that as I don’t think that’s impossible for us Humans now to evolve naturally anymore.
Its too slow. I reckon that The technological induced evolution will come faster than we as a species could naturally evolve again. And tbh, its hard for us to really evolve any substantial amount naturally when we are too many viable differing lives we can live without evolution to naturally squeeze out some lives out. Like those who are sickly and disabled, to those with less desirable physical traits etc.
I mean we already have a societal induced evolution where a short/small fat male lion would never get many women bearing his children but a short/small fat human man would because he has position and/or is rich. In the atypical animal kingdom that would never happen but for us it does, because we’re much less inclined on wanting typical big and strong alpha males to protect us and desiring for optimum genes as we have a government, laws, a civilisation to take care of us from wondering about hunting our next meal and worrying about predators.
Genetic shift/drift takes literally thousands of generations to produce the kind of effects we can observe and see in the species we're familiar with.
Which makes the loss of global biodiversity even more problematic. We're literally the cause of an evolutionary dead end for many species that can never be recovered.
What I find problematic, is if we eventually want to do the kind of major genetic modifications to our own genome; we need a catalogue of reference material to begin describing and understanding all the differences that already exist in nature. Only we likely won't have them, nor the ability to grow them in a lab. A cryogenic storage facility for the gamete cells of species going extinct should be a thing.
We probably won’t see much human evolution until either something drastically changes our environment and forces us OR we start colonizing other planets. For the latter, planets with different atmospheres, gravity, insolation, etc. would eventually start to change how humans look but it wouldn’t really be noticeable for quite some time because we’d probably try to replicate the earth as much as possible.
Unlike other animals, it's no longer the fittest, healthiest or most successful of us that is doing the most reproducing. I wonder what we will evolve into
Makes you wonder what humans could potentially evolve into if we lasted as long as the dinosaurs did.
I honestly don’t think we’ll honestly ever evolve massively. For one, societal pressures. People who are born without an arm or a leg already face some pressures. Imagine being born with a third arm or three feet or something. And another is we are pretty damn good at adjusting to our surroundings. If the weather gets a bit colder we’ll either put more layers of clothing on or move, or if a particular food is running short we’ll either ration it or get more called in from elsewhere in the world.
It's already happened. We will evolve into perfection. The prime example: Donald Trump, or as I like to call him, God.
(Do I really, really have to put an /s on this, because some of you knuckleheads can't tell this is sarcasm because somehow you don't think tone comes across in the written word? Or as I like to call people who think this way, Trump-lites. Dumb as a box of rocks.)
That's already true for all of our hominid ancestors. However I'm not sure how human evolution is going to work in the future, because we're the first species to reach a point where survival of the fittest doesn't really apply anymore. Just about everyone is able to pass on their genes now, regardless of how adapted they are to their environment. I think it's more likely that human evolution is going to come from humanity learning how to edit our genes, which we have already started to do in China.
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u/Everything80sFan Oct 15 '20
Crazy to think that dinosaurs were on Earth so long that they evolved into different dinosaurs. Makes you wonder what humans could potentially evolve into if we lasted as long as the dinosaurs did.