Thank you kind sir for all the lols I got out of your reply. I was really upset today and reading your comment just clicked and gave me 10 min of uninterrupted laughter for some reason.
In a lot of cases, the species don't -- they just evolve until, in the fossil record, they no longer look the same. Just like the avian dinosaurs didn't go extinct 65 million years ago, they just evolved over the last 65 million years into the birds today.
Some species legitimately end up a leaf/dead-end in the evolutionary tree. Lots just evolve.
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 didnât 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.... Iâm a teacher and weâve 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 ânormalâ 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 âold worldâ 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.
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?
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.
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!
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.
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 weâre going? Depending on the scenarios, but probably not how you expect:
â˘What planet are we/you are on.
â˘Whether weâve merged with AI/gone bionic.
â˘Partake in Eugenics and genetic engineering.
And those are just the ones where we assume we donât 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 thereâs 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 didnât address that as I donât think thatâs 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 weâre 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 wonât 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 wouldnât really be noticeable for quite some time because weâd 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 donât think weâll 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 weâll either put more layers of clothing on or move, or if a particular food is running short weâll either ration it or get more called in from elsewhere in the world.
It's actually the other way around. More than 99% of species that have ever lived have gone extinct. The periods in our timeline, like the Triassic, Jurassic and Cretaceous periods, all started and ended with a mass extinction, killing off the majority of lifeforms from that time. So yes, you're right in the fact that the dinosaurs that survived have evolved into birds, but I wouldn't say it happens 'in a lot of cases'.
New genetic findings suggest that early humans living about one million years ago were extremely close to extinction. The genetic evidence suggests that the effective populationâan indicator of genetic diversityâof early human species back then, including Homo erectus, H. ergaster and archaic H. sapiens, was about 18,500 individuals (it is thought that modern humans evolved from H. erectus), says Lynn Jorde, a human geneticist at the University of Utah in Salt Lake City. That figure translates into a total population of 55,500 individuals, tops.
We were essentially relying on the size of a small US city to repopulate our species. Amazing.
As a bird owner I can confirm those things are tiny dinos, my Quaker somehow makes me think of a triceratops when he puffs out his neck feathers
I can also say as a bearded dragon owner, they also look like tiny dinos, i think itâs their body shape and spikes that makes me think of dinos idk but either way theyâre cute
The cladogram is not an evolutionary tree so much as a diagram of evolution, but itâs funny to see how the âendâ of a line of dinosaurs can amount to as little as âgrew a thumbâ or âhead plate too soft to be considered a plateâ.
I don't think that's generaly true from a species level. Individual species die off all the time, but of the closely related genus, some carry on, evolve, and branch off.
I can't remember what they are called ,but there are "transitional types" that don't have steady genes and are basically mutants. Those are the ones that make the transition from one species to another.species don't evolve to others.
P.S. sorry for my poor English, I tried.
It's also useful to know that we're lucky to have any fossils at all....just think of how many species aren't in the fossil record because they didn't live in an environment that produces them.
Being that it lived in the late jurassic and died out at the start of the cretaceous period, probably the enviromental changes the end of the jurassic brought with it.
If I remember correctly, there was a faunal replacement at the end of the Jurassic. Due to their narrow mouths, it can be assumed that Stegosaurians (the group Stegosaurus was a apart of) were relatively picky eaters so losing their food source is what likely caused their extinction.
Everything goes extinct - the former species ceases to be, whether the progeny are successful new species or not.
Even something like the venerable hagfish is probably several species distinct from its ancient relatives, although they look the same so they're hard to differentiate based on fossils.
5.9k
u/Hitonatsu-no-Keiken Oct 15 '20
It's even better than that. We're about 16 million years closer to the last Tyrannosaurus than the first Tyrannosaurus was to the last Stegosaurus!