https://www.reading.ac.uk/news/2024/Research-News/Brains-grew-faster-as-humans-evolved-study-shows

Hey guys,

While researching about vestigial organs , I came across the third eyelid (plica semilunaris). I noticed that Wikipedia states that we also have vestigial muscles related to the Plica semilunaris, however I could not find any anatomy text book that mentions these muscles.

I also came across a science direct article that stated that there was no muscle fibers in the plica semilunaris.

https://www.sciencedirect.com/science/article/abs/pii/S0940960204800025

Is Wikipedia false here? Or am I reading things incorrectly? Thank you.

Like, are there any approved theories on the first cell (the first simplest form of life) and how did it emerge? Or we still don't know?

Hey im really interested in evolution and one thing that has always bothered me is how species transition from one niche to another. What I mean is, how can a herbivorous animal only capable of consuming plants to stay alive have meat eating descendants? Somewhere in between it had to start eating meat, but wouldn’t they get sick initially and just decide not to eat what their bodies weren’t built for, preventing them from evolving meat eating traits? same goes for animals that transition from blindness to having sight, how did they develop the ability to sense light in the first place if they never had it? Hope this isn’t a stupid question, appreciate it

I see that farming was discovered around 12,000 years ago, and the earliest big 4 civilizations around 6,000 years ago.

I also understand that biological evolution occurrs on a time scale of hundreds of thousands / millions of years.

But I am wondering, with civilization comes larger gene pools and basic needs being met, so it seems to me that biological evolution would be occur much more rapidly.

So, title?

So, I recently read from Wikipedia (not the most reliable source, I know!) that Australopithecus africanus was probably a patrifocal species, meaning that females were likelier than males to leave the central social group. A matrifocal species would be one in which the males are likelier than females to leave the central social group. My question is how we can know such characteristics from long extinct fossil species. Despite the question being prompted by Australopithecus africanus, this is really a question related to any fossil species. How can we determine such characteristics just from fossils? Behavior (alongside DNA) doesn't tend to fossilize, so I wonder what other proxies were used to determine these features. I actually asked a population genetics professor and a research supervisor in my evolutionary research project about this, and they had the exact same question themselves. They thought it would probably be based on flimsy evidence, so I'm curious what evidence is being used to determine such features in ancient hominins (and other fossils in general).

I know there are big cats and wild cats but they all basically look the same in different sizes with minor characteristic differences.

With dogs the variety is huge!

I can't find out much about the frogs from the Triprion genus, except that their heads are used to plug tree holes, and may be an example of convergent evolution within the genus itself
If anyone knows any more I'd love to know(specifically how they evolved from within the hylinae genus)

I'm specifically talking about chimps,monkeys, and other animals similar to humans, other animals can also think and reason to a certain degree but animals like chimpanzees have better memory and other thinking capabilities then humans do, my question is how is it that were much better advanced then they are?

IMPORTANT NOTE: When I say fish here, I'm referring exclusively to bony fishes (class Osteichthyes).

Here's my understanding: The ancestor of all bony fishes had both gills and lungs. It used both of them for respiration depending on the quality of oxygen in the water; if it was too low, it would go up to the surface and breathe air with its lungs. Otherwise, it would breathe with its gills in water.

When a certain subset of lobe-finned fish (which themselves are a subset of bony fish) slowly transitioned to land, their gills gradually disappeared because they became useless, and their lungs were the default for them to breathe air.

On the other hand, the rest of the bony fish that stayed in the water (mainly ray-finned fish) converted their lungs into swim bladders to help them change their buoyancy in water. They retained their gills, which became the default way for them to breathe in water. However, in a few select species like bichirs and lungfish, they retained their lungs rather than converting them into swim bladders due to the environment they lived in.

Is that view correct?

So as I write this, I am suffering from yet another flaming UTI. As a woman I know that others struggle with them all the time as well, and while sex doesn’t cause it 100% of the time, it seems like the #1 trigger, as our urethra is comically close to our behind. (I know that men get them too it’s just a lot rarer.) To make matters even stupider, (thanks evolution) each time a woman has intercourse there is a high chance for the male to push bacteria (typically E. Coli) directly into said urethra, since it is located..practically inside the vaginal orifice. There, it forms a biofilm to evade detection by our immune system, so the leukocytes can’t even target them. If left untreated, there’s a good chance it spreads up to your kidneys, cause kidney damage, sepsis and death. So…. I would think that women with more robust protection against the bacteria would have been selected for, perhaps a trait that made it more difficult for the bacteria to adhere? Or….. I guess they did just die from sex left and right? 🤷🏼‍♀️

(Adding that I have done everything I can think of to prevent it, i am clean, pee afterwards, drink cranberry juice, extra water, nothing works, seeing a specialist soon)

I am looking for a book on evolution I read but have forgotten the name and author: • it had a dark blue or black cover • I believe it had a greenish illustration, with a cell nucleus if remember correctly • it was about 350 pages long • it had a friendly tone, as if written half for popularizing the theory, half for people who know a little biology • if was written in a friendly tone, like Isaac Asimov writes non-fiction • i think it was published around the year 2000 • it was not written by Dawkins or Harari • searching the internet, What Evolution Is by Ernst Meyr rings a bell but I'm not sure it's not the Mandela effect as I am recalling the book having 2 authors. But I'm pretty sure it had "evolution" in the title. Anyway I did not find it for free to browse it and see.

What do y'all think? What is my book?

Thank you in advance!

P.S. I searche other people's posts and did not find it among the first 20 posts about books.

Can anyone recommend papers or researchers which focus on the intersection of learned behaviors in the animal kingdom and selection/speciation? When I was a kid, I used to volunteer at a nature reserve where an ornithology PhD student was working on song sparrow vocalizations and mating preferences. I've searched for him in the literature and it seems like nothing got published. I'd like to know more of the state of research along these lines. In particular, I'd like to know more of the current understanding on how learned behaviors like bird song variations may drive population segregation and speciation or how knowledge like the discovery of a good dumpster is passed down among raccoon family groups, improving survivability and altering territorial behavior. Peer-reviewed stuff would be preferable, but if there is a solid non-academic work.I'd be interested in that as well.

So i was just wondering arround if what led humans to have such an intelligence, which in my opinion is obviously partly related to communication and abstraction but also importantly is the relation humans (and other primates) have with their enviroment, there is certain need to coordinate, memorize and understand the -mechanical- limitations things like branches have to... not die, so primates developed a particular need to understand the mechanics arround their enviroment carefully, assign "properties" they need to measure by intuition and abstraction (weight, resistance, flexibility), do you think this capacity to "interface" and interact through observation with the surrounding world rather than just wandering is a big factor in the natural selection of intelligence and the later capacity to interavt with the enviroment and do things like building? I think it also plays with birds but less so as they can just fly.

What I mean by that is like, maybe they become larger, their legs become vestigial, their tail becomes adapted to the water, ect.

What does the last common ancestor of humans and bees look like?

I'm wonder if say a mass extinction event were to occur, evolution or life, if thought of as a system, have a way to rebuild strategically, by that I mean ... not starting from nothing all over again

for example keeping a repository of DNA carried around in viruses, or bacteria (dk if that's a thing)

a way to modulate the subsequent evolution process to achieve "milestones"

i guess this line of thinking is me attributing to evolution properties like meta-cognition

not in the human high-level intelligence sense but like the automatic workings of our body like for example the way homornes and neurotransmitters modulate the workings of a group of cells to coordinate them,

or immunes system sense, evolution doing something similar as a system when it comes to genetic variation,

I feel like the human body, as a product of evolution might just be a shadow of, if not a more sophisticated form of, some natural aspect of evolution, as a system,

I've asked ChatGPT (I know) and it told me that an animal must produce milk to be considered a mammal. But something doesn't click in my brain, because as far as I know, you can't evolve out of a group. And I can't seem to find any helpful document online to answer this.

If all life on Earth evolved from a single organism (Luca), how did so much genetic diversity arise over time? Shouldn’t there have been a genetic bottleneck at the start, especially if the population began with only one organism?

How did the genetic variation we see today continue to emerge from such a limited genetic pool without a significant reduction in diversity?

The best example I've heard is the different between cats, lions, and tigers. They're also very closely related (I've heard 95% genetic similarity between tigers and cats), and lions and tigers are capable of breeding hybrids. On a microbial scale, most bacterial have one circular chromosome yet there's tons of variations. So this is just out of curiosity: are there any animals with the same number of chromosomes but incredibly different genotypes(greater phylogenetic distance than that of tiger-cat), and the inability to produce hybrid offspring? Is this something that could exist in theory but we've yet to see it in nature? Thank you, I am not a specialist in evolutionary biology

Besides relativity (we're all relatively related / inbred), due to proximity, and even sexual selection, inbreeding is bound to occur in a population over time, especially since that is (dare I say) almost conceivably what speciation / genetic drift is (notice this isn't a qualitative statement, and notice I'm preempted complaints while hypothetically steel manning a likely common misunderstanding we should account for in argumentation; "almost conceivably"), and with the natural occurrence of a connoted "population" (other than humans, no species is so determined to avoid inbreeding as to selectively breed itself away from inbreeding depression or migrate away from its gene pool).

What are some examples of species bearing adaption for or perhaps even from inbreeding? Not expecting much out of the latter (because even in the best case, inbreeding is never as good as heterosis but please include such examples if you can), I'm primarily wondering about the former, as in surely there must be, at least, some adaptation specifically for mitigating the detriments of inbreeding depression. Maybe, known mechanism or not, the extant rate of defects from inbreeding is already an example of this in complex life forms i.e. maybe it would be even worse than the detriments we do observe if evolution hadn't already been forced to solve this high frequency adaptive pressure -- again, not necessarily in humans, we know better unlike other animals.

So might there be e.g. something reminiscent of DNA damage response (DDR) in some organisms prepared to check for mistakes not only of mutation but inbreeding? If this has not yet been observed, can it evolve? Is it at least possible?

PS: Though I meant otherwise, I suppose adaptations to inbreeding can include e.g. instinctive preventative measures. Do we know for certain there exist any innate incest prevention in humans or is all that irk of proximate cause? Considering the popularity of incest porn and the observation of genetic sexual attraction, I assume the answer is no, we have not confirmed any biological mechanisms or instincts for the prevention of human inbreeding but I look forward to being wrong.

🤔🤨🧐

Evolution usually takes a long time to manifest—thousands or even millions of years. But human lifestyles are changing incredibly fast. Over the past 100 years, we've seen radical shifts due to technology, urbanization, and globalization. Some aspects of our modern lives could potentially drive evolutionary change, but these conditions change so quickly that evolution might not have enough time to catch up.

So how does human evolution work in a world where the environment and ways of life are constantly shifting? Are we still undergoing biological evolution, or has culture and technology replaced the need for it?

(This was originally wrote in czech and I used AI to translate, so sorry if there are any mistakes)

We haven’t had any DNA testing up until recently, who discovered the genetic link of dogs to wolves? Was it something we already knew before that? During the Charles Darwin era did people put 2 and 2 together? Or have we known for thousands of years already?

Is it possible we’ve accelerated the evolution of chimpanzees and similar? Meaning they will be smart much sooner than they should. For example I’m aware that crows are using different and new materials because of us and we haven’t “played” with them nearly as much. I’m also thinking whether in the long run it could damage the genetic code or make it unstable. Like a whole species of Stephen Hawkings.

The ancestors of whales used to be land dwelling animals, what environmental pressures pushed them to go back to living in the oceans? Was it food, predators, or something else?