#Genetic Evolution

[familythings]

The Vanishing Y Chromosome: Is the Future of Humanity at Risk?

After the extensive debate about the true gender of Imane Khelif, a woman born with X chromosomes, who later developed a Y chromosome, scientists have claimed that the existence of the renowned Y chromosome is in jeopardy. The Y chromosome, crucial for determining male sex, is reportedly facing a significant threat to its existence. Over the past 300 million years, this vital chromosome has…

[mindblowingscience]

The sex of human and other mammal babies is decided by a male-determining gene on the Y chromosome. But the human Y chromosome is degenerating and may disappear in a few million years, leading to our extinction unless we evolve a new sex gene. The good news is two branches of rodents have already lost their Y chromosome and have lived to tell the tale. A 2022 paper in Proceedings of the National Academy of Science shows how the spiny rat has evolved a new male-determining gene.

Continue Reading.

[timid-owl]

[thoughtportal]

In eastern Mexico’s underground caverns and streams, a blind fish undergoes a peculiar adolescence: as it approaches maturity, taste buds begin to sprout under its chin and on top of its head, creeping toward its back.

“It’s a pretty wild amplification of the sensory system of taste,” says Josh Gross, an evolutionary geneticist at the University of Cincinnati and a co-author of a recent study on the cave fish in Nature Communications Biology. Gross and his team discovered that the new buds blossom around the time when the fish transition from eating larval crustaceans to gobbling up their adulthood staple: bat guano. Taste buds outside their mouths might be helping the fish detect bat droppings in the utterly dark, “food-starved” caves, Gross says.

Wandering taste buds aren’t unheard of elsewhere, especially in other fish. Some damselfish cultivate taste buds on their fins, and channel catfish have them across their midsections. And as alien as it may seem, many cells throughout the human body can taste, too. They’re just not sharing the flavors with your brain like taste buds do.

Lora Bankova is a Harvard Medical School respiratory biologist who studies tuft cells, a cell type sprinkled within human mucous tissues like those lining your nostrils, throat and gut. These “rapid responder” cells trigger the immune system if they detect an outside threat, and many of them rely on built-in taste receptors (the same kinds found on taste-bud cells) to do so. Bankova notes that many potentially harmful bacteria communicate via signaling chemicals called lactones—which also happen to activate taste receptors attuned to bitter flavors, prompting tuft cells’ immune response. And it turns out that even environmental allergies may be a matter of taste: dust mites and several mold species can also set off a tuft cell’s taste receptors, Bankova says.

“Evolutionarily, taste receptors [have moved around] the body to protect us from the air we inhale and all the attacks we’re getting through the orifices,” Bankova says. “They’re in the inner ear, the urethra, everywhere something can get into your body.”

Such “extra” taste receptors aren’t just bouncers at the door—they taste test for our internal systems, too. Receptors for sweet tastes help to tune insulin production in the pancreas and make sure neurons in the brain have access to enough glucose. Sweet, bitter and umami receptors in the gut modulate digestion.

Gross says it’s still a mystery what taste receptors the bat guano activates in the blind cave fish. “There may be some sugar content if it’s a fruit bat, maybe some protein content if it’s a carnivorous bat,” he says. So far only the cave fish has signed up to sample it.

[typhlonectes]

How did snakes lose their limbs? Mass genome effort provides clues

DNA sequencing helps explain how these reptiles got to be so unusual

Snakes are weirdos among vertebrates. Their bodies are typically too thin for more than one lung, they smell with their tongues, and—perhaps most importantly—they have no legs. Now, an extensive effort to sequence the genomes of more than a dozen snake species has uncovered mutations that likely helped make these appendages vanish, as well as the DNA underlying other unusual traits. This research “will undoubtedly have a transformative impact on snake and vertebrate biology,” says Todd Castoe, an evolutionary biologist at the University of Texas at Arlington who was not involved with the work...

Read more: https://www.science.org/content/article/how-did-snakes-lose-their-limbs-mass-genome-effort-provides-clues

Image:

Slug-eating snake (Pareas berdmorei) collected in China was one of 14 snake species newly sequenced to learn about snake adaptations. (Di-Hao Wu)

[theladart]

Rapidash/Rainbow Dash ponymon fusion: Firestorm!

Inspired by @pinxpony‘s Pinkie Pie/Flaffy fusion, Flaffy Taffy (hope you don’t mind the tag :P)

Edit: Found out that the rapidash pic I got for reference is a fakemon mega evo designed by CaseyDeanFakemon on Deviantart

[polysyndetonaddictsupportgroup]

pez dispenser update, yay!

I am Very Interested in the direction you're taking izuku here. He seems to have come out the other side of this breakdown going, "no look! I trust you guys! Here, I trust you guys so much! You can know about the severe injuries I had as a child that never got a police report!"

It's funny to read izuku's pov vs aizawa. Izuku is just like, wow this all needs to end so I can get back to being the Normal And Awesome Deku I have turned myself into, and aizawa is like thirty seconds from having his own panic attack at having a few months to turn this kid into a functional human being.

You can truly tell that with how izuku keeps insisting on that he's got this by himself, with no understanding how crazy it is to expect his friends and teachers to back out and let him take over, that he, still, still, STILL has simply 0 faith or expectation that his teacher is driven to help the little kid in izuku that he's buried so deep down there. That an authority figure who isn't all might wants to save him. I want to eat his unthinking, warped by trauma thought patterns, they are delicious.

Kinda touching that midoriya foresaw and tried to avert the all might conversation issue. Rip, dude really tried, but baby izuku is like one of those puddles in flooded old buildings you can find videos of people dropping a rock in -- it doesn't look that deep, but if you tried to put your foot in, you would be getting a whole lot more than your shoe wet.

Yeahhhhhh Izuku’s really not handling it the best.

Izuku genuinely didn’t keep everything a secret all these years because he didn’t trust his friends. It wasn’t that he thought they’d react poorly or hurt him with the information or spread it around or anything like that. This was purely due to his own internal issues around it.

But they’re three years deep into being in the fucking trenches together. And Izuku very much is considered a bedrock of the class. You can see it in their internal monologues—everyone trusts him implicitly. It’s Izuku. If one of them was going through something sensitive or painful, he’d be at the top of the list of people to turn to. For like, the entire class.

And while Izuku isn’t per se aware of the fact that the entire class views him as the best of them, he is painfully aware of the fact that they’ve opened up to him over the years. And that this is making it look like he didn’t tell them a single detail about his life before he came to the school. Which is fair, because he sort of didn’t.

So he’s overcompensating. He doesn’t need privacy because he trusts them so so much and this proves it, right?? They can totally know the sordid details of the past he’s in active crisis over.

He’s scared that he’s going to lose the people who have trusted him over the years because he seemingly didn’t trust them back. But they all trust him so much that they’re more beating themselves up than blaming him.

Todoroki and Mirio were in that scene like “uuuuhhhh you look like you’re a second from a panic attack we can totally give you space if it makes you more comfortable” and Izuku’s in a spiral like Why Would I Need Space I Trust You Both Implicitly Please Ignore The Obvious Distress.

Fundamentally, Izuku has never processed what happened to him as a kid. He didn’t tell them because he wasn’t ready to confront how bad it was back then. It wasn’t about trust. Telling them meant saying aloud what happened. He just wasn’t ready for that.

And from the path canon took, I don’t really see Izuku trusting adults. His childhood did absolutely nothing to make him think teachers would protect him. And for all Aizawa did right, I think this is one bag in canon he legitimately dropped.

I want to be clear—Aizawa was working at a severe disadvantage. He didn’t even have a lot to tell him the problem existed, let alone how to address it. But it’s specifically the Hero Killer Stain Arc that makes me think that Izuku only would trust Aizawa to a certain point.

After the Hero Killer Stain Arc, Aizawa canonically calls out Iida, Todoroki, and Izuku in front of the entire class. He doesn’t mention what it's about, but he makes it very clear that he knows what happened and that he disapproves. And his criticism is specific: In instances where you are out matched, it is better to run and get help. Iida, Midoriya, and Todoroki need to understand that

The thing is that Izuku and Todoroki both considered that as their first option and then correctly deduced that they'd be burying Iida if they did that.

I will actually die on the hill that is that Izuku and Todoroki did everything right when it came to the Hero Killer Stain. Iida caused the problem, but the fact that he made mistakes was the point of that arc for him. But Izuku and Todoroki?

They both reacted perfectly. And if they had done a single thing differently, they'd have two dead bodies.

When Izuku realizes that Iida's in danger, the city is on fire, Nomu are attacking the train, and his supervisor has fucked off to fight monsters attacking the city. He does not have an adult hero who is free to bring with him, and we know for a fact that he did not have time to hesitate or try to find other options, because he arrives the second before Iida dies as-is. When he's on scene, his absolute first instinct is to run. Izuku canonically clocked the fact that he was out matched, evaluated whether he could safely retreat, and realized he’d never be able to get out of there with Iida and Native. He’d have to leave one or both of them to die.

So he asked for help the safest way he could: sending out the mass text and stalling for time. And canonically, he wasn’t hoping a classmate would show up to the fight. He was hoping they’d report it to their supervisors and get him help, which is exactly what multiple of his classmates did.

Todoroki, for his part, correctly clocked that something was wrong with Izuku when he got the message. And he didn’t just fuck off without telling anyone where he was going. He evaluated the situation, realized the city was on fucking fire and there wasn’t a single hero free to go with them, and told the heroes with him that they needed to go to this exact location the first second they could. And he didn’t have a moment to hesitate or figure something else out, because he also showed up at the very last second before Iida took a sword to his spine.

Frankly, Todoroki and Izuku couldn’t have possibly handled the situation better, but they got absolutely shit on in the aftermath. I don’t recall a single adult who told them they did the right thing, except maybe Native. They had the fucking chief of police telling them they were no better than the guy who tried to kill their teenage friend with a sword and their teacher publicly calling them out in front of the class without the benefit of context.

If I was Izuku, I would have walked out of that entire thing having my preexisting distrust of adults affirmed. Like. There isn’t a world where Izuku realistically looks back on his actions and thinks “damn I really should have left Iida die.” He’s not going to change a fucking thing in what he did. Every single time, he’s going to go save his friend. The only realistic take away Izuku could have from Aizawa’s call out was “wow, that guy is not going to have my back if I have to make a tough call. So if I have to make one, then I’m just not going to him for help.”

Which is kind of where we're at in pez right now, and Aizawa's starting to realize it. Don't get me wrong, Izuku trusts Aizawa more than any teacher he ever had growing up. He doesn't think Aizawa is going to be actively malicious to him. But he also doesn't necessarily think Aizawa's going to have his back.

The crux of it is in chapter 4. Tiny Izuku says that Mr. Aizawa is already on Izuku's side, and Izuku's immediate reply is, "I promise you that Mr. Aizawa has never once been on my side." He back pedals fast, clarifies that he thinks Mr. Aizawa is fair and not on anyone's side, but his knee-jerk reaction is undeniable.

And to me? It's because Aizawa genuinely has not been on Izuku's side since he came to UA. And I don't mean Aizawa has been malicious to Izuku. Fundamentally, the issue is that he misdiagnosed the problem.

Aizawa has spent his entire time with Izuku mistakenly believing that the source of Izuku's issues was the same as Bakugou's. He is only now realizing that his issues were more like Shinsou's.

Fundamentally, Aizawa correctly recognized that Izuku's problems came from the fact that he was raised in an unjust system. But he misunderstood what Izuku's position in it was.

Here's what Aizawa knows, from the jump: Izuku and Bakugou came from the same school. Both have very powerful Quirks. Both have obvious issues with the other. Izuku specifically moves and looks like he had a professional trainer, meaning someone invested in his training as a hero. Bakugou talks like someone who's been told his entire life that the sun shines out his ass and never got punished for being a little shit. Izuku's more muted, but he came from the same school. Two kids with powerful quirks? Likely were getting away with the exact same shit.

When you have an unjust system, you have the people running it, the people benefitting from it, and the people being victimized by it. If the teachers at Aldera were letting kids with powerful quirks get away with murder, both Izuku and Bakugou were likely benefitting from that. And it is absolutely vital that Aizawa undoes that damage before they debut.

He doesn't even need to think Izuku, specifically, was abusing his position in this power imbalance. The damage is done from how the teachers at aldera were likely treating him. Teachers that produce kids like Bakugou tell talented, powerful kids that they're special, that they're above the rules, that they've got something so fundamentally important about them that they can get away with more. Even if you don't chose to abuse that narrative in the moment, that's a hell of a formative experience.

They're about to have a ridiculous amount of power. They are about to be in charge of enforcing the rules. And people who are in charge of enforcing the rules and think they're above them turn into Endeavor.

Aizawa's approached Izuku from a sort of tough love perspective from the jump. He didn't cut him an ounce of slack, and it's because he genuinely was trying to do right by Izuku. No, he's not going to get to smash up his body and make himself a hazard. Figure it out, or go home.

He's had plenty of time to learn how to manage his quirk, after all.

With Stain? I don't think Aizawa, if he knew the full circumstances, would genuinely say the right call is to have Iida's fucking funeral. I think he'd agree with the decisions Izuku and todoroki made. But he didn't have all the information, and, fatally, he didn't ask. He assumed.

He's got three powerful, bullheaded students who end up in a back alley in the middle of the night, having all separately ditched the heroes they were supposed to be joined at the fucking hip with. He absolutely thinks that they either planned it together or that, when they realized what Iida did, Todoroki and Iida went after him in secret to try to keep Iida from getting in trouble--and almost got them all killed in the process. There is absolutely no way Aizawa knows that they actually tried to run and get help at every turn.

Aizawa made assumptions. And a big reason why he felt comfortable making those assumptions was because he thought he knew what Izuku's problem was. He thought Izuku, like Bakugou, had been benefitting from teachers turning a blind eye to his misbehavior for years. But the problem was the exact opposite. Teachers had been turning a blind eye to his victimization for years.

He shouldn't have been treating him like Bakugou. He should have been treating him like Shinsou.

Aizawa's trying to correct the damage of past teachers. If they've spent years telling Izuku he's god's gift to mankind and it doesn't matter what he does because he's a hero and that makes up for it, Aizawa needs to hold him to the fucking rules. He needs him to understand that he's not special, he's not the main character, he's not intrinsically better or more important or above the rules in some magically important way. He doesn't want to hear excuses. He doesn't want to know why this time it was different. Izuku needs to understand that he has to live by the rules too, because he's going to be in charge of enforcing them soon.

But if they've spent years telling him he's worthless, that people can hurt him and it's okay, that he can never, ever expect help from them because he's not worth it? Then fuck, Aizawa needed to do the opposite. He needed the same end result, don't get me wrong--an understanding that the system equally applies to everyone--but he needs to make Izuku believe that the system will protect him again. That Aizawa will protect him. And Aizawa's combing over every fucking interaction they've ever had, and realizing that he hasn't done that, because he spent all his time trying to correct a problem that didn't exist.

I think Aizawa's been beating his head against the problem that is Midoriya Izuku for the past three years. Because Izuku's a hard-worker. He is brilliant. He is a natural leader. He is the fucking cornerstone of the class. He is shining so bright that it's going to kill him, because Aizawa knows how to recognize a star that's burning out.

For three years, Aizawa has tried and failed to get Izuku to realize he can and should ask for help. And he has failed because he thought the problem was that Izuku didn't think he needed help, when the problem was actually that he thought no one would give it to him.

In this last chapter, Izuku finally said aloud the reason behind the core issue Aizawa’s had with him his entire time at UA: Growing up, he thought that there was literally one man on the planet who would care enough to save him. He was the most hero-obsessed boy Aizawa’s ever met, and he thought All Might was the only hero alive he could count on to care if he lived or died.

There it is. The exact answer about every scrap of self destructive behavior that Aizawa’s been trying and failing to remedy for years. Why the fuck would he ask for help when he needs it? He’s spent his entire life living in a world where people wouldn’t piss on him if he were on fire. Aizawa needed every day of those three years to reverse that kind of damage, and he’s out of fucking time.

Aizawa is legitimately terrified that he fucked up and that it's going to kill Izuku.

Izuku’s Quirklessness is the missing piece of the puzzle that makes everything fall into place—which is why he’s so pissed at All Might for not telling him. Aizawa’s actually kicking himself for not noticing the obvious discrepancies in Izuku’s past. The fact that he grew up with a powerful Quirk was the factor that made him return to the same incorrect conclusion again and again. There were enough hints that he feels guilty for not figuring it out anyway, but if he had known about Izuku’s Quirklessness from the start? He would have figured it out in seconds.

Now that he knows, Aizawa’s changed how he handles Izuku. He doesn’t let there be a single doubt about what he’s doing or why. He makes Izuku explain himself, so that way there’s no more miscommunications around what he means. He makes sure to compliment him whenever he does something right—he’s trying to change courses, but he’s panicking that it’s too little, too late.

And now he’s got this goddamn criminal investigation that Izuku wants to bury, and it’s killing him. Because that’s his student, and he was hurt horribly. And his student just cannot comprehend why Aizawa cannot let it go.

And then there’s All Might.

All Might’s conversation with baby Izuku, for me, forecloses the possibility that explaining OfA is a solution here.

All Might really went in and knocked it out of the park with the best possible attempt at convincing Tiny Izuku that he’s himself. He immediately failed, albeit, but he honestly couldn’t have done better.

There he is, Izuku’s lifelong hero. And he’s there to say the things Izuku’s spent his whole life wanting to hear. All Might met him, and Izuku inspired him. He reminded him of himself when he was young. He thought he could be a hero. He was so impressed he offered to personally mentor Izuku.

And he loved him. Believe you are him, because I loved you too much to ever let anyone take you from me. There is a fundamental flaw in your theory that simply no one cared enough to notice or stop him, because I love you with all of me. I would have noticed. I would have saved you.

If there is absolutely anything that could have convinced Tiny Izuku, it would be that. This isn’t about quality of the explanation. There’s an internal issue that needs to be fixed before Tiny Izuku will believe any of this.

And I think Izuku recognizes this, on a level. As much as he and Tiny Izuku clash, Izuku gets him. He can typically predict Tiny Izuku’s exact responses to things.

But he’s never approached Tiny Izuku like someone he can explain this to. He’s spent this entire time trying to cheat code his way out of this situation. He wants Mr. Aizawa to erase him or to go find the Quirk user and find away to negate the Quirk. He’s never actually even considered explaining this all to himself as a solution.

Because he knows that there’s some kind of fundamental impossibility about it. Even if he can’t say exactly what it is, he knows that there’s an internal issue that means he’s not going to be able to just tell Tiny Izuku the truth.

Voice of God, he is dead fucking right about Tiny Izuku not buying OfA and being liable to tell everyone out of spite. Tiny Izuku would have that shit on the news.

Fundamentally, Izuku is aware that there is a deeper problem driving Tiny Izuku. He knows that it’s not about the quality of the explanation. There is something deeply, profoundly wrong because of what happened to him that makes him absolutely unable to accept that Izuku is him.

But Izuku has never known how to solve the mental wounds his childhood left him with. He still has them himself. He’s been burying them for years, and he can’t anymore.

When action opens in pez, Izuku himself is not okay. He’s just… bleeding internally. He knows how to hurt in ways people can’t see. But you can see how much his childhood is still bothering him in his defense of Mirio. He has never been able to let go of what happened to him. The wounds never healed.

And he doesn’t know how to go to these people he loves and tell them that what they’re trying fundamentally will fail, because he knows he’s been hiding this fucking shipwreck of his own mental health for the past three years but they don’t have a fucking clue at the scale of the problem.

At the end of the day, All Might went in there because he wanted to save Izuku. And Izuku told him not to because he cannot imagine himself being saved.

[lizardsaurus-art]

A little something something with my punnett cubes

This is one of the “heads” of my recent alien design, they have antler-like projections that I decided to test out the three possible allele types. The classic is dominant A, recessive a, and my addition, alpha as the third option. It’s not perfect for I’d most likely have to rework the whole genetic system cause dominant vs recessive is a pretty binary mechanism and it’s hard to imagine how would a third option affect the organism’s phenotype. Here I’ve decided to test it out on the percentage of the antler that gets covered by flattened out surfaces, with both the dominant and the alpha allele increasing its surface area, the difference being that the dominant allele creates fewer large disks, while the alpha allele creates many smaller disks that branch out like cactus leaves.

Enjoy my crappy notes again:

[s30620]

Chapter 103: Vamola 3

Note: This chapter contains material that may cause discomfort in some readers. Please be careful if you choose to read this chapter!

This was their lowest point. Vamola, Banga, Tome and Aja were all ready to die then and there. However, Banga is holding on to one last hope, one miniscule chance that things can still work out for the Sumerian people, and that hope is possible because she has Vamola. I love the way she bounces back from the despair in this moment. Even in the face of death, Banga doesn't give up that easily.

I love these old ladies. Even when they're dying they still got the energy to banter.

[vespula-acadica]

I so badly want to study the genetics of tlt universe

[ranticore]

sorry if this question is already answered elsewhere but how much time passes between the creation of ishmael vs the modern siren setting with qedivar et al?

intentionally never stated because i don't want to box myself in with a ridiculous number that i have to retcon later haha. safe to say it's several centuries, maybe a thousand years, maybe less. who knows!

[bonnibelleangelica]

Imagine if someone wrote a book about that concept...

@statusquoofficial <<<<< my new book about evolution!

[mindblowingscience]

The longest genome of all the animals on Earth belongs not to a giant, or a cognitively advanced critter, but a writhing, water-dwelling creature seemingly frozen in time, right at the cusp of evolving into a beast that can live on land. These are the lungfish, a class of freshwater vertebrates whose peculiar characteristics are reflected in a colossal genetic code. Able to breathe both air and water, with limb-like fins, and a well-developed skeletal architecture, these strange ancient creatures are thought to is thought to share a common ancestor with all four-limbed vertebrates known as tetrapods.

Continue Reading.

[gregor-samsung]

Birthmarked (Emanuel Hoss-Desmarais, 2018)

[three-crows-in-hiking-boots]

WOF Phylogenetic tree!

Okay, so who are the ancestors? What are their traits? I don't have names for them at the moment, but their traits, based on the resulting generation of most likely ancestral traits created by the phylogeny program, are the following:

12: heightened senses, venom, vibration sensing, 4 wings, metamorphosis 13: venom, 4 wings 14: 2 wings, venom, prehensile til, photosynthetic abilities 15: 2 wings, chromatophores (color changing) 16: 2 wings, heightened senses, larger size, large lungs, webbed claws, gills, bioluminescence 17: 2 wings, elemental breath, larger size, large wings/extremities 18: 2 wings, elemental breath, extreme thermal tolerance 19: 2 wings, elemental breath, extreme thermal tolerance 20: 2 wings, elemental breath, heightened senses, forked tongue

Data/methods below the cut, as well as a (brief) dive into evolutionary history for Beetle-Night Hybrids and why I want some history on Beetles lol

Night-Beetle Hybrids and HiveWings Before anyone gets on my tail about BeetleWings evolving before HiveWings and Hives being hybrids of NightWings and BeetleWings, I'm not a huge fan of that in canon, but don't mind the interbreeding in general. I just mind the genetic bottleneck that would have occurred with only one NightWing (Clearsight) breeding with a BeetleWing and their offspring resulting in a completely new species. Now, mutations can arise, and maybe NightWing traits were dominant in passing, but for a whole new species to arise from a single generation of interbreeding with a single pair of mates, it doesn't really make sense, especially since BeetleWing traits were (presumably) selected for their environment.

Selection occurs based on the following: 1) Environmental adaptation (species with traits more suited to the environment will live longer and be able to reproduce more) 2) Mutations (the rate is slow over time, but adds up over LONG time scales as alleles accumulate in populations) 3) Migration (Low migration rates (such as occurred in Pantala) mean that genetic drift, selection, and mutation occur independently between populations, ie, what happens in the BeetleWing/NightWing populations won't affect the other, genetically, due to low interbreeding)

Basically, with only a SINGLE Nightwing individual, and assuming there was no prior cross breeding, there MUST'VE been an extinction event that removed the pool of pure BeetleWings from the population, otherwise the proportion of BN to BB should have stayed the same over time (Hardy-Weinberg principles). This, obviously, isn't the case. As far as we know in canon though, they simply dissapeared. My evolutionary biology brain needs some history. Alas, I'll write my own (mwahaha). Don't even get me started on genetic bottlenecks lol. Biology is CRAZY.

Tree Creation The tree was generated based on species traits assigned as base pair markers on DNA with one base pair indicating a 1 (trait present) or a 0 (trait not present)! Since phylogenies can't be built with 1s and 0s, I randomly assigned ACTG to them, being sure to make all of the traits that were 1s into the same letter in a single column to ensure it was (hopefully) denoted as present.

The traits

Green indicates a trait is present (would have been a 1), while white is not present (0)