And I'd thought the nickle-sized clear jellyfish living in Little Grassy Lake here in equally land-locked Southern Illinois were as small & strange as they got. Thanks SciShow!
The translucent jellyfish living in a freshwater lake that sink for nitrogen & rise for sunlight, to fuel algae growing inside them, as the jellyfish's sole food source, are pretty amazing, too!
I'm still trying to understand how they could have such a great description of mixazoan just days after repeating misinformation and misconceptions about immortal jellyfishes though it were real. And for reference, immortal jellyfish are not immortal. We had a misconception about how alternation of generations worked in most animals and we noticed that the immortal jellyfish was an exception except it turned out it's not actually an exception and we just had a very wrong understanding. Basically immortal jellies don't do anything special beyond the fact that they clone instead of producing sex cells when they revert which is actually not that weird either. I guess you could argue the way that they maintain a good chunk of their tissue is a little bit different, but fundamentally it's really not that weird and it's definitely not immortality. It would be like suiciding by jumping in a blender which then resulted in your children being born except those kids were younger clones. Sounds weird but really not terribly different than what a lot of life forms do. Act never mind they got confused by an ancient parasite that's mostly found in the ocean existing on land, I'm concerned about the writing lately. I can't even begin to describe how many ancient aquatic parasites are heavily distributed on land. There is a huge difference in people not noticing them and them not actually being prevalent. More research please, fewer assumptions... Actually in both cases they seem to be pretending to be stupid to be more relatable and that's a concern in and of itself. I don't know I have watched this channel for years and I'm suddenly feeling very unsure of it.
I don't think it's accurate though. A turducken is three different animals stuffed into each other, but this is three of the same types of cell. I'd say it's more of a molecular Matryoshka doll.
Yes they're definitely a bird thing. Honestly they're one of the more obnoxious groups of parasites because they just show up everywhere in the weirdest places and can be overlooked for ages before all of a sudden they get some sort of mutation or environment thing that makes them go bonkers and kill something you care about. They aren't the worst surprise parasites but they're up there top three at least.
okay so uh sure Hungary is landlocked, but there is a pretty significant body of water there, a massive lake. It's no Great Lake, but it is the size of Lake Michigan's Green Bay, and apparently famously is full of cnidarians
I'm pretty sure that they got dispersed worldwide in extremely long time ago so we really shouldn't be surprised to find them anywhere. That is an old group of animals. They also aren't the only group of parasites that started in the ocean and are now found just everywhere on land because they moved to land along with the aquatic organisms that first moved to land.
I genuinely would like longer forms of content. I understand that it is difficult in the current media, but there’s so much interesting information that could get left out.
And it's also not too unreasonable to see that those tiny critters might have ended up inside the ground when earth transformed from ice ball into "more water-less land" ball. The melting water had to go *somewhere*
The raft hypothesis is plausible for a few species to have survived such crossings, but there's so _many_ species requiring such explanations... Dramatic changes in landmass elevation (losing ~10000ft in
Stop trying to suck up to the enemy. They will destroy us all and give no respite to collaborators! Whereas, if you eat more undercooked bacon, who knows? You could get a cabinet post out of it.
How about eels? Getting infected in the sea, swimming upstream, dying and getting eaten by worms or infecting worms in shallow waters or whatever - boom, terrestrial population in the middle of a landlocked country. No idea about shrews though
Wouldn't 'mosaic evolution' be the rule rather than the exception? Even for a critter with only a few genes, surely some would be strongly conserved while others would be freer to mutate.
It depends. Some molecular machinery combinations are less robust than others when it comes to deviation. Hammonds for example have walled ourselves in pretty tightly in a lot of ways that aren't true of other lineages of organisms, but there are other critters out there that are even more walled in than we are
This is such a well-written (and presented) video! I feel like I learned 20 minutes of cool stuff in a 6 minute video. Being accurate while being concise is super hard, and you mastered it. Also, great glasses!
Ok, maybe I missed something. Honest question: how do we know when they evolved? Do we have fossils of myxozoans from that time period? Seems wild that we know they were around but their hosts definitely were not
If I understand it correctly, what scientists do, is they take genomes of many myxozoan species and they look at how different the genes are, if they are not very different, it implies that the species have diverged relatively recently, and if they are very different than species should have diverged long ago, and the scientists estimate how long ago that was by looking at the species for which we do have fossils
Correct. Also, there's lots of "junk DNA" that remixes generationally, allowing measurements of duplication & mutation count, to clue us in on how many recombinations have occurred (that part doesn't work for all types of reproduction, though).
Genetic drift happens at a specific rate. If you look at the difference in genes between one species and another, you can get an estimate of how long those species have been genetically diverging.
Mostly correct, but one major correction: they ignore the genes! Rather, it’s the junk DNA that’s focused on. Genes are selected for, they can stick around or go away at rates fairly independent of actual timescales. Junk DNA (DNA that isn’t translated into genes) isn’t selected for and thus the only thing impacting the mutation rate is how many generations have occurred. This method of comparing mutations to estimate how long ago two lineages diverged is called the molecular clock!
"The shrew is almost _completely_ blind, and must rely on its barely adequate sense of -panic- smell to avoid its natural predators... the fox, the badger, and the cat. ...the dog, the bear, the dolphin, the donkey, the bat, the crayfish, the buffalo, the crab, the toad, the plane, the monkey, the post, the polar bear, the fork, the banshee, the harpsichord, the common earthworm, the myxozoan, and other shrews."
This video would be fun but its kind of annoying 1. They didnt properly explain what makes them animals and not protists besides "they are multicellular" 2. They act like them surviving on land is some crazy thing despite the fact that theu are parasitic and dont truly survive on land but rather inside a body
Honestly, my best guess about the land-locked jellies is that they traveled upstream from the Black Sea through the Danube River- probably by hitch-hiking on fish (and the river is known for hosting migratory fish, albeit near impossible now since the first 'Iron Gate' in 1974). Otherwise, I like to think these little horshoe-crab-looking things have just taken a train to Budapest. I heard it's nice there...
*turducken* _noun US_ a roast dish consisting of a boned chicken inside a boned duck which is then placed inside a partially boned turkey. SciShow is so informative!
I could've done with an explanation of the lifecycle of the myxozoans that inhabit shrews and how that compares with the lifecycle of the marine versions - is it directly comparable with the shrews replacing fish in the loop? Or does it differ beyond that? Yeah, I could just google it, but I'm SO lazy. Also a little buzzed. Love the "Impossible Astronaut" shirt (at least that's how I'm choosing to interpret it.)
I am no scientist by a long shot bit I could think of a few ways these creatures could get to land lock areas ? One being large storms like hurricanes and tornadoes that can pick up sea water and dump it miles from where it was pick up ? another would be migrating birds, and that just 2 off the top of my head ?
Being multi-cellular or single-celled has nothing to do with being microscopic or macroscopic. There is at least 1 single-celled organism that can grow to up to a few centimeters in diameter. Then there are tardigrades, which are extremely complex multi-cellular organisms that are microscopic.
Well, NOTHING to do seems a little silly. There's clearly a strong correlation. The organizational complexity necessary to exist as a single organism at sizes humans can see seems to be far easier to achieve with more than one cell.
How many stories of worms from the sky attributed to bird vomit have you heard? I would look for a migratory bird to be the likely vector. Can't wait to hear more.
I love how confident the opening of the video is that there is zero percent chance that someone young, curious, and poor could have this video as their first scishow episode.
I haven't adjusted a clock for daylight wasting time, in years. It's a bad idea, but fortunately we can just ignore it! (Most of the world doesn't use it, so time & date settings do offer the option to disable it. No time like the present!)
Well has anyone checked to see if they parasite on sea birds or even regular birds? Also they could have made it that far inland sometime in the distant past. That region could have been partially underwater. Then it became an inland sea then eventually landlocked. Maybe Millions of years ago. Always keep asking questions.
The back & forth between commonly accepted geologic timelines, being overturned by biological traces, which in turn are often puzzling until the mystery is overturned by new geologic data, would be amusing if it didn't result in so many misunderstandings! Rapid elevation changes of up to 10000ft, & intermittent seawater flooding, etc, are far more well evidenced than commonly believed just ten & twenty years ago. Catastrophic geology remains controversial!
What if they were originally inside an ocean creature, and then the ocean creature gets eaten by a bird, and then the bird shits in Hungrary. And that's how they got there?
Also people bring in fish and discard it + our waste can also land in nature, so ... Yeah. It's odd, but that usually just means that we're missing information :'D
5:12 ummm but Hungary has rivers that reach the sea. isn't that a possible corridor? there are freshwater jellyfish all be it rare. this is less strange than you made it out to be but thanks for the info.
What is now Hungary wasn't always landlocked (and I don't just mean 1920). A good chunk of the Carpathian basin was once covered by the Pannonian Sea yonks ago
Wish they'd brought up Buddenbrockia plumatellae, a myxozoan which independently re-evolved tissues and became a worm-like... thing. Buddenbrockia has muscle; myxozoans basically ditched the concept of being an animal and one of their descendants went, "Wait, go back."
