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The Fish that Strolls on the Sea Floor
YouTube: | https://youtube.com/watch?v=a0NPlmWGlLA |
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View count: | 123,645 |
Likes: | 6,556 |
Comments: | 278 |
Duration: | 05:38 |
Uploaded: | 2021-10-19 |
Last sync: | 2024-12-03 02:00 |
Citation
Citation formatting is not guaranteed to be accurate. | |
MLA Full: | "The Fish that Strolls on the Sea Floor." YouTube, uploaded by SciShow, 19 October 2021, www.youtube.com/watch?v=a0NPlmWGlLA. |
MLA Inline: | (SciShow, 2021) |
APA Full: | SciShow. (2021, October 19). The Fish that Strolls on the Sea Floor [Video]. YouTube. https://youtube.com/watch?v=a0NPlmWGlLA |
APA Inline: | (SciShow, 2021) |
Chicago Full: |
SciShow, "The Fish that Strolls on the Sea Floor.", October 19, 2021, YouTube, 05:38, https://youtube.com/watch?v=a0NPlmWGlLA. |
We may never know when our ancestors walked out of the water into dry land. But it's possible they may have been walking in water for millions of years!
Hosted by: Hank Green
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Bryan Cloer, Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams, Tom Mosner
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Sources:
https://www.cell.com/cell/fulltext/S0092-8674(18)30050-3
https://bioone.org/journals/copeia/volume-2003/issue-3/CG-02-153R1/Punting--An-Unusual-Mode-of-Locomotion-in-the-Little/10.1643/CG-02-153R1.short
https://royalsocietypublishing.org/doi/abs/10.1098/rstb.1993.0007
https://royalsocietypublishing.org/doi/full/10.1098/rsif.2020.0701
https://www.seas.harvard.edu/news/2021/03/ancient-vertebrates-had-everything-they-needed-walk-underwater-millions-years
https://www.sciencedirect.com/science/article/abs/pii/S0944200617302052
https://onlinelibrary.wiley.com/doi/abs/10.1002/jmor.10865
Images
https://www.storyblocks.com/video/stock/fish-chub-swimming-in-the-aquarium-hrik9al3pkik77cft
https://www.storyblocks.com/video/stock/young-female-with-retriever-dog-walking-leisurely-on-the-path-at-sunset-r_qfvxo98ka3yan53
https://www.storyblocks.com/video/stock/multicoloured-koi-fish-swimming-graceful-in-a-water-of-an-garden-colorful-koi-fish-in-the-pond-with-dark-coloured-ground-moving-around-saz2atdjwj2aldr3u
https://www.storyblocks.com/video/stock/flat-fish-lying-on-the-bottom-and-trying-to-merge-with-the-mud-b3t53aeork17ww9iy
https://www.storyblocks.com/video/stock/4k-dog-running-up-driveway-gimbal-shot-sej0rxo9xizy9a7pu
https://www.shutterstock.com/image-vector/structure-motor-neuron-impulses-transmitted-through-423991636
https://www.istockphoto.com/photo/skate-fish-gm185275955-19891926
https://commons.wikimedia.org/wiki/File:Heliobatis_radians_Green_River_Formation_(cropped).jpg
https://www.istockphoto.com/photo/modern-hospital-physical-therapy-patient-with-injury-walks-on-treadmill-wearing-gm1335020216-416920392
https://commons.wikimedia.org/wiki/File:Valkyrie-robot-3.jpg
Hosted by: Hank Green
SciShow is on TikTok! Check us out at https://www.tiktok.com/@scishow
----------
Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:
Bryan Cloer, Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams, Tom Mosner
----------
Looking for SciShow elsewhere on the internet?
SciShow Tangents Podcast: http://www.scishowtangents.org
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Instagram: http://instagram.com/thescishow
----------
Sources:
https://www.cell.com/cell/fulltext/S0092-8674(18)30050-3
https://bioone.org/journals/copeia/volume-2003/issue-3/CG-02-153R1/Punting--An-Unusual-Mode-of-Locomotion-in-the-Little/10.1643/CG-02-153R1.short
https://royalsocietypublishing.org/doi/abs/10.1098/rstb.1993.0007
https://royalsocietypublishing.org/doi/full/10.1098/rsif.2020.0701
https://www.seas.harvard.edu/news/2021/03/ancient-vertebrates-had-everything-they-needed-walk-underwater-millions-years
https://www.sciencedirect.com/science/article/abs/pii/S0944200617302052
https://onlinelibrary.wiley.com/doi/abs/10.1002/jmor.10865
Images
https://www.storyblocks.com/video/stock/fish-chub-swimming-in-the-aquarium-hrik9al3pkik77cft
https://www.storyblocks.com/video/stock/young-female-with-retriever-dog-walking-leisurely-on-the-path-at-sunset-r_qfvxo98ka3yan53
https://www.storyblocks.com/video/stock/multicoloured-koi-fish-swimming-graceful-in-a-water-of-an-garden-colorful-koi-fish-in-the-pond-with-dark-coloured-ground-moving-around-saz2atdjwj2aldr3u
https://www.storyblocks.com/video/stock/flat-fish-lying-on-the-bottom-and-trying-to-merge-with-the-mud-b3t53aeork17ww9iy
https://www.storyblocks.com/video/stock/4k-dog-running-up-driveway-gimbal-shot-sej0rxo9xizy9a7pu
https://www.shutterstock.com/image-vector/structure-motor-neuron-impulses-transmitted-through-423991636
https://www.istockphoto.com/photo/skate-fish-gm185275955-19891926
https://commons.wikimedia.org/wiki/File:Heliobatis_radians_Green_River_Formation_(cropped).jpg
https://www.istockphoto.com/photo/modern-hospital-physical-therapy-patient-with-injury-walks-on-treadmill-wearing-gm1335020216-416920392
https://commons.wikimedia.org/wiki/File:Valkyrie-robot-3.jpg
[♪ INTRO].
Our ancient fishy ancestors first transitioned from life in the sea to walking on land millions of years ago, and it’s usually understood to have been a gradual change. That makes sense.
I mean, gravity would be a real downer if your little fish fins are used to life in water. But when along that timeline our vertebrate ancestors developed the ability to walk is still a mystery. We may never fully know the answer, but thanks to one little fish that loves to stroll along the seafloor, we are getting a little closer.
And it turns out, ancient fish might have been ready for walking millions of years before they took to the land. Controlling the way we move about the world is a vital function of our nervous system. There are just two basic types of locomotion we see in vertebrates.
For us and many other land animals, we prefer to get around by directly controlling our limbs, called ambulatory locomotion. That applies both to four-legged gaits, like most land vertebrates, and two-legged gaits like ours. So what is the other main type of vertebrate movement?
Have you figured it out? Well it depends on a back-and-forth movement using muscles along the spine. It’s called undulatory locomotion, the way that most fish get around.
However, there are some fishy exceptions, like skates and rays. These close relatives of sharks actually have a pretty immobile spine. So instead of the typical side-to-side wiggle, they have large pectoral fins to generate forward propulsion.
But even with the ability to glide along on these wing-like fins, some species of skate opt to stroll along a sandy bottom instead. One particular species, the little skate, uses unique movements of their small pelvic fins to create a distinct walk when they’re cruising along. Adorably referred to as ‘punting’, it’s actually the preferred mode of transportation for this fish.
Now you might be wondering, why bother walking when you can swim? Well it’s actually an important part of their feeding strategy. Little skates use electroreceptors in their head and throughout their pectoral fins to help locate their prey.
By keeping their big fins still while they punt along the seafloor, they might be better able to pick up on sensitive changes in their environment that could reveal their next meal. Now, walking along on fins is not unique to the skates and rays. There are some other incredible fish species, like flatfish and red-lipped bat fish, that also prefer to stroll along on limb-like fins.
But these walking fish still use undulatory locomotion, the side to side swim you see in most fish families. Whereas the little skate also has a very specific left-right saunter more characteristic of ambulatory locomotion. And while we’re not totally sure yet, this could tell us something about how ambulatory locomotion evolved.
It is widely thought that four-limbed land animals evolved their ability to walk starting from that fishy undulatory movement, with species shifting to more direct limb control over time. See, walking is not just about having limbs. Specialized cells along the spine called motor neurons tell those limbs what to do.
And neurons don’t keep well in the fossil record. But looking at the nervous system of the little skate is helping us better understand how and when walking may have evolved. If the little skate’s genes are any clue, fish may have had some of the necessary tools long before they ever left the water.
Our motor neurons are guided by certain proteins called transcription factors that determine which genes get used by the cell, and to what extent. Essentially, they guide what the neurons do. A study published in the journal Cell in 2018 looked at skate embryos and found that they had a lot of the same transcription factors and other molecules also present in the motor neurons of land animals.
This includes factors that control that left-right walking motion of limbs, as well as the bending and straightening of limbs. Not only that, but the way the neurons were connected to muscles was also very similar. The researchers were able to show that the skates have the genetic blueprint for controlling movement, as well as bending and straightening limbs.
And this potentially shifts the evolution of walking way back. It suggests that the common ancestor of skates and modern land vertebrates may have already had the neural tools required for complex walking behavior 50 million years before land animals first began strutting their stuff. To build on this research of skate neural pathways, researchers at Harvard used a theoretical model to show how underwater walking may have evolved in that ancient common ancestor, even building a bipedal robot to show their work.
Using a mathematical framework, they considered the environmental and physical constraints that an ancient sea-floor dwelling fish would have experienced. They showed how the left-foot, right-foot type gait that little skates share with land vertebrates can evolve with the help of the neutral buoyancy of water. Essentially, their framework showed it wouldn’t take much specialization for fish to begin strolling around fairly efficiently.
The constraints of moving onto land wouldn’t be a hard requirement. This provides further evidence that long before our fishy ancestors made their way into land, they had already worked out the kinks of a steady walking motion. Now while we still might never know exactly how the first land walkers came to be, these studies can help us better understand vertebrate evolutionary history.
They can help us in other ways too, like in building better walking robots. The little skate can also now serve as a model organism to help us study limb control, which could help us improve recovery from spinal injuries. So thank you to the little skate.
Your adorable stride is teaching us so much. And from here on out I’m not swimming at the beach, I am punting. Thank you for watching this episode of SciShow, and thanks as always to our patrons for helping to make it possible.
If you’d like to join a great community, and get to see some cool stuff like our newsletter and our monthly bloopers, you can get started at patreon.com/scishow. [ OUTRO ].
Our ancient fishy ancestors first transitioned from life in the sea to walking on land millions of years ago, and it’s usually understood to have been a gradual change. That makes sense.
I mean, gravity would be a real downer if your little fish fins are used to life in water. But when along that timeline our vertebrate ancestors developed the ability to walk is still a mystery. We may never fully know the answer, but thanks to one little fish that loves to stroll along the seafloor, we are getting a little closer.
And it turns out, ancient fish might have been ready for walking millions of years before they took to the land. Controlling the way we move about the world is a vital function of our nervous system. There are just two basic types of locomotion we see in vertebrates.
For us and many other land animals, we prefer to get around by directly controlling our limbs, called ambulatory locomotion. That applies both to four-legged gaits, like most land vertebrates, and two-legged gaits like ours. So what is the other main type of vertebrate movement?
Have you figured it out? Well it depends on a back-and-forth movement using muscles along the spine. It’s called undulatory locomotion, the way that most fish get around.
However, there are some fishy exceptions, like skates and rays. These close relatives of sharks actually have a pretty immobile spine. So instead of the typical side-to-side wiggle, they have large pectoral fins to generate forward propulsion.
But even with the ability to glide along on these wing-like fins, some species of skate opt to stroll along a sandy bottom instead. One particular species, the little skate, uses unique movements of their small pelvic fins to create a distinct walk when they’re cruising along. Adorably referred to as ‘punting’, it’s actually the preferred mode of transportation for this fish.
Now you might be wondering, why bother walking when you can swim? Well it’s actually an important part of their feeding strategy. Little skates use electroreceptors in their head and throughout their pectoral fins to help locate their prey.
By keeping their big fins still while they punt along the seafloor, they might be better able to pick up on sensitive changes in their environment that could reveal their next meal. Now, walking along on fins is not unique to the skates and rays. There are some other incredible fish species, like flatfish and red-lipped bat fish, that also prefer to stroll along on limb-like fins.
But these walking fish still use undulatory locomotion, the side to side swim you see in most fish families. Whereas the little skate also has a very specific left-right saunter more characteristic of ambulatory locomotion. And while we’re not totally sure yet, this could tell us something about how ambulatory locomotion evolved.
It is widely thought that four-limbed land animals evolved their ability to walk starting from that fishy undulatory movement, with species shifting to more direct limb control over time. See, walking is not just about having limbs. Specialized cells along the spine called motor neurons tell those limbs what to do.
And neurons don’t keep well in the fossil record. But looking at the nervous system of the little skate is helping us better understand how and when walking may have evolved. If the little skate’s genes are any clue, fish may have had some of the necessary tools long before they ever left the water.
Our motor neurons are guided by certain proteins called transcription factors that determine which genes get used by the cell, and to what extent. Essentially, they guide what the neurons do. A study published in the journal Cell in 2018 looked at skate embryos and found that they had a lot of the same transcription factors and other molecules also present in the motor neurons of land animals.
This includes factors that control that left-right walking motion of limbs, as well as the bending and straightening of limbs. Not only that, but the way the neurons were connected to muscles was also very similar. The researchers were able to show that the skates have the genetic blueprint for controlling movement, as well as bending and straightening limbs.
And this potentially shifts the evolution of walking way back. It suggests that the common ancestor of skates and modern land vertebrates may have already had the neural tools required for complex walking behavior 50 million years before land animals first began strutting their stuff. To build on this research of skate neural pathways, researchers at Harvard used a theoretical model to show how underwater walking may have evolved in that ancient common ancestor, even building a bipedal robot to show their work.
Using a mathematical framework, they considered the environmental and physical constraints that an ancient sea-floor dwelling fish would have experienced. They showed how the left-foot, right-foot type gait that little skates share with land vertebrates can evolve with the help of the neutral buoyancy of water. Essentially, their framework showed it wouldn’t take much specialization for fish to begin strolling around fairly efficiently.
The constraints of moving onto land wouldn’t be a hard requirement. This provides further evidence that long before our fishy ancestors made their way into land, they had already worked out the kinks of a steady walking motion. Now while we still might never know exactly how the first land walkers came to be, these studies can help us better understand vertebrate evolutionary history.
They can help us in other ways too, like in building better walking robots. The little skate can also now serve as a model organism to help us study limb control, which could help us improve recovery from spinal injuries. So thank you to the little skate.
Your adorable stride is teaching us so much. And from here on out I’m not swimming at the beach, I am punting. Thank you for watching this episode of SciShow, and thanks as always to our patrons for helping to make it possible.
If you’d like to join a great community, and get to see some cool stuff like our newsletter and our monthly bloopers, you can get started at patreon.com/scishow. [ OUTRO ].