The First Animal on Earth Is Finally Found

Bright Side

Ever wonder what the very first animal on Earth was? 🐾 Scientists believe they’ve finally figured it out, and it’s not what you’d expect! It wasn’t a dinosaur or a giant sea creature—it was a simple, jelly-like organism called a comb jelly. 🌊 These tiny, shimmering creatures existed over 500 million years ago and paved the way for all animals today. What’s mind-blowing is how their simple bodies and nervous systems can still teach us about evolution. 🧬✨  Credit: b3ean0 / Reddit Life in the Ediacaran sea: By Ryan Somma, CC BY-SA 2.0, https://creativecommons.org/licenses/by-sa/2.0/ , https://commons.wikimedia.org/wiki/File:Life_in_the_Ediacaran_sea.jpg Zeedruif met razendsnel trillende Ripplaatjes: By Peter van Rodijnen, CC BY-SA 3.0 NL, https://creativecommons.org/licenses/by-sa/3.0/nl/ , https://en.wikipedia.org/wiki/File:Zeedruif_met_razendsnel_trillende_ribplaatjes-4931687.webm Pleurobrachia pileus (Sea gooseberry), Kijkduin, The Netherlands: By Bj.schoenmakers, CC0 1.0, https://creativecommons.org/publicdomain/zero/1.0/ , https://commons.wikimedia.org/wiki/File:Pleurobrachia_pileus_(Sea_gooseberry),_Kijkduin,_The_Netherlands.jpg Scientists use infrared microspectrometer 20221206: By OIST (Okinawa Institute of Science and Technology Graduate University), CC BY 4.0, https://creativecommons.org/licenses/by/4.0/ , https://commons.wikimedia.org/wiki/File:Scientists_use_infrared_microspectrometer_20221206.jpg Scolionema sanshin: By Toshino, CC BY 3.0, https://creativecommons.org/licenses/by/3.0/ , https://commons.wikimedia.org/wiki/File:Scolionema_sanshin_(10.11646-zootaxa.4344.2.4)_Figure_5.png CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa/4.0/ : Lampocteis cruentiventer — MBA: By Eric Polk, https://commons.wikimedia.org/wiki/File:Lampocteis_cruentiventer_-_MBA.webm Sea Gooseberry: By Sgerbic, https://en.wikipedia.org/wiki/File:Sea_Gooseberry.webm Hormiphora californiensis: By Julius Senegal, https://commons.wikimedia.org/wiki/File:Hormiphora_californiensis.jpg Northern Comb Jelly (Agurkkammanet) (Beroe cucumis) - Senja, Norway 2023-07-10 (01): By Ryan Hodnett, https://commons.wikimedia.org/wiki/File:Northern_Comb_Jelly_(Agurkkammanet)_(Beroe_cucumis)_-_Senja,_Norway_2023-07-10_(01).jpg Lobed comb jelly swimming – MBA: By Eric Polk, https://commons.wikimedia.org/wiki/File:Lobed_comb_jelly_swimming_-_MBA.webm Hormiphora californiensis: By Julius Senegal, https://en.wikipedia.org/wiki/File:Hormiphora_californiensis_video.webm Animation is created by Bright Side. ---------------------------------------------------------------------------------------- Music from TheSoul Sound: https://thesoul-sound.com/   Check our Bright Side podcast on Spotify and leave a positive review! https://open.spotify.com/show/0hUkPxD34jRLrMrJux4VxV   Subscribe to Bright Side: https://goo.gl/rQTJZz  ---------------------------------------------------------------------------------------- Our Social Media: Facebook: https://www.facebook.com/brightside  Instagram: https://www.instagram.com/brightside.official TikTok: https://www.tiktok.com/@brightside.official?lang=en   Stock materials (photos, footages and other): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ----------------------------------------------------------------------------------------  For more videos and articles visit: http://www.brightside.me

Transcript

00:00Have you ever wondered what animals looked like when they first appeared in the ancient

00:05oceans over half a billion years ago?

00:08Well scientists have been scratching their heads about this for more than a century.

00:12And now, they believe that they've finally found the answer.

00:16So let's take a look at their discovery.

00:19You see, our ancient ancestors probably lived 600 or 700 million years ago.

00:24They were soft-bodied, so unfortunately, they didn't leave any fossils behind.

00:30Scientists decided to uncover the secrets of these ancient creatures by comparing them

00:34to all the animals that exist today.

00:37First, we need to ask ourselves, what is an animal?

00:40Well, we know that they're incredible creatures with heads, innards, muscles, and brains.

00:46And we know that humans are part of this animal gang too.

00:50We're called bilaterians, and we have all these cool features that evolved around 500

00:55million years ago during the Cambrian Explosion.

01:00But there are also awesome creatures with very simple body plans.

01:03We've got jellyfish, sea anemones, sponges, ctenophores, and many more.

01:10They may not have fancy brains or muscles like us bilaterians, but they still have the

01:15essential qualities of animal life.

01:17For example, they develop from fertilized eggs into living beings.

01:23So researchers decided to take a look at them to figure out which group was the earliest

01:27branch on the tree of life.

01:29To solve this mystery, they used a technique called DNA sequencing.

01:34They looked at the genes of these animals.

01:36The similarities and differences in the genes helped scientists understand how creatures

01:41are related and how they evolved.

01:43By comparing DNA, scientists could piece together their evolutionary family tree.

01:49The list narrowed down to two candidates – sponges, which are basically lazy filter-feeders,

01:55and comb jellies, which are fierce predators cruising through the oceans.

02:01But the controversy remained – who came first?

02:05Sponges may seem to be simple fellows.

02:07After their free-swimming phase, they settle down and filter tiny food particles from the

02:12water.

02:13They may have no nerves or muscles for them, but their hard parts make excellent scrubbers.

02:18For a long time, scientists believed that sponges were the very first branch of the

02:23animal family tree.

02:24They thought that before anything else, there had been these tiny single-celled creatures

02:29called protozoans.

02:31Then these protozoans came together and formed colonies that eventually evolved into sponges.

02:37And from there, sponges became the ancestors of all animals, including humans.

02:43But hold on!

02:44Meet the comb jellies, those mesmerizing creatures you often see in aquariums.

02:49They may resemble jellyfish, but they're not even close relatives.

02:54Instead of squishing through the water, ctenophores use rows of beating cilia like combs to propel

02:59themselves.

03:00You can spot a sea gooseberry, a common ctenophore, along the California coast.

03:06It's about an inch in diameter and quite fascinating to observe.

03:11Anyway, now we have two contenders.

03:14To find out whether sponges or comb jellies were the first, the biologists turned to an

03:19unexpected superhero – chromosomes.

03:21You see, each species has its own unique chromosome number and gene distribution along those chromosomes.

03:29For example, humans have 23 pairs of chromosomes.

03:33So scientists didn't just look at the genes each animal had, they also checked where those

03:39genes were located on their chromosomes.

03:41You see, as animals evolve, their chromosomes rearrange, and genes move around.

03:47Once they move, it's really hard for them to go back to their original spots.

03:51So the clever biologists figured that the animal with the least shuffling of genes on

03:56their chromosomes must have appeared first.

03:59They basically had to find a puzzle with the least shuffled pieces.

04:04To crack this mystery, the scientists compared the gene placements in sponges and comb jellies

04:09to their closest single-cell non-animal relatives.

04:13These single-cell relatives were like cousins to the first animal and held clues about the

04:17original genome.

04:19The closer an organism's genome was to the original, the less it had changed and the

04:24more likely it was to be the sister.

04:28So the research team discovered something incredible.

04:32Despite more than half a billion years of independent evolution, sponges, jellyfish,

04:36and many other invertebrates share similar sets of genes on their chromosomes.

04:42It basically meant that animal chromosomes evolved slowly.

04:45It also gave the researchers a golden opportunity to digitally reconstruct the chromosomes of

04:51the ancient common ancestor.

04:55There was another big problem, though.

04:57They had no idea what the chromosomes in comb jellies looked like until the year 2021.

05:03That's when brilliant biologists finally cracked the code.

05:07They discovered the chromosome structure of a particular comb jelly with a pretty complicated

05:12name.

05:13Yeah, I'm not even gonna try.

05:15Anyway, let me tell you, it was like nothing they had seen before.

05:19Strangely, the chromosomes of these comb jellies were totally different from the chromosomes

05:24of other animals.

05:26The scientists were perplexed.

05:28Is it because they had changed a lot over millions and millions of years?

05:32Or is that because they actually appeared before all other animals?

05:37It took scientists some time and a lot of hard work to fill in those missing pieces.

05:43And guess what?

05:44Finally they found the answer.

05:47It turns out the first branch of the animal tree belonged to comb jellies.

05:53This came next, and then all the other animals, including us humans.

05:59So let's discuss this little funny creature from which we all originated.

06:03Jellies, including comb jellies, are simple creatures with few specialized organs.

06:09They can sense chemicals in the water to find their food, and they even have a special structure

06:14called a statocyst that helps them orient themselves in the water.

06:19Comb jellies are also known as ctenophores.

06:21They're cute little creatures that live all around the ocean, from the North and South

06:25Poles to the sunny equator.

06:28They can be found from the surface all the way down to the deepest part of the sea.

06:33These amazing animals belong to the group of invertebrates, which means they don't

06:37have a backbone like we do.

06:39They come in various sizes, depending on the species.

06:42And by the way, despite their extraterrestrial appearance, their soft bodies are perfectly

06:47designed for their underwater world.

06:50They're more than 95% water, which makes them lightweight and agile.

06:56Comb jelly is a fascinating creature with an oval shape and 8 rows of tiny comb-like

07:01plates.

07:03It uses these combs to swim gracefully through the water.

07:06And guess what?

07:07When it moves, its combs create a magical rainbow effect as they diffract the light.

07:12It's like swimming through a shimmering prism!

07:15But they aren't as cute or harmless as they seem.

07:18In reality, comb jellies are voracious predators.

07:22They love to feast on other jellies, and some of them can even stretch their stomachs to

07:27hold prey that's almost half their own size.

07:30So their diet consists of other comb jellies as well as some salps and syphonophores.

07:36Talk about having a big appetite!

07:40And here's another interesting fact.

07:42Even though comb jellies got a head start in branching off from the tree, both they

07:47and sponges have been evolving since then.

07:49They've been on their own journeys, adapting to their environments and developing new features

07:54over time.

07:55It's a reminder that evolution is an ongoing process.

08:01It also shows how important it is to take care of these unique creatures and their environment.

08:07Changes in jelly populations can be a sign of bigger issues, so it's crucial to protect

08:12their habitats.

08:14But why is all this so important?

08:17Well, these discoveries help us understand how animals have developed.

08:21By studying the early branches of the animal tree of life, we can understand about the

08:25characteristics and traits that all animals share.

08:29For example, how they sense their surroundings, eat, and move.

08:33We can also learn all sorts of cool things about how animals first emerged and evolved

08:39into the wondrous array of species we have today.

08:43The scientists were really excited about their discovery.

08:46They knew that they had found a relic from a very ancient time.

08:51So there you have it!

08:52This discovery is like a magical time machine that allows us to peer deep into the past.

08:58It's a treasure trove of knowledge about the origins of animal life.

09:02I'm sure scientists will find out more interesting things in the future, so stay tuned!

09:09That's it for today!

09:10So hey, if you pacified your curiosity, then give the video a like and share it with your

09:14friends.

09:15Or if you want more, just click on these videos and stay on the Bright Side!

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