Is Australia a (Biogeographic) Island?

I was always taught there were seven continents, Australia being one of them. However, I've been doing this long enough to know many of my international viewers might've been taught something else; that Australia is an island within the continent of Oceania. This has in turn generated a lot of confusion surround Australia and its status as a landmass. Of course as we all know, these terms are meaningless, which is why lately we've been using biogeographic realms instead. I hope by using these alternative units for dividing the earth, we might finally get to an answer as to whether Australia is an island!
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Sources / Further Reading
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link.springer.com/article/10....
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www.science.org.au/curious/ea....
en.wikipedia.org/wiki/Biogeog...
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www.researchgate.net/publicat...
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[@abbycaldwell3166]

I love the detail of Steve Irwin being the reference for human scale on the size comparisons

[@somebonehead]

16:38 for Steve

[@SanilJadhav711]

Gotta represent the Australian icon beside the Australian fauna

[@honglianglim8637]

It is a comparison of Australian fauna after all

[@TheMageOfVoid]

*Irwin. Sorry, I'm Australian and he's basically a saint here so I'm obligated to correct you.

[@SanilJadhav711]

@@TheMageOfVoid Respect ++

[@shaungambrill8972]

It's not well known, but the largest marsupial carnivore that has existed in Australia wasn't the Thylacine, but rather Thylacoleo carnifex - roughly large jaguar/small tiger sized,. Worth a video of it's own, along with Australian megafauna in general.

[@Mhc-zp9kc]

Well, I don't think the Thylacine is thought as the largest carnivore marsupial ever by anyone, but the largest within certain timeframe - historic times.

[@Ass_of_Amalek]

it also looked absolutely terrifying

[@tasty8186]

A Thylacoleo is shown (pretty sure at least) at 12:00, so maybe he just forgot to include it when comparing size?

[@ErrSid]

I'd watch him discuss this

[@justbecause3187]

You read my mind, but we also shouldn't forget about Megalania(a giant monitor lizard) if we're talking about large extinct predators from Australia.

[@EndreaiYT]

I think New Zealand deserves a biogeography video of its own, seeing how many clades of birds independently became flightless here (Kiwis, Kakapos, Moas, Takahes, Wekas, etc…)

[@sebastianramirez3546]

Gondwana lore supremacy. saludos desde Chile, Gondwana

[@Alan_Hans__]

Australia's deadliest carnivore, the dropbear, wasn't mentioned :( The height of the eucalyptus trees gives the dropbear a massive advantage when it comes to attacking ANYTHING.

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@mitchellskene8176]

@@VeganSemihCyprus33 Please stop with your spam BS!! It's incredibly annoying!!

[@owenshebbeare2999]

Those damn Drop Bears, they killed my entire family...but made friends with my cat, the only animal they cannot compete with.

[@betula2137]

I have nets around my property because of them

[@uberdice]

Tourism Australia actively censors any mention of drop bears so that a whole section of the economy doesn't collapse.

[@stevenh1978]

You forgot to highlight Tasmania when you highlighted Australia - no doubt making a lot of Tasmanians sad :(

[@johnconnor2572]

I was waiting for him to say it and I'm from the states

[@modmaker7617]

At my British High School when we where taught about Australia they forgot about Tasmania too

[@ItzRetz]

Tasmania? What's that? Never heard of it. - The rest of Australia

[@voongnz]

Suck it up. New Zealand gets left of world maps all the time. Tazzie is more recognized.

[@tcaruso2]

I was surprised about that as well considering it looked like Tasmania was the path to Australia.

[@KhAnubis]

Oh wow, now I’m imagining what human history would’ve been like had Australia been slightly further north or south. (Also congrats on the house purchase!)

[@Eulers_Identity]

true, although that would just extend the realms a bit to the south or north

[@GmodPlusWoW]

Personally, my mind is leaning more towards "What if Australia had more mountains". 'cause Australia being relatively flat, combined with the abundance of cold currents along its western and southern flanks, is why so much of the continent is arid and relatively "barren" IIRC. Southwestern Australia is one of the two exceptions to the situation, since not only does the Leeuwin Current bring warm waters (and thus greater evaporation) to the region, but it just so happens to have an upland region in the form of the Darling Scarp, which likely helps orographic lift work its magic in squeezing moisture out of the air. Though with that said, given Western Australia's higher elevation relative to the rest of the continent, maybe that part of Australia would be a little greener if it had a few more lowlands? Or maybe it just needs more moisture overall, who can say?

[@StuffandThings_]

@@GmodPlusWoW The western parts of Australia still wouldn't be productive even with more rainfall, as its some of the most ancient land on the entire planet (part of why there aren't really any mountains there) so the soil is extremely nutrient poor. The wetter east coast also just so happens to have had some quaternary volcanic activity (and even some within the time that humans were present on the continent) so has much more fertile soils. Much of Australia just happened to have the exact wrong combination of factors to be an incredibly barren and inhospitable place, save for the narrow strip along the eastern coast and Tasmania.

[@AtlasPro1]

Had it been a little further south it might’ve hosted the biggest temperate rainforests on earth. A little bit more north and it could host a tropical rainforest comparable in size to the Amazon. But only like this does it get to have all of the above and more. It’s a win-win-win either way!

[@ppppppppp64]

New Guinea seems like what Australia would look like if it were further north. And Tasmania and New Zealand are what it would look like further south

[@frostyguy1989]

New Zealand is a realm of its own. In Australia, *marsupials* dominate every ecological niche, but in New Zealand (until humans arrived) *birds* dominated every ecological niche. I'd go so far as to call New Zealand the last place on Earth where dinosaurs continued their reign after the K-T Event.

[@tinto278]

"New Zealand is a realm of its own. " yea its part of china now!😂😂😂😂

[@DarrenGedye]

Yep, the only native mammals in NZ were bats. But for me Australia will always be an island: The North Island, The South Island, and The West Island 😉

[@paulfri1569]

@@tinto278 hahahahaha

[@nooneatall1830]

He did make the distinction to compare NZ and Australia, meaning he considers them separate realms to some degree. Prolly considers it to be either the last surviving extension of the Artic Realms before freezing or its own realm as Zealandia

[@lukewilki6343]

There are common flora, but fauna is completely different. Apart from the map at the start which included NZ, this video was only relevant to Australia, New Guinea, part of Indonesia and possibly Melanesia.

[@robertb6889]

It’s really interesting how the biogeographic realms also reflect cultural divides not evident on the continents, like North-Africa vs Sub-Saharan Africa, or the USA/Canada and Latin America.

[@monicabello3527]

I completely agree, we are animals after all and we have moved around the world in the same way other animal do. For instance there is much more cultural exchange between Spain and Morocco than Morocco between Nigeria. So Morocco should be part of Europe as in fact it is part of the western palaeartic region.

[@habibi_sport312]

@@monicabello3527 Well not Europe but Paleaarctic (or Eurasia) yes.

[@Korvisio]

Exactly, Mexico is also divided into the part that is economically dependent on the USA and the part that isn't. The Indomalayan realm is the Indosphere + Vietnam (which conquered its modern coastline from Khmer) and South China (which was also conquered by northern Han)

[@surface3122]

I love that you use Steve Irwin as a yardstick when discussing heights of birds and humans. It's always great to see that he's still remembered. One of our best exports, that guy. Also, as far as I can remember, I was taught that Australia was an Island Continent.

[@GeoCaptTerror]

Came to the comments to see if anyone else appreciated using Steve Irwin as the benchmark human. Good choice!

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@harbour2118]

He is the reason why I love and Hate stingrays at any given time

[@mim3097]

I think we Aussies are going to have to fight for our island status to be restored. I'm beginning to appreciate how Pluto must feel 😂

[@loonyt22]

I think New Zealand has been seperated from Australia far too long and by too large a gap for them to realistically be considered part of the same biogeographic realm, if anything they share a common original mainland of antarctica.

[@KironVB]

Yep, New Zealand is absolutely it's own biographic "realm", very different plant species, no mammals or marsupials. Geographically as well it's part of it's own sunken "continent" Zealandia. Another weird one is Tasmania, which actually geographically has it's origins in North America.

[@robertmurray8763]

New Zealand 🇳🇿 does have some plant the same as Australia 🇦🇺. Tea tree for one but New Zealand has no Indigenous mammals.

[@wellurban]

@@KironVB Yes, we’re sometimes included in Oceania or Australasia if we absolutely have to be lumped in to a larger “continent” from a cultural or geopolitical standpoint, but from a tectonic or biogeographical perspective we’re part of the continent of Zealandia.

[@monkeypie8701]

As a New Zealander myself, remember that we only have 2 mammals, which are bats, its mostly birds which flew over from Australia and evolved from there

[@RubyDoobieScoo]

@@monkeypie8701 There's sea mammals too like the NZ Fur Seal.

[@SymphonicConvergence]

will we eventually get a video on living islands? (massive animals that have their own self contained ecosystems) or would there be not enough examples to draw from?

[@Real_Eggman]

Technically, every animal is a living island, by your definition.

[@JaKingScomez]

@@Real_Eggman good one nerd

[@anonymousfellow8879]

@@JaKingScomez They’re not wrong though. Bacteria, gut flora, viruses, parasites…

[@JaKingScomez]

@@anonymousfellow8879 did i say they were Einstein

[@yingfortheking]

Idk if there are any aninals with enough symbiotic relationships to warrent them being a micro ecosystem in the way you're describing. Maybe some of the larger aninals like bison or elephants have enough birds and bugs on them to count? I bet some of the giant sauropods had plenty of various species hanging out on their backs!

[@philwood5288]

As an Australian, I was taught that Australia is the biggest island, and the smallest continent at the same time. This was primary school education in the 70's.

[@carlosandleon]

All continents are islands

[@petert3355]

​@carlosandleon Good luck claiming that North, South America and Europe, Asia are islands.

[@carlosandleon]

@@petert3355 they are

[@rizkyadiyanto7922]

​@@carlosandleonoceania??

[@carlosandleon]

@@rizkyadiyanto7922 is not a continent

[@sumwun2445]

I myself live in australia and we get taught that our country is both and island AND a continent which is kinda odd but anyway have a good 1

[@anentiresleeveoforeos2087]

I also live in Australia and can confirm you're a filthy liar

[@normanwierzbicki7434]

We are both because we are a part of australasia the continent but are still surrounded on all sides by ocean

[@tomatosoup44]

Small correction, mammals never stopped being synapsids. We still are synapsids, just derived ones, in contrast to the more basal ones like the cynodonts you showed.

[@smitty1647]

indeed. it seems cladistics is still slow to catch on

[@davidpnewton]

Similarly we never stopped being fish or amphibians and birds never stopped being dinosaurs (and fish and amphibians).

[@willowarkan2263]

@@davidpnewton Well fish aren't really a useful term as far cladistics go, as far as I can tell it's more like calling something a tree. as for amphibians they are a related group of tetrapods, but not basal, we likely evolved from aquatic/semi-aquatic reptiliomorphs. Mind at least from what I found looking it up just now the exact relationship between amniotes, in the sense of reptilomorpha and amphibians, in the sense of batrachomorpha isn't settled. Basically there may have been an eel-like reptile-like aquatic animal on the way, that was closer to reptiles then to amphibians, in our ancestry. So we aren't part of the monophyletic group of amphibians, since we are amniotes. As for fish, yeah something people would call a fish was in there, but a lot of things get called fish. As for trees, depending on definition some grasses are included and if you want to go real wild a mushroom. Basically big tall plant with some apical dominance, depending on definition not even wood is necessary.

[@tomatosoup44]

@The Philosoraptor most definitely

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@camfunme]

What I was taught in school in Australia, was that the country is the Commonwealth of Australia (shortened to Australia) located on the continental shelf of Australia. Thus making it both an island and a continent.

[@marthanewsome6375]

I just wrote a comment stating that Australians consider it both an island and a continent. I guess we consider it an island because we are not connected to anything else and are surrounded by sea and a continent because we are the biggest land mass on the continental plate. But also we are a mainland. Tasmanians consider the big land mass as the mainland. So we are all of them.

[@thejollygreendragon8394]

@@marthanewsome6375 "Tasmanians consider the big land mass as the mainland" No we don't. Australia is the Island, and Tasmania is the continent. There, fixed it for ya 😊 🐉

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@joavisr5011]

the tectonic plates are really aligned with the modern day continents and some smaller ones are added to bigger ones. but the Australien plate is definetly seperate with the surrounding islands.

[@NorthCitySider]

To an extent. The exceptions are that far eastern Russia is part of the North American plate despite being in Eurasia while the Arabian, Indian, and Caribbean plates exist independently of the plates of their respective continents. And of course there is no distinct plate for Europe but everyone should already know that the boundary between Europe and Asia is artificial in every meaningful way.

[@mattnorris529]

@@NorthCitySider I thought it was continental plates too. You said it perfectly.

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@BlackSakura33]

By that definition India is a continent.

[@disontago5729]

@@BlackSakura33yes it is. Geologists call it a subcontinent

[@marcopanzironi6612]

You said that New Guinea is the only highly productive region of the Australasian Realm, but what about Tasmania? It dwells in the temperate region, so it doesn’t have to deal with the same problems as the Australian mainland; plus it’s filled with lush temperate Rainforests

[@normanwierzbicki7434]

So is Victoria

[@lukemcniven4131]

Those are cold climate rainforest. They're almost unique in the world. They are not productive ecosystems unless you're a bird or tiny mammal. The Aboriginal peoples avoided lingering in the rainforest areas, there's no food

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@DneilB007]

@@lukemcniven4131 There are cold-climate rainforests in BC, Canada (and, I think, Washington State). The wildlife seem to do just fine there (when we’re not killing them or uprooting their trees).

[@boronialinquest]

Yes, in Tasmania there are a few regions; much of the island was covered by glaciers, which is why the Midlands are still productive despite being dry, while the nutrient-poor west gets a lot of rain. Tasmanian Aboriginal peoples lived across the island, including rainforests (wet sclerophyll and Gondwanan), where we know of landmarks in the north-west and caves across the west and south. Villages were also built in these areas, where trading was done on the highlands -- there is also quite a variety of bushfoods, but for lifestyles, aquaculture was more common. Unfortunately, the Nara people are the people we know the least about, because the majority of the nations and cultures were subject to genocide.

[@allonzehe9135]

One of the most unique channels on KZbin. This is so esoteric and niche and I absolutely love it. So many channels become bland and same-ish, but this one is staying awesome!

[@pronumeral1446]

"lower productivity deciduous forest" - Australia's forests are almost entirely evergreen (eucalypts are evergreen). Only a few species are dry-season-deciduous (eg: the Illawarra Flame Tree), and only one species is winter-deciduous (nothofagus gunnii, endemic to Tasmania).

[@vivecald-vehk6978]

I won't lie, I'm a proud Aussie and as soon as he said that I was like "wait, what? Aren't almost all out trees (save for the imported trees) NON-deciduous?" Evergreen, like you said, which I prefer as a term seeing as how Green is my favourite colour But he is 110% spot-on when he said Koalas are the most Aussie animals we have, such a shame we are driving them to the endangered zone if they aren't there already... (fkn LNP bustards...)

[@terrybarnes5266]

I think you’re misunderstanding what is meant by “productivity” in this context. When a plant community’s productiveness is measured, what they’re trying to quantify is how much above-ground biomass is produced per acre/hectare over a given timeframe (usually one year or growing season). In terms of land area, the overwhelming majority of Australia’s tree containing ecosystems are made up of semi-arid savanna/woodland that is relatively unproductive compared to New Zealand’s forests and those that exist along the eastern coast of Australia and in Tasmania.

[@stevenbalekic5683]

He may have been speaking in the context of millions of years ago...when gum trees weren't the dominant species and there was deciduous trees here before dying out.

[@billbishopboyiscool]

Yeah, I immediate thought of Queensland's forests and thought they were evergreen.

[@jesserowlingsify]

@@terrybarnes5266 no, the issue was not with the 'productivity' comment, but the 'deciduous' comment. the video stated that australia was left with x, y, and the "lower productivity deciduous forests". as established elsewhere, this is simply not true due to a lack of deciduous forests in aus. i'm finding that there are simple errors and mistakes like this in almost all of this guy's videos, it's really putting me off. i am fairly well-educated in geography and urban issues as it's my area of work and study, so i can spot some of these if they're things i know about, but it concerns me how many other things may be wrong when it's topics or areas i'm unfamiliar with.

[@dmax9946]

The thing I find funniest is that Australia + Tasmania are completely with on its own tectonic plate. In other words no tectonic/major fault lines run through Australia meaning no big earthquakes (we do occasionally get small quakes because our landmass is stretching as we move north)

[@janeteholmes]

Australians are taught that Australia is “the island continent”. So a continent that is islandy.

[@modmaker7617]

Are Australians taught about Oceania?

[@arwon2227]

That Oceania concept isn't really specific enough when looking at the world from here, NZ, PNG, the Pacific nations, and South East Asia are all pretty different places. It's the name of the soccer confederation we used to be stuck in though.

[@modmaker7617]

@@arwon2227 Here's a video with the best definition for Oceania; kzbin.info/www/bejne/eZuUnn19idJ_iNU

[@Newportal1]

As an Australian myself, I was told Australia was the Smallest Continent AND the Largest Island.

[@peepeetrain8755]

@@modmaker7617 yes. We are told we are in Oceania, we don't consider ourselves to be our own continent really.

[@simonburke8341]

This was such an interesting video. As an Australian I’ve been told marsupials came from South America but they never explained why no other mammals did (accept for monotremes). The land bridges you described with all the sea barriers were very informative! Thank you for releasing this!! 👍

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@Dragrath1]

The situation with marsupials and their relatives is probably a bit more complicated than this since newer fossil evidence seems to suggest that these mammals actually appear to have had a much more cosmopolitan distribution during the late cretaceous such that it makes determining when "modern" marsupials split off quite a bit more difficult given that mammal fossil records like most small vertebrates tend to be exceptionally poor with teeth being the most common fossil representation of these kinds of animals. However it happened they never really seem to have recovered after the KPg extinction in much of the world where as placental mammals diversified and radiated out perhaps because they were far more specialized on average based on study of their most prevalent fossils their teeth. Of course in this context we need to recognize that only South America, greater India, greater Australia and Antarctica remained independent continental arenas to use his terminology as Zealandia was drowned below the waves. However even Zealandia which has been independent though much of the late Cretaceous onwards once had Marsupial mammals according to the fossil record they just couldn't survive their continent getting drowned. We infer that land brides or rafting events must have occurred based on genetic evidence and or fossil evidence but in many ways we have limited evidence and are grasping at limited data. Currently whether marsupials made a long migratory journey in the manner he described or whether they had a much broader earlier distribution during the Cretaceous we don't know as only a small number of fossils are known. What they do seem to indicate is that marsupials are older than we had once thought I'm leery to interpret more than that in the face of extremely sparse evidence.

[@jayteegamble]

It's really interesting that marsupials evolved in North America. North America's only extant marsupials arrived after the Panama land bridge formed (which is basically yesterday in geologic time)

[@ruxshine7488]

As an australian, i was taught that australia is an island and the continent is oceania. Great video! You are always very entertaining :)

[@GTR-V1]

Yeah, it think that's how it is

[@christophhanke6627]

16:45 Shout-out Steve Irwing in this graph. Legend of my early childhood^^

[@Bad.Example]

love it how you used Steve Irwin's silhouette to represent the human in the graphics for Australia video

[@Faerandur]

Great homage to a great guy

[@PhoenixIsTrash]

Amazing video pointing out Australia's unique biogeography. What I find interesting about our biosphere though is that we are not entirely isolated. Most of our Flora and Fauna is traceable to Gondwana through either Antarctica or the Indian Subcontinent. However we have had two recent radiation events from the pacific and South East Asia. During the last ice age, the Sunda-landmass (Malay Peninsula, Sumatra, Borneo) and the Sahul Landmass facilitated a two way corridor for both plants an animals to cross the biogeographic regions. Giving us a dominant Gondwanan community with smaller newer Laurasian communities.

[@katehobbs2008]

Geologically, it is a continent, the continental plate extending to part of New Guinea, Ashmore Island, and some other Coral Sea Islands. That is the fundamental property. The evolution and variation of biota are a surface function on the continent. It is sophistry to try to define the Earth’s massive continental plates in terms of their biota. Those form geographical regions. New Zealand, New Caledonia and some other islands are considered to form part of an almost entirely submerged continental plate called Zealandia.

[@keithwagg4112]

As an Australian who loves science and biology in particular, I absolutely loved this!

[@KabirHart]

This was a great video love from Australia. Would you be interested in doing a video on introduced species in Australia?

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@erinr5585]

The Australian desert is teaming with flora and fauna. As fast as I know there is also vast area of rainforest, both tropical and temprate, along the northern, eastern and southern coast.

[@chrisconnors7418]

Love your videos. I used a few short clips when I taught biogeography a year ago. They nicely summed up some concepts I wanted to bring across to the students.

[@simonschopman5461]

I think you definitely did a great job of opening discussion on the meaning of continent, realm, island, etc. Watching your shows makes me look at the world differently. Wonderfully done! So very informative! Thank you very much!

[@kentross1134]

Great video! I loke the biogeographic theme. I think you could also mention that Australia has it's own tropical rainforest in the northeast that hosts a pretty substantial amount of biodiversity.

[@rageingrhino]

You are incorrect to suggest that Australia is only made up of deciduous Forrest, grass land and desert, it is much more diverse than that. The fourth largest rainforest in the world dominates the north east, there are cooler temperate rainforests in the southeast, there is an alpine region larger than Switzerland that receives regular snowfall, even the deserts much more diverse, the great sandy desert is nothing like the Simpson desert for example.

[@TheOnlyCaprisun]

This channel is my favourite, I have watched these videos almost religiously for 3 years.

[@AlecMuller]

18:20 I love that the "human" in this plot is clearly Steve Irwin. RIP.

[@ljphoenix4341]

Australia is a continent, and an island, I was taught. New Zealand is separate, sitting on Zealandia, aka the lost continent. This coming from someone who has a New Zealand education, having gone through high school within the last 10 years, and has an interest in geography/history.

[@modmaker7617]

Zealandia doesn't count as the majority is underwater. Oceania is a better term.

[@brathernumzy]

@@modmaker7617 why doesn't it count ?? If new zealanding is included in the video ??

[@modmaker7617]

@@brathernumzy It's underwater.

[@brathernumzy]

@@modmaker7617 not when sahul was a continent

[@modmaker7617]

@@brathernumzy Sahul is then a historic continent.

[@billbishopboyiscool]

I love how you're getting more and more into biogeography! The passion is exciting.

[@notpurple]

Always love your videos! Informative and entertaining

[@axellgaard8644]

I just can't describe how much i appreciate you're videos. keep up the amazing work man :)

[@toni4729]

Cassowary is also found in Queensland.

[@korakys]

I take a geological view: take the entire area of a crust zone (in this case Sahul), is the largest contiguous above water portion at least 50% of that? If so it's a continent, if not an island. The tricky part is now defining the crust zone, but, roughly, the Australian mainland constitutes 72% of Sahul. Therefore Australia is a continent.

[@thealmightyaku-4153]

Geologically, Australia is definitely a continent, containing and built out of major crustal cratons, and all the lands and islands around it exist because of volcanism as the continental plate it sits on pushes north into Asia.

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@Dragrath1]

@@thealmightyaku-4153 Yeah not only is it built from cratonic cores but it also includes one of the oldest "intact" Cratons known or rather half of one of the oldest cratons because the other part got split away into Africa during the rifting of Gondwana if not earlier. Also from a geological POV based around Cratonic cores India once counted as its own former continent. I still find it fascinating that during the Early Cenozoic as the main mid ocean ridge of the Indian ocean effectively became extinct it seems to have caused the Indian and Australian plates to fuse together. It was only recently thanks to the data from the great Sumatran quake of 2004 that we were able to determine that the main portion of this break up fisnished around 3 million years ago due to the strain from the forming Himalayas became too much forcing the Indo Australian plate to break apart again with the Indian plate to this day continuing to fragment apart. The complexity of Earth geologically is fascinating. I'm especially intrigued by the new paradigm that is emerging from the combination of seismic tomography and more extensive igneous volcanic and metamorphic petrological dating as it suggests a need to rethink the context and scale, particularly in regards to depth of plate tectonics as extending down to at least the Mantle Transition Zone between the upper and lower mantle. It is this picture which helps explain why Zealandia is so different from the main continents as in this picture true continents are more like giant silicate analogs of ice sheets floating within the larger much more mafic upper mantle and thus extending well below the crust. Zealandia is in terms of volume still too small to rise to high above its surroundings hence why it is mostly under water despite being primarily continental in composition.

[@thenightscythe2030]

This.

[@DaveTexas]

Your videos are always fascinating! How I wish all teachers had your enthusiasm, your ability to make every topic so interesting, and your ability to engage the students (us). Don’t get me wrong - I loved school and I absorbed knowledge like a sponge, especially once I got to college and could take courses in areas of study that I found the most interesting. However, if I’d had teachers like you throughout my schooling, I would have been much more engaged in subjects that I wasn’t particularly excited by, like statistics, economics, and…I hate to say…geography. I was much more interested in the realms of mathematics and the hard sciences, along with music and art. Anyway, I just wanted to let you know that you really inspire me to keep learning!

[@jorgevarela3722]

Congrats about the house, It is a big archievement and It is really well deserved for the quality content. Hope the channel keeps growing

[@emmadenton1826]

The Komodo dragon would have been another good example you could've used! As they look like a classic case of island gigantism, but their current isolation is a actually a result of changing climate (and probably a loss of all the megafauna). These dragons used to have a much larger range that extended well into Northern Australia. And Komodo dragons are a pretty typical size of species that used to be around 😊

[@ahha6304]

I love how you show the picture of human as the legend Steve Irwin aside with the Australian animals

[@SomeRandomDevOpsGuy]

Since college I thought we should use the major techtonic plates to distinguish geographic regions. I like this idea of Biogeographic, it seems to have better applications in making distinctions between different places.

[@thenightscythe2030]

This categorization is simply based on the "surface creatures"...while it is good for separation of animals... It is not as accurate as the Actual Tectonic Plates that are defined.

[@sampagano205]

This video leaves out an important part of the case for Australia being the mainland of it's realm, which is also that it's home to a stunning diversity of lizards and snakes, with many species on new Guinea being pretty clearly derived from Australian stock like the Indonesian blue tongue skink and the Papuan spotted python.

[@Gecko...]

Great video, love how in-depth they get.

[@noahpowers1597]

"The koala is the most Australian animal possible."-I'm dead 😄🤣😂

[@maxwellbarrett]

This is incredible science communication i cannot commend you enough! Please know we see all the work youre putting in. Thank you for sharing your work and knowledge with everyone i hope someome out there is paying you ha. Please keep going youre amazing!

[@michaljanovsky8966]

what an awesome and enriching vid! love the biogeography and natural history presented in your videos

[@barross0505]

Would you ever consider doing a video on savanna’s and how where they form and why they do? Like the pine savanna’s of the southeastern United States, the Serengueti plains, the Great Plains, and the Tibetan plains, and the extensive plains of Africa. (I also think there are some in Argentina but I’m not sure). Great videos as always keep it up.

[@lsamaknight]

Relevant to the video, there's actually a savannah in Australia as well in an area known as The Gulf Country, south of the Gulf of Carpentaria (between the pointy triangle of Cape York Peninsula in the East and that weird central blob that is Arnhem Land if you're looking for it on a map).

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥🔥🔥

[@nellym46664]

As a map nerd, I like to think of savannas as the transitional zones between the most extreme biomes such as deserts and forests.

[@barross0505]

@@nellym46664 it seems like that but there’s a really interesting paper (I wish I could find it now) but it was about how savanna’s and forests can occur in the same regions but the usual deciding factor between forest and savanna was the presence of fire and large animals.

[@kumisz2]

I'm from Europe (Hungary) and we were taught that Australia is a continent but also Oceania is a large area including Australia.

[@stevenbalekic5683]

Yes, that's how we are taught in school too here in Australia. Oceania is similar to the Middle East...it's a region. Also Australasia is just a word for "south of Asia " which isn't really a name.

[@Andrew-cv2uf]

Based Education

[@augzer261]

Hey Atlas, As an Australian just wanted to let you know that the Cassowary is native to Australia living in the now isolated rainforests along the North East coast. Due to the short term nature of Papua New Guinea and Australia's separation ~10,000 years ago much of the species are very similar. I would make the case that Papua New Guinea and Australia are both the mainland of Australasia as with every cycle of the ice age reuniting the species that had been separated. The only species that remained separated were those who are adapted to specific environments such as the interior arid lands like the Kangaroo. Really great video and I've subscribed!

[@AtlasPro1]

While it's true as single species of cassowary, the southern cassowary, still has a little extension of its range into Australia, the vast majority of its range lies in New Guinea, along with the two other species of cassowary, which are only found on these islands. So sure Australia have a cassowary or two but New Guinea is still clearly their homeland.

[@betula2137]

@@AtlasPro1 Why not both?

[@ngaireg7736]

@@AtlasPro1 Cassowaries originated in Australia and dispersed into New Guinea. Current belief is that Casuarius casuarius is the oldest cassowary species and that C. bennetti and C. unappendiculatus evolved in isolation after sea level changes removed the land bridges between Australia and New Guinea. The latter two are more closely related to each other than to C. casuarius - which makes sense if they evolved in isolation in New Guinea.

[@Gutterrat69]

Amazing production as always, best channel on here

[@TheMarslMcFly]

Finally my question gets answered! Thank you Atlas! 💜

[@parrotking8315]

It be interesting to add the mountain building of Australia from the great dividing range to the peterman ranges. Because Australia did undergo lots of mountain building in the long past.

[@andrew7955]

Yeah, I believe Uluru and other rock formations in Central Australia used to be part of a massive Himalaya-like range

[@Ayrustration]

i hope there will be an episode for papua newguinea too... really love your content!!!

[@fwWill]

It's crazy you still goin up I been watching for like 4 years crazy vid bro

[@mirin9851]

I grew up and was educated in Australia. We always referred to Australia as an 'Island Continent'

[@thenightscythe2030]

Technically, this term applies to New Zealand more so than it does to Australia. Australia has always been above the Ocean. As New Zealand has not fully reemerged from the Pacific Ocean.This is where "island-continent" is more applicable.

[@ouroboros5474]

​@The NightScythe New Zealand is comprised of several islands though.

[@ElicBehexan]

I always thought Australia was a continent because of its singular life forms. No other landmass, outside of its region has its various species. The last few other pouched mammals are part of their trek to Australia.

[@dominiquelaflamme7804]

I just love your videos so goddamn much! Thanks for doing what you do, man!

[@seacucumberable]

Love this channel - congratulations on the house!

[@avhuf]

It seems that including life as a factor in the definition of continents or the like is not satisfying as it makes those definitions for instance dependent on ice ages... the only imo satisfying classification should be based on the tectonic plates everything is located on.

[@vernonfridy8416]

6:38 Mammals never stopped being synapsids, therapsids, and cynodonts, considering them as monophyletic clades. Really, mammals are still synapsids in the same way marsupials are mammals.

[@leanmateric4698]

Just wanted to say thank you for the quality content you provide us with.

[@aydinoner1378]

Love your videos keep up the good work.

[@DanielCrabbprn]

"Undefeated military power". Ouch, right in my Australian Pride.

[@hisownfool1]

I don’t think that the internet is ever going to let the Australian military live that down. 😀

[@betula2137]

If you have Australian pride, celebrate the victory of you emu comrades! Pshaw, ungrateful civilians nowadays, don't respect veterans.

[@LeSethX]

Australia seems to be the Pluto of continents. Also, I find it funny eucalyptus trees migrated from South America to Australia and have been transported here in North America (California specifically). I was actually surprised when I found out they aren't native to here.

[@xo-1320]

Eucalyptus also produces an oily flammable substance. This is why Wild Fires are more and more of an issue for California as at the time the people who did this had no idea the trees take a century to grow and are naturally flammable.

[@yodorob]

While New Guinea has most of the Australasian realm's tropical rainforests, the northeast coast of nearby Queensland also has some. Plus, there are quite a few parallels between Australia and South America (or parts of them anyway) in terms of climate and fauna. Both of those continents have been isolated from the rest of the world for millions of years and they've had plenty of marsupial evolution going on. Of course, and especially after South America was joined to North America two million years ago, Australia has diverged that much further, such that South America now ranks only second in terms of these things.

[@frodosadventures8757]

No mention of Tasmania, which like New Guinea, was joined then cut off several times as sea levels rose and fell. Tasmania is a bit like a mini Auatralia, with a diverse range of climates and landscapes. It has a lot of the same species of plants and animals as mainland Australia, but also has some species that are unique to Tas.

[@betula2137]

Yep

[@chazsaw]

Repeatedly referring to thylacines as Australia's largest carnivore is, I am sorry to say, a bit of an oversight when you bring in other extinct animals. Even if I am happy to move on from the implied stipulation of "fully terrestrial" that takes saltwater crocodiles out of the running, I think @Atlas Pro should take a look at thylacoleo and megalania.

[@jonedwards5953]

In addition to the larger thylacinids and the ever cool quinkana

[@chazsaw]

@@jonedwards5953 Oh, I forgot about quinkana, good call. Though to be fair re. T. potens (I am not trying to flex here, I had to re-look up the name :P ) it could have been being referred to under the umbrella "thylacine", and wasn't a HUGE amount bigger. Incidentally, I don't know much about the mekosuchids, but I know many were fairly small. Were there other large species worth looking up? Or was quinkana the only one to break into the megafauna category?

[@NorthCitySider]

I think he meant in terms of recent fauna, he put the extinct ones on his map and also in the one he did for paleobiology of the Ice Age, he probably knows about them.

[@scaper12123]

Everyone: Oceania US, UK: how ‘bout no?

[@ishaanupreti6438]

I don't think UK counts, even though it is an English speaking country, they say Oceania. But one English speaking country we should ask, is Australia itself. What do they consider themselves ?

[@EpicCorn0]

@@ishaanupreti6438 Usually we think we are the main continental landmass of Oceania or Australia or whatever you want to call it. Australia is the continent. New Zealand, Pacific Islands and New Guinea are the islands surrounding it, like how Madagascar is considered part of Africa or Japan part of Asia. Australia itself serves as the main body.

[@Pantalaimon91]

Growing up in the midwest in the US I learned Oceania. Not sure why mine and even my parents experience in this part of the country was so different than everyone else's here. I mean, it's absolutely the sheer lack of educational standardization but I was really surprised when I found out on his poll that most people in the US learned something else.

[@ishaanupreti6438]

@@EpicCorn0 So you still use the term Oceania but also refer to Australia as a continent. But then how do you decide which islands are part of Oceania ? Indonesia is considered part of Asia, but half of New Guinea falls in Indonesia. Also, isn't New Zealand it's own continent ?

[@EpicCorn0]

@@ishaanupreti6438 Let me remind you this is all arbitrary, there is no right or wrong answer. Yes we use Oceania sometimes, it refers to Australia, New Zealand, New Guinea, the Pacific Islands stretching out to Hawaii and sometimes the more western Indonesian islands up until Sulawesi, but it usually just stops at New Guinea. No, New Zealand is not its own continent. It lies on a fault between the Australian Plate and the Pacific Plate, and there is a large underwater ‘continent’ connecting it with other islands but if you were to count that as a continent you would also have to count Sahul and several other sunken landmasses as continents, which I think is kinda unreasonable.

[@rais1953]

One slipup that I noticed, the suggestion that Australia was left with "deciduous forest." If there is any deciduous forest in Australia I've never seen it and I've travelled over much of the country. An interesting thing to note is that in semi-desert regions we have a lot of rivers that only flow on the relatively rare occasions when it rains. However these rivers are not just dry riverbeds the rest of the time. Under their dry, sandy riverbeds they conceal narrow, shallow desert aquifers where the inhabitants of the desert region, both human and animal, can dig for water. And along these riverbeds are trees, not stunted desert bushes but sizeable eucalypts of the kind that must have covered this landscape before it dried out.

[@betula2137]

Back then is when he was describing. There are still a few deciduous trees left and one winter-deciduous (Nothofagus gunnii), and we used to have many.

[@francoisBurger]

This was a great video much appreciated from down under :)

[@EdbertWeisly]

Oh yeah and Antarctica

[@sandrios]

If I remember correctly what I was taught in school, Oceania is a region and Australia is a continent in it. That's the way how I think of it

[@AholeAtheist]

I think I was taught something similar, only difference being Australia can be considered part of and sometimes not part of Oceania, mostly not though as it's a continent, with Oceania being made up of the Melanesian Islands(New Guinea, Solomon Islands, Fiji), the Polynesian Islands(Aotearoa, Fiji, Samoa, Tonga, Hawaii, Tahiti, Rapanui) and Micronesia(the Marshall Islands etc.).

[@VeganSemihCyprus33]

A warning to humanity: The Connections (2021) [short documentary] 🔥

[@IGNEUS1607]

In school in Australia, we were taught that Australia is the dividing line between island and continent, and thus that it is both the smallest continent and largest island.

[@george.yarzadv]

Awesome channel bro!

[@Freshbott2]

To anyone who might find it interesting. The dominance of Eucalyptus in Australia is extremely recent geologically. Like marsupials they first evolved in South America after the Cretaceous extinction, were in Australia and the rest of the Antarctic biome by 45 million years ago. Over the last 10 million years they diversified, but would have only been significant or dominant in the dry interior. The coasts were dominated by southern beach trees and ancient Gondwanan‘pines’ still found in South America, New Zealand and some parts of Tasmania. Only since the last 50,000 years they’ve become dominant in almost every Australian biome, probably because of burning by humans which eucalyptus are resistant to. Only since the end of the ice age did they get the distribution we know now. But in a circular turn of events in the last 100 years they’ve been brought to the places they were native millions of years ago. Because Australian geology is extremely old and eucalyptus distribution so new, there are so few fossils that the only thing we can deduce is that they weren’t there. But there are some. The pinnacles in WA are formed from fossilised Karri trees in what’s now almost a desert. Today those trees are found in a tiny patch. At the time where they are now would have been dominated by deciduous beeches. Today that’s 600km to the south along a tiny sliver of coastline which shows the dramatic change in climate. They also show the changes that could happen with a further changing climate. If it gets any warmer or dryer over the next thousand years, the largest trees in the world will have no biome to migrate south to. Side fact. The only relatives of the other giant trees in the world, the sequoias in California- are from Tasmania and there’s no explanation for how they ended up in both. But genetic testing shows they diverged and remerged as species multiple times before being separated. At one point one patch was in far Northern Canada, with the other probably on Antarctica.

[@nenenindonu]

Continents can contain a wide range of unique cultures as well as fauna and flora, distinct from those found on other continents. Islands on the other hand can only contain features on a smaller scale and scope so the answer is NO

[@davidteachout1888]

Every continent is technically an island since they're all surrounded with water

[@anentiresleeveoforeos2087]

arbitrary town population you

[@stephaniekelly4384]

Largest Island, smallest Continent, from Eastern Australia

[@stephaniekelly4384]

From Eastern Australia (NSW)

[@ryanharris1052]

Excellent video as always.

[@emmahkhoza3434]

Congratulations on the new house❤️

[@cjyoung7372]

So is new zealand it's own realm or is it to small? P.S I love the little nod to Steve Irwin that was a nice touch 👌

[@AholeAtheist]

It probably should be, it doesn't have any indigenous marsupials.

[@thenightscythe2030]

It is its own Realm, as far as Animals and Plant life. Until it has been emerged long enough to create its Own Bio diversity, from interaction from nearby Islands / Australia (besides Birds, which were the only ones to have access to New Zealand up till now) The entire Pacific ocean is considered its own "Realm" because of island-hoping animals... For now, New Zealand fits in this category, as far as Bio-Diversity/Bio-Geography is considered.

[@AustinPerdue]

I'd like to point out that New Zealand has neither marsupials nor eucalyptus (that are native). So, arguably it is not an island to Australia's (or New Guinea's) mainland.

[@judithwalker3600]

Well said! very interesting!

[@antiisocial]

Congrats on the house and great video. Ty.

[@atypicalprogrammer5777]

I love the idea of using biogeography to solve these questions, like how many and what continents there are. But could the same be done for the oceans, that is, are there distinct realms of oceanic life? (well ok there are deep sea creatures and life near the surface, but are some seas like the Mediterranean acting like their own underwater continents?)

[@jasonreed7522]

To my knowledge only the ocean around Antartica is truly hydrologically separate from the rest of the world ocean. (And ironically the "southern ocean" is the one most often not considered an ocean since we usually define them by drawing lines across narrower sections of the ocean) But it would be interesting to see an attempt to aply the same categorization of biogeographical realms to the oceans and figure out what are the real "mainlands". Its probably useful to include large rivers and lakes in this discussion.

[@nivumdeterraartemisiae275]

Just to mention: You said that marsupials evolved to have underdeveloped younglings, and that mammals other than marsupials are called placental mammals, which are both incorrect. Giving birth to underdeveloped babies without having a pouch is how early nippeled and eggless mammals reproduce. From such ancestors, one surviving lineage evolved a structure called PLACENTA which allows us to have well developed babies. The another lucky group, the Marsupials, who NEVER had Placenta, instead evolved a pouch around their nipples as kinda external womb, also allowing their babies to developed more before independence. All other eggless nippled mammals later went extinct, leaving Placentals and Marsupials the only two surviving eggless nippled lineages today. Monotremes diverged earlier from the ancestor of both groups and instead never lost their eggs and never evolved nipples. Another mistake in the video is that Australia actually had mammals during the Mesozoic, just not the eggless and nippled ones as in other regions but Monotremes and their relatives. Some Mutituberculates' fossils, a kinda eggless mammals but diverged before nipples evolved, are also found Australia.

[@nivumdeterraartemisiae275]

Also South America as an island before the Great American Interchange might be worth mentioning in this Island series especially since South America was first colonized by African animals and later by Eurasian-North American ones

[@mariejanes7207]

Great job! And congrats!

[@TheBlueMuzzy]

You're awesome. This was such a well represented thought exploration.

[@rastan49]

I really like your explanation. Here in Australia, we see and taught Australia is the continent with New Guinea being part of it and obviously Tasmania. This whole Oceania is a continent argument is a strange one, UK is taught this and it's incorrect. Oceania is just a geographical location which Australia is part of. New Zealand isn't really part of Australia as they are on their own submerge continent. But technically only parts of NZ South Island and majority of the North Island sit on the Australian plate.

[@Andrew-cv2uf]

Best comment to the question thank you

[@Jayson_Tatum]

The continents aren't necessarily related to the ecosystem. Continents are defined under geology and geography, whereas ecosystems fall under biology. They shouldn't be compared. The continents are significant, exposed (from the oceans) portions of land correlating with their respective continental plates. The plate tectonics are what separate each "continent". And the plate tectonics aren't really... debatable...

[@mbvoelker8448]

Exactly. You can't simply deny geology and handwave it away because it's inconvenient.

[@xasleyter]

Ancient Lakes feel like a topic that would be perfect for this channel. Most Bodies of water are less than 18,000 years old, there are only 20 that are at least 1 Million years old. The majority are categorized as tectonic (like Lake Baikal) but 2 are Crater lakes, one is Volcanic, and one is Subglacial (Lake Vostok in Antarctica, under 4km of ice). Add in some geographic isolation, they provide some valuable and interesting evolutionary case studies.

[@jasonreed7522]

I'm sure that the subglacial lake in Antartica is beyond facinating as an evolutionary case study, its such an extreme environment and incredibly isolated. (It could even be considered an analog for ice moons like Europa and Enceladus or rouge planets, granted this lake wasn't always isolated beneath several km of ice so it isn't exactly a perfect comparison to these places)

[@hamedmas7742]

well you answered the question by causing more confusion and creating more question 😄 love your videos and their very well made keep your great work

[@RippyLol]

The entire world is a island because they are all surrended by water

[@MrMokokokoloko]

Oceania has always been at war with Eurasia

[@afterimage1993]

I'm so glad I found your KZbin channel through freeriderhd. You should make another track!

[@henrylockhart495]

Let’s go! Time for another great video!!!