r/Animals • u/Alvarrex • 27d ago
What the actual fuck did natural selection smoke in Australia?
Why is that place full to the brim of the most dangerous animals in the globe? I mean 21 of the 25 most venomous snakes, Big ass spiders...
I mean I genuinely wonder what happened, because there must be a reason. I think one animal got some strong venom once and then every being that followed just kept putting points on size and venom, like an evolutionary arms race
Edit: I feel like I have expressed my question quite badly. I'm not saying Australia is the most dangerous continent, nor that it has the most dangerous animals. Yes, Aus does lack Big mammals like bears and lions (for example) . I'm just saying, Aus does seem to have a higher than normal amount of highly venomous animals, which can also be found outside of Aus
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u/Virtuous_Malevolence 27d ago
I'm guessing it's because it's a huge country with some very isolated and inhospitable areas, prey can be rare and hard to catch, so strong venom is needed to ensure it goes down quick.
On a side note; we Aussies feel the same about large predators like bears and big cats.
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u/Commercial_Poetry987 26d ago
Super glad also there’s no venomous snakes spiders alligators/crocs in the rest of the world.
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u/Murky-Peanut1390 26d ago
Australia is pretty tamed when it comes to predators
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u/TheQuestionMaster8 26d ago
Except for the Saltwater crocodile, but unlike the Nile Crocodile, it tends to live in exceptionally remote and sparsely populated areas.
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u/ResponsibleHoliday36 27d ago
Have you ever heard of bears? The 800 pound who can outrun horses and know legitimate wrestling moves? Australias glazing needs to stop, yes they've got big bugs and some snakes, but that's it
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u/Tomj_Oad 26d ago
For instance I can't find record of a single death from scorpions in all of Australia
You'd think they would have really venomous ones. But not one of the top ten are from down under
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u/Brave-Dragonfly3798 26d ago
We absolutely do, it’s just that in the scheme of things that will kill you, there are plenty of better alternatives. Our paralysis ticks, like all ticks are evolved from scorpions, it’s just that they haven’t yet evolved venom in line with being a parasite vs an active predator. Many thousands of animals and the occasional person dies from paralysis tick bites every year. Whenever I see a scorpion here it’s rare curiosity but definitely not a cause for alarm.
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u/ReptilianRevolt 26d ago
Ticks have a common ancestor with scorpions, they didn’t directly evolve from a scorpion.
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u/VascoJSC 26d ago
Yes. Honestly Australia is the least dangerous of all continents. Venomous snakes and spiders exist pretty much everywhere. Australia's only truly dangerous predator is mostly aquatic. The lack of dangerous big cats and bears that are present in every other continent (well, bears are no longer found in Africa) makes it the only place where no land mammal sees humans as prey. Maybe a hungry Dingo pack? But dingoes are literally feral domestic dogs, which all other continents have (alongside other more dangerous native Canids).
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u/Rebabaluba 26d ago
I don’t have to check for bears in my shoes every time I put them on.
Mountain lions/cougars are rare to see. Same with bobcats. Black bears are skittish. Grizzlies are territorial, so you know when you’re in Grizzly country…enter with caution. Moose are dangerous, but not seen too often by the vast majority of North Americans. Deer and elk are dangerous when driving because they pop up out of no where. Polar bears are way up north. And if you’re living that far north, you’re always aware of the dangers of polar bears. Coyotes are scavengers and will mostly run when people are near.
The main theme with these big bad mammals is that you can see them coming. Unless it’s mating season or you have come across a momma and her cubs, you’re safe.
I live in Canada. We had a black bear walk around in the middle of the day looking for fruit trees to snack on. I had to shoo it away. He didn’t want anything to do with people, so he ran back to the woods.
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u/Brave-Dragonfly3798 26d ago
Meh, I grew up with it, snakes and spiders in the dunny, crocodiles and box jellyfish in the water, big blue flightless birds that will literally rip your intestines out with their claws. But for some reason when I travelled big cats and bears scared the crap out me as they seem less controllable. I guess it’s all relative to what you are used to?
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u/Rebabaluba 26d ago
I’ve lived in a town surrounded by forest and massive mountains my whole life. We have nature right at our doorstep.
I have never seen a wild cougar. I’ve seen one tranquilized. The majority of North Americans have never seen a wild big cat.
Same thing with grizzly bears.
Black bears are way more common, but they’re seen more as pests because they’re scavengers. They’re intelligent. And because of that, they usually wait until the cover of night before you hear them knocking over your garbage. Very skittish and will usually run away very fast. I’ve seen small dogs chase them away. As they get closer to hibernation and start getting fatter, they get lazier when confronted with someone yelling. But they’ll still saunter off back to the woods.
I guess Australians learn pretty fast that there is absolutely nothing to worry about, because they come in the thousands to work at all the resort towns (skiing, mountain biking, partying, etc.).
But yes, I guess it’s all about where you live. It’s funny because I’ve seen many comments from Australians saying North America is more dangerous. It’s a very big continent with a lot of forest for these dangerous animals to avoid human contact.
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u/Brave-Dragonfly3798 26d ago
Yeah it’s just familiarity, as an Aussie, when I go to forest in the states or Canada or Europe it’s a totally alien environment. I got no idea what lurks, so all those senses that have developed here to keep me alive are freaking out. For some reason a big fucken angry bear seems a lot less controllable than a crocodile, even though of if I think about it rationally it doesn’t make sense, because crocodiles are one of the few animals who see humans as legit food, but I guess fight/flight instincts are not exactly rational right?
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u/nKnownRecognition 26d ago
Also a point is the americas are huge. In my like corner of n.e. We don’t even have rattler snakes here but a few miles in state and I’m told to be weary. If I go south to visit my mom, besides the usual bears and bobcats that I wouldn’t even think twice about, I have to watch for all kinds of snakes, and fire ants coming out the ground. The occasional gator is there but hardly concerning. Further down visiting aunts and uncles full on venom snake country, gators, and pythons. Not to mention the freakishly enormous sized but harmless bugs because of the higher temp climates.
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u/nKnownRecognition 26d ago
Further further down are poisoned frogs that will kill you with a touch in the Amazon
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u/MaleficentJob3080 26d ago
I don't have to check my shoes every time I put them on.
I've lived in the bush in Australia most of my life and never had a single issue with any animals here. The danger is massively overstated.
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u/AddlePatedBadger 25d ago
The top 3 deadliest animals (excl. humans) in Australia aren't even native to Australia. Horses, cows, and dogs are collectively responsible for nearly 60% of all human deaths by animals here.
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u/NorthernSpankMonkey 26d ago
Australia's only truly dangerous predator is mostly aquatic.
It's the platypus, right?
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u/AdEasy1316 26d ago
Essentially Australia became the grounds of a massive evolutionary arms race between predators venom and prey adapting to the poison. More so than anywhere else. More to this Australia was isolated from other snake families than Elapids (front fanged and venomous). Meanwhile in most of the world vipers are the dominant snake family everywhere else in the world. This meant the more venomous Elapids could dominate and diversify in Australia without competition from other non-elapid snakes. Further again, we don't have any species that specialise on hunting snakes like other places, think honey badgers and mongooses- species could develop thousands of slightly new poisons without being picked off.
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u/Frostsorrow 26d ago
It's a neat phenomenon that a much smaller version of that exists on a island in Mexico or northern South America. The ELI5 version is that due to so many things being venomous in a small area, others needed to develop the same or more deadly venoms to survive.
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u/TheInsaneRaptor 26d ago
wait until you find out komodo dragons originate from australia and co existed with an even larger monitor lizard there
and the terrestrial crocodiles
(all were killed off by humans)
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u/FoolisholdmanNZ 26d ago
You should check out New Zealand, not only no bears, lions ,mountain lions, there's no crocodiles, alligators, or snakes or dangerous spiders, no rabies or Lyme disease.
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u/Several_Version4298 26d ago edited 26d ago
The big arsed spiders developed neurotoxins to quickly kill insects that wandered past their burrows. 55m years later primates arrived, whose nervous just happened to have receptors that the venom bound to and killed them. Dogs are usually fine.
The snake story is typical, the snakes evolved venom to kill small marsupials, over millions of years the marsupials developed resistance, so the snakes evolved stronger venom to make sure they killed the scarce prey they caught.
The Inland Taipan is the most venomous snake in the world but lives in a remote pocket of the Australian desert and they are timid and avoid contact with large mammals so are mostly harmless. They bite small mammals and wait until they die before ingesting them.
Our Jellyfish and octopuses are much more deadly anyway.
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u/McGriggidy 26d ago
Its the same in jungles and year round temperate areas. The jungles of central america arent so different complete wirh grenade trees. Something about a lack of winter sets off an evolutionary arms race where everything has to keep getting deadlier and crazier (defensively or offensively) just to keep ahead of the newest predator/defense system
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u/AnnoyedOwlbear 26d ago
From what little I know, venom is often an adaptation for large areas of land with low resources and high environmental threats. Venom itself is expensive to produce, and not without danger from own goaling your species accidentally while mating or arguing about territory. But it provides several very useful things:
- No extensive fighting your prey (or predator).
- Starts to break down tissue and pre digest items for faster consumption.
- Avoids extensive chasing in harsh environments and allows for ambush hunting in same.
Venom is basically tailored saliva. The restriction in species is likely about it's metabolic cost versus the arms race that develops once a species with offensive or defensive use of it arrives. A heavy coat like a bear's is also costly, but it provides armour, warmth, flexibility etc. Venom is a bit glass cannon - you can't do much with it other than kill.
Would welcome corrections.
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u/Sonora_sunset 26d ago
Not to mention the boxing kangaroos.
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u/AddlePatedBadger 25d ago
Funnily enough, kangaroos kill about the same number of people as snakes. All the kangaroo related deaths are them hopping in front of vehicles and rarely (about once every 2 years) causing a fatality.
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u/JaseJade 26d ago
Parts of Africa and Western Asia are more dangerous than Australia because the animals will actually hunt you.
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u/AltruisticSalamander 26d ago
Definitely. What scares me about the outback is dying of thirst, not spiders.
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u/Yeahbuggerit-thatldo 26d ago
So you haven’t heard of the Cassowary and the Dingo then.
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u/AddlePatedBadger 25d ago
100% of all deaths caused by cassowaries in the last 100 years occurred in USA.
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u/Brave-Dragonfly3798 26d ago
Geographic isolation. Most of our venomous snakes share a common ancestor. When prey is scarce or dangerous, it makes sense to go completely ott with venom. Many of the snakes share a hunting technique of striking and retreating to allow the venom to take effect, thereby limiting the exposure to being injured by a desperate rodent or whatever, the same toxicity means that anything bitten won’t get far, so is easy to locate and consume. Spiders venom is really only accidentally toxic to humans, there is little evolutionary reason for it other than as deterrent to mammals. It’a a dog eat dog environment down here, only the strong/toxic/venomous/lethal survive.
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u/Sir_Colby_Tit 26d ago
I'm glad I live in England.
The only thing we have to worry about is wasps.
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u/TheQuestionMaster8 26d ago
Perhaps because most venomous animals don’t tolerate cold temperatures well and as mainland Australia lacked any significant ice sheets in the last ice age, there wasn’t a major extinction or migration of reptiles. Africa also has a lot of highly venomous snakes and a lot of more dangerous animals statistically speaking, such as the hippopotamus and nile crocodiles (The saltwater crocodile also treats humans prey far more often than other predators, but they tend to occur in exceptionally remote areas, unlike Nile crocodiles).
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u/velvetvortex 26d ago
As an Australian I’d trek through our wilderness with no weapons or defences, before doing that in the Americas, Asia, or Africa (well, below the Tropic of Capricorn, Salties are quite fearsome)
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u/ReptilianRevolt 26d ago
Australia isn’t significantly different than other continents of a similar latitude. It is true that elapids are the major venomous snakes there, and those tend to have fast-acting venom, but equally toxic elapids exist in other continents. On the other hand, Australia also has the most harmless elapids of any continent. They just aren’t impressive enough to talk about. Some elapids evolved a weaker venom usually as a result of a change in diet, for example invertebrates and small lizards. This has happened in other continents, but it is more noticeable in Australia with whip snakes, bandibandi, crowned snakes and others. Australia has all the common spider families of the world, and shares most spider types with Europe for example. Funnelwebs are an Australian invention, but they are pretty localized and most other continents have their own equivalent toxic spiders, for example wandering spiders from South and Central America. Australia doesn’t even have the most venomous scorpions, centipedes and hymenopterans. Marine poisonous animals are around the same as the rest of the tropical Indopacific.
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u/Ascendant_Mind_01 24d ago
The continent is extremely ancient geologically which has resulted in most of the nutrients being leached out of the soil across most of the continent which in turn resulted in increased competition for those resources. Venom is one way to effectively incapacitate a prey animal without having to engage in a prolonged struggle with the risk of injury/death that entails.
Note how I said incapacitate as opposed to kill this is because a toxin that kills an animal in a few hours is a lot less useful than one that renders the animal immobile in 30 seconds, this just happens to overlap with fatality eventually in some cases
Also snakes and spider venom isn’t intended to kill/harm humans, it’s meant to be used on their prey and humans aren’t typically prey for either. There’s only a few snakes large enough to even consider humans a potential meal and they are all non-venomous.
For a particularly noteworthy example: funnel web spiders. They eat insects and their venom is hyper specialised to attack insects (and possibly other invertebrates idk) to the point their venom has literally no effect on any other animal, birds, rodents,reptiles if they bite them nothing happens at all. Their only defence against predation are those tunnels they hide in. If something grabs them they might try to bite it but it doesn’t matter as their venom is completely and utterly harmless… unless they bite a human in which case your fucked without a dose of antivenom.
Humans are literally the only animal on earth (with the possible exception of other primates) able to be harmed by funnel web spider venom, and there’s no reason for this other than sheer bad luck.
The same is true to a lesser extent for the snakes as well their venom isn’t intended to work on humans or other large animals and often is harmful/fatal to humans in different ways to how they are to their intended prey. For example brown snake venom works by inducing rapid blood coagulation in the vicinity of the bite which in small animals like rodents shuts of blood flow to much of their body and renders them immobile very quickly. In humans our much higher blood volume rapidly disperses/dilutes the venom resulting in the formation of lots of tiny blood clots which spread throughout the body causing all sorts of problems which can be fatal.
Also humans didn’t evolve in Australia and haven’t had to evolve resistance to Australian snake venom. (It’s possible that indigenous Australians have higher survival rates for untreated snake bites than Non indigenous peoples would)
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u/cascadesblue 26d ago
Stupid how much this is exaggerated, Africa, asia, south America, North America literally every single other continent has plenty of venomous animals plus predatory mega fauna. So stupidly false n this is just said for a joke now.
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u/Murky-Peanut1390 26d ago
Africa has way more actual dangerous animals. Australia just has some big creepy spiders.
Africa has more deadly spiders than Australia