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Depends on the Environment The big issue to overcome with gliding is the initial height. Gliding is defined as horizontal movement through the air without any significant gain in elevation beyond maybe an initial jump (like in flying fishes and flying squid), where the rate of horizontal movement is greater than the falling speed due to gravity. Thus, ...


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H.G. Well's novel Time Machine. Made into a movie. In the movie, some humans went down into bomb shelters and learned to survive there, while others stayed up top, and they evolved to be pretty different


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Somebody sed using the fat as fuel; don't forget whales - fat used for lamps, and it used to be a component in WD-40. There's one more: If I park a bear in my front yard, I expect the number of robberies to markedly plummet. Foo you say, but Guard dogs... Drug sniffing dogs. Hunting should include hawking; not really mega? I don't know if any hawkers have ...


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I like the other answers. Buffalo were shot by the thousands from trains that were just passing through, just to see if you could bring down a buffalo in one shot. Many buffalo hunters only took the tongues. The herds went from millions to thousands in just a few years. The majority of large predators were killed in Utah as it was rapidly settled and the ...


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We can try and do this in reverse. First stop them from interbreeding, then have them evolve differently (sympatric speciation). We cheat, introducing devilgrass. This is a very nourishing, sturdy perennial plant that is almost ubiquitous (an infestant, actually); it was rarely used as food since it's also poisonous, and requires special cooking to be ...


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Anthropologically speaking, when humans have come across an animal that had no useful purpose to us, and that was a threat to us in some way, directly or indirectly, we have hunted that animal to extinction if at all possible. It's what we do. One has only to look at the British Isles for proof of that; bears, wolves and large cats were all extinct on the ...


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Without evolutionary pressure, the answer is never. Evolutionary change comes from random mutations plus an environmental factor that selects for that change. If random mutations happen within individual nobles and peasants, but nature doesn't effectively favor these individuals, then these mutations won't become "norm" in the population. If no large changes ...


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A common definition of species is "a group that interbreeds in the wild to produce viable offspring." If two groups do not meet in the wild, or if they meet in the wild but choose not to mate, then they are different species even if they can produce viable offspring in captivity. There are numerous examples of such divisions. For the cases where the groups ...


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This can't really be answered in any definitive terms as it relies way to much on a ton of specific factors. Speciation in the past happened by selective pressure from environmental conditions over long periods of time. This isn't as applicable in modern or future civilizations where we have more control over our local environment. Modern humans have been ...


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The factor you're looking for isn't time. That sounds funny, doesn't it? But it's true. You're looking for a divergence in the human gene pool to the point where it would be incapable of reproducing with the previous point. And to that end, time is one factor among many, and not even the most important one. There are species on this planet which have ...


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Transportation and Construction A rule of thumb is humans mostly domesticate animals to do things we can't. Horses run much faster than we can. Cows turn grass into edible food (either as milk or meat). Dogs can smell and hear things we can't. Cats catch small rodents. The tricky thing about megafauna is it's difficult to domesticate them because they need ...


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Food for a domesticated species which assists humanity with hunting. Dogs can safely eat food which would kill humans. They can also be used as hunting aids. We don't want the dogs to eat the good animals, and the herbivores in question are too large for dogs to kill, so humans kill your megafauna to provide sustenance to their hunting companions.


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It existed! The larger species could only glide, and easily surpass your minimum size.


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The answer is a qualified yes. Adaptions would certainly help an animal survive fire, but only to a point. Big animals can get overheated very quickly so the problem is more one of temperature control than fire resistance. If the soil was loose or sandy it might pay for the animal to dig itself a hole or at least a hollow in which to lay so that only the ...


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TL;DR: The materials in their bodies are great for uses other than consumption. Here are their uses: Furniture. Due to their size, they will by necessity have large bones. The size of the bones would make them useful for making furniture. Weaponry. The abundance of useful bones will also make it really easy to make bone clubs and hammers. These will ...


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Bones, Sinews, leather and Glue. No matter what the creature, if it's large, you can make use of it. Megafauna means big. There is a lot of material there, even if you aren't gonna eat it. So the bones. Long bones will provide a building material of various uses, be it a tent support, a handle for a club or axe, or you could use the ribs to make armor. ...


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Yes it is possible. Such a situation might be encouraged where the environment was dark. In this way the prey would not be able to see the predator coming. If the creature could echo locate its prey it would then be able to fall on it without being detected. Another encouraging factor would be a fairly open understory without lots of crisscrossing branches ...


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Ecological succession. The Herd rules this world. Where the herd has passed, nothing remains. Thorns and toxins which dissuade lesser herbivores are eaten with disregard. Trees are uprooted and bark stripped. Roots are pulled from the ground. The earth is torn and trampled. The Herd is like a fire, travelling a destructive and voracious circuit around ...


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It is important to be very clear about the definition of the word species in this question. Many definitions count separated groups of animals that have evolved different characteristics (and either do not meet each other or do not choose to breed if they do) as different species for example polar bears and brown bears, however by other definitions polar ...


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The normal process of speciation tends to require: A relatively small population. ..that is isolated from interaction with surrounding populations ..that has significant divergent selection mechanisms acting on it. Google "punctuated equilibrium" evolution including the quotes. Look at dogs. We've had dogs with us for tens of thousands of years, and have ...


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Competition The animals tend to eat whatever humans are growing in their fields. It's not fun to lose the year's harvest and have your family starve because of some quadrupede bugger, so you off them on sight. Fences would normally do to keep animals away from the crops, but this is megafauna we're talking about. So hunting is the next most viable option.


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Competition If the megafauna eats plants that (much more tasty) domesticated herbivores eat, then it's a safe bet that the megafauna will be either driven off the land or killed.


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Reputation. If the creature is dangerous, killing it might accomplish something valuable to an individual in the community, for example marking the moment a child becomes an adult, or to be considered a fully fledged hunter.


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With any animal, there's more than just meat and furs, here is a list of uses of general animals Food Clothing Work/Transport Science Medicine Hunting Pets Sport Art Many of these are removed by your conditions, Furs can still be used even if they do not look very nice Medicine - Not 100% sure how this applies, guess it depends on the type of animal. ...


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So why would people want to hunt animals that they can’t use for food, and don’t have pretty furs or ivory? As long as an animal is seen as a menace, it will be hunted down. And, well, all animals defend their territory if needed. You don't eat a bear, but if you wander around its cubs be sure it will pat you in the face hard with his cute "little" paws. ...


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It depends on your definition of "cannot breed". If it is completely impossible to have a hybrid (like human and chimps) - then no. It needs a statistical miracle or genetic engineering to make it happen. If species can have a hybrid, but it is infertile - then (partially) yes it is theoretically possible. For example, mules are infertile, but there are ...


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Absolutely, Insect farms exist for protein and they are very low-tech, I'd suggest grasshoppers or crickets would be a good candidate. A pile of reed matting kept suitably moist would be a great home, and dinner, for grasshoppers. In order to breed the same species all year round, you will need very large indoor (or underground) spaces, a cave complex, or ...


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Yes, it is possible. There is a known event where two separate specialized species of fish inhabited some African lake, one was pelagic and other benthic, they did not cross-bred due to pre-zygotal isolation (not trying to mate each other even if biologically capable). But then, pollution to the lake led to disruption of their habitat, and they merged into ...


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to attack prey moving on the forest floor, by jumping and silently gliding with relatively little horizontal gain it is still able to safely and silently land on the back of its prey and kill it with a swift and strong bite (think of a leopard) Gliding with very little horizontal gain is probably better called diving. In my understanding gliding is when ...


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Ruddy ducks! For one animal species, the answer is well in excess of ten million years, and that's a minimum. It might be as much as 50 million years during which it didn't happen. When the Atlantic Ocean opened, it separated two populations of ducks. One evolved into the North American Ruddy Duck, the other into the European White-headed duck. They have ...


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Yes, but... This would be a pack hunting technique rather than for solo hunting. If you're happy to have your dragons hunt in packs then it's entirely valid. For a solo hunter it may be almost impossible to maintain more than a very short drive. Setting the fires too early may close off the path to the cliff, setting the fires too late would allow the ...


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I do not believe that dragons would normally resort to the need for game driving. Keep in mind why humans needed to resort to game driving to get their food, we were slower than most animals so we had to resort to traps and teamwork to kill them to get food quickly (before we made weapons that allowed us to do so at range). On the other hand, traditionally ...


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I don't see any reason not, specifically. I can't think of any cases of biomagnification in the terrestrial realm off the top of my head, but I bet there are some. The reason you hear more about biomagification in aquatic ecosystems is that aquatic ecosystems tend to be four or five links long because most of the base of the food chain is plankton and most ...


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. Meet Euchambersia. It's a type of proto-mammal called a therocephalian from the late Permian of South Africa, just before the Great Dying. It's about the size of a small dog. And it's most likely venomous. There's been some debate over whether or not it was, but most research on the subject has concluded that venom at the very least the most likely ...


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A method of controling the osmolarity of their bodies One of the big challenges in moving on land is dealing with osmotic balance (how salty the internal environment of the cells in the body is). Most organisms have internal cell contents that are quite salty, but maintaining a consistent salinity level is necessary for survival and proper metabolism. A ...


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They get it from their food You don't really need a booze-bladder. A lot of animals pick up toxins from their food, and end up storing them in their body. Some animals do this unintentionally, like sea lampreys and poisonous heavy metals, and some do it intentionally, like poison dart frogs and monach butterflies. The pen-tailed tree shrew (Ptilocercus ...


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Horns and Tusks The extinct mylagaulid rodents evolved very prominent horns, which are thought to have been used for defense against predators and are angled such that they can poke predators by flicking the head while the animal is in the burrow. Lagomorphs could develop something similar, which would also be useful in mating disputes. Tusks are another ...


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The primary issue I can see is that insect antennae aren't a body covering in the same way that mammalian hair, reptile/fish scales, or bird feathers are. They're a distinct pair of legs that have been twisted and modified into a pair of sensory organs, in the same way that four pairs of legs have been crammed into the head to form the maxillae, mandibles, ...


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The increase in nerve tissue would imply a substantial increase in brain size. Their brains could support two antennae. Now, they have millions, perhaps, or hundreds of thousands, maybe. Their brains would need to increase proportionally to process the new information. The antennae and nerve tissue would need the ability to regrow if part of it was ...


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TL;DR: Based on the genetic progression we have observed in ourselves and other species thus far, at least 300,000 years and possibly more than 700,000 years of strict genetic segregation would be required for humans to see an irreconcilable genetic difference between genetically-segregated humans, heralding the creation of a truly distinct species of humans....


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Human gestation periods were originally keyed, I imagine, to environmental factors, with an optimal strategy of conception in late spring, brooding through the winter months, and birth in early spring. This is a typical pattern for creatures on an estrous cycle, at any rate, because it gives offspring the most favorable conditions for survival in their ...


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In reality: not in a time scale that is compatible with any sort of society we're familiar with. Others have covered this well, I have nothing to add on that. There are workarounds for this, for example you could invoke divine favor to keep this society going for a Really Long Time. As long as you're not trying to maintain real-world astrophysics and ...


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How well would it function as a smelling organ? Antennae can be used for a variety of sensory purposes, and scent-detecting antennae are already common in the world today. Solitary insects often find mates through the use of pheromones, among other methods, and eusocial insects rely on the use of dozens of different pheromones in order to organize and ...


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The only problems I can foresee with this are the duplication, location, and structure. The duplication part is kind of questionable since limbs or body parts do not simply duplicate. This is especially true of complex sensory organs like an antenna. The location is at the BACK of the head. Imagine trying to smell your lunch if your nose was there! The ...


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It works well Smell is more dependent on the number of olfactory receptors in the nose than on its size or shape. For instance, dogs have nostrils about the same size as humans', but they have far better senses of smell because they have more cells dedicated to smelling. If your insects line these "hairs" with olfactory receptor "branches", they can ...


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L.Dutch's answer would lead to a predictable result--less food, longer gestation. Instead, there is a trace element the body needs that is in limited supply. Shortages are common enough that the body evolved to limit fetal growth to the supply of this trace element rather than suffer deficiency problems from it's lack. Required trace elements have been ...


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The speed of the "speciacion" depends on both mutation pressure, selection pressure and the quality of the separation between populations. As per your scheme, peasant population is not insulated by definition. Medieval science and technology (and human nature in general) imply that no actual control of gene transfer can be implemented. In the wild, it takes ...


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Pockets of humanity have been cut off from contact from others for thousands of years at a time and this physical separation between populations did not result in speciation. The administrative separation within your populations would not have a more marked effect than an actual physical separation.


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In medieval terms.. the children of peasants and nobles always fail to thrive; you don't need any more detail than that. It could be caused by the noble females, being closely related, all carrying an incredibly rare mitochondrial mutation x, being a mitochondrial mutation it is passed unchanged to all of their offspring. Some noble males carry an equally ...


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This is semi-science based and more in the spirit of "speaking burning thing". You need a tree that have leaves which are producing a lot of oxygen when they mature. Which is near the same time the seeds are ready to ripe. Now the trees are seeding themself on altitudes where oxygen is scarce due to gravity. But the threes are located in pockets where ...


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