Would humankind remain the dominant species in a world with twice as big animals?

Question

So, a little bit of pseudo backstory first.

Imagine mother nature would be some godly being, that actually exists. Somewhere. In spiritual form.

Now imagine humankind would be a big thorn in her eye, as we've ruined the ecosystem to an unrecoverable amount. (Yes, I'm talking about nowadays) She wants to take countermeasures. So, in order for nature to fix itself, she transforms every animal to a twice as big being. Well, actually it's 2 times the height, 2 times the length and 2 times the width, resulting in 8 times the size all in all. The physical abilities scale accordingly of course.

The transformation of all animals (or brain containing living beings, if you like so), except humankind of course, happens worldwide at the same time and needs only a minute or so and is permanently. Now imagine there would be enough food for them. It is a slightly fictional version of our earth after all and, well, mother nature sure wants to keep her children alive.

Yes, I'm talking about our very earth, with everything as close to real life as possible, with the exceptions mentioned above.

To my question: Would humankind with the help of modern technology be able to remain the dominant species of the world in this scenario or would we be replaced by animals at some point?

(Question inspired by the raptor-theory of Jurassic Park III)

Answer 1

Unquestionably Yes.

Without a doubt Homo Sapiens is the most adaptable species on Mother Nature.

Evolution

Through the last 5 million years Homo Sapiens (latin: wise man) has toughed it out through (geologically) swift climate change, near extinction, and unbridled warfare. Unlike our cousins in the Homo Genus, we've adapted at every single turn or died off. As glaciation swept back and forth throughout Europe wiping out Homo Neanderthalensis (and potentially Homo Erectus), we survived.

If the Toba catastrophe theory holds true, then 70,000 years ago Mother Nature's toying with the Toba Supervolcano failed to kill us. Yes we were reduced to 3-10,000; but like every other catastrophe and change in climate in the previous 5 million years, we persevered.

As warm temperatures broke the spine of the last Ice Age, we swept forth. Within a mere 70,000 years we populated every unfrozen continent, learning to adapt to nearly every imaginable biome on earth. Desert, Ice, Tundra, Jungle? Nothing stopped our advance. Even the great pacific ocean couldn't hold back the ancient polynesians!

Civilization

Eventually we settled down, and began to build civilization itself. We mastered stone and mud, then copper, followed by iron. We learned engineering, astronomy, mathematics, and language. We passed the knowledge we learned to our descendants, first through oral tales, then through the precision of written language. We learned how to weather any storm, how to hunt, trap, or tame any beast. Eventually we learned to question our existence and environment. Such philosophy developed into inquiry, then science. Soon we learned how to break down Mother Nature into her constituent parts. All of a sudden, the unknown failed to hold us back. We created gunpowder, industry, and slavery. We learned, through revolt and diplomacy, to never underestimate the human spirit under oppression. We created guns and rifles, chemical weapons, and primitive bioweapons (small pox rags against Native Americans). Then we discovered nuclear science and rocketry. We developed the nuclear weapon and rockets. We extended our reach beyond Mother Nature's Bosom. Then we learned to fear our own existence. We learned to fear how easily we can wipe ourselves out; but, as with any inquiry, we learned how well we may endure such apocalyptic scenarios. Then in (not so) secret, we began to prepare contingency plans against such doomsday scenarios. We even included contingencies against the most far fetched of scenarios!

The Transformation

Every single animal on Mother Nature (save Homo Sapiens) has grown 8x larger. We'll take a beating initially for sure; but, we've prepared for far worse. We have tasers, pesticides, and floodlights. We have guns and walls, electric fences and ultrasonic weapons. We have airplanes and aircraft carriers. We have rockets and satellites. We have bioweapons and chemical weapons. And in the event where all bets are off, we have tens of thousands of nuclear weapons.

[Mother Nature] wants to take countermeasures.

Please. She's in for a rude awakening.

Answer 2

Oops. Turns out She helps us more than a little.

Most of our biggest hassles since learning to make cities (other than each other) have been vermin related. If rodents need bigger holes to get into our granaries and houses it's easier to stop them and much easier to spot the intrusion. The same goes to mosquitoes, roaches and ants.

The immediate concern wold be pets. We'd have to feed them much much more. Fortunately we'll have enough livestock to cover it once we adjust, but in the transition some large dogs and cats might consider alternative food sources. Bobcats (something like a 2x housecat) have been known to attack children, and feral dogs are sometimes problems.

But guns. Our armies certainly aren't in any danger from animals of any size. A tank is still not going to be bothered. A helicopter is still faster. A rifle can still hurt probably kill from farther away than most animals notice.

If bees fail to work since you aren't changing flowers that might be bad, but some of our staple foods work through wind pollination so we're still not in trouble.

Answer 3

Homo has never been the biggest player on the court along its evolution. It has however become dominant. Just as an example, Mammoths and Cave Bears, bigger than contemporary men, are extinct because of men.

Homo has become dominant thanks to its intelligence and its great ability in manipulating its surrounding environment, to an extent which has no equals among other animals.

This neglecting the square-cube law, which would make any scaled animal unable to move or simply stand.

Answer 4

Even without humans as part of the equation, nature itself is headed for destruction. Unless plants (or at least their flowers) get a commensurate size increase, pollination is going to be difficult or impossible for many species. Lots of flowers are perfectly sized for a particular bee or hummingbird to pollinate them as it collects nectar. If the animals get bigger but the flowers stay the same size, that arrangement gets significantly disrupted. Eventually that will cascade through the food chain, leaving animals without enough to eat. That includes humans, since many of our important food crops are pollinated by bees.

Answer 5

Are animals that are 2x bigger actually more dangerous? (not really) This analysis assumes that all the organs of the animals are scaled evenly in every direction.

There is something called the square cube law. There are many good things that grow with the square of the scale like muscle strength (which is proportional to the cross section area of the muscle) so 2x in each dimension is 4x strength.

There are many bad things that grow with the cube of size like weight which is proportional to the volume of the creature. So 2x in each dimension is 8x weight. Since the creature is carrying 8x the weight it must consume 8x the calories to not starve. Thus the required strength of the lungs and heart, which now must supply oxygen to 8x muscle and push 8x the blood volume, must be 2x higher.

Assuming that running speed is proportional to strength or weight we would expect large creatures to be twice as slow.

A larger creature has a harder time with stealth.

What does this mean

• Some species will die out.

Some species would no longer fit in their ecological niches, bees would be to large to drink pollen from flowers monkeys could no longer climb trees water striders would no longer walk on the surface of the water. Some could not consume enough calories. Cows eat most of the day to get enough calories, there is not time for them to eat 8x more. They would either have to switch to a more calorie dense food or starve.

• The large animals would be highly vulnerable to firearms

The creatures are very large targets that are significantly slower than the ones we have today. They have 2x higher blood pressure so they will bleed out much faster if wounded. They are huge targets and will have trouble sneaking up on anything. They must eat much more so they cannot afford to stalk or wait long they must attack.

• They would be much more deadly at close range.

A giant lion would be capable of impressive destruction, but if a lion reaches you, you are dead whether it is giant or normal.

Answer 6

Considering the Earth used to have such animals, and its quite likely humans helped kill them all off, I'd go with yes.

The Holocene extinction is mainly caused by human activity. Extinction of animals, plants, and other organisms caused by human actions may go as far back as the late Pleistocene, over 12,000 years ago. There is a correlation between megafaunal extinction and the arrival of humans, and human population growth, most prominently in the past two centuries, is regarded as one of the underlying causes of extinction.

Answer 7

Throughout human history, other animals being larger than humans hasn't stopped humans from spreading and reproducing. I can't imagine a case where bigger other stuff would be more of a problem.

Keep in mind that while humans may not have the collective goal to make life better for other animals, humans don't have a generally antagonistic relationship with them. That is, we're not at war with the dogs, or whatever.

Most animals generally ignore humans, and humans generally ignore most animals. There's birds, rats, rabbits, etc. all around us, and most people ignore most of these animals.

There's billions-trillions of ants/flies/bugs that just do their thing, regardless of whether there's a human nearby. They wouldn't become more dangerous toward humans if they were suddenly huge.

In stories, one trope that writers use to characterize nature and animals is that they can be inherently chaotic. More animalistic nature does not make these animals more scary. Hippos are already dangerous. Hippos twice as large would be equally advised to avoid. Ants are already a nuance. Ants twice as large would be also a nuance, but not more spooky or dangerous.

What makes animals scary is when you strip away that chaotic nature of them. The Birds, the short story, was terrifying because there was nothing chaotic about it. The birds acted with malice, intent, and coordination. Dogs live in our homes, and occasionally dogs will freak out, or get rabies, and bite someone. But we still have dogs living and sleeping with us, and it's not scary. What if you take away the chaos? What if all dogs suddenly, and at once, attacked their owners?

She wants to take countermeasures.

If she wants to take effective countermeasures, she should do something she hasn't already been doing. Animals already fly, have sharper fangs, have more dangerous poison, have nastier bite, are more resilient to nature, are better swimmers, are bigger, are more numerous, etc.

What animals aren't, is collectively focused and coordinated. A pack of dogs can chase down game for a meal. Can a pack of dogs build a fence, have one rancher manage the game, then spread out and have the rest of the pack do other tasks?

Humans didn't become dominate by out-naturing nature at nature's game. Let others be faster, stronger, bigger, more numerous.

Humans became dominate by refusing to play the nature game at all. Making animals more nature-y, or more physically large, will be of almost no consequence.

Answer 8

Mother nature got it wrong: Instead of making the animals bigger she should've made all humans bigger.

The bigger the animal (including humans) the more ressources (space, food, ...) they need. If one can assume that body mass is proportional to the energy consumption that means you'll need 8 times more food. But where should that come from? A lot of humankind already suffers from undernourishment / starvation (~10%).

The technical term for this effect is overpopulation and it will become a huge issue. As soon as that happens there will likely be conflicts (from the point-of-view of mother nature: hopefully these conflicts will turn into wars, big wars).

The bad news is that bigger humans will need some time to figure out how to put their bigger fingers on the triggers of guns, fit their body into tanks, hit the right key on the keyboard to launch nuclear missiles, ... but as soon as humans figure out how to work around these obstacles they will start reducing their population themself and mother nature and the animals can watch the fireworks (probably better to do that from a safe distance when they find out how to launch the nuclear missiles).

Answer 9

My answer is more brief (and less scientific) than other answers, but I think that humans aren't the dominant species anyway. There are quite a few animals that are larger than humans, e.g. Gorillas, Lions, etc. we still kill them with our technology. If we did not have technology, we would not be able to do this, rather we would use our superior intellect to evade predators. So we would still continue to kill animals that are bigger than us. Size would continue to be irrelevant.

Answer 10

There are other things to consider, here. For instance, if everything doubles in size, then I would suspect that consumption would increase also.

One thing to consider; if you were to make bees and other pollinators twice the size, then the usual flowers may not be able to sustain them. This would lead to competition and possibly an extinction event amongst them, in turn leading to a reduction in pollination and, ultimately, a massive reduction, due to starvation and war, of the human race.

Presently, possibly one of the main things keeping us alive, today, are bees. As Maurice Maeterlinck stated in The Life of the Bee (no - not Einstein), and Darwin in his Origin of Species (se also Quora), life would be pretty interesting without them for a very short space of time.

There are ways around this, obviously, but the main point is mass eradication. Most of the world depends on the production of pollinated crops. Smaller communities could depend on other crops, such as tuber vegetables and other plants that propagate through other forms of propagation. But, remember the various potato famines!

Once the cattle double in size, though, I still bet you won't be able to get a decent steak from a supermarket...