25
$\begingroup$

Assuming that as a species, we do ourselves in, not through war but through environmental neglect and overpopulation, what species will benefit most from the effect we have had on the planet during our brief time at the top of the food chain?

I am writing a short story about an alien world where the inhabitants hold a predecessor species in high respect for all the treasures left behind before they disappeared long before the current sentient age. At the end of the story, I want the reveal to be that the planet is Earth and humanity is the predecessor species whose garbage and relics have helped the current race thrive.

I've considered rats because they already thrive on what we discard, and dogs because I would love to see a more noble species take the throne after us. But I am sure that there are other candidate species which might lead the story into wonderful new realms.

My criteria for "benefits most" is based on how much what we would leave behind might shorten the species's evolutionary journey to sentience.

$\endgroup$
  • 2
    $\begingroup$ Required reading (if you can find it): Breed to Come. (You, ahem, might be able to find a copy online. That's how I first read it. I now own a rare and expensive instance of the hardcover with the beautiful gold illustration.) $\endgroup$ – Matthew May 17 at 20:43
  • 1
    $\begingroup$ I've heard/read it said that one of the best candidates for replacing humanity as a sentient tool using species is the racoon! $\endgroup$ – Grimm The Opiner May 18 at 7:11
  • 1
    $\begingroup$ This is a bit of an extreme case so I wouldn't post it as an answer, but it reminds me of how Pikmin 1 and Pikmin 2 explicitly have 1 cm tall space men come and collect Earth trash and bring it back home as treasure. The value of the 'treasure' is very tongue-in-cheek so I would not count it as a serious answer. $\endgroup$ – Zibbobz May 18 at 13:14
  • 4
    $\begingroup$ Why would dogs be "more noble" than rats or humans? They run around killing other animals for fun ( at least semi-domesticated ones do ) ? $\endgroup$ – bytepusher May 18 at 20:59
  • 2
    $\begingroup$ The bigger issue is what we didn't leave behind: accessible fossil fuels. What level of technology do you want your successor civilization to have? $\endgroup$ – chepner May 20 at 17:40

17 Answers 17

19
$\begingroup$

I think some of the creatures that would benefit most from humanity’s existence would have to be the ones we consider to be pests, such as rats, mice, and cockroaches. After all, they thrive off of the waste we leave behind, and we have even allowed them to expand their range much farther than they ever could on their own, as rats stowed away on human ships in ancient times, and are now found on almost every continent.

Birds such as pigeons, crows, and starlings could also be good candidates because they too thrive upon human civilization.

| improve this answer | |
$\endgroup$
  • 1
    $\begingroup$ Great idea! I wonder about rats or roaches still thriving on us generations after mankind is gone, though. It seems like they are thriving on us while we're alive but after we're gone? With the smaller amount of waste being generated because of the pandemic shutdown right now, rats are eating each other. I don't know what's going on with roaches. $\endgroup$ – Jamie Watts May 17 at 20:08
  • 3
    $\begingroup$ I like the general idea, but per @JamieWatts' comment, I think it would need to be something which doesn't depend on the continued existence of humans for whatever benefit it derived from us. (Which... makes me want to suggest horses, but I'm not sure if that would work?) I like the idea, though, that it might be birds. $\endgroup$ – Matthew May 17 at 20:40
  • 5
    $\begingroup$ Roaches are tropical insects and can only survive in non-tropical climates so long as humans are around to heat their homes. Once we're gone, they will quickly die outside their natural habitat. $\endgroup$ – Schwern May 18 at 4:22
  • $\begingroup$ I am not sure they have lived close enough to our technology to be able to adapt it into their life. They have certainly been around humans, but have they experienced our lifestyle and tool use the way domesticated animals have? $\endgroup$ – Justin Thyme the Second May 18 at 12:54
  • 4
    $\begingroup$ They benefit due to humanities waste. If you remove the humans, the benefit quickly goes away and they will die off en masse. There'll no human relics which would benefit rats, crows or cockroaches within a few years. $\endgroup$ – Innovine May 18 at 14:57
28
$\begingroup$

Okay, so I had a long talk with my cat (ginger, of course) about this and came up with a plot.

Humans advance to the point where robots and AI pretty much do everything for us.

Some benevolent human owner trains his AI Alexia to understand meows and operate under meow control.

So cats learn how to operate this AI voice command system and use touch screens.

For some reason (future alien archaeologists found mass human graves with unaccountable cat scratches all over them, and hints in the data base records that humans had become expendable) humans go into decline.

Cats survive by ordering out from the robotic food delivery service called 'Skip the Can Opener'.

Did I mention the great conflagration that enveloped the world, the great Cat and Dog Fight for world domination, because apparently dog owners did the same training?

Only the ginger cats won, owing to their supreme intelligence, cunning, and strategic thinking abilities. The dogs' loyalty to humans did them in.

| improve this answer | |
$\endgroup$
  • 11
    $\begingroup$ It is only fair to share any rep gained from this answer with Ginger. $\endgroup$ – Criggie May 18 at 4:27
  • 2
    $\begingroup$ Reminds me of "Cat" from Red Dwarf. $\endgroup$ – Michael May 18 at 21:44
  • 1
    $\begingroup$ 'The Door Into Summer', Heinlein. $\endgroup$ – Justin Thyme the Second May 18 at 23:56
26
$\begingroup$

Large mammals and fish will benefit most.

Any species which relies on humans: rats, seagulls, pidgeons, roaches; these will all quickly die off outside their natural habitat as their source of food and shelter disappears.

On the evolutionary time scale of hundreds to millions of years necessary to evolve intelligence, assuming natural selection goes that route again, almost none of humanity's treasures will remain. Almost all will have been plowed under, ground up, and disintegrated by life, weather, and other natural processes. Metal will have corroded away. Plastic and concrete will have long since crumbled.

Instead, look at our long scale effects.

  • We wiped out, or brought to the brink of extinction, most of the top level predators.
  • We also wiped out, or domesticated, most herd animals except game animals.
  • We reduced biodiversity.
  • We brought about rapid climate change.
  • We carried species across natural barriers to new territory.
  • We produced a very thin, but very noticeable, layer in the rock strata.
  • We dumped a lot of long-term nuclear waste and heavy metals.

That last one will be one of the last tangible remains of humanity. Plus their long-term warning signs and other projects designed to stand the test of time such as The Clock Of The Long Now.

The changing planet will be left with an ecosystem of scrambled species, reduced diversity, and a dearth of large predators or herd animals.

With the top predator (humanity) gone, adaptable medium sized predators which humans have carried to new territory will fill the niche. Likely felines and canines. Living together. Mass hysteria.

Similarly, without humanity to compete with for territory and food, herd animals will return. Horses, cattle, and elephants.

Finally, without human fishing activity, populations of large sea creatures and fish schools will rebound.

This is currently being played out within the Chernobyl Exclusion Zone, now one of the largest (involuntary) Eurasian wildlife parks. Wildlife is recovering demonstrating that humanity might be worse for the environment than a nuclear disaster.

| improve this answer | |
$\endgroup$
  • 2
    $\begingroup$ Chernobyl isn't particularly healthy for its inhabitants, it's just that you don't see the animals that die from cancer. Otherwise a great basis for an answer (not an actual answer, unfortunately). $\endgroup$ – toolforger May 18 at 5:04
  • 10
    $\begingroup$ @toolforger, animals in the wild mostly don't live long enough to develop cancer: prey animals get eaten, while predators starve (usually after a hunting injury). The only animals that tend to die of old age are large herbivores like elephants that don't have any predators (besides humans). $\endgroup$ – Mark May 18 at 21:57
  • 1
    $\begingroup$ I like this way of thinking. Of your suggestions I would favour elephants, because they can use their trunk to manipulate tools. Using tools was supposedly very beneficial for the evolution of intelligence in humans. (Increased calorie intake, increased rewards for problem solving ability...) $\endgroup$ – craq May 19 at 5:42
  • 1
    $\begingroup$ @Mark yes they do develop cancer. Larger animals less so than small ones. Search for "why don't blue whales don't get cancer", there's even a video on the topic. I do agree that developing cancer will typically get them eaten; still, radioactivity should increase the cancer development rate. $\endgroup$ – toolforger May 19 at 20:10
  • 1
    $\begingroup$ @toolforger Large mammals have returned in abundance to the exclusion zone, in spite of the toxicity. This is the point: humanity is worse than nuclear fallout for large animals. $\endgroup$ – Schwern May 19 at 20:46
15
$\begingroup$

We need an animal that is pretty intelligent already, and who can pick up and use the tools left behind by humanity. Having a flexible diet wouldn't hurt.

I present to you: The Raccoon!

| improve this answer | |
$\endgroup$
  • $\begingroup$ I really, really thought about the raccoon, having experienced first hand their ability to get into camping fridges and their ability to work in groups, one distracting the human while the others get into the car, and so yes they are a good contender. However, do they have the experience with our digital technology the way domesticated animals do? Do they know what a remote control is? When they can use a garage door opener pad to get into the garage, then yes I will vote for them. They have proven they can use our technology. $\endgroup$ – Justin Thyme the Second May 18 at 13:42
  • 1
    $\begingroup$ Still though, I don’t think domesticated animals really understand technology. Sure, maybe it’s possible to train most animals to use basic technology (push button, get treat) but that requires a human to train and set the machine up. I don’t think the trained animal would really be able to use tech anymore than a raccoon $\endgroup$ – Alex May 18 at 22:11
15
$\begingroup$

Some kind of invasive species

What we call "invasive" species, are really species that we humans have moved to new habitats where they thrive. They may thrive because they have no natural predators in the new habitat, or because we've eliminated their predators, or because we've made their prey unnaturally abundant. In other words, we've given them an unfair advantage that will allow them to dominate the new ecosystem. There are lots of these, so you can pick a part of the world and probably find a good candidate.

In North America, my favorite would be wild horses. They'll have a huge range when we're gone, and although they do have predators, I don't think they'll be eaten to extinction. They also have the genes of domesticated horses bred for speed, endurance, and temperament, so they're a little more noble than plain old wild animals.

Another good one might be whitetail deer. They're native to North America but have a much wider range thanks to human activity. Also, as I understand it, they carry a parasite that is fatal to moose, elk, and caribou and (in my state at least) they have forced those species northward and taken more habitat for themselves. It's hard to think of deer as a pest, though, because they're beautiful and delicious.

Some kind of a dog-wolf-coyote hybrid might also be a good choice, and less boring than just going with domesticated dogs. This one is more realistic because it already exists. You have the strength of a wolf, intelligence of a coyote, and courage of a dog. Also if you want different dog breeds to be different castes like in Planet of the Apes, there you go.

I guess wild pigs are also a realistic option. They are pretty hardy and adaptable creatures, and tough enough to defend themselves, and we humans will leave plenty of members of the species behind.

| improve this answer | |
$\endgroup$
  • $\begingroup$ Beyond the gene pool minimum size, species headcount does not make much a difference: If the species thrives when humanity is gone, it will exponentially grow into its niche, if it does not thrive, it will decline. (Wild pigs are still an interesting thought, for the stated reason but also because they are social and pretty smart.) $\endgroup$ – toolforger May 18 at 5:01
  • $\begingroup$ That Eastern Coyote is the first time I’ve seen a species be listed as concerning because they are too attractive to the species they’re supplanting. $\endgroup$ – Joe Bloggs May 18 at 6:51
  • $\begingroup$ There are feral dogs in Chernobyl, which arrived with humans and are still present now. $\endgroup$ – marcellothearcane May 18 at 7:28
  • 1
    $\begingroup$ @toolforger I'm not sure that's entirely true. I don't believe that any event in evolution is inevitable based on pure genetic "fitness". Realistically multiple species could fill certain niches, and the species that gets there first may dominate the ecosystem. We've established (for example) pigs on islands where other big game are absent and they may thrive in the absence of predators. $\endgroup$ – workerjoe May 18 at 11:33
  • $\begingroup$ One theory I've heard says that dogs are just wolves with a genetic disease that makes them really unhappy if they don't receive affection. Sauce: youtube.com/watch?v=aDVS8PlNM8M $\endgroup$ – John Dvorak May 18 at 12:25
10
$\begingroup$

Robots

Maybe it is a stretch to call robots a "species", but when it comes to owing their rise to humans, they fit the bill perfectly. In your future world, humans may have achieved a state where robotic automation becomes so good that robots can reproduce and adapt on thier own. Some robots mine, some run the factories, some distribute goods, etc. They also have a deep respect for humans because it is hardwired into thier design.

Instead of the stereotypical robot apocalypse where the robots rose up and destroyed humanity, these are "properly" designed to never resist the will of thier human masters. So when overpopulation and environmental damage became to severe for humans to survive, the robots just kept on keeping on as the loyal servants they were giving us all the cars, smart phones, and indoor lighting we desired until it killed us all.

They would also continue to survive and even thrive no matter how badly we mess this world up. Human technology makes us very adaptable; so, once the world becomes so hostile that we can not find a way to survive, there will not be a heck of a whole lot of other species left to take over.

Another advantage here is time-frame. Waiting for another intelligent species to replace us after we are gone will take millions of years as a bare minimum, but most things made by human hands turn to dust within a few thousand years. By the time another species rises to intelligence, there will be so little evidence left of human civilisation, that they may not even be sure that we were an intelligent species. Just that there was a dramatic, difficult to explain climate change event. An organic successor race would have just a vague notion of how global warming affected thier evolution the way humans have a vague notion of how important the ice age is to us. Robots on the other hand have the best chance of developing intelligence along side humans, and then just outlasting us giving them a societal memory of the humans that once were.

| improve this answer | |
$\endgroup$
  • $\begingroup$ I agree that waiting a million years for another species to evolve to our potential, and then having anything of our civilization left that would be useful, is a stretch. Certainly, if any species that is around today COULD evolve into advanced human sentience, it would have done so by now. So I suspect that whatever makes the 'leap' would have had to have a 'helping hand' from humans, some boost, or in Mathew's terminology, some 'uplift'. The rub is does the phrase 'where the inhabitants' allow robots to be the inhabitants? They would clearly be artificial constructs, needing some 'creator'. $\endgroup$ – Justin Thyme the Second May 18 at 19:34
9
$\begingroup$

All current answers are too mammal-centric.

My nomination would be the birds. If you want to breed for intelligence, tool use and problem-solving, you don't want dogs or even cats - you want crows. They are the first animal ever seen to construct complex tools (defined as a tool with more than one element).

Crows are fully omnivorous, and will eat anything - and meat-wise, that could be in just about any state of decomposition. They have very few predators, at least as adults, because they can fly and they are relatively large birds. And unlike many mammals, they have two claws and a beak which allow grasping and relatively fine motor control.

More usefully for our purposes, crows are social creatures. They defend against the predators they do have (mainly other birds seeking to raid nests for eggs and chicks) by ganging up on the bigger birds - so they already have tribal instincts. They learn from each other too, so a new technique figured out by one bird in a flock/tribe/area will be copied by others, and that's the biggest thing to build on.

How would our existence help them? Lots of tall buildings with safe roosting opportunities, is the simple answer!

| improve this answer | |
$\endgroup$
  • 1
    $\begingroup$ Yes, crows were on my list, too. I discounted them because of their size. Would they have the mass and size to operate our technology? Not without robot assistance, I fear. They are certainly goal-directed, tool users, and cunning, and they have a sense of self, but do they have the necessary experience with our technology? And would they have the will, the drive, to master it? They fit well within their niche as it is. Why aspire to anything greater? $\endgroup$ – Justin Thyme the Second May 18 at 14:14
  • 1
    $\begingroup$ @JustinThymetheSecond You could ask the same question about apes on the African savannah, around 4 million years ago. Nothing "aspires" - it simply moves into the next available niche, where one exists. Crows are already more sophisticated tool users than chimpanzees, so let's guess at 1 million years to catch up with us. Except that studies suggest Neanderthals were no less intelligent than us - they simply had less technology. So maybe half a million years for crows to catch up? The final result will be as different from crows as we are from chimps though. $\endgroup$ – Graham May 18 at 14:26
  • $\begingroup$ Pre-humanoid 'versions' of humans went for over a million years without ever advancing beyond stone tools. They did not 'move' at all, into any 'next niche'. Humans only evolved in the last 50,000 years or so, and only exponentially in the last eight thousand years or so. There was no 'drive to aspire' for millions of years, until human genetics was altered enough to create such a drive. Then, we took off. Like you said, intelligence alone can not explain it. There had to be 'something else'. $\endgroup$ – Justin Thyme the Second May 18 at 15:31
  • 2
    $\begingroup$ @JustinThymetheSecond I'm sorry if this sounds rude, but you don't really know very much about archaeology. There is substantial variation in the precision of stone tools as time goes on, and they were designed very precisely to do specific tasks. We know Neanderthals 50,000 years ago had art, jewellery and religion (or at least the concept of an afterlife). And we did not "take off" 8,000 years ago - what happened was that with each new invention down the line, different niches became available. We just kept improving our tools, is all. $\endgroup$ – Graham May 18 at 15:48
  • $\begingroup$ @ Graham Not only does it sound rude, it IS rude. Perhaps one of us does not know much about archaeology. Paranthropus boisei lived at the same time as homo erectus, for about a million years, never developed in that time span. Australopithecus africanus spanned over a million years. Homo habilis a million years. Over four million years, until stone tools. No 'next niche'. humanorigins.si.edu/evidence/… $\endgroup$ – Justin Thyme the Second May 20 at 12:57
6
$\begingroup$

I kinda feel like the various monkeys/apes are the best candidate - albeit a pretty boring one. Some scientists already consider that they have entered Stone Age and that's the furthest any species has got so far. With humans out of the picture - well, it's just a matter of time. Mind you, I don't know how much of human presence would still remain by the time the apes got intelligent enough to start to care. Probably not much. Perhaps you need a doomsday vault that gets opened later on.

| improve this answer | |
$\endgroup$
  • $\begingroup$ I thought about monkeys/apes as well, since they have a good start on the evolutionary intelligence scale, but have we taken them too close to extinction for them to recover? It would seem to me that the ones who are familiar with human technology and that have been trained are all in captivity, and would probably not survive a human apocalypse (would we turn them all out of captivity when the end was near?) and those that are in the wild have survived only because they are far from human contact, and would have no experience using our tools and technology. $\endgroup$ – Justin Thyme the Second May 18 at 13:48
  • $\begingroup$ @JustinThymetheSecond - I think that whether or not they are "trained" is pretty irrelevant, because human tools and technologies are simply way too complicated for any animal species to comprehend and use properly. Best they might find our knives useful - for a while. Without many more millenia of evolution, there's nothing out there that could make use of our stuff. By the time any other species gets that far, most of our legacy will be dust. The question is - who will be the first to get there (my guess: monkeys) and what will be left at that point. $\endgroup$ – Vilx- May 18 at 15:48
  • $\begingroup$ @JustinThymetheSecond - And even then - remember how much time it took for humans to start treating History as a science and actually care about the past? Yeah. Up until a few centuries ago, "old stuff" was either religious relics, junk, or maybe (at best) collector's pieces. Preserving legacy for the sake of preserving legacy? Pfft. Useless. Although I guess the OP intends to handwave this part away. In which case I suspect that most of our stuff will become sacred religious artifacts rather than usable tools. $\endgroup$ – Vilx- May 18 at 15:51
  • $\begingroup$ @Vilx-, you're sort of making my point for me why I would start with critters that are already some ways into uplift. $\endgroup$ – Matthew May 18 at 16:39
  • $\begingroup$ @Vilx- Having watched the destruction of the past by ISIS recently, I truly wonder that we have even reached that point as a species? $\endgroup$ – CGCampbell May 18 at 20:46
5
$\begingroup$

Intelligence is nothing more than an evolutionary tool. Because it is our main tool, we are biased in saying that it is different and we overvalue, after all, we cannot run very well, we have no claws, inoculate poison, keep alive in very adverse situations, etc.

Our intelligence is the product of the 16 billion neurons in the prefrontal cortex, which added to the 70 billion neurons in the cerebellum form a mass of 86 billion neurons that consume about 500 kcal / day.

The cerebellum is the main seat of command for our movements and the various organic activities that keep us alive. In the cortex are interpretations of the senses, it is where you really see, smell, hear, etc. and intelligence is the result of this interaction of the environment.

Only when our ancestors were able to access new energy levels, when they were able to have more calories from food and spend less time eating or looking for food in the time they stayed awake did intelligence emerge.

For your story this brings excellent news: the improvements we have made in agriculture over the millennia have made countless plants robust sources of extra calories with easy harvest. The naked apes are all obese thanks to that.

Many talked about small animals in the other answer: forget them all. They need substantial physical growth to also increase their cranial box to accommodate a growing brain. Not only because of the size itself, there is also a relationship between neuron density and sleep time, animals with small heads and many neurons in the cortex need to sleep too much and have little time awake to feed and still have free time where the imagination can operate.

Intelligence is also not an individual product. If we humans needed to invent the wheel in each generation today, we would still be in the stone age. A species that is unable to communicate with each other in any way, to develop complex ways to do so, such as our facial expressions, in addition to voice and later writing, certainly has no success in evolving intelligence, just as it needs to be able to accumulate knowledge.

Knowing how to handle tools with fine movements, as we do thanks to our opposable thumb is also an important differential. It is one of the things that make crows one of the most magnificent beings in the animal kingdom. That is what makes those poor bastards assholes of the seas, the dolphins limited in relation to us, even though they have more neurons in their cortex than we do.

A species that is large, with a long life span and is capable of making fine movements, at the same time that it is able to transmit information through generations, preferably that already has a massive brain that would only need an extra increment are the best bets.

In this case, only the other apes: orangutan, gorilla, chimpanzee, bonobo, or else ...

With amazing 257 billion neurons in the whole brain, almost 3 times the human brain, but only 1/3 of neurons we have in our prefrontal cortex, my favorite bet: The elephant.

| improve this answer | |
$\endgroup$
4
$\begingroup$

I would like to offer a bit different view of the answer - of course the obvious species would be pests who nurture on our biological waste for their nutrition. But this would be short-lived as there is a final amount we have had left behind us, and once that's digested - well, it's gone :) If we think about a sentient species that will come thousands of years after our demise, it would have to do more with the non-organic man-made creations left on the planet.

So I would think of concrete (roads, buildings, bridges) and of metal (planet-stretching copper wiring, and the inevitable abundance of stainless-steel utensils our new species will seem to be digging up everywhere...)

Maybe they will treat "findings" of buried cities and of old roads like we treat newly-found deposits of gold or precious stones? Maybe they need the concrete or thrive on the magnetic/conduciveness of the metals?

If you haven't read it already - I highly recommend the book "A World Without Us" which describes what would happen if suddenly, in a blink - all humans would vanish, but nothing else will change. It goes form the immediate consequences, to days, weeks, years and into the dar future - what would the world look like? It contains some cool ideas like the utensil example I have just 'stole' from it :) Look it up!

Good luck with the story!

| improve this answer | |
$\endgroup$
4
$\begingroup$

On thinking about the other answers, I'm not sure this is possible without a little "something extra"... If humans suddenly die out, nature is likely going to reclaim most of our stuff more quickly than something else can grow to the point of being able to care about it consciously and preserve it.

That "something" is uplift.

There are several species that would make good candidates, but really, you could use whatever suits your fancy. The upshot is that humans are revered not just because of all the stuff we left behind, but because we are responsible for your species' sapience, and they know it.

This might work better if full sapience arises only slightly after we're gone, or if we don't realize it's happened. To that extent, your best candidates are probably dogs (for obvious reasons) or possibly horses (similar reasons as dogs), or else laboratory animals (either monkeys or, ahem, rats).

If you're interested in the notion, I would strongly recommend reading Breed to Come by Andre Norton. You might also find That Which Survives interesting. (Go read it now; it's free and it's not much longer than this answer. Thank you FuzzyBoots for dredging that up for me!)

| improve this answer | |
$\endgroup$
  • $\begingroup$ Dogs will die out if the humans stop feeding them. There isn't enough of the natural ecosystem left to allow a dog population to survive in any great numbers. $\endgroup$ – Innovine May 18 at 14:59
  • $\begingroup$ @Innovine, they'd need to figure out ranching pretty quickly, and/or would indeed go through a major population bottleneck first, but unless wolves and coyotes also go extinct, I think some would make it. Remember also, I'm talking about uplifted dogs, here; they'd be close to having civilization even before humans go poof. $\endgroup$ – Matthew May 18 at 16:32
2
$\begingroup$

It would be a toss-up between cats or dogs, but I would bet on cats.

Both have been bred by humans for intelligence, so they have a head start on evolution. Both have gone well passed the critical threshold of population numbers for independent survival. Both are very familiar with human habitats, living conditions, and culture, and have adapted to domesticated living.

Some breeds of dogs are estimated to have a mental age of a three year old. They already have a head start on evolution, being purpose-bred. However, dogs are much more dependent on humans for survival, having been raised under strict master-pet conditions.

Cats are more cunning and better problem solvers, overall, with a greater sense of how to survive in the wild, without humans (having never been truly domesticated). They are independent enough to survive the extinction of humans. Cats can truly have an intelligent conversation with humans. Cats only meow in the presence of humans, for instance, and their own mothers just after birth. They might not have a large human vocabulary, but they definitely understand human communication using emotion, facial expression, intonation, and other non-language cues. You do not train a cat, you talk them into doing what you want, convincing them that they really want to do it. They also have good math skills. Just try to convince a new cat mom that it has one less kitten than the original litter. They have an innate sense of quantity. Cats also have very good manual dexterity, able to manipulate things in their environment far beyond just 'fetch'.

But my third choice would be pigs, having achieved the human five year old level. Pigs would actually be my first choice, except that they have no opposable thumb (hard to hold tools with a hoof) and they would never forgive us for our love of bacon. They would never, ever revere us. There also isn't a critical threshold of domesticated pigs that could be expected to survive human extinction.

Trained and domesticated chimps and other such primates are perhaps far more intelligent, but they just don't have the critical mass of population that would enable survival. We have pretty much taken them to extinction.

And if anyone has ever encountered the tremendous manual dexterity and problem-solving abilities of a raccoon to get into garbage cans, one would definitely have to put them high on the list. However, they just don't have the same experience of living in a home and mingling with the technological environment, and interacting with human tools, that cats do. Cats will watch tv, and even learn to turn the channels to get to what they want to see. At least mine does.

| improve this answer | |
$\endgroup$
2
$\begingroup$

Another answer from me, from a different perspective.

I just re-read your criteria:

how much what we would leave behind might shorten the species's evolutionary journey to sentience.

So, that's actually pretty specific. What in all our stuff would push a species to evolve higher intelligence? This immediately lays down some groundwork: first, there has to be evolutionary pressure. Something that kills off the individuals which are less able to adapt. Second, our things must help the evolving species to survive, so the better they adapt to our legacy, the better their survival. Third, the survival must depend not only on learning to use things, but also to understand them - otherwise we don't get to science. The smartest individuals must be able to survive the best.

At the same time, this must be something very primitive, because even the most advanced animals today can't use more than simple tools. And it has to last a long, long time, because even at the fastest pace, we probably won't get another intelligent race for a few millenia. And finally it has to be plentiful enough to support large populations, not just a single tribe.

Hmm... well, I'm kinda stumped. Nothing comes to mind that would fit these criteria.

Perhaps stainless steel knives and other tools? Those should last a pretty long time, depending on their storage and quality. And there's plenty to go around. A knife is a pretty versatile tool. But would it lead to faster evolution? I don't know... Maybe if their wielders (I still can't get the primates out of my head) started to use them for warfare between themselves. Then the ones who could adapt to their use faster; come up with novel moves or traps - would have a better chance or survival. Maybe. But at best this might get them to Bronze age or something. After that...

Maybe there can be series of tools? Once the simple ones are mastered, they can move on to more complicated ones. But I'm still unsure what could survive that long.

Unless.... humans actually designed for this? Make a trail for new species to follow, with perks being unlocked along the way. Those could be made super-durable to last millenia. But what would they be? Still no idea...

| improve this answer | |
$\endgroup$
1
$\begingroup$

In terms of mankind's presence passively helping another species achieve sapience, there probably wouldn't be any species that fit your criteria. Humans haven't been creating strong selection pressures for higher intelligence, and the only way our presence would help another species achieve sapience is if we outright uplifted them. There have been suggestions that the complex artificial environments created by humanity have selected for larger brain sizes in squirrels and such, but it's not going to act on them to the point that they develop sentience. Indeed, in the absence of humans it is possible that these squirrels might lose any increase in brain mass, in a similar case to how the peppered moth returned to a non-black morph when industrial pollution levels fell.

The species that will benefit evolutionarily will primarily be invasive species mankind introduced to isolated landmasses, such as islands. By introducing these organisms to new landmasses, mankind has increased the total range available to these animals, created new opportunities for speciation, and reduced the chance that these species will go extinct by creating potential refuge populations where they could continue to adapt and thrive (especially on islands). Many groups of animals, like ungulates and carnivorans, are normally terrible at crossing water barriers, and humans represent an unprecedented opportunity for them to get to landmasses they would otherwise be unable to. Hawaii, New Caledonia, and New Zealand are good examples of this, as non-flying mammals would otherwise have no chance of reaching these landmasses for over 100 million years. Although some of these islands, like Hawaii, would eventually sink beneath the waves, many species could still keep island hopping the way Drosophila did in Hawaii and some islands such as New Caledonia, Madagascar, and New Zealand are actually continental fragments and would last a very long time.

There are some qualifiers to this. Although many species in Eurasia have been introduced to North America and vice versa, many of these species would have gotten to these locations anyway the next time the Bering strait closed and species could freely migrate between the Old and New Worlds. For example, there are no native true rats (Rattus) in North America, but there are plenty in Asia and they would have just crossed the strait some time in the next hundred thousand years or so.

Human-introduced species are a big deal compared to other species that currently benefit from human aid (livestock, pests) because while it took human intervention to get them there, human intervention isn't required for them to survive there. Which means that if humans go extinct these new, invasive populations won't go extinct with them (this is the problem with things like cockroaches).

Given these factors, I would say the species that has benefitted the most from the presence of humanity (considering their current distribution and how extensive their distribution was pre-humanity) would have to be...

Rainbow Trout (Oncorhynchus mykiss) and Goldfish (Carassius auratus)

Freshwater fishes have a much harder time dispersing to new habitats, since they are dependent on either shifts in river flow, floods to overcome barriers like waterfalls, or travelling through the ocean to get to new rivers. Even catadromus/anadromus species can be blocked by continental landmasses or mountain ranges. Rainbow trout are native to the Pacific Coast of the U.S. and Canada and the Kamchatka Peninsula in Russia, but they have been introduced absolutely everywhere, including eastern North America (which it wouldn’t normally be able to get to due to the Panamanian land bridge and the Rockies), Eurasia, South America, Africa, Australia, New Zealand, and even Hawaii. They are now on every continent and most major land masses except Antarctica. That is a huge expansion of their range, and they would not have been able to get to many of these places naturally. Brown trout (Salmo trutta) have a similar history. In some places these trout are artificially bred, but in most they have breeding populations.

Goldfish are kind of similar. They’re native to eastern Asia but have been introduced just about everywhere as a consequence of their status as common pests, and got to places like North America where there were no native carp beforehand. Common carp are less so because they already had a large range prior to human introduction, humans have not benefitted them as much.

And a terrestrial runner-up would be...

House cats (Felis catus)

Species of Felis are native to most of Africa, Europe, and Asia, but humans have introduced them to every major landmass and most islands except Antarctica. Cats aside from tigers are normally terrible at crossing water barriers due to their hypercarnivorous habits. Additionally, compared to other domestic animals (except maybe goats and dogs), cats are much better at surviving in the absence of humans. Humanity's presence has single-handedly given cats a whole bunch of evolutionary opportunities they normally wouldn't have.

Rats (Rattus spp.) are a potential third place, but rats are already good at dispersing to places and there are already native rat species in far-off places like Christmas Island, the Phillipines, and Australia long before humans came along. Getting to places like the Galapagos or Hawaii by human introduction is notable, but overall the species hasn't benefitted long-term as much as cats have.

| improve this answer | |
$\endgroup$
  • $\begingroup$ While this is all true, I don't think that any of these animals are likely to become sapient. $\endgroup$ – nick012000 May 19 at 8:16
1
$\begingroup$

Because of mankind's huge impact on the planet and the environment, generally speaking I think the species that would benefit most from mankind's departure are those that are close to the fringes, such as the endangered species in the fragile parts of the polar ice caps, rain forests, wetlands, etc. For example polar bears might be one of the largest benefactors even if they in turn don't have much impact on the planet as a whole.

For a sci-fi plot I think an interesting question is what species evolves to take mankind's place and how that transpires. Humans evolved from primates, some say just through a fluke or random selection, others say that some primates were forced into a new ecosystem where they began eating a much higher protein diet (the oyster theory), etc. So how would some other species make the same leap?

There are many existing species such as elephants, dolphins, pigs, primates, that exhibit signs of intelligence, empathy, communication, memory, and other things we consider to be human or highly evolved traits. And a lot of sci-fi has been written about this, such as Barsk with the sapient elephants, or Planet of the Apes, where on another planet the primates evolved slightly differently.

| improve this answer | |
$\endgroup$
1
$\begingroup$

If you're looking for a species to become the new humans, I think cats are really your best choice. They don't have many natural enemies, can adapt to a wide range of climates, and have other biological benefits that other answers have already explained.

There's more to it than biology, though. You don't rise to the point of being a diverse planet's dominant species merely by biology (the arms race that is evolution all but guarantees there will always be competition). At some point, you have to want to win. You have to make the decision that mere survival isn't enough, you deserve to run the show and have all other species see you as superior.

This psychological leap is where cats have a huge advantage over other species. Some researchers believe this may have already happened1. We have entire human civilizations that raised cats for centuries and worshiped them as gods. This sort of species-wide superiority complex is currently held at bay through the use of cutesy nicknames and tiny hats but once humans are gone, the Era of Humiliation will soon be forgotten.

Once cats develop even the most primitive sort of archaeology (which shouldn't be long given their propensity for digging in the dirt), they'll uncover a wealth of evidence that they can easily interpret as proof that they were once the dominant species:

  • Humans built everything from statues to shrines to monuments to theme parks, all to honor cats and seek their favor
  • Humans obviously loved their sports, but "lions", "panthers", "wildcats", and "tigers" were among the most popular names for sports teams.
  • Humans invented many powerful forms of security, but cats forced them to include backdoor access methods to ensure they could still manage their human subjects without restriction. Cat-based names were given to humans who were proficient at bypassing security.
  • Humans developed entire art forms and language constructs centered around their cat masters.
  • Humans spent centuries developing mathematics, science, industry, and technology, all so that they could build a system designed around sharing, talking about, and revering cats in the most efficient way possible.

With millennia of historical evidence inspiring them, there's nothing stopping the feline quest to retake their position as the dominant species.

[1] Source: you've met a cat, right?

| improve this answer | |
$\endgroup$
1
$\begingroup$

So some chimpanzees and monkeys are already in the stone age. ( http://www.bbc.com/earth/story/20150818-chimps-living-in-the-stone-age ) Assuming that the loss of humanity didn't also wipe out the primates one of those is likely to step up to fill the niche, but that will likely take many millennia.

IN the interim as others have suggested, large predators will recover, as will herd animals. Domestic cattle will have a rough time at first, though the hand of natural selection will probably fix much of that quickly. Wild pigs and boar will do really well (think of how hard the are to deal with now)

We'll also see significant reforestation across Europe, and much of eastern North America, Brazil and possibly some reversal of desertification in sub saharan Africa (a lot of that is caused by tree removal for firewood)

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.