The end of the age of humans dominating the Earth started rather subtly. The first to notice the changes weren't leaders of nations, government officials, or brilliant scientist, but rather those who were more in touch nature and spent much of their time outdoors. Gradually over time forests became denser, animals once simple to capture were now much more evasive, and domesticated animals started to break out of confinement and escape into the wild. Even crops began to become larger and produce more yet became increasingly harder to harvest. It wasn't very alarming at first as it was a very gradual change like how a waistline that grows a quarter inch a year is mostly ignored until years later when, to your dismay, your belt no longer fits. As is so often the case, by the time the public started to pay attention, it was far too late. Not that anybody could have done anything about it anyway.
Of course, the initial reaction was to look for someone or something to blame, not trying to fix the problem — some blamed global warming, others the gradual depletion of the Earth's natural resources. Talking heads dominated the daily news for decades resulting only in more and more political infighting and civil unrest. The continued ineffective leadership eventually led many nations to the brink of anarchy as its citizens repeatedly looked to their respective leaders for answers and found none. So, while nature seemed to be marching to take back the Earth gradually, humans not only didn't fight back effectively, they made it that much worse.
It was easy to blame these leaders for their lack of answers, yet even the brightest scientific minds of the day were baffled as to why ninety-nine percent of the Earth's plants and animals seemed to have begun a rapid mutation which varied from species to species. While most started to become larger, stronger, and more resilient, others began to exhibit more and more intelligence. Some plants even became mobile and their proliferation rapidly increased. Also when plants and animals were captured and studied, the scientists were shocked by how much they grew in confinement, forcing the building of new and stronger cages continually, along with additional safety precautions to ensure their containment.
An analysis of their genes, DNA, and CRISPR revealed that these test subjects seemed to have experienced thousands of years' worth of evolution in less than a year and were still were experiencing this evolution in captivity. Which meant the evolution wasn't based on parentage or new generations, instead was an ongoing process. Even when isolated from their habitat, their evolution continued which also ruled out external or environmental factors. The only way that seemed to slow down their mutation was to starve them near to death yet even then; it didn't stop completely. It just didn't make sense as the food fed to the test subjects was the same food that humans consumed only prepared slightly differently. What was so different about humans that this evolution affected every other animal or vegetation, but not them? Even chimpanzees and gorillas which share most of the same genes as humans still evolved at the same pace as the rest. Despite a considerable amount of time spent researching, in experimentation, and studying the problem, humanities greatest minds could still not answer the questions of how or why this evolution was occurring or for that matter, why it was not happening in humans.
In the ensuing years, humans were forced back repeatedly. Many efforts at resisting were attempted such as military means and controlled forest fires. Some countries even tried using nuclear weapons or radioactive material to stifle the pace of nature's aggression. But all attempts failed miserably. Humans despite their years on the top, became one of the most helpless creatures on the planet, hurting themselves more often than not with every attempt to curb the tide. Most forests were now mostly fireproof, and many plants and animals showed strong resistance to high levels of radiation. During these assaults nature at first, seemed primarily unconcerned with humans only attacking when they were 'in the way,' however, that slowly began to change as humans fought back with increasingly destructive means. In response to the tactics of the animals seemed to shift as they began to organize. Vast swarms of animals, now looking more like mythical monsters and beasts, would annihilate their attackers killing them all without exception. They quickly shifted from apathetic to offensive, destroying any human settlements in the area in retaliation.
After witnessing this time and again, humans finally took a more defensive strategy. In some instances, huge ditches and walls were erected around cities to protect their residents, while others decided to dig down into the bedrock of the earth itself. In every geographical area, whether it was a forest, an ocean island, a desert oasis, or a mountaintop stronghold; each environment posed many new and deadly challenges to continued human existence. Many cities and communities perished entirely, and humans were repeatedly forced back until the day came when almost the entire human population, save for a few exceptions, were forced to live in large walled compounds.
This assault on humanity went on for almost a thousand years and only the strongest survived. If one were to have kept track of the year based on the old calendar system, then the year would now be 3025 CE or AD for those who still clung desperately to their old religious beliefs. In this new world, nature had wiped away all of that nonsense as few bothered to keep track to of any ideas or actions that didn't aid in their survival. Strangely, however, for the past half-century or so, the plants and animals seemed to have stopped their assaults on these human compounds as if nature had finally obtained its necessary balance. The Earth's human population once approaching 10 billion people, was now a mere 10 million.
Along with nearly 99.9% of the world's population, much of its technology had been lost as well. Despite being able to use more easily obtained sources of power in the 21st century, the world's reliance on fossil fuels had created a single point of failure. Anyone in now extinct Information Technology field would have been able to predict that if their system's resiliency only had a single point of failure, they would be fired immediately when the inevitable system outage occurred. That is unless they had warned their bosses of this time and time again, and they did not provide the budget for it…then the boss would be the one that was fired. Despite this, world governments remained idiotically short-sighted in their thinking and opposed massive investments into these renewable energy sources. Both themselves and their surviving ancestors would come to suffer as a result of this idiocy as comfort, food storage, technology, transportation, and communication were crippled due to lack of readily available electrical power.
Now the world did not completely revert to the dark ages as some engineers and brilliant minds had enough foresight to pass on their skills and knowledge through both the written word and the education of their children. With the cessation of the beast attacks, these compounds were finally able to focus on these technologies once again and had established large solar and wind arrays on the tops of their walls and structures to capture and harness their power. When combined with rudimentary battery and capacitor storage, they were once again able to provide their compounds with limited amounts of electricity.
Unexpectedly, about the same time as the cessation of attacks, people also noticed themselves visibly getting stronger, faster, and in some cases developing special abilities like in superhero stories of old. As if nearly a thousand years after the Earth's creatures and plants had started to evolve, humans had finally begun to as well. With an almost nonexistent communication infrastructure and little to no contact between compounds, information on these evolved powers and abilities remained very scarce. The only thing that people seemed to agree on was the evolutionary changes seemed much different than what happened to animals and plants one thousand years ago.