What fossils will mankind leave behind for the future?

  The earth has undergone earth-shaking changes in 1 million AD… Robot archaeologists have discovered an unknown civilization. Through research on some relics and fossils, robotic archaeologists believe that this civilization still existed at least 900,000 years ago. It seems to be built by a kind of hairless animal that walks on two legs…
  Seeing here, we can guess that that kind of hairless biped probably refers to humans. Although this scenario is only an imagination, it can not help but make us think of a question-if human beings become extinct, what traces might they leave on the earth?
  Fossils are not easy to leave
  from today’s point of view, the human impact on the planet than any animal in the past, we will hilltop razed to the ground, the construction of high-rise buildings on the ground, dug mines and criss-cross the huge underground Mines, draining lakes, planning new channels for rivers, etc. But with the passage of time, these traces of human change will be erased by nature. At that time, I am afraid that only fossils will remain.
  So, what kind of fossils will the Anthropocene, which is still booming now, leave in the future?
  There are many types of fossils. Bones, shells, marks left by animals, plants or microorganisms on stones, objects preserved in lakes, hair, NDA residues, etc. are all fossils. The formation of fossils must meet the conditions of “time, place, and people”. First of all, the so-called human and refers to the object itself must have hard parts, such as shells, bones, teeth, etc.; geographical advantage refers to the location of the object, preferably volcanoes, deserts, glaciers, swamps or other environments with sediments ; And Tianshi refers to objects that need to be buried quickly before being destroyed. Once these conditions are met, it will take a long time for the object to become a fossil.
  Even under the most ideal conditions, organisms are rarely preserved as fossils, and the fossils that can be found are only a few of them. It is estimated that the number of species known through the fossil record is less than 1% of all biological species that once lived on the earth.
  And humans seem to be very good at one thing-mining. Take a look around us. Old buildings are torn down and new buildings are built; after the crops in the fields are harvested, the soil will be loosened again and planted with new crops; the former garbage dump may become a high-end community after a hundred years …This means that the various traces left by humans may be destroyed before they can become fossils. Therefore, it is difficult to say how many Anthropocene fossils will be found in the future.
  But no matter what, this era will always leave some fossils for the future. If the Anthropocene fossils are preserved, what kind of fossils will there be?
  Human and animal fossils of living together
  different strata saved fossil their own characteristics, they represent a species that period, the characteristics of the environment, human fossils of human nature is a sign of the world.
  In ancient times, people usually bury their dead companions in one place. Gradually, orderly cemeteries began to appear. Nowadays, cremation is advocated in many places, and the tombs are no longer corpses, but ashes. With the rapid increase of the population and the reduction of land use area, people in the future may adopt more environmentally friendly disposal methods without even keeping ashes. Under such circumstances, there are probably not many human fossils preserved in the Anthropocene strata.
  Now dozens of animals disappear from the earth every day in the world. Some scientists believe that we are experiencing the sixth mass extinction event in the history of the earth, and it is human beings that caused this mass extinction. This means that in the Anthropocene strata, many fossils of wild animals will suddenly disappear, replaced by fossils of unique Anthropocene animals.
  For example, the fossils of animals domesticated with humans-chickens, pigs, cows, cats, dogs, etc., may be huge. Human activities have led to the extinction of many wild animals. The number of domesticated animals far exceeds that of wild animals in areas where humans gather, and the number of chickens may be the largest. According to statistics, the world consumes more than 66 billion chickens every year, and humans domesticated chickens as early as 7000 to 10,000 years ago. In the future, humans will eat more chickens. In this way, chickens in the Anthropocene stratum The bone fossil should be regarded as a kind of iconic fossil.
  And these fossils of human domesticated animals have one characteristic-they bear human marks, especially with the development of genetic technology, the traces of human changes will be more obvious. Through the study of these fossils, future archaeologists will be able to discover that these animals have different foods from their wild ancestors, their body shapes have changed, and their growth rates have increased. Some of these changes require information under natural conditions. It may take tens of thousands, or longer, to evolve.
  The selected human fossil plants
  and domesticated animals similar to fossils of plants domesticated humans may also become a representative of the world of human fossils. More than 10,000 years ago, humans began their agricultural life, domesticating various crops. Up to now, although there are many types of crops planted by humans, there are several that are most widely distributed in the world and have the largest planting area, including corn, wheat, soybeans, rape, and rice. The food harvested from these crops is eaten by us, but their pollen may be retained. Pollen is like a “fingerprint” of a plant. The pollen is covered by a layer of sporopollen, which is resistant to corrosion, high temperature, and extremely difficult to oxidize, so it can form pollen fossils.
  Some people may say that there are many wild plants on the earth, and they also produce pollen. These pollen may also become fossils. Why can domesticated crops become a representative? On the one hand, as the population increases and the scope of human activities expands, the living space of wild plants is continuously compressed. In terms of quantity, agricultural crops are more numerous than wild plants, and they produce more pollen. On the other hand, the distribution of these agricultural crops also has characteristics of the Anthropocene. With the development of modern agriculture, more and more places now gather small plots of arable land and connect them into large plots, and through scientific planning, with the help of science and technology, a certain kind of crop is concentrated. In this way, future archaeologists will find a single plant pollen fossil in a large area, which is a sign of the existence of the Anthropocene.
  Fossil artificial material
  technology fossils – fossils of plants and animals in addition to the human world also possible that some of the formations until all formations have no fossils appear. “Technological fossil” is a new term coined in 2014 by paleontologists and colleagues at the University of Leicester, UK, and refers to the fossils of things created by human technology. Plastics will undoubtedly be among them, in addition to concrete, artificial glass, artificial gems and so on.
  Take plastic as an example. This is one of the materials most used by mankind at present. Plastic waste is spread all over the world. Under natural conditions, it is difficult to completely decompose plastic waste. Some of it may be buried in the sediment, and over time, together with the sediment Squashed and chemically reacted, it became part of the rock like a dinosaur bone.
  In addition to being directly part of the rock, plastic may also become fossilized in an unexpected way. In 2013, people discovered a small sphere containing plastic trash, pebbles and sand in the Hawaiian Islands. These small spheres were formed after the bonfire that burned day after day. American geologists put forward the concept of “plastic rock balls” based on this phenomenon. They believe that in the natural environment, due to volcanic activity, sand, stones, dissolved plastic, glass, and other garbage discarded by humans will merge together to form a new kind of rock. These rocks are extremely hard and resistant to corrosion, and their composition is completely different from that of natural rocks in the past.
  Humans have changed the earth tremendously, but we don’t know how many valuable fossils can be preserved in the Anthropocene, or how people in the future will interpret these fossils. If they found a large number of chicken bones and pig bones in the stratum, but no human fossils, they might think that there was a civilization built by chickens or pigs in the world. If they find large tracts of wheat pollen fossils, then they may think that the species of plants on the Anthropocene earth are single, and infer that the climate and environment are also single. It seems that the Anthropocene in the eyes of future people is a very big unsolved mystery!