In the movie "Jurassic Park", scientists resurrected dinosaurs with dinosaur blood from mosquito fossils, and in real life, there are many scientists looking for dinosaur DNA left in fossils all over the world, expecting to achieve the same feat. Although this matter does not seem to be very promising at present, if one day, dinosaurs are really resurrected, can they adapt to modern society?
The environment has changed
According to archaeological findings, the atmospheric composition of the jurassic to Cretaceous period, the era in which the dinosaurs lived, differed markedly from modern society. The oxygen content at that time was 130% to 150% today, which means that the oxygen content on the flat land today, if placed in the Jurassic period, is equivalent to a plateau of more than 3,000 meters. What does this mean? For human beings, a person who has never lived on the plateau suddenly comes to the plateau area, and it is very normal to have headaches, dizziness, chest tightness and shortness of breath, and some people will have more serious lung edema, cerebral edema and other lesions, and even lead to death.
Altitude sickness would have been much more severe than in humans if it had occurred in dinosaurs, because most dinosaurs weighed far more than humans, and they maintained more oxygen than humans needed to maintain normal physiological activities. Dinosaur scientists estimate that a 30,000-kilogram bewildered dragon maintained normal physiological activity, inhaling 1,700 liters of air per breath. If the oxygen content drops, the breathing rate is faster, and at the same time, it consumes more energy and needs more oxygen, which is an unsolvable cycle. I am afraid that dinosaurs in modern life will be inseparable from oxygen tanks for a lifetime.
In addition to oxygen, carbon dioxide during the Jurassic period was also much higher than in modern times. It is estimated that the amount of carbon dioxide at that time was 6 to 7 times that of the pre-industrial era. The reduction in carbon dioxide had little effect on respiration, but the effect on temperature was significant, which directly led to temperatures during the Jurassic period being 3°C to 4°C higher than today. You may think this is trivial, but it is not so for the warming animal dinosaurs. Crocodiles, the modern closest relatives of dinosaurs, were afraid of the cold, spending most of the winter in hibernation and moving much slower during predation than in summer. In addition, the temperature can even determine the sex of the crocodile, when the temperature is lower than 30 ° C, the young crocodile is all female, above 30 ° C to give birth to male crocodile. Will the effect of temperature on dinosaurs be as significant as that of crocodiles?
The era in which the dinosaurs lived, the climate was also very different from today, when there were a large number of tropical rainforests on the earth, the humidity was very large, and the humid and hot climate made the dinosaurs feel like a fish. Throughout today's earth, most of the plains are occupied by humans, full of high-rise buildings, and urban centers tend to be dry and hot. In the wild environment, which gradually changes from flaky to dotted, the area of tropical rainforest is drastically decreasing, replaced by sparse temperate shrubs and dry grasslands, which do not seem to be suitable for dinosaur life.
Plants are very different
It's hard to know what plants were preferred by plant-eating dinosaurs, but one thing is clear: compared to the Jurassic and Cretaceous periods, the types of modern plants have changed dramatically, and the gymnosperms that once dominated during the Jurassic period have been completely suppressed by angiosperms. That is to say, no matter what the plant-eating dinosaurs loved to eat at that time, in modern times, I am afraid that they have to change their taste, but this matter does not seem to be as easy as imagined.
Cycads are an ancient gymnosperm that reached its peak during the age of dinosaur life: paleontologists found the richest and most diverse cycad fossils in the strata of the pre- and post-Cretaceous period. Since the life period is so similar, it can be speculated that cycad should be one of the foods that dinosaurs often eat, and the dinosaurs who can use cycad as food should have evolved their own skills, at least it is difficult for humans to resist the "toxicity" of cycads.
Animals of the age of the dinosaurs
The more common toxins in cycads are cycadine in leaves, cones and seeds, and eating cycad seeds can cause diarrhea and vomiting, and excessive consumption is even at risk of death from liver failure. And according to animal experiments, cycadine also has carcinogenic effects, and oral feeding to rats can cause liver cancer and kidney cancer. A more unique "poison" is the cycad symbiotic candida, which creates a potential neurotoxin that cycad absorbs into the plant for longer periods of time. Once a person overdoses cycads for a long time, they may suffer from Parkinson's disease or alzheimer's disease (often manifested as muscle weakness and atrophy, bulbar palsy of a motor neuron disease).
Of course, Cycad itself does not want to become food for humans, nor does it expect to rely on humans to continue life, it and dinosaurs are cooperative partners. Some studies have made it clear that sauropods fed on the young leaves and seeds of cycads, and that the scarlet fleshy outer coat of cycads evolved to attract large sauropods. After the dinosaurs ate and digested the fleshy outer seed coat, they would excrete the seeds inside, so that cycads spread throughout the world following the footsteps of the dinosaurs.
Ginkgo biloba, a close relative of cycads that also flourished in the Jurassic, also has similar characteristics, and the storage tissue of ginkgo seeds contains 4-methoxypyridoxine (MPN), cyanosides and other toxins. MPN is also a neurotoxin, and excessive consumption can induce seizures and convulsions, while cyanidine hydrolysis can produce highly toxic cyanide. Heating and cooking can make toxic substances such as cyanosides decomposed by heat, but it cannot inactivate MPNs, so if we eat ginkgo seeds raw, we must be prepared for first aid, even if cooked, ginkgo seeds can not eat more. However, dinosaurs did not worry about this, as one of the few tall trees at that time, the existence of ginkgo biloba just met the dietary needs of large plant-eating dinosaurs.
Dinosaurs loved gymnosperms
But, resistant to poison like dinosaurs, can they tolerate the toxicity of angiosperms? In order to adapt to different environments, angiosperms have produced many different metabolites, such as polyols related to low temperature resistance, alkaloids and tannins that resist drought environments, and betaine and proline in many halophytes. Some of these metabolites are highly toxic and have the effect of "seeing blood and sealing the throat" on plant-eating animals, and some may only have a peculiar smell or special taste, making the animals uncomfortable. But how "effective" they were on dinosaurs, we have no way of speculating. In addition, angiosperms also had fungi and bacteria that coexisted with them, and could dinosaurs tolerate their metabolites? If dinosaurs were stocked directly in the wild, they might be like ancient humans who tasted hundreds of grasses, not even knowing which grass poisoned them.
Animals have also changed
Not only plants, but also animals that once competed in the same land as dinosaurs or were unilaterally crushed by dinosaurs have all changed.
If the dinosaurs were resurrected, their first thought might be that they had come to the villain kingdom. This is indeed the case, because of the good climate and ecological environment of the Cretaceous Period, the high oxygen content in the atmosphere and other factors, the size of the animals and plants at that time was very large, even small insects such as mosquitoes and flies were 2 to 3 times larger than the present, and some dragonflies could grow to more than one meter long. Not to mention the giant reptiles that can be compared to dinosaurs, which usually weigh in units of ten tons, equivalent to the weight of several or even dozens of elephants.
The animals became smaller, and the first major impact on carnivorous dinosaurs was food shortages. In general, mammals consume about 10% of their body weight per day, such as a 4-ton elephant that eats more than 300 kilograms of food a day. Most dinosaurs weigh up to tens or even hundreds of tons, if they are calculated by the same standard, then a single dinosaur will consume tons or even dozens of tons of food a day, which is also equivalent to several or even dozens of elephants. Can modern society afford such a "big stomach king"? If it lives in the ocean like a blue whale, it may not be a big problem, but living on land, the ecological balance is likely to be quickly destroyed.
Can dinosaurs live well in modern times?
Because of their smaller size, modern animals may be powerless against dinosaurs. African elephants weigh an average of about 3.1 tonnes, and the most significant elephant recorded so far is a male elephant in Angola, Africa, with a net weight of 13.5 tonnes, equivalent to the size of 9 cars. However, as the largest land animal in modern times, the African elephant is only a small point in front of the Tyrannosaurus rex. The Tyrannosaurus rex has the most powerful jaws ever built on land, and it is very easy to bite an elephant, and more often than not, the elephant may not even have a chance to escape. Other animals except elephants are smaller, rhinos and hippos are like tigers catching roe deer to Tyrannosaurus rex, while zebras and antelopes are like tigers catching rabbits and mice. Once dinosaurs appear in the wild on a large scale, the tragic image of corpses strewn across the field will soon appear.
In this way, even if the dinosaurs are really resurrected, they can only survive in the zoo that humans have built for them like a movie. But even so, this model may not last long, because dinosaurs consumed too many resources. And as the number of dinosaurs increases after breeding, will they threaten human society like Jurassic Park? When the time comes, for its own safety, will humanity once again exterminate them?
For dinosaurs, maybe not resurrecting is a good thing, let their mighty figures only live in the imagination.