Earth is a target in cosmic range. Humanity is the first species in history that can also do something to defend itself
One of my hobbies as the website editor is to check which keywords people use to enter the articles on the website. In light of the interest in near-Earth objects and the danger inherent in them, the question "Can the age of the dinosaurs repeat itself?" caught my eye. I decided to pick up the gauntlet and answer this question, at least as it can be understood from the context - can the extinction of the dinosaurs repeat itself.
In recent times, evidence is accumulating that meteorite impacts had important consequences on the surface of the earth, and especially on biological evolution. Such an injury could pose a danger from a natural source to life on Earth. Twice in the twentieth century, large meteorites are known to have collided with the Earth (Tongska) and this week (Friday 15/2/2013) as mentioned we received a double reminder of the threat: on the one hand An asteroid with a diameter of 50 meters that passed close to the Earth's surface, 2012 DA14 (only 27 thousand km, less than the orbit of the communication satellites), and a few hours earlier Meteor explosion in the air in Russia, which caused over a thousand injuries as a result of glass explosions in houses and cars due to the shock wave.
If the impact is large enough, it could disrupt the environmental conditions on the entire planet and cause an ecological disaster. The most recorded impact of this type occurred 65 million years ago, at the end of the Cretaceous period. This period in the earth's geological history is marked by a mass extinction, when more than half of the species on earth became extinct.
Although the geological record tells of dozens of mass extinctions, the mass extinction at the end of the Cretaceous has always intrigued paleontologists because it marks the end of the age of the dinosaurs. For tens of millions of years, these creatures thrived and developed a wide variety of specializations. Then, suddenly, they were gone.
The body that hit the Earth at the end of the Cretaceous period was a meteorite with a mass of over a trillion tons and a diameter of at least 10 km. The scientists identified this impact in 1980 after examining a layer that surrounded the entire world at the time, as a result of sediments that fell from the dust cloud that enveloped the Earth after the impact. This sedimentary layer is enriched in the rare metal iridium and other elements that are abundant in meteorites, but very rare in the Earth's crust.
Even after being diluted by the terrestrial material excavated from the crater, the chemical composition of meteorites is still easily identifiable. In 1990, geologists excavated and found the actual impact site in the Yucatan region of Mexico. The diameter of the crater, now buried deep underground (and to the waters of the Gulf of Mexico), was originally about 200 kilometers.
This impact released a huge amount of energy, creating a crater twice as large as the Tycho crater on the moon. The explosion lifted 100 trillion tons of dust into the atmosphere, as determined by measuring the thickness of the sediment layer that formed when this dust settled to the surface. Such an amount of material completely blocked the sunlight, and darkened the earth for a period of cold and darkness that lasted at least several months. According to the calculations, the explosion also produced large amounts of nitric acid and molten rock that were sprayed over large parts of the Earth's surface. The heat ignited a wave of widespread fires that probably consumed forests and pastures. Presumably, these environmental disasters could have been responsible for mass extinction, including the death of the dinosaurs.
There is a suspicion that mass extinctions at transitions between geological periods were also caused by impacts from large celestial objects, but none of them were as dramatic as the Cretaceous event. Even without such specific documentation, it is clear that vulnerabilities of this magnitude do occur and that their results can be disastrous. However, a disaster for one group of animals may create opportunities for another group. After each mass extinction, there is a sudden evolutionary burst and new species develop and fill the ecological niches emptied of their previous inhabitants by the event.
Meteorite impacts represent an important mechanism that can cause global disasters and affect the evolution of life all over the world. According to some estimates, most of the great extinctions of species could have been due to impact from space. This changes our perspective on biological evolution. The standard criterion for the survival of a human species is its success in competition with other species and adaptation to a slowly changing environment. However, an equally important criterion is the ability of a species to survive random global ecological disasters such as a meteorite impact.
Little by little, as a result of the insights in the discovery of the reason for the extinction of the dinosaurs, the recognition that Earth is a goal in a cosmic range penetrated the consciousness. In 1991, the United States Congress asked NASA to investigate the risk of a large celestial object impacting the Earth. The group that conducted the study concluded from a detailed analysis that such vulnerabilities can indeed be dangerous. The conclusion was that one should prepare for such events, but only recently did they actually start taking steps. NASA itself scans the sky in search of near-Earth objects and as soon as such an object is discovered, it receives close monitoring and a constant calculation of its chances of colliding with the Earth.
Other space agencies as well, and in particular the Russian one (which has also recently received reinforcement for its need to act), as well as many governments and even the United Nations Office for Outer Space Affairs, are seeking to increase activity on the subject.
Recently we also heard about A proposal to build satellites that would focus sunlight with laser beams that would be launched towards asteroids such as to change their course or even blow them up.
Although this is an insurance certificate, and in these days of budget cuts it seems like an impossible expense, but nature tells us that we don't have too much time for deliberation. It is our duty to act to prevent man from a fate similar to that of the dinosaurs and the one that he himself causes countless species of animals and plants (but we have written about this in the past and will write about it in other columns on environmental issues).
49 תגובות
ב
what is your point You are describing an imaginary situation if a lot of assumptions and what conclusion do you draw from it? There are really situations where species will develop relatively quickly. Ask anyone dealing with antibiotics.
Right :
I assumed there was one mutation. and that its effectiveness for survival remains constant.
But it is possible to assume several mutations that occur at the same time.
It is clear that the effectiveness of a mutation can depend on its percentage in the population. But even if we consider only a part of the time when the mutation is effective, we still get a much shorter time than the millions of years that are usually talked about.
It can also be assumed that there are mutations that benefit and accelerate each other.
for example:
1) Higher neck.
2) A stronger heart.
Each of them increases the effectiveness of the other. thus speeding up the process.
ב
Usually the effect of a mutation is much smaller, when it comes to natural selection in domestication the situation is different - every year there are new varieties of roses for example, and see what the domestic dog looks like after a few thousand years. Think that cabbage, cauliflower, broccoli and Brussels sprouts are artificial varieties of the same species - domestication again.
Darwin wrote about "the origin of species and the preservation of favored varieties". He never referred to disasters like mass extinction. I see no benefit in referring to disasters in the context of evolution. It doesn't contribute to the conversation.
In the example of the giraffes:
Even if the population is a million instead of a thousand, the process of changing the population will take about 200 years.
This is still very fast when talking in terms of evolution.
ב
Ah. Take an extreme example. Your limit of 1000 items is very artificial. The assumption that there are no more mutations and the assumption that this mutation is good even when the percentage of those with the mutation increases. You can't assume that much and draw a conclusion from it.
ב
Interesting calculation. I guess he is right. This is indeed evolution. what is your point
The biological system can be compared to a thermodynamic system.
The thermodynamic system moves from one equilibrium state to another equilibrium state.
The transition can be continuous or jerky.
Transition is a process. Even if it is continuous and even if it is jumpy.
Suppose a population in which a mutation occurs:
For example, a population of 1000 giraffes, 1 of which develops a neck 10 cm longer than the others.
Let's assume that this feature clearly gives her the ability to survive and pass on the genes to her offspring.
Let's say the giraffes give birth once a year.
In the first year there will be one offspring with the mutation and the rest are normal.
In the second year:
1 offspring of the mother, 1 offspring of the daughter, and the rest are normal. The general population size is maintained i.e. 1000.
in the third year:
1 descendant of the mother, 1 descendant of the daughter, 1 descendant of the granddaughter, and again the general population size is preserved, i.e. 1000.
And so on!
In a rough estimate: after about ten years, approximately 10% of the population will have the trait of the mutation.
After about twenty years, approximately 30% of the population will have the trait of the mutation.
After about thirty years, approximately 50% of the population will have the trait of the mutation.
After about forty years, approximately 90% of the population will have the trait of the mutation.
And from an evolutionary point of view very quickly. In fact, within a period of about a hundred years, almost the entire population will change and the mutation that gives an advantage will become the absolute majority of the population.
ב
I suggest you check the definitions in the dictionary. Everyone talks about a process and not an event. The closest word in Hebrew to evolution is development.
Of course you have the right to think differently, but when we talk about development we mean small steps that lead from one species to another. An asteroid collision is not considered evolution anywhere that I know of.
Every event is part of evolution.
including extinction or mass extinction.
ב
Evolution does not happen in leaps and bounds. Just small steps. The chance that a large mutation will increase the rate of reproduction is extremely small. Don't forget - at any given moment, the existing species are the result of evolution and are therefore already quite adapted to their environment. That tree of life you described does not contain big jumps.
When a certain species turns itself into another species - this is not evolution. The extinction of KT changed the face of the living world but I wouldn't call it part of evolution. Such a one-time event is not optimal and certainly exterminated many species that without this event would have developed in wonderful directions.
I would love to know how to prove the effectiveness of evolution 🙂 🙂 I have several explanations for this but none of them prove the claim.
Regarding the efficiency of the process:
I agree that this process is very effective.
In fact, it can even be proven mathematically that this process is many orders of magnitude more efficient than commonly thought.
Evolution is a process of adaptation. In this process, there may be "small" adaptations within the framework of the species, but there may also be "large" adaptations that are outside the framework of the species.
The process of changing and choosing the right one works at any scale. from the largest to the smallest.
inside and outside the species.
When a certain species gives way to another species, it is not fundamentally different from a certain species giving way to another species. It's the same thing but on a bigger scale.
If we describe the totality of all creatures as a kind of tree then this tree will have large central branches and also smaller and even smaller branches down to the smallest.
Evolution occurs in every branch of the tree. from the largest to the smallest.
The success of one species in competition with another species is no different from the success of a particular individual within the species in competition with other individuals within the species.
ב
No - it is not part of evolution. It is part of life, part of nature and affects the division of species. There is no "development" here - but the extinction of species. Evolution is built from the inability of items to reproduce in the population of a certain species.
I insist on this because it is the basis for another claim - that evolution as a process is more efficient than any other process that can be planned. That's another debate
Also between species.
for example:
The lion and the hyena.
It is possible that the lion will win the fight and survive and the hyena will become extinct, but it is also possible the other way around.
Such a thing is absolutely possible. And this is part of evolution.
ב
Absolutely right - the advantage depends on both place and time. But - again - the advantage for the trait is within a certain species and not between species.
ב
Your last sentence is what I've been trying to say from the beginning 🙂 That's what I call "differential reproduction rate".
One of the problems in understanding evolution is the concept of survival of the fittest. This definition may be interpreted as circular. That's why I always talk about differential reproduction.
Along with this, it is still possible that in a certain period of time or under certain conditions an advantage will be revealed to species A while in another period of time or under other conditions an advantage will be revealed to species B.
I realised:
When you say reproduction rate you mean the rate of population growth.
It already sounds much better.
Although it's not perfect either.
There may still be a more adapted population that has a slower growth rate than another population.
Population growth rate is only one measure of adaptation. There are other metrics.
The correct definition would be:
The increase in the population from the beginning of the species to the moment of measurement.
When we talk about rate, we talk about growth for a certain period of time, but the more accurate measure is the total growth and not the growth per unit of time.
But even that is not accurate enough.
It would be much more accurate to talk about the total growth in the population of those with a certain trait compared to the total growth in the population of those lacking this trait.
ב
Suppose the camel fills the space ... everything is true, and everything remains true even if the giraffe is not extinct. Actually - if the giraffe does not become extinct, the environmental pressures will be greater and the evolution will affect faster!!! The rest of the description is fine.
Your camel and sheep example is a bit funny. If the sheep reproduces faster than the camel then by definition there will be more sheep than camels. Think about it for a moment 🙂
Your goat thing is also wrong. You don't quite understand what the word "suitable" means. If the white goat reproduces faster then it is more suitable for the desert!!!!
I think our misunderstanding stems from the concept of multiplying quickly. If the white goat has more offspring, but these offspring do not reach maturity then I say that its reproduction rate is not high. You are probably looking at the amount of offspring and therefore the disagreement between us. Again - I look at the reproduction rate over time - by how much the population grew as a function of time.
Suppose the camel fills the living space vacated by the giraffe.
Then two kinds of camels begin to form.
1) The desert camel.
2) The jungle camel.
Over time these two species will be so different that there will be no hybridization between them.
This is certainly one of the ways in which evolution can occur.
And we will continue with other examples:
Suppose there are two species in the desert:
1) Camel means a species that reproduces slowly but is adapted to desert conditions.
2) Sheep means a species that reproduces much more quickly than the camel but is not adapted to the conditions of the desert.
The species that will fill the desert will be the camel even though it reproduces more slowly.
The same thing also happens without exception to the gender sphere:
For example, for a goat:
There is a black desert species that reproduces relatively slowly.
And there is a white variety that reproduces faster but is not suitable for the desert climate.
The goat suitable for the desert climate is the one that will fill the desert living space despite its low reproduction rate.
ב
What you describe is development, maybe, but it is really, really not evolution. Look at it this way. Let's assume Darwin was wrong and there is no evolution. What you describe will happen after all is true. Over time, many species will become extinct, but no new species will be created. It suits Aristotle to think like this, not a modern man……
And about the goats. There is a phenomenon called alliopatric speciation (as opposed to sympatric). This happens when populations are separated geographically. It certainly has an effect on evolution. A good example is the Gouldian finch in Australia. You should read about it here http://phys.org/news156706578.html#nRlv – This is really amazing!!
The separation you made into two islands is similar to domestication. Cows are selected for breeding according to their milk yield (just an example). As a result, breeds of cows were developed that are all descendants of aurochs (which is already extinct) - and these are really not the fastest breeding cows.
But but but - this is not a natural choice. Natural selection is determined by multiple offspring. An example of what you describe is peacocks - here the male with the most beautiful tail breeds. That's pretty much all that matters and that's why the peacock tail is so ridiculous. On the other hand - the peacock with the beautiful tail breeds more…….
If, for example, in a competition between lions and tigers, the lions win and cause the extinction of the tigers, then there is development here. The development is that the tiger species will no longer exist. He will become extinct.
Just like in the competition between the individuals of the same species and between the varieties of the same species.
The more successful species will over time fill the entire living space. There will only be lions in the jungles. The tiger gene pool will cease to exist. In its place will be a lion gene pool.
This is definitely a development.
Development is not just a change in the neck length of the giraffe. It can also include the extinction of the giraffe. After the giraffe becomes extinct, another animal will come (for example the camel) and fill the living space vacated by the giraffe.
The giraffe can become extinct as a result of competition with the camel or it can become extinct as a result of other things.
In any case: there will be a change in the global genetic database.
Although most genetic changes are mutations within the species, this is not the only way of development.
Regarding the goats:
There is evolution here.
In future generations, only goats of the more successful breed will exist. That is, the species whose reproduction rate is lower and therefore more adapted to the environmental conditions.
If by chance at a later stage the possibility of emigrating from the isolated island opens up. So the species that survived will fill the entire living space, while the extinct species will not be there. The gene pool of the goats will change!
ב
You are wrong on both counts.
1. Let's assume there is a competition between lions and tigers. Then there will be more lions, or tigers. But there will be no development!!!! Development will only happen when the lions compete among themselves. Because then - the lions that have the good qualities (ie - rapid reproduction) will multiply relative to the other lions. Understand - competition between species does not cause a change in the species. The only thing that can cause a change in sex is competition between members of the same sex. It is important to understand this in order to understand what evolution is and why it is so "strong".
2. Once you have separated the goats then there is no competition between them. In this case those that reproduce faster will indeed survive for the least amount of time. But there is no evolution here….
Regarding the goats:
Suppose two isolated islands.
It is clear that the goats that are suitable for food will survive and on the other island the goats will not survive.
Evolution is a process of development.
There are two factors in the process:
1) Change.
2) Choice.
The change was caused by changes in the genes. This of course happens in the context of sex.
Selection is caused by environmental pressures.
It is certainly possible that the choice will be between one species and another.
for example:
A choice between a lion and a tiger.
A choice between a cow and a buffalo.
Choice between mammals and reptiles.
ב
again.... Evolution calls within a species, as a result of competition between individuals in the species. Even without predators/preys there is evolution - even a single species will undergo evolution if the 3 conditions I mentioned are met.
Many things have an effect, such as cooperation between species. But - evolution itself reads exclusively between individuals of the same species.
I would love to hear what else is related to evolution beyond genes. I know that it is claimed that culture is also inherited, hunting methods or nest building for example. Chava Yablonka for example supports this. Dawkins also believed in this in the past but he also does not support it today as strongly as he used to.
And regarding the goat - you prove my point and contradict your point 🙂 The number of goats that reproduce quickly will increase at the expense of the goats that reproduce slowly. This is a beautiful case of tragedy of the commons - what is good for the individual is not necessarily good for the whole. Evolution strengthens the individual - and in the case of the goats, they will multiply quickly until there is not enough food - and then they may become extinct. Basa - but that's the situation
I think you'm wrong.
Relationships between different species are an integral part of evolution.
for example:
1) predator and prey relationship.
2) Ratio of competition between different predators.
3) Attitude of cooperation.
What you meant to say is apparently that genes are inherited only within the species. But the inheritance of genes is only part of evolution.
In the case of the goat:
The goat that reproduces too fast in relation to the food is a goat that is less adapted to its environment than the goat whose reproduction rate matches the amount of food. Therefore the goat whose rate of reproduction is slower will survive better.
ב
This is simply not true. Evolution only happens within a population of a species.
In the case of your goat the situation is simple. The one that reproduces faster, and provided that the reason for this is inherited, will be more common and survive for a long time. In the case you described it is not "for the benefit of the goats", but it is their misfortune. They will be able to do a lot, multiply quickly and eventually they may become extinct when there will be nothing to eat.
Remember, evolution does not work in anyone's favor - it simply calls.
Evolution occurs on all levels. Both within the species and between the species.
Even if we check what happens within a certain sex:
for example:
Goats.
Does a goat that reproduces quickly and eats all the grass in its environment have an advantage over a goat that reproduces at a slower rate so that there is always grass in the environment that it can eat?
ב
Evolution is not about competition between species. Evolution happens only within species. There is competition between species, that's clear, but it has nothing to do with evolution.
Your example of bacteria is also wrong for the same reason. The issue is competition within the species and not between species.
I will say again what I said above - evolution happens when there is a differential multiplication that results from destructive traits. These are the sufficient and necessary conditions for evolution. Let me put it a little differently - evolution happens if and only if there is a heritable trait that has variation, and this variation affects the rate of reproduction.
What is true is that competition with another species can accelerate evolution. Let's take a look at cheetahs in Africa. If there are many deer then there will be no competition between the cheetahs. But if the lions also prey on deer - then a shortage can arise that will cause a different reproduction rate within the cheetah population.
Sardines multiply very quickly.
The whales reproduce at a very slow rate.
Do sardines survive better than whales?
Breeding rate is but one trait. There are many more features.
A high reproduction rate does not necessarily result in survival.
for example:
Bacteria have a high reproduction rate but cannot survive in an environment that is not suitable for them.
That is, their ability to survive is limited to a certain environment.
In contrast, insects have a lower reproduction rate but are able to survive in a more diverse environment.
Mammals have a relatively low reproduction rate but they survive in a wide variety of conditions.
ב
You probably don't understand evolution 🙂 You are so wrong it worries me 🙂
All that is interesting in evolution is reproduction rate!!!!! What do you think is meant by "appropriate"? Only one thing!!! - The "suitable" is the one that reproduces the fastest!!!
Where do you come up with this claim that reproduction rate is not important? Where did you read that??
There is no such condition! The reproduction rate is not important.
The fit survives!
That's the whole theory.
If he is suitable because of the height reproduction rate. This is just one of many forms of adaptation.
Yaron
The concept of "cultural evolution" is not necessarily a correct description of reality. A basic condition of evolution is "reproduction at a variable rate depending on an inherited trait". I'm willing to bet, for example, that lack of intelligence is such a trait.
Think about it…..
Right. The singularity is just a possible scenario intended to make it clear that if we can defend ourselves, then in my opinion the meaning we give to our existence is that we are fulfilling the dream of cultural and technological evolution.
We must preserve life if we can. No one knows whether cultural or natural evolution is better.
Yaron
You are starting from Kurzwild's assumption that there is indeed a "singular point". We have never been so far from this point 🙂
We are free to write our own story. Our story is That we open a human integrated consciousness stronger than our consciousness. There will be many who will abuse power. There will perhaps be a "prophet" who will see further and with a small group will use consciousness not to subjugate an ordinary person but to carry out scientific research, cultural research, moral research, to promote whoever is possible to a heightened level of consciousness integrated with a machine.
The majority of humans will perhaps be enslaved to those cyborgs, and a minority of them will be sons of holes. The problem is that once intelligence reaches the singularity, knowledge will increase at a strong exponential rate, while cultural internalization has a slower rate of its own. That's why only if a group of smarter "awares" go to a place isolated from the others, it is said that another planet will have a chance to develop a "good" and moral civilization. Sounds like fantasy and science fiction, but I think this is a possible scenario. In the path of the singularity will stand the jihad - the desire to stop the development of free thought, because our cultural progress is slower than the technological one. It is not known if he will stop the development of artificial intelligence, or if the singularity will make him irrelevant, or if Islam will harness the intelligence to his benefit.
Asaf
Your argument that if we are destroyed by an asteroid then something developed from man will develop is not true. It is clear that new species will develop, but it is not clear to me why they will be more developed than us. If we are exterminated then it is very likely that the great apes will also be exterminated and perhaps most mammal species. Maybe in tens of millions of years a developed species will be created from us, but - in my opinion - it will happen anyway because we will not be here in millions of years in any reasonable case.
Dr. Rosenthal, I understood that when my father posed the question "Can the age of the dinosaurs repeat itself?" It refers to the extinction of the dinosaurs.
Be that as it may, there is no unequivocal answer to both questions because we don't know what awaits us.
When referring specifically to the era of the dinosaurs, I guess the answer in this matter would be "no". Humans have established a developed technological culture which, unfortunately, along with the many benefits has also brought ecological damage, created a "hole" in the ozone layer and in the not too distant future the quantities of water and food will be scarce. I wonder if nature will be able to turn the wheel back or move forward and creatures will evolve that will be adapted to the environment that humans will leave behind.
The next step is genetic engineering.
That is, the mind, which is an evolutionary product, will begin to produce an evolution of a new and exponential variety.
We are in the development of a new era in a new type of creation
To Dr. Rosenthal,
According to the decision of the Academy of the Hebrew Language, these are שלינייים
Regarding the definition of what a developed species is, I have to disagree with you. If evolution was only interested in Peru and Rabo, we would have stopped at bacteria, but luckily for us, life continued to evolve into more "developed" or, if you will, more sophisticated forms. The mechanism that activates the bacterium is infinitely simpler than the one that activates a mammal. With each extinction we evolved a little more. The mammals were able to survive after they were able to develop a special mechanism for maintaining body heat, the negative ones were able to grow a placenta that allows the fetus to grow for a long time and therefore also allowed the brain to develop into a more complex form.
The next stage will be evolutionary in the case of global extinction or initiated if we assume we start changing ourselves genetically but in any case we will be more complex and developed than we are today.
confidentially,
To get an answer you have to know how to ask the right question,
My father "translated" the question
"Can the age of the dinosaurs repeat itself"
to the correct "semantic" form and tried to give an answer to the question
If there is a possibility of a mass extinction similar to the one that wiped out the dinosaurs,
Who wants to know if the dinosaurs can reappear
(since this is the essence of the original question)
You have to ask if there is a possibility that there will be a mass extinction and then conditions will be created
that will enable the development of reptile species such as the dinosaurs...
To assemble
You should know that "primitive" means initial,
That is, whoever was before, is not necessarily "less developed"...
If you meant the shiliaitans? You should know that in zoology it is who counts
More "developed" is a species with higher chances of survival,
The species Homo sapiens has only existed for about 100 thousand years,
(and most of the time is busy with self-destruction)
His nation has species that exist for hundreds of millions of years...
and will also survive the environmental and self-destruction that man will cause,
So who is more "developed"?
Every extinction is also an opportunity, in the previous attacks the primitive creatures were exterminated or greatly diluted and allowed more developed creatures to thrive. This is also what happened in the last extinction, following which the shilini and their son, man, developed. Perhaps another extinction is only for the better, and creatures more developed than man will succeed where we have failed.
My father's article is in place. You understood the need and the problem, and combined the previous contents, including the research
that evolution is affected by collisions. The clarifications are semantic. It is clear to all of us that the meteorite was a wake-up call.
As for the laser weapon, it deploys the fusion part of the asteroid by deflecting it scattered over a year. I think it's too dangerous. You also need a stun weapon that wreaks massive destruction in a fraction of a second. A nuclear weapon that will wait for the asteroid and explode before impact is a complementary solution. It is obviously limited, because it is not possible to blow up a bone with a diameter of 500 meters made of metals, without drilling into it, and this is not feasible. Like Israel's defense system - multi-layered.
I also have doubts about the question of whether the era of the dinosaurs can repeat itself, the more correct question should be whether the extinction of the dinosaurs can repeat itself.
Father, I do not find in this article an unequivocal answer to the main question - "Can the era of the dinosaurs repeat itself".
This article puts a question mark around this question because we don't know what awaits us, and it is clear that the answer will be "yes" as long as we do not have the tools to deal with threats from space when it comes to an asteroid whose diameter is a little larger than 50 meters and weighs a lot.
So the answer will be "no" as long as we have the tools to deal with threats from space.
I also see a need to separate the human race from dinosaurs and other animals, especially when it comes to this issue.
The human race has awareness and does not act solely according to natural instincts, and it can create protection for itself. An animal will survive the impact of a celestial body as long as it is built for it.