Thomas Halliday: "Instead of trying to revive extinct animals, it would be better to protect our amazing planet"

• Adriana Ocampo (NASA) "The asteroid that extinguished the dinosaurs helped humans appear"

Imagine that next summer, instead of traveling anywhere on the planet, you could take a safari through the past and move to one of the landscapes that existed millions of years ago: the lands walked by the titanic dinosaurs, giant penguins and other fabulous creatures already extinct, or perhaps the lands of Kenya in which the first hominids lived.

The evolutionary biologist paleontologist Thomas Halliday (Edinburgh, 1989) invites us to this time travel in

(Debate), a book in which he reconstructs with the precision of a witness the geological history of our planet during the last 600 million years .

His story, however, is based on what scientists have learned over centuries of studying the traces that have been preserved from those worlds that have already disappeared.

Because for Halliday, associate researcher at the University of Birmingham, fossils are "true biological hieroglyphs" and his literary journey through extinct ecosystems is also a wake-up call about the disturbing future that awaits our planet due to the environmental crisis caused by human activities and that is translating into rapid changes in landscapes, as he points out during an interview with EL MUNDO in Madrid.

In his book he describes what some regions of the Earth were like in certain geological periods, such as the Mediterranean area 5.33 million years ago.

How would you summarize the evolution of the area occupied by Spain today and how long did it take to form the Iberian Peninsula as we know it today? Well, it all started, like the rest of Europe, in the Jurassic, with an environment more similar to the tropical climate , 200 million years ago.

There were large islands and one of them was Iberia.

Europe began to emerge, Africa began to move north and that led to the formation of mountain ranges like the Alps.

The formation of the Iberian Peninsula as we know it today is partly due to this phenomenon, although sea levels have fluctuated over the last few million years, rising and falling.

And at that time you mentioned,

in which the Mediterranean had dried up, Spain and Africa were connected.

The area where the Strait of Gibraltar is now was occupied by long and very deep canyons.

The geological history of Spain is fascinating and preserves very important testimonies.

For example, Las Hoyas, in Cuenca, has wonderful dinosaur fossils from the time when it was an island, and Atapuerca has some of the oldest human fossils. You say that since the last Ice Age, large species have been disappearing from all continents or about to, and that our world is beginning to resemble a post-extinction world.

Some scientists say that we are experiencing the Sixth Great Extinction, do you believe it too?

The area where the Strait of Gibraltar is now was occupied by long and very deep canyons.

The geological history of Spain is fascinating and preserves very important testimonies.

For example, Las Hoyas, in Cuenca, has wonderful dinosaur fossils from the time when it was an island, and Atapuerca has some of the oldest human fossils. You say that since the last Ice Age, large species have been disappearing from all continents or about to, and that our world is beginning to resemble a post-extinction world.

Some scientists say that we are experiencing the Sixth Great Extinction, do you believe it too?

The area where the Strait of Gibraltar is now was occupied by long and very deep canyons.

The geological history of Spain is fascinating and preserves very important testimonies.

For example, Las Hoyas, in Cuenca, has wonderful dinosaur fossils from the time when it was an island, and Atapuerca has some of the oldest human fossils. You say that since the last Ice Age, large species have been disappearing from all continents or about to, and that our world is beginning to resemble a post-extinction world.

Some scientists say that we are experiencing the Sixth Great Extinction, do you believe it too?

in Cuenca, it has wonderful dinosaur fossils from the time when it was an island, and Atapuerca preserves some of the oldest human fossils. You say that since the last Ice Age, large species have been disappearing from all continents or they are about to, and that our world is starting to look like a post-extinction world.

Some scientists say that we are experiencing the Sixth Great Extinction, do you believe it too?

in Cuenca, it has wonderful dinosaur fossils from the time when it was an island, and Atapuerca preserves some of the oldest human fossils. You say that since the last Ice Age, large species have been disappearing from all continents or they are about to, and that our world is starting to look like a post-extinction world.

Some scientists say that we are experiencing the Sixth Great Extinction, do you believe it too?

It is difficult to measure.

Many of the elements of judgment that we have available now do make us glimpse that a mass extinction has occurred, but when we look at the past we have the problem that we do not know everything that there was.

Certainly, as a species we are having an impact on the unusual world, which is not comparable to that of any other species that has lived in the past.

So my answer is that we are destroying ecosystems that in turn make life possible.

We are at risk of mass extinction, but all is not lost.

The good thing is that we know how to combat it, what tools to use to counteract this trend, such as reducing CO2 emissions.

Are there examples of animals still living today that survived the asteroid impact that wiped out the dinosaurs 66 million years ago, but are now threatened?

All living things today have ancestors in the past that survived extinction;

However, if you ask me for a creature whose current way of life is similar to the one it had in the past, we can talk about crocodiles, although the variety of crocodiles we have today is not remotely similar to the one that existed, for example, in the past. Cretaceous.

We have to consider that the environment in the Cretaceous world was very different from what we have now, for example, there was no ice at the poles and the climate was moderately hot, while in the last 30 million years we have had a much colder world. .

As a result of that change, all species had to adapt.

The increase in temperature due to CO2 concentrations that is forecast for the year 2100 would reach levels that would approach those that existed 35 million years ago.

Humans have never been exposed to temperatures like these.He states in his book that the presence of plastic everywhere is proof of our impact, and also that there are already microbes that feed only on plastics.

Tell me about them. That's right, this microbe,

, was discovered in wastewater from a plastics recycling plant in Japan.

It digests the bonds of PET plastics, which have many uses, for example to make plastic bottles.

We have seen that throughout evolution, when a new material such as plastic appears, organisms tend to adapt to that new situation, and in this case they digest it, which can be useful in addressing the problem of what to do with these waste and also shows us how versatile the evolution and adaptive capacity of living beings can be.

We are frequently seeing new temperature records, including in Antarctica.

According to estimates made by paleobiologists,

What period of the Earth was the warmest and which the hottest throughout its history?

If you ask me to go back to the beginning of the Earth's geological history, 4.5 billion years ago, about 600 million years ago we were coming out of the so-called snowball period, during which almost the entire planet was frozen and they could only live microorganisms.

It was perhaps then that multicellular organisms began to develop.

That would be the coldest time, and the warmest took place during the Permian, which ended 250 million years ago, and which is the period during which the greatest mass extinction of living beings occurred.

There was only one landmass, a single megacontinent within which temperatures were extreme.

The asteroid that fell 66 million years ago and wiped out the dinosaurs is one of the best-known geological episodes.

In your opinion, do we take the asteroid threat seriously today? I don't know much about the asteroid threat, it's better to ask a space specialist, but I think it's something we can't do much about , considering the speed at which they travel and with which they eliminated the dinosaurs, in a fraction of a second.

Obviously now we have many more chances of detecting it, but we can't do much so I think that what we should worry about and what we should work on is solving the things that we can solve, and not despair about issues for which we can do nothing .

Are we taking the asteroid threat seriously today? I don't know much about the asteroid threat, it's best to ask a space specialist, but I think it's something we can't do much about, considering the speed at which they travel and with which they eliminated the dinosaurs, in a fraction of a second.

Obviously now we have many more chances of detecting it, but we can't do much so I think that what we should worry about and what we should work on is solving the things that we can solve, and not despair about issues for which we can do nothing .

Are we taking the asteroid threat seriously today? I don't know much about the asteroid threat, it's best to ask a space specialist, but I think it's something we can't do much about, considering the speed at which they travel and with which they eliminated the dinosaurs, in a fraction of a second.

Obviously now we have many more chances of detecting it, but we can't do much so I think that what we should worry about and what we should work on is solving the things that we can solve, and not despair about issues for which we can do nothing .

considering the speed at which they travel and with which they eliminated the dinosaurs, in a fraction of a second.

Obviously now we have many more chances of detecting it, but we can't do much so I think that what we should worry about and what we should work on is solving the things that we can solve, and not despair about issues for which we can do nothing .

considering the speed at which they travel and with which they eliminated the dinosaurs, in a fraction of a second.

Obviously now we have many more chances of detecting it, but we can't do much so I think that what we should worry about and what we should work on is solving the things that we can solve, and not despair about issues for which we can do nothing .

Going back to your question about temperature extremes, a lot of people say, well, it's hot, but that's not a big deal either, because there have been times in the past when it was really hot.

The bad thing is not that the temperature rises a lot, but the speed at which these changes are taking place.

These sudden and abrupt changes are the problem and are very harmful.

It is not to have a temperature record, but it is to have so many temperature records in such a short period, year after year. Have you seen the movie 'Dont look up', about a large asteroid that is headed for Earth? I have seen it, but I interpret it as an analogy with the problem of climate change.

From your experience, do politicians heed the warnings of scientists?

Until now, I would say no.

The first studies showing that carbon dioxide (CO2) was a greenhouse gas were published in 1877, just two years before gasoline became commercially available as a fuel.

And the first US president who was warned about the negative effects of CO2 in the atmosphere was Lyndon Johnson.

I think that, little by little, there is a greater awareness and it is an issue that is increasingly in the public debate.

Politicians are also realizing that it can also help them win more votes, as we just saw in the Australian election [Anthony Albanese of the Labor Party won].

But although things are improving, in the United Kingdom, for example, a new tax has just been announced for fossil fuel producers -coal, oil, etc-,

which also affects wind energy producers, due to the rise in prices.

Renewable energies are going to have to pay for something they have not caused.

At the moment, there is no connection between what politicians say and what they do.

There is great concern about the war in Ukraine and the possibility of a nuclear attack;

In addition to the millions of deaths it would cause, how could it affect the Earth?

We talked about the idea of ​​nuclear winter.

66 million years ago an asteroid hit, the sun was blocked for two years and as a result, plants could not photosynthesize and ecosystems collapsed.

I am not an expert in the effects of nuclear weapons, I think that some of their effects would be similar, but a nuclear war in theory should not have such a devastating effect as that of the asteroid,

We are now talking about two different catastrophes.

We have an environmental catastrophe that the human being is causing little by little, and another that depends on a concrete action of the human being.

I am more concerned about the one that is taking place little by little, the environmental catastrophe. Now scientists can extract DNA from some extinct animals, such as mammoths.

If technology allowed it, should we try to revive extinct animals? It is a nice idea that you propose, to imagine that we could see these creatures alive, instead of seeing them petrified;

but I think that reviving extinct species raises many ethical dilemmas.

To begin with, your environment no longer exists.

In Siberia, the Zimovs are trying to rebuild the ecosystem in which the mammoths lived.

You need an Indian elephant, which is your closest living relative,

to give birth to a creature that you don't know if it will survive.

Elephants and probably mammoths are highly intelligent, they pass on their culture and all the information they need to survive in the world around them to their young.

How would we teach these mammoths created by us to function in an unknown environment?

Instead of pining for a bygone world and trying to resurrect it, I think we should focus on protecting our amazing world today, and making sure it survives for many years to come. If I were to bring you a time machine now, what period of geological history would you travel to? Like tourist would go to the Mediterranean 5.33 million years ago, when it dried up and began to fill up again.

First the water reached Italy and Malta.

A huge waterfall originated, much larger than the fall of the Angel Falls in Venezuela.

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