The world without us

2008/06/01 Galarraga Aiestaran, Ana - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Biologia
• Eboluzioa
• Ingurumena

In response to the first question, there are already several articles and books. Among the best known are the article "Imagine Earth without people" ("Imagine the world without us"), by biologist Bob Holmes, in New Scientist magazine, and the book The world without us, by journalist Alan Weisman. When we call them to propose the realization of this exercise or game, we made a mention of these two works, but without ties to them we ask them to play freely. A week after putting the theme we met each other.

Arantza Etxeberria: importance of the question

Starting to think about this question, as a philosopher I think about how much the thought of society has changed in recent years, and especially in the XX. In the twentieth century.

Philosophical tradition has always regarded man as the centre of creation. Until recently, it was thought that the Earth and all the resources of the Earth were at the service of man. Now that has changed, man has rediscovered nature, we have realized that we have a deep relationship with Earth as a whole and with other living beings: we are able to put ourselves in place, we feel some member. Therefore, before your question, it could be said that it would be beneficial for the Earth and for the other living beings that dwell in it to disappear. And that's a revolution.

The system of values is changing; the XIX. and XX. Prestigious ecologists of the twentieth century pointed out that nature has value for itself, beyond what it brings us or what we assume. Without them, now no one would ask that question and, much less, no one would think that the situation posed by the question would be beneficial to life. But we have harmed the ecosystem so much, now it seems logical to think that without us they would flourish and develop.

There are two lines of reflection on the value of life, both individual and global. The mentality that the most valuable is the individual focuses on the complexity of beings, and there it should be noted that with the disappearance of the human being, intelligence and cultural expressions would disappear in the long term. However, the complexity of the human being is linked to other living beings and our abilities to think, feel and do are not so far from those of other animals. Hence the recognition of the obligations to animals and, in some cases, of their rights, their well-being. However, the disappearance of our species would be a huge loss from that individual complexity.

On the contrary, the concern focuses on a group that has more and more strength in ecology and philosophy: if we live as we are now lost, life would win in its entirety, at least to the extent that biodiversity would increase. And that response demands a profound change of life.

Kepa Altonaga: new balance

Here I have another book, After man by Dougal Dixon. A zoology of the future , in this book explains how fauna on Earth can be 50 million years after the disappearance of man. It is very interesting, but it must be taken into account that it was 1981, and at that time it was not admitted that in the past there could be terrible catastrophes that would affect evolution. Later came the theory that relates the disappearance of dinosaurs with the impact of the meteorite. However, this book is prior to the creation of this theory.

The author proposes at the beginning of the book that there will be a climate change that, as the human being has spent a lot of time outside the influence of evolution, will not be able to adapt and disappear. From there he explains what evolution would have done. At first there would be a totally chaotic time, since without human beings the situation changes radically and in this new situation we must achieve balance. According to Dixon, this balance will reach 50 million years after the disappearance of man.

Then, the biome with biome proposes the animals that will be in each of them. For example, in forests and meadows of temperate climate proposes some animals coming from rabbits. Of course, there would also be predators and from rats invents wolves as rats. They would look like rats, but they would be bigger and hunted in group. In the subsoil, on the other hand, the animals coming from the caps would predominate.

In short, what is there in this book? Dixon thinks that man has disappeared by a gradualist change and 50 million years later these animals are on Earth. Since 1990, however, disasters have another acceptance. From this perspective, questions of post-destructive speciation are now analysed.

For example, we now understand that over 65 million years ago dinosaurs dominated part of Earth's history. But when they disappeared, they left several empty ecological niches. The rest of species then entered a race in which, due to their personal capacity and their adaptability, there were evolutionary winners. In this way, the mammals experienced a spectacular boom, while the birds also occupied different corners.

And here is an interesting thing. When did mammals and birds occupy the space left by dinosaurs? So between 35 and 45 million years after his disappearance. So, if we now propose that man will disappear, and seeing what has happened in the past, we can think that it will take about 50 million years to achieve balance. Precisely that time is what he mentions in his book Dixon.

And in that new balance, what? Possibly a team will prevail. The current dominion of the human being is an epiphenomen, that is, a secondary phenomenon. Mammals are the main group and within them is the man. At a given time it has been imposed, but on a geological scale it is only a moment.

Therefore, once the man has disappeared, a group will dominate, not a single species. It would be necessary to see what conditions are on Earth in this case and those that best adapt to those conditions will advance. For example, today, animals that suffer the most from human consequences are large mammals, such as primates and many other animals that are running out of habitat. For them it would be good for the man to disappear.

But if we think that the conditions that would mean the disappearance of the human being will be absolutely detrimental to the living beings of today, there would be a very different situation. For example, we breathe oxygen, essential for life, but oxygen is a highly polluting substance that cyanobacteria contributed from metabolism. The evolution has managed to adapt later, but in reality the oxygen is oxidizing...

Then, for example, if a great radioactivity was to disappear, there are bacteria that live well with it, and perhaps from there evolution. However, radioactive isotopes would stabilize over time and then the situation would be different, while living beings were adapting to this situation. And another meteorite can fall at that time...

Apart from this, it must be clear that the species that are lost when a change of these characteristics occurs do not return: the dinosaurs disappeared and do not appear again. With us the same will happen. That is, if the human being is lost, he will not believe again.

Unai Ugalde: the possibility of creating intelligent beings

When listening to this question, the first thing that occurs to me is how would the human being disappear? As in these books and articles, it is recognized that man has disappeared without more and from there we can begin to create hypotheses. But for me it is interesting to think how the human being would disappear. And it is that for the world it is not the same to lose only man to disappear with him many other living beings.

To begin with, we would have to spend something very evident and serious to end all human beings. 6,500 million people spread all over the world, and the death of all by one agent is very difficult. I think that to kill everyone there would have to be a radical change in the atmosphere; with other disasters, I think someone would always be able to face it. If the cause is a disease, it should also cause infertility. It is very difficult.

Suppose, therefore, that there has been a great change in the atmosphere, which is unsustainable for human beings and who die. But if it is so harmful to human beings, it will also affect the rest of the living beings. Only a few would survive. There are safe insects, genetic and evolutionary studies have shown that when dinosaurs were lost, for example, insects advanced. They would also survive some creatures living in unique places such as subsoil, caves, and seabed.

Think now that after a time the atmosphere is recovered. Then there would be a new evolution; the lost species would not be created again, because there would be the survivors of the catastrophe, willing to occupy an empty space.

In this evolution would appear the first great marine invertebrates, as the great jellyfish. As there were no large predators, they would develop a lot; they would have new structures of movement, like candles...

Other large invertebrates, the cephalopods, would also be extended, which would become kings of the sea. Perhaps some vertebrate species would appear, some small fish would increase and eat plankton. Mammals would be missing and other species would occupy their place.

It would take millions of years to arrive and meanwhile, on land, it would not be alive. However, some seeds are likely to remain after this change in the atmosphere, such as moss and some gymnosperms, as well as microorganisms and fungi. From these seeds, over time, vegetation on the surface would be produced again.

At sea, biodiversity would increase and, as happened before, it is very likely that some species of protection of predators will land to lay eggs. They could move through the ground, for example, thanks to structures like the tentacles of octopus or... Advancing in the evolution would be created animals capable of living on the terrestrial surface and with flying wings.

Yes, they would not be like the current ones; they would have other structures, they would be otherwise. However, raptor chains would be formed and hierarchical networks would be created.

And I wouldn't rule out the possibility of creating intelligent beings. In fact, if there is an equal competition between two species, what is capable of elaborating sophisticated strategies or inventing something intelligent will prevail to anticipate the other. So, I think you can create intelligent beings.