On the run

 Race on Tuesday, December 24 Race on Friday, December 27 Today was a 12 km long run to close 2024. This week, I came across a note on the Internet that caught my attention and was the reason for my wandering today. In a cave in France, evidence of human use of fire was found. The age of these hearth remains is 270 thousand years, making them the oldest remains of fire use in Europe. Something that the authors highlight is that at that time modern human beings had not yet arrived in Europe, so those responsible must have been Neanderthals (Homo neanderthalensis) or probably H. heidelbergensis , the common ancestor of Neanderthals and us. That there is evidence that humans before us used fire did not surprise me, that is well known.  Fire has always existed, but originally it must have scared our ancestors and the rest of the animals: it is lethal. When they saw fire, they must have run away. But once the danger had passed, some things must have caught the attention of our ance...

Bullfight on Wednesday, December 18 Friday, December 20, bullfight I hesitated to get up today, Friday, to run, yesterday I had a very good time with dear friends and I ate too much, so I didn't sleep well. Fortunately, I did run. This month, there were two news stories about human ancestors that caught my attention. The first was the discovery of fossil footprints of Hominins, which is what they call the great apes (Hominids) that walk upright. They were discovered in Kenya in 2021, but the conclusions have only been published until now. Of the footprints, there are some that are perfectly human, the others have some details that make them different, their age is about 1.5 million, we did not exist at that time, but if the Homo erectus , who from the neck down were the same as us, so the human footprints are theirs. Of the others, the study concludes that they are Australopithecus ( Paranthropus ) boisei . Another interesting thing, the authors of the study conclude that the foo...

Wednesday race Friday race In this wandering, I am going to comment on the variations of 2 gases in the composition of the atmosphere, carbon dioxide (CO₂) and methane (CH4). And what do these gases matter? These gases are responsible for the greenhouse effect, playing a predominant role in the climate, and have been responsible for changes in life on earth. For example, about 800 million years ago the concentration of CO₂ was between 1,000-10,000 ppm and that of CH4 was 10-100 ppm. With that concentration, the greenhouse effect was very high, and the earth was very warm. But then oxygen (O2), produced by the first phototrophic organisms, began to accumulate in the atmosphere and oxidize CH4, transforming it into CO₂, the problem is that CH4 has a greenhouse effect of more than 30 times that of CO₂, so That 700 million years ago the greenhouse effect decreased drastically, so much so that the earth completely froze. Fortunately, volcanic activity caused CO₂ to increase, causing the tem...

Race on Tuesday, December 3 Race on Friday, December 6 I'm still not speeding up, but increasing the distances of my runs, meandering as I run. When do we leave Africa? Obviously, I am referring to humans, I have never been to Africa. All the evidence shows that that is where we come from, the first humans, understood as human being a great ape that walks upright and makes stone tools, appeared there.  Virtually everywhere we look we find that humans expanded out of Africa with Homo erectus a million years ago and were already in Indonesia by 700,000 years ago. This species, based on the time it lived, was the most successful human, a little less than two million years. But haven't we gone out before that? There are very interesting remains, about 1.8 million years old, humans of approximately 1.5 meters, apparently the first human hunters. With similarities to earlier humans, such as H . habilis , but also to H . erectus , from the neck down they were already human, for some t...

Race on Tuesday, November 26 Race on Friday, November 29 A quiet week, two races back from the half-marathon, still enough time to wander. Suddenly, more than 540 million years ago, multicellular organisms appeared, and they not only appeared in quantity but also in variety. The question is, why do so many critters appear so suddenly? The truth is, I think it was not so sudden, we are talking about many millions of years ago, and as long as organisms with rigid structures did not appear, the possibility of them fossilizing was very low. But, even so: what determined that such a great diversity of life appeared in such a short period? The truth is that nobody knows. Let's wander... The concentration of oxygen in the oceans and atmosphere increased until reaching values ​​greater than 10% of the current level; This surely had an important weight. Aerobic organisms, taking advantage of oxygen, oxidize food by using oxygen more efficiently. It sounds like a mouthful, but that's how...

There were no races, rest week after the half-marathon. When you think of the Jurassic you think of dinosaurs, in fact, only dinosaurs appear in the films of that series. These animals have always captured our imagination.  But my favorite Jurassic critters weren't dinosaurs. When I was a child, in the house of Niño Jesús (that's the name of the street in Mexico City where my house was) there was a collection of books, a small children's encyclopedia called “My First Knowledge.” In it I encountered pterosaurs for the first time, with the knowledge of that time the books described them, fleshy wings with folds that joined the extremities to the body. I remember the book said that they were gliding animals, since with their great weight and size it would be impossible for them to take flight. It explained that these animals lived in areas of cliffs from which they could jump to plan and fish. I was a child, but it sounded absurd to me; The amount of energy they would expend e...

Race on Wednesday, November 13 Race on Sunday race, November 17 In the last entry I said that the crafty apes began to make stone tools, what were these tools used for by the first humans? To have access to food that they didn't have before. An animal less than five feet tall in the steppe required something to give it an advantage. There was food; There is always carrion in the African steppes, but for our ancestors, there was a major problem, they were very small and in scavengers there are hierarchies, so when it was their turn there was practically nothing left, only the most difficult to obtain. But with their stone tools, they could break the bones and reach the marrow, the most nutritious food that was out of reach for other scavengers. But would there be a way to get more? Yes, leaving carrion and becoming hunters. There is something that few people currently know, human beings are among the most physically resistant animals. Few animals can last as long doing non-stop phys...