Deism and atheism

There are those who believe that everything wonderful in the universe is the work of God, however, with all the powerful that they consider, they do not judge him author of the evils and human tragedies. That is why there are more and more people who consider that the divinity is a human creation, that the powerful created it to subdue the weak. Christopher Hitchens considers that God has all the attributes of goodness and love, provides the good, but misfortunes are not attributed to him.

He affirms that "From God come compassion, consolation, health, love, and when none of that comes, when life is a hell of suffering, responsibility is never attributed to God but to fate. God is almighty, but the evils that happen are the work of the devil or are there to test the faith of men and make them worthy of eternal life. "

He asks "if the human species is a dream of God or God is the oldest dream of the species", and quotes Luis Borges stating that "theology is a branch of fantastic literature, (that) Einstein made sarcasm famous that being an expert in God was equivalent to being an expert in fairies. "

Taking Eagleton Ferry that "there is a link between fundamentalisms and global capitalism, which generates hatred, anxiety, insecurity and feelings of humiliation." Concludes that if God does not exist, man is the only source of values ​​("God is not good", Debate, Buenos Aires, 2008).



Since 1996 Michael Behe ​​defends the theory of intelligent design, biblical creationism. This theory was adopted by the government of George W. Bush, and imposed in some states of the Union, although Darwin showed that species, including humans, "are the result of a chain of natural transformations."

Religion was always opposed to scientific evidence, as the universe is the result of an infinite chance. There will always be people who yearn to return to the conservative past.

The opinion of George Clooney or Emma Watson on the theory of evolution has more impact than that of biology teachers

Only in the first months of last year, four states in North America studied laws to authorize the teaching of creationist theories in science class. And is that, despite the scientific consensus around Darwinism, human evolution remains a controversial issue in much of the world.

Therefore, many scientists are dedicated to pursuing strategies to better convey evolutionary ideas and make them stop in a reluctant society. It is true that this problem is especially strong in the US where 42% of the population believes that man was created as it is today. But that is precisely what is helping us to learn things: like where a celebrity gets to take off a biology teacher.




Through the New Evolutionary Illustration, I came to a work by Steven Arnocky and his team realized that no research had explored whether the acceptance of evolution could be susceptible to the opinions of other influential people. To study it, they selected 158 subjects to different opinions to see which of them had a greater effect on the population.

On the celebrity side, they chose George Clooney and Emma Watson (who were selected because a previous investigation showed that they met the maximum criteria of social attractiveness). On the side of the academy, they created a prestigious biology professor named George Rooney.

The sample is small and homogeneous, but as exploratory research it seems correct. In addition, the conclusions go in the line of previous investigations. The data indicate that, indeed, the opinion of a celebrity on the evolution influences the social acceptance of the same (more than the one of the experts in the field). It is not a big surprise. We already knew that celebrities can influence the fundamental values ​​and beliefs of people, on important issues, such as political orientation or religious affiliation.

But, more important, what the study points out (and previous ones) is that once the celebrities make a statement, the impact is very difficult to eliminate. "Public statements made by celebrities that contain scientific misinformation continue to exert an influence on people's opinions, even after they have retracted," the authors explain.



That is, the results show that, for better or for worse, celebrities have a fundamental role in the scientific literacy of the general population. In evolution, but also in vaccines, climate change or transgenics, the influence of celebrities seems to be decisive. It is something to keep in mind.

A flaw in the thinking that unites creationists and conspiranoids

Says Steven Pinker in Los Angeles that leads within humanity took a great leap forward when he decided to accept that much of the misfortunes is not behind the will of a God angry with our behavior or the spell of a witch. The English phrase "shit happens" is one of the foundations of civilization. Scientific thought in particular, the idea that "everything happens for a reason" or that something "had to happen". However, they are phrases that are often heard with some frequency.

In a recent article published in the journal Current Biology, a group of researchers led by Sebastian Dieguez, from the University of Freiburg (Switzerland), has tried to understand what is behind this type of thinking flaws and has found a relationship between two Evidence seemingly separate: creationism and theories of conspiracy.

"Both belief systems share a very powerful cognitive bias that we know as teleological thinking," says Dieguez. "It is a way to deal with complex issues but they are easy to understand if we have a distant and last cause that made everything as it is now," he continues. "In the case of creationism, that ultimate cause is God, who created everything as we know it," he adds.



That way of thinking made the appearance of the theory of evolution difficult, because it was a less intuitive way of understanding the world. "The way of thinking that says that trees have leaves to give us shade or that the sun rises to warm us up, seems to be something very intuitive and is the way the brain works spontaneously, seeing that things are good for something", indicates Dieguez. "Small children, for the most part, think like that, whether they are children of a religious family or not. And neither is it a completely stupid way of thinking, because to say that white bears are white to hide in the snow makes sense. That way seems the easiest to assume for the human being, but scientific progress and especially Darwin's theory of evolution has given us another way of seeing reality, "he says.

In previous works that try to understand these ways of thinking, Dieguez had shown that conspiracy is not explained because it is believed that nothing happens by accident. The conspiracy see that the world is complex and that there are random factors in its operation, but still believe that what happens in the world has one or several active minds behind that make it happen with an intention. The researcher from the University of Freiburg saw similarities between this way of thinking and creationism and tried to see if both were related to teleological thought and were related to each other. "Conspiracy is a way of thinking that does not involve a creator god but a group of people identified, but very nebulous, very strange, hidden, that clarifies everything," Dieguez recalls. "Everything you see is an attack or a natural disaster, it seems very complicated, but it is easy to understand if a distant and ultimate cause is the explanation of everything that made it as it is," he concludes.



After studying several groups of people in Switzerland and France from questionnaires, they observed that there was an association between believing in creationism and conspiracy theories. By pointing out this relationship, the authors want to highlight the flaws in this type of theories so that people can detect them. "Conspiracy is a kind of creationism that refers to the social world and knowing it can help to deal with some of the most widespread problems within our post-truth era."

"Creationism is a kind of conspiracy theory because to believe it, you must also believe that scientists or biologists are not only wrong but have a plan to discredit religion and sacred texts. It is a conspiracy against God, "says Dieguez. "On the other hand, conspiracy theories are a form of sociological creationism. As soon as you see something that is spectacular like a terrorist attack or a natural disaster, you are looking for a very clear explanation and a function. That has been seen with the bridge in Genoa. On Twitter and Facebook there are people saying that it is very strange that it happens now when there are certain problems in politics in Italy or France and that it is used to distract people's attention from other problems. Someone managed to make it happen completely perfectly and hidden for something, although it is not clear who did it or for what, "he concludes.


Darwin's theory of evolution confirmed: the moth changes color to adapt to the environment

Scientists from the University of Exeter (United Kingdom) have shown that the spotted moth, also known as 'Darwin's moth' for having been identified as an evolutionary example, uses its color to better camouflage itself from the birds that feed on them, which caused them to darken when industrial pollution blackened British forests in the nineteenth century.

"It is one of the most emblematic examples of evolution, but fiercely attacked by creationists who seek to discredit the theory of evolution," says Martin Stevens, of the Center for Ecology and Conservation of the Penryn Campus of the University of Exeter. The study has been published in the journal Communications Biology.




The mottled moth or butterfly of the birches (Biston betularia) owes its name to this tree, whose trunk it uses to camouflage itself before the predators. In the 19th century, with the Industrial Revolution and the atmospheric pollution produced by the coal dust, the bark of the trees darkened, which also caused the moths to darken.



This phenomenon, called industrial melanism, in which the darker varieties prevail in contaminated areas, served to demonstrate Charles Darwin's theory of evolution by natural selection, being a subject of debate between evolutionary and creationist biologists. Afterwards, the disappearance of the coal dust pollution returned to harmonize the amount of lighter moths, which were majority before the Industrial Revolution.

The study by the University of Exeter has shown that moths manage to camouflage themselves in the trunks of trees effectively to the vision of predatory birds. "Using digital image analysis to simulate bird vision and field experiments in British forests, we compare the ease with which birds can see dark and pale butterflies, and determine their risk of predation," explains Professor Stevens.

"Our findings confirm the conventional history presented by the first evolutionary biologists: that the changes in the frequency of dark and pale butterflies were due to changes in pollution and camouflage," adds the Exeter researcher.




An investigation could rewrite part of the theory of human evolution

The new hypothesis indicates that the species progressed in dispersed and isolated populations from the extreme south to the coasts of North Africa, and not from a single and concentrated population.

A group of researchers from the University of Oxford determined that the human species evolved at first in dispersed and isolated populations in Africa, contradicting the usual narrative.

The extended theory defends that "Homo sapiens" progressed from a single ancestral population in a region of Africa about 300,000 years ago.

However, the team led by the University of Oxford scientist Eleanor Scerri concluded that the first humans understood a pan-African meta-population "subdivided, changing and with physical and cultural diversity".

"This fits with a subdivided population model in which genetic exchanges are not random or frequent and allows us to begin to detail the processes that shaped our evolutionary history," Scerri said, according to the specialized journal Cell Press.

Natural barriers, such as rivers, deserts and forests, that separated these populations, created opportunities for migration and contact between groups that had previously separated.

The theory presented today, which points out that there was mixing and isolation of populations from the extreme south to the coasts of northern Africa, is more consistent with the fossil and genetic data than a single population model.

The analysis of fossils of "Homo sapiens" combined with inferences made from contemporary DNA samples suggested levels of early human diversity that supported the changing subdivided population model of the researchers.

"For the first time, we have examined all relevant archaeological, fossil, genetic and environmental data to eliminate field-specific biases and assumptions and confirm that a mixture of pan-African origin fits much better with the data we have," Scerri said.



In the future, according to the authors, this research will allow models of human evolutionary history to reject the simple linear progression of what might be called "archaic morphology" towards a more precise explanation of the complexity and irregularity involved in evolution.

"We are an evolutionary lineage with deep African roots, so to understand this history, we must re-examine the evidence from various sources without an a priori conception," concluded the scientist.

Does the theory of evolution still affect the human being?

On February 12, 1809, Charles Darwin was born, the British naturalist who completely changed our vision of life, based on divine creation until then. 200 years ago nothing was known about the origin of the first living organisms and how they had laid the foundations of the exuberant biological wealth of our planet. Charles Darwin postulated that all species of living beings have evolved over time from a common ancestor through a process called natural selection. Natural selection is based on the fact that certain organisms present hereditary variations that enable them to live longer and leave more offspring than others, so that in the long term, generation after generation, there is an accumulation of favorable characteristics that improve the adaptation of the species to its surroundings.

There is some controversy in the scientific community about whether the human being continues to evolve, and therefore, experiencing changes in its genome that make it unrecognizable in a matter of centuries. Some researchers are convinced that natural selection has stopped affecting humanity thanks to technological advances, which allow, for example, the genetic manipulation of the zygote. However, most suggest that man is in constant evolution and that the natural and sexual selections are still valid in our species, since we have not reached the maximum degree of adaptation to the environment, which is increasingly changing due to precisely , to this technological development.

These are some of the changes experienced by the human being during the last thousands of years and that would demonstrate that we are still subject to evolution:




Less intelligent: According to a study by the University of Umea (Sweden), the human being has seen its IQ reduced in recent decades because smarter people choose to have fewer children, while people with less favorable genes increase his offspring.


Smaller brains: The latest measurements reveal that the average volume of the brain of the human being has decreased by 10% in the last 30,000 years, that is, the equivalent of a tennis ball. According to experts, this brain reduction has its explanation in that we have developed more sophisticated forms of intelligence and we depend to a lesser extent on the gray matter that controls our body to survive.


Best musicians: According to various studies, musical ability is an index of good learning abilities or fine motor skills, which would explain the greater reproductive success of those who practice it. On the other hand, man has developed an innate predisposition to dance from birth, also considered an indicator of social skills and communication skills.


Monogamous: A study by the University of British Columbia (Canada), stated that communities that allow men to have several wives develop a higher rate of violence, poverty and gender inequalities, while monogamy reduces male competitiveness, thus decreasing the associated social problems and ensuring greater longevity.


Better cooks: Cooked meat provides more energy than raw meat, according to a team of researchers from Harvard University (USA). This finding suggests that humans are biologically adapted to take advantage of the benefits of cooked foods.


Liars: Some researchers suggest that knowing how to lie is an evolutionary advantage, since conflicts of interest cause that nature is favored by individuals who suppress or misrepresent information.


More readers: According to an investigation carried out by the American researchers Jonathan Gottschall and Joseph Carroll, the literature favors social behaviors that fulfill an adaptive function and incite us to fight basic impulses and work cooperatively.


The new strategy of Creationism against Science

The theory of the evolution of the British naturalist Charles Darwin is a fallacy and the existence of the human being can only be explained by a "creator". This is what creationists want to be taught in schools since the 1920s. And they have not always used the same strategy for it. As their particular arguments have been rejected by the courts as unconstitutional, they have been adapted with others modified to gain influence and power. Does it sound like something? Is not it precisely what animals and plants do to survive? A new study by the National Institute of Mathematical and Biological Synthesis (NIMBioS) and the National University of Australia (ANU) ensures that, ironically, the particular creationist battle over the years to modify the way in which biology is taught in The classrooms are very similar to the theory of evolution that they criticize so much.

The researchers, who have published their findings in the journal Science, have developed a kind of phylogenetic tree that reflects the variations in the texts of the legislative proposals of these fundamentalist ideologues in favor of Creationism from 2004 to the present, ten years totaling 65 bills.



Initially, the creationists advocated directly to eliminate the teaching of the evolution of the classrooms. They managed to enact prohibitionist laws in several states, but the Supreme Court considered them contrary to the Constitution in 1968. They then opted for a new strategy and tried to introduce an alternative subject to biology, so that students could also learn the "design intelligent ", which maintains that life is so complex that it can only be explained as a designer's work, just as a watch is the work of a watchmaker. After achieving it several times with great controversy, Justice turned its back on them again.


The "critical analysis"

As "intelligent design" challenged legality, creationists opted for a stealthier last strategy, which fosters policies of "critical analysis" of evolution and the origin of life, and of other scientific aspects such as cloning or global warming. This is what happened in Louisiana and Tennessee, where they managed to pass laws so that schools can study Creationism. The trick is to defend that teachers have academic freedom to teach what they want and question what is in the textbooks. So if a teacher says that the theory of evolution has gaps and that there are alternative explanations, it is in all its right.

"It is clever, because they do not mention creationism, but they give teachers permission to include pseudoscience and protect them from public administrations that say that these things should not be taught," explains Nick Matzke, ANU researcher. However, his analysis shows "that most of these bills can be related to Creationism again through the presence or absence of phrases that reveal their shared history".

In fact, the study found that anti-evolutionist proposals show evidence of "offspring with modification", suggesting that anti-evolutionist legislators are copying proposed ideas recently, instead of writing new bills from scratch. "Most of the proposals do not make sense, they have been copied from another State and changed without thinking," says Nick Matzke, and jokes: "They are not terribly well designed."

They allow to extract 40 samples from the Grand Canyon to a creationist who sued the national park

The followers of the "creationism of the young Earth" believe that our planet is not more than 6000 years old, despite the enormous amount of evidence that indicates the contrary. One of those tests is the Grand Canyon of the Colorado, whose layers exhibit about 2,000 million years of the geological record.

How does a creationist defend himself against an argument the size of the Grand Canyon? For example, assuring that its erosion is actually due to the Universal Flood mentioned in the Bible. Or at least that's what the group Answers in Genesis believes to which the doctor in geology Andrew Snelling belongs.

Snelling has been working for years on an explanation of the Grand Canyon that is consistent with the Bible. In 2013, he asked the National Park Service for permission to collect some rock samples in the Arizona canyon, but he was told that his project had no value to justify the extraction.



The creationist geologist wanted to collect a rock type known as a deformation structure to show that all the folds of the canyon were formed from soft sediments, which do not require long periods of time to create those structures. However, one of the academics advising the park said that such samples could be found anywhere in the world, so Snelling could pick them up outside the Grand Canyon.

The creationist did not get his permit and in May of this year he sued the National Park Service. He argued that his rights had been violated when the federal agency rejected his request for his religious opinions.

Finally the national park gave way to pressure and Snelling withdrew its claim in June. The creationist geologist will be able to collect about 40 samples the size of a fist, as long as he freely publishes the results of his study.

Sighting test of "Yangtze River goddess" gives great hope to Chinese ecologists

The baiji, nicknamed the "goddess of the Yangtze River", is considered an extinct species, however, some observers claim to have sighted it last month.

In fact, more than a decade has passed since the baiji was declared "functionally extinct".

However, a recent image tries to show that the "goddess of the Yangtze River" still exists, awakening hopes in keeping this mammal alive thanks to the recovery of the ecological vitality of the longest waterway in Asia.

Many observers believe that this type of dolphin, the only one of its kind to inhabit fresh waters, is only found in the middle and lower reaches of the Yangtze River.

Some environmental scientists have never stopped believing that somewhere in the immense area of ​​the third longest river, hiding from stubborn human activity survive a few Baiji who fight every day for their survival.

Earlier this month, the China Foundation for the Conservation of Biodiversity and Green Development published a photograph of a creature that resembles a baiji. The photo was taken in April on a section of the Yangtze River, near Wuhu, Anhui Province.

Previously, two fishermen's reports had already been distributed, which declared a group containing adult and juvenile specimens.



A growing optimism

The China Foundation for the Conservation of Biodiversity and Green Development confirmed that several researchers who know this species well have confirmed that the creature in the photo is a baiji.

"Although the baiji is very likely to have been drastically reduced in the wild, there are chances that a few will still survive in those waters," said Wang Kexiong, a professor at the Institute of Hydrobiology of the Chinese Academy of Sciences in Wuhan Province. from Hubei.

"But without performing other tests of rigor, it is unwise to identify as a baiji the creature that appears in the photograph," the Institute said. However, other experts warn that it is too early to label the baiji as an "extinct" species.

"The test goes beyond a photo," says Fei, director of the baiji program of the China Foundation for the Conservation of Biodiversity and Green Development.

For three years, this institution has organized observation trips in the hope of spotting freshwater dolphins in the Yangtze. In May of last year, several expedition members claimed to have sighted the mammal.

"Baiji does not live in isolation," said Li Xinyuan, researcher and recovery activist for the baiji, who was present when the picture was taken last month and described the meeting as "very exciting."

"For two days in a row our companions witnessed a baiji, but escaped before obtaining the snapshot." On the third day, photographer Jiao Shaowen decided to use a camera lens instead of binoculars to observe the surface of the water, so he was able to to take the picture when the baiji emerged, "says Li, who in the 1980s commanded a cabinet program for the conservation of mammals.

He thinks that if the animal detected is really a baiji, it is very likely that there are others swimming nearby.

"Thanks to state protection, it is clear that the water quality of the Yangtze and the ecosystem have improved in recent years," Li acknowledged.

He added that many Chinese environmentalists admit that if the level of environmental quality in the region continues to improve, there is a good chance that the Baiji will reappear.



Necessary resources

Hua Yuanyu, one of the scientists who participated in the 1980 census, advises that "to protect the possibility that the Baiji dolphins survive, emergency actions must be taken using the best resources, specialists and technology in the country."

"River transport along the Yangtze River should be properly managed to reduce the noise that has seriously affected the lives of these dolphins that are oriented by their sonar," said the veteran professor at the Institute of Life Sciences of the Nanjing Normal University. Jiangsu province.

Hua also condemned destructive fishing methods such as electro-fishing, gillnets and the dynamic wall, a technique that equips the nets with "knocking" devices to scare the fish out of hiding.

"These practices must be strictly prohibited and any violation must be punished severely in order to protect the baiji and its food chain," Hua said.

"Baiji is a mammal that uses the lungs to breathe in. If they are affected by an electric shock, they can become unconscious and drown," said Hua, pointing out the danger of electro-fishing.

And he urged to train local fishermen in law enforcement and in better environmental education, so that they become efficient protectors of the ecosystem.

"The protection of the Yangtze must not only include the quality of its water, but also the banks and the wetland must be taken into account throughout its trajectory because the ecosystem functions as an indivisible whole," Hua recalled.

The prominent professor also suggests that the protection zone of the Baiji should be expanded to include the habitat of the possible last baiji of Wuhu.

"I am optimistic, if the environment continues to improve, the baiji will reappear," adds Hua, creator of the sonar guidance method to observe and infer the size and distribution of the Baiji population in 1986.

In the mid-1980s it is estimated that there were about 300 Baiji divided into 42 groups.

Hua's hypothesis is that these intelligent mammals have hidden themselves from human activity and industrial waste and live in calm waters that are difficult to access.



The ecological restoration

It is estimated that the baiji lived on the Yangtze River for 20 million years.

However, in recent decades the peaceful existence of the Baiji was shattered by the boom in the fishing industry and river transport.

The ancestors considered this mammal as a goddess who protected the fishermen and sailors along the 6,380 kilometers of waterway that originates in Qinghai Province and flows into the East China Sea of ​​Shanghai.

The last Baiji that lived in captivity died in 2002. After an international expedition carried out at the end of 2006, no proof of its existence could be found. The following year the species was declared "functionally extinct".

In the Red List of Endangered Species of the International Union for the Conservation of Nature, the baiji is defined as "critically endangered and already probably extinct".

Due to the absence of the "Yangtze River Goddess", China has been making great efforts to restore the ecosystem of the vital river.

The construction of an ecological civilization has already been defined in the Constitution of the Republic as a national development objective.

As a result, scientific studies have confirmed an increase in the number of black porpoise and other mammals of the Yangtze River.

The supposed reappearance of the baiji is further evidence of the ecological improvement of the Yangtze, says Hua.

For his part, Professor Wang, of the Institute of Hydrobiology of Wuhan, insists that there is still a long way to go in protecting and restoring the natural habitats of the river for species such as the black porpoise.

"But the current development strategy is in the right direction," he said.

"Monitoring, protecting, revitalizing and restoring the ecology and natural habitats of the Yangtze River should be prioritized tasks for the next 50 years," Wang concluded.

When ecology and economy are in conflict

MEP Maria Heubuch gave a lecture on the state and future of agriculture - Hot discussion on glyphosate.

Even the bare facts may surprise: The share of agricultural land in Germany is 52.4 percent - followed by the forest areas with about 30 and the settlement and traffic area with about 13.5 percent.

But in terms of gross value added in the total spectrum (GDP), farmers generate just 0.8 percent. However, Germany is still - after France - the second largest agricultural producer in Europe. Which wrestling takes place around this 0.8 percent, which press concerns, what demands and hopes are in the room: This is what Maria Heubuch, member of the Greens of the Greens, talked about on Friday evening before quite committed and sometimes quite heated discussing visitors in the stadium restaurant.



In doing so, the agricultural expert immediately put her finger in the wound: she used various examples to show how ecology and economy are often irreconcilably confronted with how difficult it is to harmonize this sad conflict, which in the main is being carried out on the general public.

From the tradition farmer woman as well as owner of a dairy farm allgäu, she was direct witness of the milk crisis in the years to 2014/15, which had cost in the end 4081 enterprises in the existence of Germany. The common European agricultural policy (CAP) had demanded this in the context of a structural change, had set profitability norms.

Among other things, this has a detrimental effect on diversity and also means that fewer and fewer farms produce more and more food. Quality of life is lost - and at all levels. Above all, biodiversity suffers from structural changes, such as with regard to insect and bird life.

The stimulus word "glyphosate" (a weed control), which appears in almost every public debate when it comes to healthy nutrition, also largely dominated the discussion that followed the lecture. It was precisely here that there was considerable dissension between the experiences and interests of the farmers present on the one hand and the ecological agenda of the ecological party on the other.

Again and again, the speaker pointed out that the problems that surround biodiversity, sustainability and responsible economic activity should be seen not only with regard to the Kraichgau, but "that we all sit in the same boat, after all", that all people have to look beyond the domestic demands that lie on their doorstep and have to think globally.

Ultimately, consumer behavior determines which direction the development is going for. If you want quality and variety, you also have to dig deeper into your wallet, stressed Maria Heubach.

Ecology has determined the great development of the human brain

There is no scientific consensus on why the human brain has such a large relative size, compared to other living beings. Numerous evolutionary theories have tried to explain this singularity, but none has been able to discern whether its growth is a cause or an effect of other factors.

One of the best known hypotheses is that our brain grew to allow our ancestors to function better in an increasingly complex society. Another hypothesis is that this increase in size is related to the fact that our ancestors began to eat meat. The greater protein contribution would have allowed the reduction of the digestive system, in favor of an increase in brain mass.

A new study published this week in Nature rejects those hypotheses. "Our results indicate that ecology has been a determining factor in the evolution of the size of the human brain, and not social aspects such as cooperation or competition", explains Sinc Mauricio González-Forero, researcher at the Faculty of Biology at the University of Saint Andrews (United Kingdom).

Among these ecological factors are problems such as finding food, storing it, and processing it to consume it. "The hunter-gatherers who live in the African savanna solve these problems through animal tracking skills, construction of tools such as bottles and leather containers, and with the production and control of fire to cook food," explains the researcher.

The study concludes that when the environment is inhospitable and individuals can continue to learn how to solve problems long after childhood - for example, because they can learn difficult techniques from other individuals - that combination between ecology and knowledge accumulation produces brains of size human.

On the trail of a larger brain

With the help of a computational model, the authors have analyzed the energy costs and benefits provided by a larger brain. The larger the size, the more energy is consumed and the less energy available for other functions, such as the reproductive organs. However, a larger brain also tends to allow the individual to solve more complex problems.

"The model calculates how large the brain should be as a result of natural selection when individuals have evolved by finding problems of different types. We have considered ecological problems and three types of social problems (cooperation, competition between individuals, and competition between groups), "explains González-Forero.

In this way, 60% of the determining factors are of an ecological nature, 30% would be related to cooperation and only 10% would be based on competition between groups. The competition between individuals would not have been relevant for the evolution of the brain.

These percentages are consistent with the fact that human psychology is characterized by its tendency to cooperate. Cooperation among individuals plus competition between groups, which involves cooperation among individuals in the group, provides a high proportion of cooperation problems - 40% - that could have shaped human psychology.

"Our model refutes the hypothesis that the human brain expanded throughout evolution due to social demands. On the contrary, we found that such demands contribute to decrease the size of the brain ", explains González-Forero.

"That does not mean that we should diminish our social interactions to promote a bigger brain, because the consequences of something like that would take hundreds of thousands of years to have an effect and could involve negative consequences that the model does not anticipate," concludes the researcher.