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."