We carry the history of our ancestors with us, so it makes perfect sense for us to know our natural history.
Paraphrasing the beginning and title of the book by Condemi and Savatier (2018), “Latest news from sapiens”, the sapiens (the sage) is a unique animal. It is the only species that modifies the environment to the point of influencing its own evolution, as well as that of other species.
The impact of our existence on the planet is such that the era we live in today is called the Anthropocene, literally, it was human.
And after about seven million years of coexistence of several species of humans, today we are the only living species.
We are unusually alone.
There are a whole range of questions about our evolutionary history that should interest everyone. Apart from that, the past of the sapiens elucidates your future, ours.
And what are our attributes? From the outset, we have a brain that is three times larger than what you would expect in a primate of our body size, that is, one of our great distinguishing features resides in the brain, which is not only huge, but has a unique complexity.
It is important to emphasize that this characteristic is closely linked to our diet and the way we move. We are currently the only bipedal primates. It's a key evolutionary triad: brain-diet-locomotion.
Fossils are the most real clue to who our ancestors were, and how and why we became the species we are today. In recent times, the methods of approaching the bones of our ancestors, one of the most frequent types of fossils, have allowed us to decode the information stored in them, in some cases thousands of years ago.
Effectively, bones can be considered as a repository of memories that need to software sophisticated to unravel it.
The decoding of ancient DNA, mitochondrial and nuclear, is a good illustration of these technological advances. The incredible feat of being able to access the nuclear DNA of fossils from Atapuerca, namely the Sima de los Huesos, which is about 400 thousand years old, was achieved.
Nevertheless, we cannot expect this chronological barrier to be surpassed indefinitely, as the preservation of DNA in fossils over 1 million years old, if it happens, will be negligible.
But Atapuerca, a mountain range near Burgos, in Spain, is a key place to learn about the evolutionary history of our species, namely since about 1,5 million years ago.
And very recently another fantastic study was published, this time concerning Gran Dolina and the homo predecessor, one of the first inhabitants of this mythical and mediatic mountain range, who lived about 1 million years ago.
Currently, the analysis of ancient proteins with mass spectrometry, an approach commonly known as paleoproteomics, makes it possible to overcome the chronological barrier of ancient DNA, as ancient proteins survive much longer than ancient DNA, allowing access to phylogenies based on molecular data. , beyond the limits of DNA degradation.
The analysis of paleoproteins from the enamel of a tooth of homo predecessor allowed access to genetic information that is 800 years old. The proteins suggest that the H. predecessor was a close relative of the last common ancestor of humans, Neanderthals e Denisovians.
These three species, ours, the Neanderthals and os Denisovians, coexisted in Europe and Asia for the past 70 years.
Very recently, it has been confirmed that the lithic industries of the first modern European men and of the Neanderthals coexisted for over 100 years.
Furthermore, it has been confirmed that our most recent relatives, the Neanderthals, already had language. Based on a high-resolution CT (Computerized Tomography)-based investigation, which allowed to recreate the 3D structures of the ear of the Homo sapiens and Neanderthals and fossils of the Sima de los Huesos, it became known that the auditory abilities of Neanderthals approached ours.
Yet another recent study shows that, like us, the Neanderthals they weaned the babies at roughly the same time and also introduced solid foods into the children's diet around 5-6 months.
That is, one more proof that, behaviorally, they were very similar to us, and that the growth patterns were similarly similar.
These kinds of discoveries were made on the basis of a thorough analysis of the baby teeth of three Neanderthal children.
Remember that several archaeological discoveries have shown that the Neanderthals they were also artists: they could paint caves and wear necklaces, for example.
If we add to all this the fact that the genomes of these two species are now decoded, we are now sure that we, sapiens, we crossed with other species, namely with the Neanderthals. They are like that among us, because about 2% of the genetic material in our genome, of non-African populations, is Neanderthal.
This is just a short note about current news from the sapiens. It is important not to forget that the sapiens will continue to evolve. And, above all, the sapiens you will have to remain truly wise to survive in this new era, where pandemics pose a complex challenge.
Author: Eugénia Cunha is a visiting professor at the Department of Life Sciences, FCTUC. Director of the National Institute of Legal Medicine and Forensic Sciences, Southern Delegation, Lisbon.