Modern man meets Neanderthal
Well, they actually did it. And the whole world knows about it now, even if the news is tens of thousands of years old. It was, of course, a juicy story for the world’s media: Neanderthals mated with modern humans! But for Svante Pääbo, Department Director at the Max Planck Institute for Evolutionary Anthropology in Leipzig, this is not the most important aspect of his discovery.
What makes us unique?
But Svante Pääbo had several additional priorities: “We can now produce a catalog detailing all of the changes in our genome that make us unique – the changes that distinguish us not only from chimpanzees, but also from our closest relatives. And regions where positive selection seems to have affected modern humans after their separation from Neanderthals.” The researchers have already found more than 200 such areas. The 20 most important ones are outlined in the Science article. “These are the areas that fascinate me the most,” says Pääbo.
It is still too early to offer any definitive comment; instead, there are vague suggestions. Genes relating to cognitive development have been found. Mutations in these genes are related to schizophrenia and autism in humans. “But this does not mean that Neanderthals suffered from these problems,” cautions Svante Pääbo. Another gene of interest is RUNX2. In its mutated form, it leads to cleidocranial dysplasia in humans, a condition characterized by skeletal deformities: the rib cage becomes bell-shaped, the shoulder bones change and the brow area protrudes. The result is almost like the skeleton standing behind Svante Pääbo. But the paleogeneticist plays it down: “No, that would be too easy,” he laughs.
It is not that easy to identify the genetic differences between humans and Neanderthals. Or sometimes maybe it is? The main thing is that it is possible at all now. We will come closer to understanding the genetic secrets that make us unique by seeing ourselves in our closest relative. The work has just begun.
Cell organelles surrounded by a double membrane that contain their own genetic material (mtDNA) whose role is to provide the cell with energy in the form of ATP. New mitochondria are only formed in a process similar to binary fission. They are believed to have originated at an early stage of evolution, by eukaryotic cells (cells containing a nucleus) absorbing bacteria and changing their function (endosymbiosis).
Nucleotides are the basic building blocks of DNA and RNA. They consist of a phosphate unit, a sugar module and one of the five nucleobases Adenine (A), Guanine (G), Cytosine (C), Thymine (T) or Uracil (U). The latter are the letters of the genetic code and form the DNA sequence.
This technology is used to determine the sequence of letters from genetic fragments within a very short time. This leads to a huge increase in the generation of sequencing data and reductions in cost. In the foreseeable future, it will be possible to sequence entire genomes for a few thousand euros.