What gave us the advantage over extinct types of humans?

Apr 22, 2014
This image shows Hebrew University researchers (from left to right): Prof. Eran Meshorer, Dr. Liran Carmel and David Gokhman, plus an unidentified ancient "friend." Credit: Juan Schkolnik

In parallel with modern man (Homo sapiens), there were other, extinct types of humans with whom we lived side by side, such as Neanderthals and the recently discovered Denisovans of Siberia. Yet only Homo sapiens survived. What was it in our genetic makeup that gave us the advantage?

The truth is that little is known about our unique as distinguished from our archaic cousins, and how it contributed to the fact that we are the only species among them to survive. Even less is known about our unique epigenetic makeup, but it is exactly such that may have shaped our own species.

While genetics deals with the DNA sequence itself and the heritable changes in the DNA (mutations), epigenetics deals with heritable traits that are not caused by mutations. Rather, chemical modifications to the DNA can efficiently turn on and off without changing the sequence. This epigenetic regulatory layer controls where, when and how genes are activated, and is believed to be behind many of the differences between human groups.

Indeed, many epigenetic changes distinguish us from the Neanderthal and the Denisovan, researchers at the Hebrew University of Jerusalem and Europe have now shown.

In an article just published in Science, Dr. Liran Carmel, Prof. Eran Meshorer and David Gokhman of the Alexander Silberman Institute of Life sciences at the Hebrew University, along with scientists from Germany and Spain, have reconstructed, for the first time, the epigenome of the Neanderthal and the Denisovan. Then, by comparing this ancient epigenome with that of , they identified genes whose activity had changed only in our own species during our most recent evolution.

Among those genetic pattern changes, many are expressed in brain development. Numerous changes were also observed in the immune and cardiovascular systems, whereas the digestive system remained relatively unchanged.

On the negative side, the researchers found that many of the genes whose activity is unique to modern humans are linked to diseases like Alzheimer's disease, autism and schizophrenia, suggesting that these recent changes in our brain may underlie some of the psychiatric disorders that are so common in humans today.

By reconstructing how genes were regulated in the Neanderthal and the Denisovan, the researchers provide the first insight into the evolution of along the human lineage and open a window to a new field that allows the studying of gene regulation in species that went extinct hundreds of thousands of years ago.

Explore further: Genetic testing shows Neanderthals less diverse than modern humans

add to favorites email to friend print save as pdf

Related Stories

Revolutionary new view on heritability in plants

Feb 11, 2014

Complex heritable traits are not only determined by changes in the DNA sequence. Scientists from the University of Groningen Bioinformatics Centre, together with their French colleagues, have shown that epigenetic marks can ...

Recommended for you

Evolution of competitiveness

Oct 29, 2014

Virtually all organisms in the living world compete with members of their own species. However, individuals differ strongly in how much they invest into their competitive ability. Some individuals are highly competitive and ...

Status shift for whale pelvic bones

Oct 29, 2014

For decades, scientists assumed that the relatively small pelvic bones found in whales were simple remnants of their land-dwelling past, "useless vestiges" that served no real purpose, akin to the human appendix ...

Is the outcome of evolution predictable?

Oct 28, 2014

If one would rewind the tape of life, would evolution result in the same outcome? The Harvard evolutionary biologist Stephen Jay Gould came up with this famous thought experiment. He suggested that evolution would not repeat ...

How did complex life evolve? The answer could be inside out

Oct 27, 2014

A new idea about the origin of complex life turns current theories inside out. In the open access journal BMC Biology, cousins Buzz and David Baum explain their 'inside-out' theory of how eukaryotic cells, which all multic ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
1 / 5 (5) Apr 22, 2014
http://www.ncbi.n...24693353
Nutrient-dependent/pheromone-controlled adaptive evolution: a model.

"Two additional recent reports link substitution of the amino acid alanine for the amino acid valine (Grossman et al., 2013) to nutrient-dependent pheromone-controlled adaptive evolution. The alanine substitution for valine does not appear to be under any selection pressure in mice. The cause-and-effect relationship was established in mice by comparing the effects of the alanine, which is under selection pressure in humans, via its substitution for valine in mice (Kamberov et al., 2013).

These two reports (Grossman et al., 2013; Kamberov et al., 2013) tell a new short story of adaptive evolution. The story begins with what was probably a nutrient-dependent variant allele that arose in central China approximately 30,000 years ago. The effect of the allele is adaptive and it is manifested in the context of an effect on sweat, skin, hair, and teeth."

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.