Tag Archives: human genetics

Human Ancestors?

The Neandertals lived around 30.000 years ago. The Oetzi died around 5.000 years ago. For both human ancestors researchers were able to fully sequence the genome now. Prof. Pääbo and his group from the MPI in Leipzig published around ~60% of the Neandertal genome in Science (2010). And quite impressively from my point of view is that they give full access to the genome to everyone: they simply put all data on their website. What also fascinated me is that it is quite difficult to study the resemblance between the Neandertal and modern humans since most of the bones found from the Neandertal are “contaminated” with modern human genes. And of course this is obvious since no anthropologist is wearing gloves by default and therefore all people touching the bones to do studies about age and the lifestile of our ancestors will leave their genes on the bones.

An eye opener for me is also that the most obvious thing we discover in the genome is always the impairment of a species. A good example is the recent publication of the complete genome of the Iceman (Oetzi). 96% of the Iceman’s genome has been sequenced and what did we learn: he belonged to blood group O, was lactose intolerant, had probably a genetic tendency towards coronary heart disease, and was carrying Lyme disease.

But researchers also found interesting information about the linkage of both Oetzi and Neandertal to modern humans:

The genome of Oetzi has been compared to 1300 Europeans, 125 North Africans and 20 people from the Arab peninsula. The study revealed that his closest living kin are found on Sardinia and Corsica.

For the Neandertal five modern humans from different populations were used for comparison studies. The stunning result is that some Neandertals and early modern humans interbred since 1 to 4% of the DNA of many humans who live outside of Africa originate from the Neandertal.

In all the discussions about our ancestors and close relatives I sometimes come to think if we will be close relatives in let’s say 1 million years? Wouldn’t it be possible that a new population or species of humans develop? It sounds absurd or science fiction-like but who are we that we think there is nothing “after us”?

 

 

Human Genome Project – Experience Report

John Lauerman, reporter with Bloomberg News got his genome sequenced. He is part of the Human Genome Project of the harvard medical school, where 10 genomes have been sequenced and analysed so far (Bloomberg).

After receiving his result he was first relieved to find no hint to have the APOE4 gene variant that raises the risk of Alzheimer’s disease. But what he learned then is that “No news wasn’t always good news; it just wasn’t bad news”. (Bloomberg) The researchs told him that the sequencing simply didn’t reveal information about APOE4. A study update however revealed later that the APOE4 gene variant indeed is present in his genome. This variant means an approx. 3 percent increased risk of developing the disease by age 80. But what does that mean in any single individual’s genome? At least Lauerman was less worried being his parents in the late 70s and 80s and having not developed Alzheimer’s disease.

But the researches have found in addition the rare JAK2 variant in Lauerman’s genome that is linked to a cancer-like blood disorder.  Knowing the risk, he now has the chance with increased vigilance to evaluate a potential disease early and to react accordingly.

And in that context Lauerman pointed out an even more important point: as a reporter working on a story about genomics, he had access to experts and genetic counselors that many people wouldn’t. What will happen as more people get results from broad genome sequencing? (Bloomberg) The question is if people can even handle the reports.

So as a personal conclusion I suppose I would be worried to hell when I would get to know my genome disorders. But it might be also a good thing, like in John Lauerman’s case. You would have the chance to detect a potential disease in an very early stage. You never know…

 

DNA – The Next Generation

Great retro webcast: Nobel laureate James Watson and former NHGRI Director Francis Collins discuss the history and future of human genetics. It was created in 2003 when the human genome was sequenced the first time. In 2003 the 50th anniversary of James Watson and Francis Crick’s Nobel Prize winning description of the DNA double helix was also celebrated.