Professor Skeptical About 145 Human Genes Transferred From Other Organisms

UC Davis professor Jonathan Eisen has been the lead voice of dissent featured in several articles about a potentially groundbreaking Cambridge research paper highlighting the presence of foreign genes in the human body.

The paper, published in Genome Biology on March 12, claims that as many as 145 genes have been transferred from other lifeforms to humans in our evolutionary past in a process known as horizontal gene transfer (HGT). This runs contrary to the accepted scientific concept of vertical gene transfer in humans, where DNA is passed down from parent to offspring.

Horizontal gene transfer is a common process involving the movement of genetic material between organisms outside of the parent-offspring model, but is typically associated with bacteria and other simple eukaryotes.

The Economist reported on the research, informing their readers that “it might surprise many people that they are even to a small degree part bacterium, part fungus and part alga.”

On his blog, Eisen summarized a few of his responses to reporters, stating that while he found the paper implicating the discovery of foreign genes in humans interesting, he was “not overwhelmed” by it.

“I note – for the record I am including the full text of some of the email comments I made to the reporter here and would like to reiterate,” Eisen commented in Science.

“I think this is an interesting study but I am not convinced that they have done enough controls to conclude that these observations are due to HGT.”

Lead Cambridge researcher Alastair Crisp and his colleagues acknowledge the controversy of humans acquiring genes via HGT in their abstract, but point out that their research suggests otherwise.

“We argue that HGT has occurred, and continues to occur, on a previously unsuspected scale in metazoans and is likely to have contributed to biochemical diversification during animal evolution,” they wrote.

Crisp and his team conducted research on 40 genome sequences of different animals, including fruit flies, zebrafish, gorillas and humans. They found that when computationally compared gene-by-gene, animal genes, including those of humans, closely matched the gene sequences of bacteria, fungi, plants, and viruses.

While Eisen didn’t rule out the possiblitiy that researchers were correct, he stated that it was “impossible to judge the quality of this paper without being able to see the alignments they used for each phylogenetic tree.”

In other human evolution news, the Inquisitr reported on a Richard Dawkins explaining whether or not evolution is observable.

In Dawkins’ first book, The Selfish Gene, he explores human evolution from a gene-centered viewpoint.

[Image via]