Evolution News and Views (ENV) provides original reporting and analysis about the debate over intelligent design and evolution, including breaking news about scientific research.

Evolution News and Views
Junk DNA NEWS
 

No Spin: Endogenous Retroviral Sequences Are Important for Brain Function, and Aren't Junk

4638080569_894d5040e5.jpg

Ann Gauger recently wrote an excellent piece about interpreting scientific writings minus all the unnecessary evolutionary gloss. Let's apply her methods to a couple recent news stories showing that endogenous retroviral sequences are important for brain function.

The claim is that junk DNA helped our brain cells evolve. The raw data shows that what we typically have called endogenous retroviral sequences are not necessarily junk but are genetic elements that are important for controlling brain function. Yet science journalists have been spinning the demise of this evolutionary icon as a win for Darwinian theory, the very opposite of what it really is. The Daily Mail frames the study this way:

It's long been known that DNA from so-called retroviruses make up around 5 percent of our genetic makeup.

But for years, this was dubbed junk DNA with no real use, and was considered to be a side effect of evolution -- until now.

New research suggests that, over the course of evolution, the viruses took an 'increasingly firm hold' on how cells work, and they may have made brain cells in particular more active and dynamic, ultimately making us smarter.

In particular, the study from Lund University in Sweden claims that inherited viruses, which are millions of years old, play an important role in building up the complex networks that characterise our brains.

Very similarly, an article at R&D Magazine states:
Researchers have long been aware endogenous retroviruses constitute around 5 percent of our DNA. For many years, they were considered junk DNA of no real use, a side effect of our evolutionary journey.

In the current study, Johan Jakobsson and his colleagues show that retroviruses seem to play a central role in the basic functions of the brain, more specifically in the regulation of which genes are to be expressed, and when. The findings indicate that, over the course of evolution, the viruses took an increasingly firm hold on the steering wheel in our cellular machinery. ...

"We have been able to observe that these viruses are activated specifically in the brain cells and have an important regulatory role. We believe that the role of retroviruses can contribute to explaining why brain cells in particular are so dynamic and multifaceted in their function. It may also be the case that the viruses' more or less complex functions in various species can help us to understand why we are so different," says Jakobsson, head of the research team for molecular neurogenetics at Lund University.

Let's try rewriting that without the evolutionary overlay. Here's what the Daily Mail story might look like, with my inserted words italicized and their deleted words struck through:

It's long been known that DNA from so-called retroviruses make up around 5 percent of our genetic makeup.

For years, this was dubbed junk DNA with no real use, and was considered to be a side effect of evolution -- until now.

New research suggests that, over the course of evolution, the what we once thought were viruses and a form or parasitic, junk DNA took an 'increasingly firm hold' on how cells work, and they may have made are actually important genetic elements that play a vital role in making brain cells in particular more active and dynamic, ultimately making us smarter.

In particular, the study from Lund University in Sweden claims that what we once thought were mere inherited viruses, which are millions of years old, are actually normal DNA sequences that play an important role in building up the complex networks that characterise our brains.

Likewise, we can rewrite this passage from R&D Magazine:
Researchers have long been aware endogenous retroviruses constitute around 5 percent of our DNA. For many years, they were considered junk DNA of no real use, a side effect of our evolutionary journey.

In the current study, Johan Jakobsson and his colleagues show that genetic elements which we used to think were mere retroviruses seem to play a central role in the basic functions of the brain, more specifically in the regulation of which genes are to be expressed, and when. The findings indicate that, over the course of evolution, the viruses these genetic elements aren't mere retroviruses but actually are genetic elements that play an important role in brain function, and take a took an increasingly firm hold on the steering wheel in our cellular machinery. ...

And there you have it: the functions of endogenous retroviruses, no longer to be considered junk DNA, are perfectly well explained without reference to Darwinian evolution. Feel free to try this at home, if you like.

Image credit: @Doug88888/Flickr.