TELLURIDE – More than half a century ago, a handful of brilliant scientists were nose-deep in deciphering what appeared to be a double-stranded helix − a molecule they eventually determined held all the instructions for making an organism.

With the advent of modern technology and research, the traditional textbook view of heredity has been repeatedly challenged. Biologists have found that a whopping 98-percent of the human genome consists of “junk DNA,” or long stretches of “bases” that do not encode a single protein.

Studies have shown that this dominant “genetic baggage” controls the rearrangement of genes themselves, not the synthesis of their corresponding proteins. Further, RNA has proven just as powerful an “instruction book” for inheritance as DNA. Turns out, environmental pressures, post-DNA transcription and RNA molecules further regulate gene activity and evolution.

The final Pinhead Town Talk of the summer, “Junk in the Trunk: How artifacts of infections tell a new evolutionary tale,” will explore the scientific and moral issues surrounding genetics. Edward Lyman, a post-doctoral fellow at the University of Utah, will present “Junk in the Trunk” on Tuesday, August 18 at 6 p.m at the Telluride Conference Center in Mountain Village. Per usual, admission is free and there will be a cash bar.

“You can write out a DNA sequence, consisting of four letters (or ‘bases’), and lay out what appears to be a well-defined, ‘mathematical’ problem,” Lyman says. “Yet out of this letter code arises amazing and complex abstraction.”

Lyman’s “abstraction” is tied to the notion that within the simple sequence of letters that defines a gene lies an enormous amount of non-coding, or what appears to be dispensable “letters.”

“The underlying question is: what function does this ‘junk,’ or transposable, DNA serve… does it play an important biological role or is it purely deleterious?” Lyman asks.

Town Talkgoers will learn that transposable “junk” DNA is essential for stitching together thousands of DNA pieces so proteins are assembled at correct times and expressed at appropriate levels. Closely tied to environmental pressures, these transposable genes can become entirely useless and deleted from the genome indefinitely, or inserted into a coding region and transcribed to make adapted proteins.

Interestingly, DNA with seemingly no genetic purpose plays a vital role in distinguishing one species from another. Researchers have found that protein-coding DNA sequences in organisms ranging from plants to nematodes to fruit flies to humans are surprisingly similar.

“The largest differences between major species groups appear to be the amount of ‘junk’ DNA rather than the number of genes,” said Peter Andolfatto, an assistant professor of biology at Princeton.

Lyman will not only debunk the “junk” in the DNA “trunk” notion, he will also address pertinent ethical issues surrounding current genetic advancements. He will discuss the medical and legal implications of filing and storing an individual’s DNA, and debate the risk factors involved in patenting genes.

Discuss your genes with Lyman at this Tuesday’s Town Talk, co-produced by the Telluride Science Research Center (TSRC) and Pinhead Institute, and are sponsored by the Telluride Mountain Village Owners Association (TMVOA).

For more information please visit www.telluridescience.org or call Nana Naisbitt, TSRC executive director at 970-708-0004.