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Study Challenges Two Icons of Evolution: Functional Junk DNA Shows “Surprising” Genetic Differences Between Humans and Apes

Casey Luskin

In 2004, cognitive scientist Keith E. Stanovich took the position that junk DNA “is essentially a parasite,” and that “junk DNA is a puzzle only if we are clinging to the assumption that our genes are there to do something for us.”1

In 2006, Michael Shermer asserted, “Rather than being intelligently designed, the human genome looks more and more like a mosaic of mutations, fragment copies, borrowed sequences, and discarded strings of DNA that were jerry-built over millions of years of evolution.”2

The following year, a human physiology textbook stated that “junk DNA” is “considered defective” and comprises “inherited sequences [that] perform no currently known ‘genetically useful’ purpose, yet they remain part of the chromosomes.”3

These sources promoting the classic “junk DNA” icon of neo-Darwinism need updating, as a Yale University news release from earlier this month recalls the fact that “[i]n the last several years, scientists have discovered that non-coding regions of the genome, far from being junk, contain thousands of regulatory elements that act as genetic ‘switches’ to turn genes on or off.” In this case, the junk triggered genes that control human thumb and foot development.

But this wasn’t the only interesting finding they made. According to the article, finding these genetic differences were “especially surprising, as the human and chimpanzee genomes are extremely similar overall.”

Most studies that have claimed that humans and apes have nearly identical genomes have primarily looked at the gene-coding portions of the genome, not the non-coding DNA (formerly claimed to be “junk”). Perhaps as biologists study the non-coding regions of our genome, they will find evidence that challenges two icons of evolution: Not only does “junk” DNA have function, but humans aren’t as genetically similar to apes as was once thought.

References Cited:
[1.] Keith E. Stanovich, The Robot’s Rebellion: Finding Meaning in the Age of Darwin, pgs. 16-17 (University of Chicago Press, 2004).
[2.] Michael Shermer, Why Darwin Matters: The Case Against Intelligent Design, pg. 75 (Times Books 2006).
[3.] William D. McArdle et al., Exercise Physiology: Energy, Nutrition, and Human Performance, pg. 1024 (Lippincott Williams & Wilkins, 2007).


Casey Luskin

Associate Director, Center for Science and Culture
Casey Luskin is a geologist and an attorney with graduate degrees in science and law, giving him expertise in both the scientific and legal dimensions of the debate over evolution. He earned his PhD in Geology from the University of Johannesburg, and BS and MS degrees in Earth Sciences from the University of California, San Diego, where he studied evolution extensively at both the graduate and undergraduate levels. His law degree is from the University of San Diego, where he focused his studies on First Amendment law, education law, and environmental law.



Junk DNA