A few years ago, Nobel laureate Sydney Brenner, a pioneer of genetics and a wit known for making wonderfully mischievous remarks, explained to me his theory about why humans have language. Grinning a Puckish smile, Brenner suggested that long ago, monkeys decided that talking got them into trouble, so they evolved to unlearn language. In contrast, we humans are less evolved because we gab on, getting ourselves into all sorts of awkward situations.

In reality, it appears that monkeys never troubled themselves with language at all. According to a research team led by Bing Su at the Kunming Institute of Zoology, in China, a single mutation in the KLK8 gene may have speeded up our ancestors' ability to learn and acquire language. KLK8 makes the neuropsin II protein, which is important for learning and memory.

The team discovered that humans have it, but monkeys don't--not even our close cousins the chimpanzees. According to an article at NewScientist.com,

KLK8 is the first human-specific discovery of a "splice variant"--a gene that is roughly the same in different species but is "cut and pasted" differently when it is expressed, resulting in proteins with new functions. Su's team have shown that KLK8 arose through a single mutation in DNA when a thymine nucleotide was exchanged for an adenine.

This small change had a huge impact, causing 45 additional amino acids to be loaded into the protein that the gene expresses.

In the language of genetics, this means that human intelligence may be based in part on a single "T" in genetic code being replaced by a single "A" in our ancestors three or four million years ago.

These single-letter variations are called single nucleotide polymorphisms (SNPs), a cumbersome term that lends credence to Brenner's "theory" about monkeys being smarter than us. They are not encumbered by such impenetrable phrases, developed by scientists, who sometimes seem intent on using their own KLK8 genes to create an ever more complicated language of their very own.

On the positive side, the KLK8 gene may have also contributed to the most beautiful forms of our language, as created by the likes of William Shakespeare. He wrote in Hamlet,

"What a piece of work is man! how noble in reason! how infinite in faculty! in form and moving how express and admirable! in action how like an angel! in apprehension how like a god! the beauty of the world, the paragon of animals!"

I wonder: would our cousins, the monkeys, agree?

Citation for article about the KLK8 gene in humans:
Human Mutation, DOI: 10.1002/humu.20547

Why do some people end up with cancer, heart disease, or autism while others living under the same conditions don't?

Answering this is likely to consume the life sciences for most of this century as scientists tease out the intricacies of how environmental factors turn on and off genes. (See "Why Cancer Strike Some.") For instance, why is it that some people can be exposed to high levels of toxic chemicals, such as mercury, and remain healthy, while others suffer brain damage? More important, is there a single gene or multiple genes that protect some people from exposure to mercury? And if so, can this protector gene be used to develop methods for defending everyone against environmental scourges?

Two titans of life sciences at the National Institutes of Health (NIH) have decided that it's time we find out. In a Science article titled "Environmental Biology and Human Disease," Francis Collins and David Schwartz say that they believe the time has come to link two disciplines--environmental science and genetics--that have for too long operated as if they aren't related. Collins is director of the National Human Genome Research Institute (NHGRI), and Schwartz is director of the National Institute for Environmental Health Sciences (NIEHS). The two write,

Until recently ... the disciplines of environmental sciences and genetics have proceeded independently; investigators in the former discipline have focused primarily on adverse conditions and diseases that are etiologically driven by environmental factors (such as benzene-induced leukemia), and those in the latter field have been finding genetic factors for highly heritable conditions (such as cystic fibrosis). Progress is now being made in identifying common genetic variations that contribute to complex diseases such as age-related macular degeneration, type 2 diabetes, and prostate cancer. However, the best opportunity to reduce risk in genetically susceptible people for the foreseeable future will not be to re-engineer their genes, but to modify their environment.

("Modify their environment" is a curious way to put this; I'll get back to that in a moment.)

Collins and Schwartz call for a massive effort to record data about how, exactly, environmental factors impact genes and physiology. Part of this idea has already been launched with the Genes, Environment, and Health Initiative, which has a $40 million annual budget. "The near-term goal of the program is to develop new noninvasive tools and biomarkers for assessing individual exposures to environmental stressors that interact with genetic variation to result in human disease," write Collins and Schwartz. They suggest that biosensors be deployed to monitor individuals' exposure to everything from pesticides to cholesterol-rich foods. "However," they write, "to fully appreciate the predictive importance of these measures of exposure, this technology needs to be deployed in large-scale case-control and population-based genetic studies of health and disease."

The NIH loves big science projects, and this might be one of the biggest in history--and one of the most complex. It's a natural outgrowth of efforts such as the Human Genome Project on the genetics side and, on the environmental side, the National Children's Study, which, among other things, has been testing the impact of pollutants on kids.

This proposed fusion comes as global warming threatens to alter our environment and as human-produced chemicals are accumulating in the environment and in us. Last year, I was tested for 320 of these chemicals--everything from DDT to plasticizers--for an article in National Geographic, and I discovered that I have detectable levels of 165 of the chemicals. An obvious question is, what does this mean for me? Do I have genes that protect me from my rather high levels of bromide flame retardants, or are these chemicals that act as thyroid hormone disruptors slowly wreaking havoc on my physiology?

The two directors' choice of words in this regard is interesting: they say that "the best opportunity to reduce risk in genetically susceptible people for the foreseeable future will not be to re-engineer their genes, but to modify their environment." Modifying our environment is why you and I have these chemicals on board in the first place--and why diseases caused by junk food and other "modifiers" are raging.

We can only hope that the huge effort Collins and Schwartz are contemplating will shock us into realizing the real damage being done by such modifications to our bodies, cells, and DNA.

Listen to this.

It's the music created by the human protein thymidylate synthase A (ThyA). Really. At least, it's the notes created to "play" the music of this string of amino acids, with each amino acid assigned a chord.

Rie Takahashi, a graduate student at UCLA, dreamed up the idea of making music out of proteins when she read about a blind meteorology student at Cornell who converted the colors of a contoured weather map into tones corresponding to different hues.

Takahashi hopes her creation will help disabled geneticists "read" sequences using sound, she writes in a report in Genome Biology. "We wanted to be able to move away from a two-dimensional string of letters across a sheet of paper, and to see if adding another dimension--sound--would help," Takahashi told Nature.com.

Helping blind biologists "hear" DNA is laudable, but I'm also finding the notion of amino acids as chords strung together to be something eerie and wonderful, like putting my ear to a seashell and hearing the ocean. In addition, the idea makes sense, given that music is essentially digital--a series of precise calibrations of sound that the ancient Greeks thought of as a form of mathematics. For instance, the ancient Greek mathematician Pythagoras developed "The Music of the Spheres" to describe the proportional movements of the planets, moon, and sun in what he believed to be whole-number ratios identical to musical intervals.

Checking out Takahashi's Gene2Music website, I discover that other musically inclined scientists have applied notes and sounds to biological activities, such as the functions of a cell. You really need to check out these strange, compelling tunes.

Takahashi's website also allows you to enter any amino-acid sequence and have it translated into music. Try it, and listen to the slightly dissonant but curiously soothing sounds of protein sequences that are in a sense singing.