Washington, Sep 19 (IANS) The "hidden" DNA code may be far more influential than our genes, passing down new biological traits more rapidly than previously thought.

The study throws up the first ever evidence that an organism's "epigenetic" code -- an extra layer of biochemical instructions in DNA -- can evolve more quickly than the genetic code, strongly influencing biological traits.

DNA, or deoxyribonucleic acid, is the fundamental building block of an individual's entire genetic makeup. A person's DNA is the same in every cell of the body, whether they are located in his skin, semen, blood or brain.

"Our study shows that it's not all in the genes," said Joseph Ecker, professor in Salk Institute's Plant Molecular and Cellular Biology Lab, reports the journal Science.

"We found that these plants have an epigenetic code that's more flexible and influential than we imagined. There is clearly a component of heritability that we don't fully understand," added Ecker, who led the research team, according to a Salk statement.

"It's possible that we humans have a similarly active epigenetic mechanism that controls our biological characteristics and gets passed down to our children."

Although based on a plant Arabidopsis thaliana, 'the lab rat of the plant world', the findings hint that other organisms, including humans, might also be influenced by biological mechanisms.

With the help of cutting-edge techniques, scientists have found the genes stored in the four-letter DNA code don't always determine how an organism develops and responds to its environment.

The more biologists map the genomes of various organisms (their entire genetic code), the more they are discovering discrepancies between what the genetic code dictates and how organisms actually look and function.

In fact, many of the major discoveries that led to these conclusions were based upon studies in plants. There are traits such as flower shape and fruit pigmentation in some plants that are under the control of this epigenetic code.