From “Environs Prompt Advantageous Gene Mutations as Plants Grow; Changes Passed to Progeny” (ScienceDaily, July 5, 2011) we learn:
If a person were to climb a towering redwood and take a sample from the top and a sample from the bottom of the tree, a comparison would show that the two DNA samples are different.Christopher A. Cullis, chair of biology at Case Western Reserve University, explains that this is the basis of his controversial research findings.
Cullis, who has spent over 40 years studying mutations within plants, most recently flax (Linum usitatissimum), has found that the environment not only weeds out harmful and useless mutations through natural selection, but actually influences helpful mutations.
Cullis published his findings in the International Journal of Genetics and Molecular Biology and repeated them in the Journal of Visualized Experiments, where he challenged other scientists to repeat his experiment themselves.
Cullis’s theory was originally dismissed on the assumption that plants pass on their genes the same way animals do, but that may not be correct.
Factoid: “Young redwoods grow by the tips of the existing branches budding into meristems. Each new meristem is different from the tree because the environment has affected its genetic makeup. And as the redwood grows, the top becomes more and more genetically different from the bottom.”
And more distant from it too … this is a giant tree, not a lichen.
If this holds up, the world of life is not what we thought and not what we’ve been taught. Are plant genomes a living template, subject to revision as need arises, rather than a cement cast? But what decides when the need arises? Some forward look must be built into the system in advance.