Alloteropsis Cimicina Photo courtesy of Wikimedia Commons under GMU Free Documentation License
Recent scientific evidence has suggested that our understanding of how evolution occurs may be incomplete. Although the passing of genes from parents to offspring will certainly remain the main method by which organisms inherit their DNA, it seems that their may also be another way. Scientists from Universities in the United States, United Kingdom, and France believe to have stumbled across an entirely new way that plants of different species can exchange DNA.
In order to test their theory, this group of scientists investigated the ancestry of two genes that encode enzymes essential to C4 photosynthesis (phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase) These genes were chosen because they are present in three closely related C4 plants, and their common C3 ancestor.
In order to accommodate the commonly accepted theory of how genes are inherited, it was initially assumed that these genes must have been initially inactive in the C3 plant, and were later modified to become photosynthetic agents for C4 photosynthesis. If this were true, the scientists would discover that the genes for these enzymes in C4 plants would be closely related to the inactive genes of their ancestor. However, this was not the case.
Instead, the scientists found that these two genes were actually closely related to those of completely different species of C4 plants. They found that in four cases, the ppc or pck enzymes found in the Alloteropsis plants (the type of C4 plant that they initially selected to study) were also found in other C4 clades.
The only explanation for these occurrences is what scientists are now calling “lateral gene transfer.” In their current model for this process, the scientists hypothesize that the genetic material from the pollen of a plant of one species is accidentally taken up by a plant of another species in an “illegitimate pollination event.” If it proves to be valid, this discovery would prove that plants have a way of creating biological diversity that was previously completely unknown to us.
What do you think the larger consequences of this discovery are? Do you think we might be able to incorporate genetic material from different species into our own bodies some day?
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