Spontaneous Generation Revisited
Date: Spring 2012
I'm curious can genes be altered and changed during our life and passed on to future generations? I ask this because I've witnessed an instance that I found most interesting... it was a father, who before he ever conceived his child lost his pinkie on his left hand, and years later he has a child and crazy as it is the child on its left hand was born with an extra finger an extra pinkie.. it has had me contemplating whether this machination has any validity in genes altering during our life perhaps because of our life choices or environmental factors ect ect.
The example you describe is pure coincidence -- not genetic.
The environment does impact our genes, and those genes can be passed
on to our children. However, the changed gene has to be in the gamete
(sperm or egg) -- these cells alone contain the genetic material that
is passed along. A change to a finger (that has not also occurred in
the gamete) would not be passed on.
Hope this helps,
That IS an awfully odd story. But I’m inclined to consider it just a coincidence. As far as I know, there is no large-scale evidence suggesting that environmentally-imposed changes to a body cause inheritable changes to the genome.
Richard E. Barrans Jr., Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
On the surface, the situation you describe sounds like a compensatory action for the loss of a finger in the father. Fortunately, the loss of a finger doesn't override the fact that our genetic gameplan still calls for a normal complement of ten fully formed digits. Traits are only transmissible if they are written into the DNA of one (or both) parents. In this case, one of the parents must have been a carrier of the polydactyly allele. This genetic condition causes extra fingers to develop in a proportion of offspring. The fact that the father previously lost a finger in an accident is an interesting, albeit purely coincidental, fluke.
Environmental factors like mutagens can cause heritable changes to DNA. However, these spontaneous mutations would have to manifest in the haploid germ cells (sperm and eggs) to be heritable. This is one reason why gene therapy has historically been limited to somatic (non-germline) cells. If anything were to go amiss, the genetic rewrites would be limited to cells that have no role in reproduction.
Dr. Tim Durham
Undergraduate Studies & University Colloquium
Department of Biological Sciences
Florida Gulf Coast University
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Update: June 2012