Mitochondrial DNA is Evolving, and That’s Amazing!
This week in the news there have been a number of articles about a new technology that has allowed the creation of an embryo from three parents, and boy it is creating controversy.
Three parents you say?
Yes. Of a sort.
The case in point regards a woman who unfortunately had a child with a deadly mitochondrial disease. Mitochondria are organelles (“small organs”) inside each of our cells where ATP, our primary energy source, is made. Mitochondria are special in that unlike other organelles, they carry their own DNA. In the case of this woman’s tragically afflicted baby, defective DNA that could not support much life.
Geneticists have developed technology to create an healthy embryo without the defective mitochondria by placing a nuclei from the woman’s mitochondrially defective egg into a donor egg, after removing that egg’s nuclei. They then fertilized the new proto-egg with the husband’s sperm to create a new embryo. In essence, the egg had three parents – two in the nuclei, and a third one in the mitochondria.
And the world shuddered.
From all corners were cries of “we’re playing GOD!!!”. “We are altering the human race!!” “We’re no better than Mengele!!”
Most of this comes from a bright line we have put around genetics research that says we will not genetically engineer human beings. Legitimate bioethicists have felt that this is something we should not do, because of a ‘slippery slope’ towards eugenics. Religious radicals are just uncomfortable with advancement in science in any kind. They say it is because it is against God, but I think it is because a true understanding of how the universe works deprecates the validity of their religion, and thus sparks a crisis of faith.
But either way, most people think that manipulating human DNA is unethical.
I, for some reason, don’t see it this way. In fact, I couldn’t be happier that we have made this leap, and hope we keep leaping. We are coming to understand how we are put together, and in such we are coming to understand how to manipulate that process. That is exciting, not concerning.
We are not “Playing God”. For us to be “Playing God”, a “God” would have to have been the reason we came to be on this earth. And unequivocally, it is not. The evidence for evolution is so unbreakably strong that to claim that we are here because of “God” is purely ignorant. Humans are on this earth because our genes were selected for over millions of years, not because somebody put us here. If you believe in God, fine. But please don’t hold humanity back from our future by claiming that we are breaking your religious rules.
Even worse is the claim that to genetically engineer a human is akin to Nazi experiments. True, Hitler wanted to manipulate the future of humanity. But he didn’t want to do it by changing the genetic information of the future. He did it by murdering the people who were already here. To claim these are the same thing is an affront to geneticists, and is too good for Hitler.
In truth, I am absolutely head over heels excited to hear that we were able to eliminate a deadly genetic disease from a family through genetic means. What this means to me is that we are actually CURING disease, not just treating the symptoms that it produces.
Evolution is something that is terribly misunderstood. Its detractors really don’t get how it works. People who don’t understand it think it is about the selection of individuals over others, and thus don’t believe it could ever have ended up in us, but that is not really how it works. It is the selection of GENES that drives evolution, not the selection of individuals.
The problem in this case is that mitochondrial genes do not reproduce sexually, but are rather copied directly from their parent mitochondira, and as such they do not evolve. As such, problems in the mitochondria are passed on forever, never changing except by random mutation.
But now, for the first time, mitochondrial DNA is evolving. Perhaps not by natural selection, but it is evolving nonetheless. And that is exciting.
Don’t take this to believe that I am ignorant of the potential problems. But they are technical, not ethical. Obviously we can not open the doors to unlimited human experimentation, but this is a first step, and it is a good one.