Meet the parents. All 3 of them.
Thanks to genetic engineering, a child can now have three parents. But is it a good idea?
Progeny is a useful word, reminding us that babies come from their parents' genes.
When it comes to humans, we take it for granted that a baby has the genes from her two parents, their DNAs spiraled together into a long information code known as the genotype: it stores the information of what the baby will look like, how tall, her potential for certain diseases, some personality traits, etc.
In essence, the mixing of DNA from the parents is the recipe for a new being, at the same time unique and predictable: unique in her makeup due to the uncertain details of the bonding of the parents' DNA, but predictable because the genetic building blocks come from two (potentially) well-known sources.
This well-known state of affairs has recently changed. In a new technological development that mixes the incredible with the fantastic, it is now possible to create babies from the genetic materials of three adults.
The technology was developed to allow mothers with devastating genetic mutations to have healthy babies.
In April 2016, a couple from Jordan hired an American medical team from New York's New Hope Fertility Center to experiment with a new reproductive technology. The team had to attempt the procedure in Mexico, as it is forbidden in most countries. (John Zhang, who led the American team, said they chose Mexico because “there are no rules." The only country where the procedure is currently allowed is the UK.)
The “real" mother suffers from Leigh syndrome, a genetic disease that attacks the nervous system and had killed her first two children. The genes responsible for the disease are located in the mitochondrial DNA, being thus naturally separated from the majority of the genetic information stored in the cell's nucleus. You can think of the mitochondrion as a sort of separate piece of equipment within the cell, a tiny engine where biochemical processes responsible for respiration and energy production occur. With only 37 genes, the genetic information stored in the mitochondrion is passed from generation to generation by the mother.
Dr. John Zhang with the Jordanian couple's baby. (New Hope Fertility Clini)
The new technique takes advantage of the mitochondrion's genetic isolation. If this is where the problem is, why not use someone else's egg and inject the real mother's healthy genetic material in it? Technicians fertilize both the mother's and the donor's eggs with the father's sperms. Before the fertilized eggs start to divide to form an embryo, their nuclei—containing most of the genetic material—are removed. The real mother's nucleus is then injected into the donor mother's egg. Now, the donor's egg, with the healthy mitochondrial DNA, also has the mother's DNA.
In the case of the Jordanian couple, the technique used was slightly different. As Muslims, the couple opposed the destruction of the embryos. Only the donor's egg was fertilized, after it already contained the mother's DNA. In the end, the result is the same: a fertilized egg with the genetic material from three people.
The couple ended up having a baby boy, and that was by design. They chose a male embryo, because adult males don't transmit mitochondrial genes, only females—but there are no safeguards that this will always be the case.
Also, accidents can happen. In the case of the Jordanian couple, tests show that a small amount of defective DNA from the mother was accidentally injected into the donor's egg. In small amounts, this shouldn't present a problem, but it's still unclear what the safe amounts are. The couple has refused to subject their baby to further tests, invalidating their experience as a true long-term scientific study.
The technique, amazing as it is, raises important ethical questions. For the first time in history, a human baby carries genetic information from three people. We don't yet know the ramifications of such science; it's not clear that the babies won't have long-term genetic problems. There have been no controlled studies.
The technique was repeated in a clinic in Kiev, where a couple now has an apparently healthy 15-month-old boy. Valery Zukin, the doctor who runs the Kiev clinic, told NPR he sees no problem with the procedure. “If you can help these families to achieve their own babies, why it must be forbidden? It is a dream to want to have a genetic connection with a baby."
So far, four babies from three parents were born at the same clinic in Ukraine, and three more women are pregnant, including one from Sweden. One of the babies was a girl who could end up passing the mitochondrial DNA to her own kids. (It is not known whether the girl's parents chose to have a female baby, or whether that was an accident.)
Still, many doctors and ethicists question the procedure, saying it's too soon for any clear-cut verdicts—whether from a scientific or ethical perspective.
“We just don't know if it's safe," says Jeffrey Kahn, director of the Johns Hopkins Berman Institute of Bioethics, who chaired a U.S. Academy of Sciences panel that examined the medical and ethical issues of the procedure. “This is an uncontrolled experiment in which women are being offered a new technology that's never been tried before. That's why it's a concern."
Marcy Darnovsky, who heads the Center for Genetics and Society, a U.S.-based watchdog group, is even more direct:
“This is pretty troubling," she tells NPR. “This is really an irresponsible kind of human experimentation. We just don't know what's going to happen to these children."
Some scientists worry that this is an important step toward a more complex direction, where it may be possible to create “designer babies," with the parents essentially choosing a set of desired genetic characteristics they want their children to have, from hair and eye color to, potentially, physical strength, athleticism, and IQ. Although current technologies are far from this, if genes from three or more people can be safely combined into a single baby, there is nothing to stop a more ambitious undertaking where genes from a larger sample of donors are swapped on demand. Could we then create “super humans"? We can envision all sort of reasons to do so, most of them wrong: from super-soldiers to super-athletes, to the effective isolation of society into separate sects defined by genetic prowess.
This goes a long way from a few decades ago, when parents didn't even know their baby's gender before birth.
Not that the new moms are worrying too much about these issues. To them, among dirty diapers, a lot of crying, and smiling, every day is a joyous celebration. “In the end, we are all children of Adam and Eve," said one of the Ukrainian moms. “So, we are all connected."
Adam and Eve or not, it is true that all living creatures are deeply connected to the history of life on Earth. We all share a last universal common ancestor (LUCA), a single-celled microorganism that lived some three billion years ago.
The novelty now is that one of these species is developing technologies capable to take their genetic future into their own hands, redefining evolution by natural selection. We are entering the age of evolution by artificial selection.
Where this is going to end, no one really knows.
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Evolution doesn't clean up after itself very well.
- An evolutionary biologist got people swapping ideas about our lingering vestigia.
- Basically, this is the stuff that served some evolutionary purpose at some point, but now is kind of, well, extra.
- Here are the six traits that inaugurated the fun.
The plica semilunaris<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwMS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY3NDg5NTg1NX0.kdBYMvaEzvCiJjcLEPgnjII_KVtT9RMEwJFuXB68D8Q/img.png?width=980" id="59914" width="429" height="350" data-rm-shortcode-id="b11e4be64c5e1f58bf4417d8548bedc7" data-rm-shortcode-name="rebelmouse-image" />
The human eye in alarming detail. Image source: Henry Gray / Wikimedia commons<p>At the inner corner of our eyes, closest to the nasal ridge, is that little pink thing, which is probably what most of us call it, called the caruncula. Next to it is the plica semilunairs, and it's what's left of a third eyelid that used to — ready for this? — blink horizontally. It's supposed to have offered protection for our eyes, and some birds, reptiles, and fish have such a thing.</p>
Palmaris longus<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMzQ1NjUwMn0.dVor41tO_NeLkGY9Tx46SwqhSVaA8HZQmQAp532xLxA/img.jpg?width=980" id="879be" width="1920" height="2560" data-rm-shortcode-id="4089a32ea9fbb1a0281db14332583ccd" data-rm-shortcode-name="rebelmouse-image" />
Palmaris longus muscle. Image source: Wikimedia commons<p> We don't have much need these days, at least most of us, to navigate from tree branch to tree branch. Still, about 86 percent of us still have the wrist muscle that used to help us do it. To see if you have it, place the back of you hand on a flat surface and touch your thumb to your pinkie. If you have a muscle that becomes visible in your wrist, that's the palmaris longus. If you don't, consider yourself more evolved (just joking).</p>
Darwin's tubercle<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgxMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0ODUyNjA1MX0.8RuU-OSRf92wQpaPPJtvFreOVvicEwn39_jnbegiUOk/img.jpg?width=980" id="687a0" width="819" height="1072" data-rm-shortcode-id="ff5edf0a698e0681d11efde1d7872958" data-rm-shortcode-name="rebelmouse-image" />
Darwin's tubercle. Image source: Wikimedia commons<p> Yes, maybe the shell of you ear does feel like a dried apricot. Maybe not. But there's a ridge in that swirly structure that's a muscle which allowed us, at one point, to move our ears in the direction of interesting sounds. These days, we just turn our heads, but there it is.</p>
Goosebumps<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNzEyNTc2Nn0.aVMa5fsKgiabW5vkr7BOvm2pmNKbLJF_50bwvd4aRo4/img.jpg?width=980" id="d8420" width="1440" height="960" data-rm-shortcode-id="8827e55511c8c3aed8c36d21b6541dbd" data-rm-shortcode-name="rebelmouse-image" />
Goosebumps. Photo credit: Tyler Olson via Shutterstock<p>It's not entirely clear what purpose made goosebumps worth retaining evolutionarily, but there are two circumstances in which they appear: fear and cold. For fear, they may have been a way of making body hair stand up so we'd appear larger to predators, much the way a cat's tail puffs up — numerous creatures exaggerate their size when threatened. In the cold, they may have trapped additional heat for warmth.</p>
Tailbone<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MzQwMjc3N30.nBGAfc_O9sgyK_lOUo_MHzP1vK-9kJpohLlj9ax1P8s/img.jpg?width=980" id="9a2f6" width="1440" height="1440" data-rm-shortcode-id="4fe28368d2ed6a91a4c928d4254cc02a" data-rm-shortcode-name="rebelmouse-image" />
Image source: Decade3d-anatomy online via Shutterstock<p>Way back, we had tails that probably helped us balance upright, and was useful moving through trees. We still have the stump of one when we're embryos, from 4–6 weeks, and then the body mostly dissolves it during Weeks 6–8. What's left is the coccyx.</p>
The palmar grasp reflex<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMyMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjY0MDY5NX0.OSwReKLmNZkbAS12-AvRaxgCM7zyukjQUaG4vmhxTtM/img.jpg?width=980" id="8804c" width="1440" height="960" data-rm-shortcode-id="67542ee1c5a85807b0a7e63399e44575" data-rm-shortcode-name="rebelmouse-image" />
Palmar reflex activated! Photo credit: Raul Luna on Flickr<p> You've probably seen how non-human primate babies grab onto their parents' hands to be carried around. We used to do this, too. So still, if you touch your finger to a baby's palm, or if you touch the sole of their foot, the palmar grasp reflex will cause the hand or foot to try and close around your finger.</p>
Other people's suggestions<p>Amir's followers dove right in, offering both cool and questionable additions to her list. </p>
Fangs?<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Lower mouth plate behind your teeth. Some have protruding bone under the skin which is a throw back to large fangs. Almost like an upsidedown Sabre Tooth.</p>— neil crud (@neilcrud66) <a href="https://twitter.com/neilcrud66/status/1085606005000601600?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Hiccups<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sure: <a href="https://t.co/DjMZB1XidG">https://t.co/DjMZB1XidG</a></p>— Stephen Roughley (@SteBobRoughley) <a href="https://twitter.com/SteBobRoughley/status/1085529239556968448?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Hypnic jerk as you fall asleep<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">What about when you “jump” just as you’re drifting off to sleep, I heard that was a reflex to prevent falling from heights.</p>— Bann face (@thebanns) <a href="https://twitter.com/thebanns/status/1085554171879788545?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script> <p> This thing, often called the "alpha jerk" as you drop into alpha sleep, is properly called the hypnic jerk,. It may actually be a carryover from our arboreal days. The <a href="https://www.livescience.com/39225-why-people-twitch-falling-asleep.html" target="_blank" data-vivaldi-spatnav-clickable="1">hypothesis</a> is that you suddenly jerk awake to avoid falling out of your tree.</p>
Nails screeching on a blackboard response?<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Everyone hate the sound of fingernails on a blackboard. It's _speculated_ that this is a vestigial wiring in our head, because the sound is similar to the shrill warning call of a chimp. <a href="https://t.co/ReyZBy6XNN">https://t.co/ReyZBy6XNN</a></p>— Pet Rock (@eclogiter) <a href="https://twitter.com/eclogiter/status/1085587006258888706?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Ear hair<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Ok what is Hair in the ears for? I think cuz as we get older it filters out the BS.</p>— Sarah21 (@mimix3) <a href="https://twitter.com/mimix3/status/1085684393593561088?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Nervous laughter<blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">You may be onto something. Tooth-bearing with the jaw clenched is generally recognized as a signal of submission or non-threatening in primates. Involuntary smiling or laughing in tense situations might have signaled that you weren’t a threat.</p>— Jager Tusk (@JagerTusk) <a href="https://twitter.com/JagerTusk/status/1085316201104912384?ref_src=twsrc%5Etfw">January 15, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Um, yipes.<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sometimes it feels like my big toe should be on the side of my foot, was that ever a thing?</p>— B033? K@($ (@whimbrel17) <a href="https://twitter.com/whimbrel17/status/1085559016011563009?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
Ultimately, this is a fight between a giant reptile and a giant primate.
The 2021 film “Godzilla vs. Kong" pits the two most iconic movie monsters of all time against each other. And fans are now picking sides.
The more you see them, the better you get at spotting the signs.