Imagine walking down the street and seeing someone who looks just like you—identical to you. Maybe you were cloned? Researchers have cloned cells and created genetically identical organisms for over a century, and humans might be next.
Taking a time machine to 1979, we would be able to watch scientists clone the first mouse by splitting mouse embryos and then implanting them into the uterus of a surrogate mouse. Soon after this success, researchers were able to produce the first genetically identical cows and chickens. In 1996, after 276 failed attempts, Scottish researchers cloned the first mammal from a sheep udder cell, creating Dolly the lamb.
You might be wondering: how do scientists clone organisms? Coning is the process of creating a genetically identical cell or organism. This is very common in nature, specifically in plants and bacteria, and even identical twins. Artificial organismal cloning is possible through embryo splitting and nucleus transfer. In nuclear transfer, the DNA is transferred to another cell and implanted into a surrogate mother’s uterus. The new embryo will be born as an identical copy of the organism that donated its DNA!
In plants and animals, the benefits of cloning, such as increasing crop yields and saving endangered species, may outweigh the disadvantages. In December 2020, with only 650 Black-footed ferrets in the world, scientists successfully cloned one by using frozen ferret cells in hopes of saving the species from extinction. “With these cloning techniques, you can basically freeze time and regenerate those cells,” U.S. Fish and Wildlife Service coordinator Pete Gober said.
When scientists successfully cloned a Macaques monkey, human cloning became a topic of discussion. Dr. Robert Lanza, chief scientific officer at Advanced Cell Technology, says that it is challenging from a technical perspective. During organismal cloning, we remove the nucleus and essential cell division proteins, which isn’t a problem in animals like mice. “But primates aren't able to do this, and researchers think it may be one reason that attempts to clone monkeys have failed,” Lanza said. Monkeys are our closest relatives, and the challenges that scientists face may parallel issues human cloning.
Scientists can clone human embryos, but have not attempted to clone humans. As of now, many countries allow therapeutic cloning of human cells (such as organ and cell regrowth) but ban reproductive cloning, and in others, cloning human cells is illegal.
Let’s say, we are able to clone humans; what would the world look like? Cloning may be the answer to providing couples with infertility issues or same-sex couples the opportunity to have children.
The downside of reproductive cloning may come down to ethics and efficiency. Some religions consider the creation of a human being unethical. Additionally, cloning mammals has an extremely low success rate; only 5%. For those who have survived, many have severe birth defects and low life expectancies.
Cloning has progressed from creating new cells to saving endangered species, who knows what the future holds! Maybe, one day, you will bump into your identical twin!