Some of our most important organs may have developed due to a random and accidental genetic mutation.
Scientists are discovering the roots of human complexity.
It seems that for all our faults, humanity is pretty lucky. If not for the occurrence of a single, random mutation, we may not be where we are today. 700 million years ago, our ancestral genetic material diverged from the ancestral genetic material of sea anemones. A short time after this occurrence, a random mutation appeared in our genes. According to a new study, this random “mistake” planted the seeds of what we would eventually turn into.
Humans are complex—not just psychologically, but physiologically as well. It’s difficult to get to the root of our complexity, to find where it all began, or to pinpoint the events early in our genetic history that led to where we are now. The discovery of this genetic mutation from hundreds of millions of years ago, however, may actually be a good start.
A small mutation can make big changes.
Researchers say that this mutation was once a “silent” one, meaning that it didn’t manifest in physical ways. It didn’t impact the way the organism carrying it looked or behaved; it was just there. However, at some point in time around 700 million years ago, it caused a domino effect among other genes, which eventually lead to humans as we are today.
First, the random mutation made an impact on a gene in a group of proteins called Fgfr, or fibroblast growth factor receptors, which play a role in cell development. Some million years later, a Fgfr-controlled network made contact with another network controlled by the Esrp group of proteins. These proteins, researchers say, are in charge of slicing up our genes and putting them all back together. This is called the “alternative splicing process”, and it takes place in some of our cells. This process allows our genome to have more proteins that it would without the Esrp proteins. As a result, we have the opportunity to evolve.
Scientists didn’t know that Esrp proteins were capable of this. What they did know about these proteins was that they regulated the interaction of cells in a developing embryo. However, the findings of this latest research tell us otherwise.
We owe some of our vital organs to this random genetic error.
The connection between the Fgfr and Esrp networks became the foundation for the development of important internal organs in humans, such as lungs, limbs, and our inner ears. Thus, a usually “silent” mutation that randomly ended its “silence” was the catalyst for the connection between the Fgfr- and Esrp-controlled networks, which eventually led to the development of some of our vital organs.
If it weren’t for that random mutation, we wouldn’t what we are today. Jordi Garcia-Fernàndez, one of the researchers, says that this is evidence of the importance of “serendipity” in evolution. The possibility that things might have been different for us, that we might not have even been us, is staggering to think about. A seemingly small thing can have far-reaching consequences. “If that one mutation hadn’t occurred,” says Dr. Manuel Irimia, another researcher, “the story of (human development) could have been very different.”
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