It is the egg you choose, but it seems that we all insist on trying to make myth a reality.
One of the most persistent myths about human reproduction is the idea that sperm compete with each other in a frantic race to the egg, which awaits the winner to be fertilized. But the idea is just myth.
Science shows us that this narrative is wrong. In truth, It is the egg who chooses the sperm.
Mammals, unlike fish, reptiles and amphibians, have evolved into a more selective and controlled reproductive strategy. While many species continue to produce large amounts of eggs and sperm throughout their lives – betting on the “numbers game” to ensure offspring – female mammals produce all their eggs before birth and release only one per cycle.
This evolutionary change may have allowed females greater control over reproduction, protecting their embryos within the body and choosing the best genetic combinations even before design, explains researcher Lynnette Sievert A.
Already in the 1980s, science had discovered that the egg plays an active role, with its protective layer called tight To test the spermallowing the entry only to those you consider appropriate. Studies from the next decade have reinforced this idea, and since then more confirmations have emerged.
But for some reason, the myth and the joke persist. “We were the fastest among millions of corridors,” we boast from time to time. By the way, here we are giving the news that the egg is to choose as if it were new.
Still in 2020, scientists from the universities of Stockholm and Manchester proved that eggs release chemicals that attract certain sperm – And what different eggs attract different sperm, even when it comes to sperm from a non -reproductive partner. The choice should be based on genetic compatibilities or sperm quality indicators, the researchers believe.
The results, obtained with biological materials of couples in fertilization treatment in vitroreveal that there is chemical communication between eggs and sperm, which allows a kind of “female choice”In the fertilization process.
