© Allison Filice for Quanta Magazine
Joe Nadeau, principal scientist at the Pacific Northwest Research Institute, is challenging this dogma. Random fertilization should lead to specific ratios of gene combinations in offspring, but Nadeau has found two examples just from his own lab that indicate fertilization can be far from random: Certain pairings of gamete genes are much more likely than others. After ruling out obvious alternative explanations, he could only conclude that fertilization wasn't random at all.
"It's the gamete equivalent of choosing a partner," Nadeau said.
His hypothesis - that the egg could woo sperm with specific genes and vice versa - is part of a growing realization in biology that the egg is not the submissive, docile cell that scientists long thought it was. Instead, researchers now see the egg as an equal and active player in reproduction, adding layers of evolutionary control and selection to one of the most important processes in life.
Comment: If true that the egg 'chooses' or selects for the best genetic package, then the idea that random mutations lead to evolution (which already has a probability so low that it can be said to be impossible) is even less likely to happen.