We are told, “The logic governing their operation is riotously complex — but it has advantages”:
Recently, by looking closely at the protein interactions within one key developmental pathway that shapes the embryos of humans and other complex animals, Elowitz and his co-workers have caught a glimpse of what the logic of complex life is really like. This pathway is a riot of molecular promiscuity that would make a libertine blush, where the component molecules can unite in many different combinations. It might seem futile to hope that this chaotic dance could convey any coherent signal to direct the fate of a cell. Yet this sort of helter-skelter coupling among biomolecules may be the norm, not some weird exception. In fact, it may be why multicellular life works at all.
“Biological cell-cell communication circuits, with their families of promiscuously interacting ligands and receptors, look like a mess and use an architecture that is the opposite of what we synthetic biologists might have designed,” Elowitz said.
Yet this apparent chaos of interacting components is really a sophisticated signal-processing system that can extract information reliably and efficiently from complicated cocktails of signaling molecules. “Understanding cells’ natural combinatorial language could allow us to control [them] with much greater specificity than we have now,” he said.
Philip Ball, “Biologists Rethink the Logic Behind Cells’ Molecular Signals” at Quanta (September 16, 2021)
Actually, the best way to understand the systems would be that they are somewhat like a great novel. To someone with no understanding of the language, it might seem like a “riot” or “mess” of meaningless characters. To someone who does understand the language and has a mature appreciation of literature and life, it seems like “a sophisticated signal-processing system that can extract information reliably and efficiently from complicated cocktails of” life.
But if we understand “molecular signaling systems of complex cells” (correctly) that way, we must assume that they are designed. Or, alternatively, that novels write themselves.