(ORDO NEWS) — A recent article in The New Yorker, “Journey to the Center of Our Cells,” says next to nothing about evolution and nothing about intelligent design.
There is no evidence that the author of the article or the scientists he interviewed are sympathetic to this idea. But it does provide a new insight into the complexity of the cell – an insight that unwittingly challenges theories of a wholly natural chemical origin of life.
The article explains that biologists are beginning to “understand the strangeness of the zone inside the cell, larger than atoms, but smaller than cells, in which there is a ‘mechanism of life'”, and further notes that “it is proteins that control the cellular world, causing chemical reactions, sending signals and self-assembling into biological machines.”
Problem for biologists
But there is a problem that biologists have long pondered – how do proteins find other proteins in the cell with which they must interact and combine in order to form these “biological machines” or carry out the necessary biochemical reactions?
The article explains that the solution to the problem was considered to be random Brownian motion in cells, when molecules suspended in a liquid medium make random movements in a limited space and eventually find their counterparts. Here’s how the article puts it:
For decades, biologists assumed that activity in the cytoplasm was essentially random; the cellular world rotates at such a tremendous speed that the right proteins will eventually collide with each other.
Brownian motion was believed to ensure that, within a reasonable time, proteins and other biochemical molecules would find their required chemical partners and interact or self-assemble to create the required structure or pathway. But new discoveries have changed this way of thinking.
Quote from the article:
But it turned out that some molecules in the cytoplasm circulate not by chance. They rotated in such a way that they united the related parties. Suppose five out of ten thousand proteins are involved in an important reaction; these five tend to hold on to each other, pulling weakly.
(Sometimes they had areas that exerted mutual attraction and which were missed in the images of proteins in crystallized form).
Brangwynn and others have found that, under the right conditions, groups of proteins can “phase separate” like oil bubbles in a salad dressing, forming structures. For decades, researchers have known that complex biochemical reactions tend to proceed faster in living cells than in test tubes.
Now they know why: conditions inside a living cell, reminiscent of a lava lamp, allow chemicals to take advantage of subtle attractive forces more efficiently than is possible in the freer and more uniform environment of a test tube or dish. We have long imagined the spark of life – but perhaps it is the physical structure of the cytoplasm that is the key.
The Humpty Dumpty Problem The
physical structure of the cytoplasm is, of course, an important aspect of the cell that exists outside of the DNA. It is a form of initial structural conditions that effectively carry extragenetic information that is the key to cellular organization and cellular function. According to an article in The New Yorker, it’s also the key to understanding what biologists call the “Humpty Dumpty problem.”
This concept has been summarized in The Design of Life, where biologist Jonathan Wells and mathematician William Dembski write about a real-life experiment testing the idea of unguided, random cell assembly. First, a living cell is placed in a test tube filled with appropriate nutrients. The cell is then pierced with a sterile needle so that its contents are poured into the solution.
Now the test tube contains all the materials necessary for life – not only amino acids, but also fully assembled proteins. However, even with all the necessary materials, the cell cannot reassemble itself. As Wells writes in the textbook, origin-of-life researchers “failed spectacularly in trying to put Humpty Dumpty back together.”
The New Yorker article also mentions failures in solving the Humpty Dumpty problem and explains how the lack of physical structure of the cytoplasm in the “pop-up cell” helps explain why the researchers were never able to assemble the cell into a functioning whole, even when all the necessary “parts” seemed to be present. :
This new understanding began to open doors. In 2017, Glass helped found the Build-a-Cell Consortium, a steering committee for hundreds of labs trying to build a working cell from scratch.
The consortium’s researchers began to combine non-living parts – proteins, ribosomes, RNA and other molecular constructs – into cell-like membranes, hoping that the mixture would come to life, expressing genes, doing metabolic work, and eventually dividing.
Drew Andy, professor of bioengineering at Stanford and co-founder of Glass, described the group’s work as an attempt to solve the Humpty Dumpty problem: Can parts fit together? Such artificial cells can be used as living factories for the production of biofuels or drugs, or as hyperefficient sites for artificial photosynthesis.
But although the necessary parts are already there, none of them have crossed the border from inanimate to living. Andy’s group experimented with slightly different ingredients; if that fails, the problem may be in how they are physically located.”
In other words, you can never just create a cage with the right parts. You also need a well-shaped cytoskeleton that can arrange these parts in such a way that the reactions and pathways proceed in a way that keeps the cell alive.
Evolution in words
The New Yorker article talks about evolution: “In the human body, there are brain cells and nail cells, blood cells and muscle cells, and dozens of single-celled bacteria. Each has been shaped to suit its niche over eons of evolution.”
But this idea is not consistent with the conclusions of the report that for the existence of a cell, not only its parts are necessary. Of course, parts are needed – they are necessary, but not sufficient for a living cell. In addition to these parts, some organization is also needed.
Thus, it is well shown in this article that the parts must also be properly organized into a physical structure, where the “physical structure of the cytoplasm” ensures that the right molecules find each other to facilitate the cellular responses needed by the cell.
The importance of physical architecture to the viability of any cell adds an element of insurmountable complexity to cellular operations and is a major obstacle to natural, unguided chemical models of the origin of life.
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