- Chemistry World: “Key Riddle of Life’s Origin May Be Answered by Primitive Protocells That Can Divide”
- Liquid droplets are self-organizing bubbles of liquid that coexist with a surrounding liquid.
- Liquid droplets can swell and split into smaller droplets.
- Liquid droplets can contain chemical reactions, such as those with RNA in a cell’s cytoplasm.
- Evolutionary biophysicists propose that liquid droplets were the “protocells” from which cells evolved.
Life? How did something so complex begin? Biological observations all show that life only comes from life. (This is called biogenesis.) Nevertheless, evolutionists confidently tell us that life evolved from nonliving chemicals through random natural processes.
Believing life began through abiogenesis despite the lack of observable scientific support, evolutionary scientists naturally search for ways to show how this could have happened. One of their latest notions suggests that the barrier between living cells and their surroundings got its start in self-replicating liquid droplets.
Liquid droplets are little bubbles of liquid floating in other liquids, sort of like oil and vinegar dressing when shaken. The liquid droplets of interest to biophysicists, however, are stable. Surface tension holds them in a spherical shape, and they coexist with their surroundings without being shaken or stirred. But in a supersaturated solution as molecules diffuse into them, these otherwise stable droplets can swell and split, very simplistically mimicking cellular division.
Because these bubbles can enclose certain molecules, concentrating and separating them from those in the surrounding liquid, they can segregate some chemical reactions from others. Spontaneous chemical reactions, possibly facilitated by the concentration of the necessary reactants, could therefore take place inside them. Outside the droplets, different chemical reactions might take place, particularly if light or some other energy source were available.
Biophysicists from Germany’s Max Planck Institute, observing the fascinating properties of liquid droplets, propose that liquid droplet physics could explain how life began. They believe that life’s essential chemicals, including genetic material, might have formed in prebiotic protocells. They call liquid droplets protocells to emphasize their evolutionary significance. Led by Frank Jülicher, the team has developed a model that they think explains how self-organizing liquid droplets, growing and reproducing before cells evolved, laid the groundwork for life’s evolutionary beginning.
Cells and Chemicals
All living things are made of cells. Cells are the building blocks of life. When evolutionists try to explain the origin of life, they must explain the origin of the living cell. Cells are not just baggies full of chemicals. They are incredibly complex, carefully compartmentalized structures in which chemical reactions are controlled and coordinated with each other.
Many chemical reactions take place inside a cell, where a complex, enzyme-rich, membrane-rich, highly organized architecture controls exactly what chemical reactions take place.
Cells have membranes that not only separate their insides from their outsides but also regulate what molecules can move through them. Many chemical reactions take place inside a cell, where a complex, enzyme-rich, membrane-rich, highly organized architecture controls exactly what chemical reactions take place.
Essential to all life is the ability of cells to grow and divide. Cells are self-replicating. They can reproduce themselves because they contain the genetic blueprint encoding instructions for their construction, organization, and operation. In multicellular organisms (like us), cells also contain the genetic information that determines how the cells differentiate and work together to make our bodies.
Everything scientists learn about cells offers another barrier to evolutionary claims that life could have evolved from chemicals. We have previously discussed the flaws in many of these claims—trickle-down chemistry, water world, RNA world, pre-RNA world, TNA world, XNA world, Darwin’s warm little pond, lipid world, nucleopeptide world, sugar world, clay theory, spinning living crystals, directed panspermia, and extraterrestrial infall.
That Which Is Seen
Jülicher’s model, though yet to be tested, is based on scientific observations. The behavior of stable liquid droplets and the molecules that make them up are observable. The chemical reactions that could take place inside them are observable. Some chemical reactions occur spontaneously, and some require an energy source. That is observable too. And because many chemical reactions interfere with other chemical reactions, chemists know that it is often necessary to separate them from each other. That the inside and the outside of these liquid droplets can sometimes separate such chemical reactions is also observable.
Depending on the concentrations of the various molecules in liquid droplets and the surrounding liquid, some molecules will spontaneously move across the boundary between the liquids. If lots of molecules diffuse into a droplet, it sometimes grows so big it splits into smaller daughter droplets. Such chemical behavior is also observable.
Cells contain many membrane-bound organelles, and cells are themselves wrapped in a cell membrane. So are actual liquid droplets a stable part of the cellular landscape? It turns out that they are! Cells contain within their cytoplasm many membrane-less “compartments” consisting of liquid collections of RNA molecules and RNA-binding proteins.1 This too is an observable fact.
Furthermore, RNA molecules can do some remarkable things. Consisting of chains of nucleotide “letters” similar to those in DNA, RNA plays a vital role in “decoding” the instructions contained in a cell’s genes. RNA copies genes and processes the information in them to manufacture proteins. RNA is also involved in the regulation of genetic expression. And some kinds of RNA molecules—ribozymes—act as catalysts for many important chemical reactions. These characteristics of RNA are likewise observable.
A Bubbly Beginning For Life
What sort of biologically relevant chemicals could be bottled up inside liquid droplets? If droplet division is to be relevant to the origin of life, these chemicals would have to be worth passing on. Naturally, the genetic material that passes on the information life needs to copy itself would be important in such a story! Therefore, biophysicists studying droplets and their evolutionary significance suggest that chemical reactions involving RNA could have taken place in primordial liquid droplets.
Ribozymes, a particular sort of RNA, catalyze some important chemical reactions. These include the assembly of amino acids to form the peptide chains of proteins and the linking of RNA nucleotides together to form more RNA or to splice bits of RNA together. Thus, some RNA can assemble itself.
The discovery of ribozymes has long fueled the RNA-world theory of abiogenesis. This is the idea that RNA was life’s original genetic material, able to assemble and replicate itself. Jülicher’s liquid droplets might, he proposes, have given this a non-living place to happen.
Perhaps self-assembling RNA, along with simple peptides, formed liquid droplets on the early earth, Jülicher suggests. If only a good chemical candidate for RNA copying could be identified, he speculates that, under the right conditions, random variations in the copying process along with spontaneous division of such “protocells” into daughter cells could have been subject to natural selection.
Jülicher and the coauthors of the Nature Physics paper describing the liquid-droplet model of life’s origins indicate that such liquid droplets could go far in explaining the cryptic origin of membranes. They believe this because a droplet’s surface naturally attracts certain kinds of molecules, including the sorts found in cell membranes.2 Could this process, purely a product of the chemical and physical properties of various molecules, have been the pre-biotic way life got started? Could non-living protocells like these have eventually evolved into primordial cells with all the necessary characteristics of life?
Jülicher’s team believe they have found the key to life.
Jülicher’s team believe they have found the key to life. The process they describe, if the right chemical components could be found, would segregate chemical reactions—including those that might randomly assemble RNA—in liquid bubbles that would not only spontaneously divide but also attract molecules of membranous relevance. So what’s the problem?
Bursting The Abiogenesis Bubble
Well, first of all, this is a model dependent on the existence of all the necessary components under the right conditions. And those conditions would have to have actually existed. Yet not only is the model hypothetical, but also the conditions on the early earth imagined by evolutionists are not know-able by the scientific method. No actual observational science can tell scientists what conditions existed when the earth was young. Why? Because no scientist was there to observe them. We can only know about the young earth because God, the earth’s Creator, has told us in His Word when He made the earth and all that in it and even what He made on each of the six days of creation. He was an eyewitness to the whole process.
What about membrane formation? The biophysicists suggest that the surface tension barrier holding each droplet together would have served as a membrane stand-in before membranes evolved. Has Jülicher’s team of biophysicists found a way protocells could have formed and re-formed until genuine membranes assembled themselves like oily bubbles in a sudsy pond of life?
The authors admit,
The steps from chemically active droplets to the first dividing cells with membranes pose a big challenge to the understanding of early evolution. While it has been suggested that ribozymes that replicate RNA could have formed by molecular evolution, it is unclear how a cell membrane and cell division could have emerged.3
Despite this admission, the authors believe the predecessors of living cells could have been liquid droplets. And because molecules like the lipids that comprise a significant portion of actual membranes can glom onto the surfaces of liquid droplets, they believe the droplets could have eventually attracted the necessary molecules to form membranes. They write, “If lipids were available in the outside fluid, lipid monolayers or bilayers could be attracted to the specific droplet surface chemistry. Our work shows that active droplets can naturally divide. Therefore, protocells could have obtained their membranes long after the first dividing cells had appeared on Earth.”4
Cells cannot exist without membranes. Many compartments inside actual cells are like liquid droplets, separated from cellular cytoplasm only by the properties of their component molecules. However, all cells have membranes. And even though the liquid droplets in Jülicher’s model can coalesce, stabilize themselves, grow, attract lipids to their surface, and divide into new daughter droplets without membranes, living cells require membranes. Real membranes. And cellular membranes are extremely complex structures, not just double-layered lipid barriers.
Real membranes contain embedded proteins and attachments for the internal skeleton of a cell. They actively control the movements of molecules into and out of a cell. They contain markers that signal other cells and, in many cases, adhere to other cells. Real cell membranes are the products of the genetic information contained in the parent cell, the necessary biomolecules manufactured in accordance with that information, and the complex cellular machinery that implements those instructions during cell division. Without such instructions and a way to follow them, a dividing “protocell” is only a bursting bubble, more reminiscent of the bursting bubbles of evolutionary claims than the origin of the living cell.
“Protocell” division—a product of the concentrations of chemicals in a liquid-droplet soup—is not a model for cell division—a genuine and genuinely complex process—or for the mythical evolution of life by natural selection. Nothing about popping “protocells” could provide actual information to pass on to generations of daughter cells, much less any information to eventually become alive.
Lack of Life’s Information
But the problem of abiogenesis goes past the issue of gathering the right substances under the right conditions through random processes. It even goes beyond the problem of spontaneous membrane assembly, if all the right biomolecules just happened to be around. Could life arise from nonliving material through random natural processes? Based on observational science, the answer must be “no.”
Perhaps the greatest scientific problem with the notion of abiogenesis is the lack of information.
Perhaps the greatest scientific problem with the notion of abiogenesis is the lack of information. The countless chemical processes that take place in a coordinated fashion in living cells occur because cells contain the genetic information to make them happen. Everything that a cell does, whether it is a single-celled organism or a component of a multicellular one, is possible because of the genetic information passed on in DNA from cell to cell.
What about that spontaneously assembled RNA the biophysicist authors suggest might have been sequestered in primordial protocells? No information is found there either. While some RNA molecules can self-assemble under the right conditions, randomly assembled RNA could not encode any information, whether bound in a membrane precursor or not. Why? Because random sequences of RNA nucleotides spell nothing. They are only nonsense. Random letters—particularly letters from a genetic language that did not yet exist in the evolutionary timeline—could not spell out complex information and instructions. Information, based on scientific observations, only comes from a source of information. It does not create itself through random processes.
The True Origin of Life
Despite the fond hopes of the evolutionary biophysicists who trumpet this latest tale in the abiogenesis story, the liquid-droplet origin of life just does not hold water. If we want to know how biological life began, we must look to the only living source of information around at the time of life’s origins. And that was the Creator God, who alone could create life from lifelessness. God alone could infuse all the living things He created with the information to follow His command—echoed repeatedly in the Genesis account of the six days of creation—to reproduce after their kinds.
God’s account of creation is not only preserved in the Bible’s book of Genesis but is also echoed in the God-inscribed commandments given at Mount Sinai: “For in six days the Lord made the heavens and the earth, the sea, and all that is in them” (Exodus 20:11). It is echoed again in the New Testament: “In the beginning was the Word, and Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him nothing was made that was made” (John 1:1–3). Those who reject God’s account of creation will remain ignorant of the origin of life, failing to acknowledge that life can only come from the one true giver of life, the Creator God.
- Did “Life on Earth” Ever “Favour Evolution Over Creationism”?
- Attempts to Trace Life Back to Chemical Origins Still Maps the Willful Ignorance of the Hunters
- Beyond the DNA-Protein Paradox: A “Clutch” of Other Chicken-Egg Paradoxes in Cell and Molecular Biology
- Where Should We Look for LUCA, Supposed Ancestor of All Life?
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