Could Life Have Evolved Multicellular Systems?
Abstract
Overview
If molecules-to-man evolution were true, how did life make the huge jump from single-cell forms to organisms with complex systems that work together? Evolution scientists think this happened many times. Creation scientists say, "Not a chance!" In addition to the problem of life arising in the first place, for this to have occurred life would have to overcome many hurdles:
- Finding a substantial benefit for transforming from the single-cell life that had been so successful for over two billion years
- Competition by “freeloading” cells in the evolving community
- Contemporary forms of life are so distinct that multicellular systems must have evolved at least 25 separate times from a single-cell ancestor
- Individual cells sometimes cooperate, but they remain individual—it's not a slam-dunk that cooperation leads to multicellularity
- The selective advantage for being a single cell will conflict with a cell’s attempt to become part of a multicellular organism
- New genes necessary for multicellular cooperation would have to evolve very quickly
- New genes would have to develop in every cell in the community at the same time
The recent report of a 1.5-billion-year-old fossil1 has brought attention once again to the alleged evolution of multicellular systems. This 30-centimeter fossil is offered as evidence that multicellular life evolved a billion years before the so-called Cambrian Explosion. Pyritic structures have also been suggested as showing that the first multicellular life may have evolved even earlier.2
Yet the key question—the “elephant in the room”—is why would multicellular systems have ever evolved? This question has long puzzled evolutionists. Single-celled (unicellular) organisms, such as bacteria, are the most versatile and adaptable organisms on earth. They are often described as Darwinian engines. Why would there be an evolutionary advantage to “evolve” multicellular systems (with more complex biological apparatus, less adaptability, and slower reproduction)?
Background
Some researchers believe life began on earth over 4 billion years ago.3 However, this early life consisted entirely of unicellular organisms. It was not until over two billion years later that the first multicellular organisms are claimed to have arisen.4
By this scenario, unicellular biology had been enormously successful for billions of years. This is an expanse of time far longer than it supposedly took for the origin of life or the transformation from a single cell to a human.5 After such a long period of biological success, why would any other type of life even arise? Why would there be any benefit to such a major biological change? What evolutionary pressure appeared after two billion years that "suddenly" made such a change advantageous?
Evolutionists have proposed various speculations but little substance.6 Developmental biologist Cassandra Extavour speculates that
Unlike the typical single cell that is tethered to a limited environment, a multicellular unit can roam over great distances in search of food or more favorable ecological conditions . . . multicellular species may find more opportunities to adapt successfully to drastically changing ecosystems that might wipe out a less mobile or less complex unicellular species.7
However, this is a significant factor only after a multicellular organism has acquired the ability of motility well beyond the microscopic state. Even evolutionists acknowledge that such motility did not appear until millions of years after the evolution of multicellular systems. Only intelligence can anticipate and plan for such a future contingency. Darwinism has no such foresight. Thus, moving great distances in search of better living conditions cannot be seriously offered as a contributing factor to the evolution of multicellular biology.
Moving great distances in search of better living conditions cannot be seriously offered as a contributing factor to the evolution of multicellular biology.
The End Doesn't Rectify the Means
In fact, many stages of multicellular evolution would almost certainly be a disadvantage to the organism's fitness. This is a distinct contradiction since each evolutionary stage of development is driven by providing an advantage over previous stages. Multicellular evolution simply has no driving force in any evolutionary scenario.
Nonetheless, evolutionists just assume that multicellular organisms formed (regardless of why). In this context, several different ideas have been proposed as to how they formed. The most popular view is that the early steps involved formation of cellular clusters. If these clusters proved advantageous, then the cell population continued to adapt. Eventually the cells would begin a phase of cooperation and division of labor. At this point, subpopulations of cells would start specializing in metabolic activities that contribute to the entire community.8 The cells then progressively lose individuality and become more dependent on each other, finally establishing full interdependence within the group.
Multicellular behavior is presumably stabilized by the evolution of new traits not originally possessed by any of the individual cells. These new traits are advantageous to the cellular community, making it beneficial for the individual cells to remain part of the multicellular system. Fitness of the multicellular organism is now no longer linked to the fitness of individual cells. The population is no longer a cluster of cells, but a single organism comprised of multiple cells.9
Cooperative Comparison?
A recent study offers three different species of algae as evidence for potential stages of such multicellular evolution.10 Of these three species, one maintains strict individuality, one lives in a colony, and one has a few characteristics of a multicellular organism. Using comparative genomics, the researchers determined genetic differences between these algae species. They then used this comparison to offer a series of genetic progressions that they speculate could transform unicellular to multicellular.
These ideas are part of the simplistic “just so” stories offered to explain how multicellular organisms evolved. There is little evidence for such scenarios—just the presumption that such evolution must have occurred. At best these are tentative historical reconstructions, but primarily they represent mere conjecture.
These ideas are part of the simplistic “just so” stories offered to explain how multicellular organisms evolved.
Yet a BBC News article declares the leap from simple to multicellular was “easy—in relative terms.”11 So easy, in fact, that multicellular organisms are supposed to have arisen independently at least twenty five times throughout earth history.12 This repeated evolution of multicellular organisms presumably “really cements the case that it was done early in the history of eukaryotes.”13
Of course, the case is only “cemented” if evolution is assumed as true. But here again is another often-overlooked problem. Evolution requires that multicellular organisms developed from unicellular organisms. Genetic analysis indicates that the relationship between plants, animals, slime molds, red algae, etc. is so distant and distinct that each must possess a unique evolutionary lineage. Each of these distinct lineages started all the way back with a single-cell ancestor.14
Spurious Substantiation
Ironically, by this scenario, evolution had to accomplish numerous times what it really has no ability to achieve even once. This does not make multicellular evolution "easy." Rather, it demonstrates the spurious nature of that claim.
Microbial studies also help reveal the difficulty of establishing and maintaining early stages of multicellular development. Even though social cooperation is required for a multicellular organism, unicellular organisms frequently employ social cooperation too.
Cooperation can be independent of multicellular biology. Individual cells within these cooperative systems can enter or leave at any time. They do not lose their unicellular individuality.
Most bacteria grow in cooperative colonies or in aggregate communities called biofilms.15 Some protozoa can form cooperative structures as well.16 These cooperative systems have many similarities to potential early stages of multicellular behavior. Within these systems the unicellular microbes can communicate, share resources, be protected from external agents, and even sacrifice for their neighbor. For example, Salmonella bacteria can commence a pathogenic attack in successive waves. The initial wave launches a potentially suicidal assault on the host’s defenses that increases the ability of subsequent waves to successfully evade these defenses.17
However, all these examples illustrate that cooperation can be independent of multicellular biology. Individual cells within these cooperative systems can enter or leave at any time. They do not lose their unicellular individuality. The gulf between unicellular and multicellular biology is far larger and more complicated than just a group of cells deciding to temporarily work together. New genes, new structures, new regulatory controls are all needed. These are not "easy" developments.
Freeloaders Are Everywhere
What is more, within a biofilm, some bacteria grow faster if they do not respond to chemical signals produced by their neighbors.18 This apparently allows them to grow with less restraint than the rest of the biofilm population. Also, some bacterial populations release polysaccharides so they can form mats on liquid surfaces (a type of biofilm), which increases the population’s access to oxygen. Within this mat though, a few individual cells will stop making the polysaccharide.19 This allows them to benefit from the mat without expending the energy to help make the mat.
Such "cheaters" take advantage of the cellular activity of others without expending energy to contribute to the community. In fact, "cheating" is recognized as a major problem in the evolution of social cooperation.20 Why do the work when others are doing the work for you?
Another major problem is that selection at the cell-level and selection at the multicellular organism-level are not equivalent. In fact, they are virtually opposite. If selection is operating at the multicellular level, it cannot simultaneously be operating at the individual cell level.21 Single cells thrive by reproducing more than their neighbors, while cells in a multicellular organism coordinate their reproduction. Thus, Darwinian views of natural selection are inconsistent with the evolution of multicellular organisms. The “selection” that supposedly formed and maintained the unicellular world for billions of years would be in diametric opposition to any “selection” supposedly attempting to form a new multicellular world.
This brings us back to my initial question—why even evolve multicellular systems?
The “selection” that supposedly formed and maintained the unicellular world for billions of years would be in diametric opposition to any “selection” supposedly attempting to form a new multicellular world.
The formation of multicellular organisms means that cells must relinquish their unicellular, programmed behavior in favor of a coordinated behavior. Why they would do this is currently unanswerable. How they would do this is also currently unanswerable, but certainly would be an enormously complicated transformation; one that is clearly far from “easy.”
What is more, any multicellular evolution almost certainly would require the formation of new genes. The development of multicellular biology requires that all the cells of the organism “have the same set of genes and obey the same rules.”22 Not only do new genes need to form during multicellular evolution, but the same genes and regulatory controls need to form in all the cells of the multicellular system. This is necessary to provide the new proteins and genetic activity required by multicellular organisms. Without new genes, single cells would remain single cells.
Regardless of what historical reconstructions and circumstantial evidence is put forward, without a plausible genetic mechanism any evolutionary scenario has little credibility.
Summary
Any evolution paradigm (Darwinism, emergent evolution, extended synthesis, etc.) presumes that new genes will constantly form as organisms evolve. Yet frequently cited examples of new gene evolution are actually the loss of pre-existing genetic activity.23 Instead, the formation of new genes remains largely undocumented.24
This is a significant problem, and one almost always overlooked by the evolutionary community. Regardless of what historical reconstructions and circumstantial evidence is put forward, without a plausible genetic mechanism any evolutionary scenario has little credibility. They are literally just a story.
Footnotes
- Shixing Zhu, Maoyan Zhu, Andrew H. Knoll, Zongjun Yin, Fangchen Zhao, Shufen Sun, Yuangao Qu, Min Shi, and Huan Liu, “Decimetre-scale Multicellular Eukaryotes from the 1.56-billion-year-old Gaoyuzhuang Formation in North China,” Nature Communications 7, (2016): 11500, doi:10.1038/ncomms11500.
- Abderrazak El Albani, Stefan Bengtson, Donald E. Canfield, Andrey Bekker, Roberto Macchiarelli, Arnaud Mazurier, Emma U. Hammarlund, Philippe Boulvais, Jean-Jacques Dupuy, Claude Fontaine, Franz T. Fürsich, Francois Gauthier-Lafaye, Philippe Janvier, Emmanuelle Javaux, Frantz Ossa Ossa, Anne-Catherine Pierson-Wickmann, Armelle Riboulleau, Paul Sardini, Daniel Vachard, Martin Whitehouse, and Alain Meunier, “Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago,” in Nature 466, no. 7302 (2010): 100–104.
- Elizabeth A. Bell, Patrick Boehnke, T. Mark Harrison, and Wendy L. Mao, “Potentially Biogenic Carbon Preserved in a 4.1 Billion-Year-Old Zircon,” Proceedings of the National Academy of Sciences, USA 47, no. 47 (2015): 14518–14521.
- Zhu et al., “Decimetre-scale Multicellular Eukaryotes.”
- Erik R. Hanschen, Tara N. Marriage, Patrick J. Ferris, Takashi Hamaji, Atsushi Toyoda, Asao Fujiyama, Rafik Neme, Hideki Noguchi, Yohei Minakuchi, Masahiro Suzuki, Hiroko Kawai-Toyooka, David R. Smith, Halle Sparks, Jaden Anderson, Robert Bakaric´, Victor Luria, Amir Karger, Marc W. Kirschner, Pierre M. Durand, Richard E. Michod, Hisayoshi Nozaki, and Bradley J.S.C. Olson, “The Gonium pectorale Genome Demonstrates Co-option of Cell Cycle Regulation During the Evolution of Multicellularity,” Nature Communications 7, (2016): 11370, doi:10.1038/ncomms11370.
- “How and Why Single Cell Organisms Evolved into Multicellular Life,” (2016), http://phys.org/news/2016-04-cell-evolved-multicellular-life.html.
- Peter Byrne, “Debate on Evolution of Multicellular Organisms Starts to Gain Focus,” Scientific American (2013), http://www.scientificamerican.com/article/debate-on-evolution-of-multicellular-organisms-starts-to-gain-focus/.
- Richard E. Michod, “Evolution of Individuality During the Transition from Unicellular to Multicellular Life,” Proceedings of the National Academy of Sciences, USA 104, no. suppl 1 (2007): 8613–8618.
- Henri J. Folse and Joan Roughgarden, “What is an Individual Organism? A Multilevel Selection Perspective,” The Quarterly Review of Biology 85, no. 4 (2010): 447–472.
- Hanschen et al., “The Gonium Pectorale Genome Demonstrates Co-option of Cell Cycle.”
- Paul Rincon, “Life Forms ‘Went Large’ a Billion Years Ago,” BBC News, May 17, 2016, http://www.bbc.com/news/science-environment-36303051.
- Richard K. Grosberg and Richard R. Strathmann, “The Evolution of Multicellularity: A Minor Major Transition?” Annual Review of Ecology, Evolutionary and Systematics 38, (2007): 621–654, doi:10.1146/annurev.ecolsys.36.102403.114735.
- Rincon, “Life Forms ‘Went Large’ a Billion Years Ago.
- Grosberg and Strathmann, “The Evolution of Multicellularity;” Hanschen et al., “The Gonium pectorale Genome Demonstrates Co-option of Cell Cycle.”
- Sivan Elias and Ehud Banin, “Multi-species Biofilms: Living with Friendly Neighbors,” FEMS Microbiology Reviews 36, no. 5 (2012): 990–1004, doi:10.1111/j.1574-6976.2012.00325.x.
- Mark J. Dayel, Rosanna A. Alegado, Stephen R. Fairclough, Tera C. Levin, Scott A. Nichols, Kent McDonald, and Nicole King, “Cell Differentiation and Morphogenesis in the Colony-Forming Choanoflagellate Salpingoeca rosetta,” Developmental Biology 357, no. 1 (2011): 73–82.
- Martin Ackermann, Bärbel Stecher, Nikki E. Freed, Pascal Songhet, Wolf-Dietrich Hardt, and Michael Doebeli, “Self-destructive Cooperation Mediated by Phenotypic Noise,” Nature 454, no. 7207 (2008): 987–990, doi:10.1038/nature07067.
- Kelsi M. Sandoz, Shelby M. Mitzimberg, and Martin Schuster, “Social Cheating in Pseudomonas aeruginosa Quorum Sensing,” Proceedings of the National Academy of Sciences, USA 104, no. 40 (2007): 15876–15881, doi:10.1073/pnas.0705653104.
- Paul B. Rainey and Benjamin Kerr, “Cheats as First Propagules: A New Hypothesis for the Evolution of Individuality During the Transition from Single Cells to Multicellularity,” Bioessays 32, no. 10 (2010): 872–880, doi:10.1002/bies.201000039.
- Sandoz et al., “Social Cheating in Pseudomonas aeruginosa Quorum Sensing.”
- John W. Pepper, Kathleen Sprouffske, and Carlo C. Maley, “Animal Cell Differentiation Patterns Suppress Somatic Evolution,” PLoS Computational Biology 3, no. 12 (2007): e250, doi:10.1371/journal.pcbi.0030250.
- Lewis Wolpert and Eörs Szathmáry, “Multicellularity: Evolution and the Egg,” Nature 420, no. 6917 (2002): 745.
- Kevin Anderson, “How are New Genes Made?” Answers in Depth 11, (2016): https://answersingenesis.org/genetics/how-are-new-genes-made/; Kevin Anderson, “Citrate Utilizing Mutants of Escherichia Coli,” Creation Research Society Quarterly 52, no. 4 (2016): 310–325.
- Kevin Anderson and Jean Lightner, “The Challenge of Mount Improbable,” Creation Research Society Quarterly 52, no. 4 (2016): 244–248; and Kevin Anderson, “How are New Genes Made?” Answers in Depth 11, (2016): https://answersingenesis.org/genetics/how-are-new-genes-made/.
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