Why Is a New Theory of Coal Formation Needed?
When a new theory comes along, better examine why the old one needed replacing.
Matthew Nelsen and Kevin Boyce of Stanford, with two colleagues, have just published in PNAS a new theory of coal formation, “Delayed fungal evolution did not cause the Paleozoic peak in coal production.” Why? What was wrong with the old theory? As indicated in their title, the old theory said that “delayed fungal evolution” allowed large amounts of woody plant material to pile up in the Carboniferous era until fungi evolved the ability to break down lignin. It’s not true, they say:
The Carboniferous−Permian marks the greatest coal-forming interval in Earth’s history, contributing to glaciation and uniquely high oxygen concentrations at the time and fueling the modern Industrial Revolution. This peak in coal deposition is frequently attributed to an evolutionary lag between plant synthesis of the recalcitrant biopolymer lignin and fungal capacities for lignin degradation, resulting in massive accumulation of plant debris. Here, we demonstrate that lignin was of secondary importance in many floras and that shifts in lignin abundance had no obvious impact on coal formation. Evidence for lignin degradation—including fungal—was ubiquitous, and absence of lignin decay would have profoundly disrupted the carbon cycle.
Time to rewrite the textbooks, in other words. The “delayed fungal evolution” theory was gospel truth in museums and classrooms. It purported to explain why that particular period of time, the Carboniferous-Permian, was so dominated by coal. Now, these geologists are saying it isn’t true. Fungi and other factors were able to degrade lignin during all that time. After considering all the factors, they say, “Taken together, there appears to have been no shortage of options available for the decomposition of lignified tissue in the pre-Permian world.”
Whenever scientists find fault with an old theory, they should try to replace it with a new one (although that is not required in philosophy of science). Nelsen et al. propose this: “Instead, coal accumulation patterns implicate a unique combination of climate and tectonics during Pangea formation.” This means it wasn’t caused by biology. It was caused by geology. OK; so what was unique about plate tectonics and climate back then? After all, most of the vast coal deposits are dated to the Carboniferous and Permian. They propose that it was something about the rate of accumulation of vegetation during those periods. Here’s their alternative theory in brief. Two conditions had to be met (Note: orogen=mountain building):
During the Carboniferous, a massive amount of organic debris accumulated in warm, humid−perhumid equatorial wetlands formed during glacial periods, which was subsequently buried during interglacial phases. However, long-term preservation further requires crustal subsidence to ensure continued deposition instead of erosion. Continental flexures formed in response to crustal thickening in active orogens (i.e., foreland basins) provide such a setting and are commonly associated with coal-bearing deposits, as their rates of subsidence and coal accumulation can be roughly comparable, permitting the formation and preservation of thick peats. Extensive foreland and cratonic basins, formed in association with the Pennsylvanian−Permian coalescence of Pangea and were positioned in the humid−perhumid, equatorial zone, ensuring the cooccurrence of both the subsidence requisite for long-term preservation of organic deposits and the climate necessary for promoting high water tables and biological productivity.
But what about later coals during the Cenozoic? They came prepared to discuss that, too, armed with the comeback that those coals don’t fit the decay-lag theory (because fungi capable of degrading lignin were already prevalent by then):
Equatorial rainforests have been common in the Cenozoic, but the passive continental margins of the post-Pangean tropics led to more localized accumulations, such as in Southeast Asia and at higher latitudes in North America during the super greenhouse conditions of the earlier Cenozoic. These warm wet conditions during the Cretaceous−Paleogene permitted the formation of woody seed plant-dominated mire ecosystems in tectonic basins along the Western Interior Seaway of North America formed in association with the Laramide Orogeny, which ultimately gave rise to the thick coal beds of western North America. Regional coal accumulation rates during this time approximated those of the Carboniferous (Fig. 1), albeit those coal accumulation rates were not integrated over so extensive a geographic area globally as in the Carboniferous. The occurrence of these substantial coal deposits 200 million years after the undisputed evolution of wood-rotting fungi sharply conflicts with the evolutionary lag model…. The magnitude of Carboniferous−Permian coal production was not a product of increased plant lignin content coupled with the delayed evolution of lignin-degrading fungi but rather a unique confluence of climate and tectonics.
In other words, the geological conditions for accumulation were different in later periods, even if plants were abundant capable of producing coal.
An article in The Economist about this new proposal starts by describing coal as “the rock that rocked the world; more than any other substance, coal created modern society.” Before examining the new theory, the article tells the evolutionary just-so story that has been repeated for decades:
Trees have to be strong, though, otherwise they will collapse. Part of their strength comes from cellulose, an ancient material composed of long chains of sugar molecules, which forms the walls of plant cells. But what really encouraged trees’ evolution was the advent of a second molecule, lignin. This is made of phenols, and phenols are much harder to digest than sugars—so hard, the thinking goes, that it took until after the Carboniferous was over for organisms that could do so to evolve. Meanwhile, the fallen forests simply piled up in the swamps. Though some of their cellulose was consumed, their lignin hung around and became coal.
Whether or not the new theory holds up, the old theory based on evolutionary biology is wrong.
Moreover, though Permian rocks in North America do not contain much coal, those in China do. That does not seem consistent with idea that lignin-consumption rates suddenly increased. And, although the fossil record cannot show which enzymes were present in fungi in the past, it does show that fungi were just as diverse and active in the Carboniferous as in the Permian. Altogether, then, the abundant coal of the Carboniferous does not seem to be the result of lackadaisical fungal effort. So, in Dr Boyce’s view, the evolutionary-delay hypothesis simply will not do.
Recognizing that after destroying a hypothesis “it also helps if you have something to put in its place,” the article turns a corner to examine Boyce and Nelsen’s new theory based on continental drift.
During the Carboniferous, the continents were moving around quite a bit. Such movement, particularly when it involves continents colliding (which it did), warps them. That causes mountains and basins to form. It is the basins which interest Dr Boyce. The downwarping that created them meant they would have flooded regularly, bringing sediment that buried the tree-laden bogs, preserving them not so much from micro-organisms as from erosion.
PhysOrg allows the authors to describe how “conventional wisdom” became a long-lived falsehood that is contrary to multiple lines of evidence. Speaking of the old “evolutionary-lag” hypothesis, they say,
“Much of the scientific community was really enamored with this simple, straightforward explanation,” said Kevin Boyce, a geobiologist at Stanford’s School of Earth, Energy & Environmental Sciences. “So, it has not only refused to die, it has become a conventional wisdom.“
In the new study, Boyce and his colleagues took a closer look at this “evolutionary lag” hypothesis, examining the idea from various biochemical and geological perspectives. “Our analysis demonstrates that an evolutionary lag explanation for the creation of ancient coal is inconsistent with geochemistry, sedimentology, paleontology, and biology,” said Matthew Nelsen, a postdoctoral researcher in Boyce’s lab and first author on the new paper.
And yet their replacement theory requires “a unique combination of tectonics and climate conditions that existed during the assembly of Pangea.” Is this special pleading? It also requires a radical departure from the old conventional wisdom. Boyce says,
Coal, as dead plant matter, is obviously based in short-term biological processes. And yet, as an important part of the long-term carbon cycle, coal accumulation is largely dictated by geological processes that operate on timescales of many millions of years that are entirely independent of the biology.
It appears they are trying to have it both ways: dependence on short-term processes and long-term processes that somehow converged in unique ways to generate vast coal beds in some times and not others. But how plausible is it to imagine plant material falling into basins and sitting there millions of years before it got buried? If, as they argue, lignin degradation was “ubiquitous” in the Carboniferous and Permian ages, it would seem to degradation was much more rapid than burial. The carbon would be recycled, and no coal would result. That’s what happens in rain forests today; we do not see accumulation of vegetable matter in deep layers except in some peat bogs. Yet some coal beds are 75 feet thick or more (creation.com), and cover hundreds of thousands of square kilometers. Geologists estimate that 3 to 12 meters of vegetation would have been required for one meter thickness of coal. No peat bog of that thickness and extent exists anywhere in the world today.
Why not “save a step” as Carl Sagan was wont to say, and postulate a single high-energy step that would (1) accumulate vast quantities of vegetation, (2) bury it quickly, (3) and move the continents quickly, with rapid formation of mountains and basins? Creation geologists have proposed such mechanisms for coal formation without any need for “many millions of years.” Their explanation also accounts for polystrate fossils (e.g., ICR) that defy long time periods between seams. In his two-volume work Earth’s Catastrophic Past, creation geologist Andrew Snelling provides multiple lines of evidence for water transport and burial of vegetation that led to coal.
One thing all the articles agree on is that our modern Industrial Revolution would not have happened without coal. The Economist concludes,
If his hypothesis is correct, then, it is the grinding movement of the continents that is ultimately responsible for the Industrial Revolution. No continental drift, no coal. No coal, and humanity, if, indeed, such a species had evolved at all, might still be tilling the fields.
Ann Gauger of the Discovery Institute has shown that the unique properties of lignin are difficult to explain by evolutionary theory (Evolution News & Views #1, #2, #3). Michael Denton described the fitness of nature for large trees because of lignin (ENV), showing that it’s not just the ability of some microbes to degrade it that sustains life, but also the rate at which they do:
Moreover the slow breakdown of lignin promotes the production of soil, which again promote the existence of large trees. It is another example of the elegance and parsimony of nature’s fitness for life, where one substance or process satisfies two or more ends.
Denton’s upcoming book Evolution: Still a Theory in Crisis will examine, among other things, several uncanny coincidences in planet Earth that allow only human beings—not any other intelligent creatures, such as dolphins, birds, or apes—to control and use fire. That has made all the difference in human civilization, he shows, from using it for cooking, for inventing metallurgy, to building rockets to Pluto.
One other thing. The authors in PNAS stated in passing that “absence of lignin decay would have profoundly disrupted the carbon cycle.” This implies that Earth needs carbon homeostasis (a balance between buildup and breakdown of carbon-based plant material) to remain habitable. Their statement suggests that the carbon footprint of the old theory could well have made life intolerable or impossible. Since we are here, breathing temperate air, that should have been enough to falsify the old theory. Examining the carbon cycle in addition to the water cycle, nitrogen cycle, and other critical balances that sustain life on our planet, intelligent design (as propounded by Gauger and Denton) looks like an option that should not be discounted.
So what do you think of the new secular theory? Notice the difference between observations and explanations. We see vast, huge coal beds in Pennsylvania, China, Indonesia, Utah and elsewhere. Nobody, however, can go back in time and see how they were formed. The best we can do is examine the characteristics of the coal, including lignin and fossil content, and appealing to known forces, produce a scenario that could account for the observations. Some predictions can be made to motivate new observations, but any given scenario must remain tentative. As we see here, “conventional wisdom” can be “inconsistent with geochemistry, sedimentology, paleontology, and biology” and yet be believed and taught for decades, even a century or more.
Now that Nelsen, Boyce et al. have minimized any role for evolutionary biology in the formation of coal, why do we need the millions of years? Creation models have the advantage of eyewitness testimony in Genesis about a cataclysm with enormous energy, enough to move continents, rip up vegetation into floating mats, and bury them rapidly where heat and pressure could turn them into coal rapidly. It would seem a theory with one cause instead of multiple unique events spanning unobserved millions of years would be the best one.
The Creation model also explains the availability of this energy source for the benefit of man. Denton is not a Christian or creationist, but he is fascinated by the number of coincidences on our planet that seem to be for the benefit of man-like intelligent creatures. Christians who accept the Flood can see the hand of God in even the destructive power of the Flood, preparing a new world like a Potter smashing a corrupted pot and fashioning an even more beautiful one from its remains, with the energy from fossil fuels He knew man would need. The post-Flood world would also forever retain the lesson of judgment for sin, evidenced from catastrophic geology (e.g., Grand Canyon) and the fossil record.
Whatever you think of the Genesis explanation, at least see here a typical case of conventional wisdom believed uncritically for decades. The new theory does not improve on the old theory; it overturns it. Those who trust in science should take warning: whatever they are telling you now could be false tomorrow.