Generally, coal is assumed to have originated in the lignin of Carboniferous forests, but now a new theory has been introduced: From The Economist:
The trees of the Carboniferous were not like those of today. Moreover, which types of tree predominated varied over the vast span of time that it covered. One pertinent observation Dr Boyce and his team make is that the peak of coal formation coincided with the dominance of a group called the lycopsids. Yet lycopsid trunks were composed mostly of tissue called periderm, which corresponds to modern bark and contains little lignin. Forests that existed both before and after these lycopsid woods (but before the supposed evolution of lignin-digesting fungi) had many more lignin-rich species in them, but have yielded far less coal.
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.
Instead, he suggests,
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.
So, Dr. Boyce argues, the actual cause was geology rather than an “evolutionary time lag” in the plants.
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, would still be tilling the fields. More.
We tend to underestimate plants.
Maybe we underestimate humans too. Coal became really important after machine power was introduced. Before that, was it not mainly just another form of domestic fuel?
See also: Stressed plants send out animal like signals? “For the first time, research has shown that, despite not having a nervous system, plants use signals normally associated with animals when they encounter stress.”
Plants moved to land earlier than thought
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