Critics of intelligent design often claim that the peer-reviewed literature published by ID proponents amounts to nothing more than a negative critique of the neo-Darwinian paradigm, as opposed to positive arguments for ID as an alternative hypothesis. The falsity of this claim has long been evident, but a new paper in the journal BIO-Complexity (to which Ann Gauger has already drawn our attention), co-authored by Matti Leisola, Ossi Pastinen, and Douglas Axe, explicitly sets out a positive argument for design.
Lignin, a complex organic polymer found in wood, is the world’s second most abundant biopolymer (after cellulose). Moreover, it is extremely rich in stored energy. Surprisingly, in 400 million years, no living organism has evolved the ability to use it as an energy source. This is intriguing, given that many spectacular innovations have emerged over the course of life’s history. The new paper explains,
It is estimated that 30% of the earth’s non-fossil organic carbon is in the form of lignin. Considering its massive abundance and its high energy content (40% higher than cellulose, gram for gram), it is striking that no organism seems to have tapped it as an energy source.
Does this observation make more sense under a Darwinian view or under an intelligent-design view? The paper continues,
The Darwinian account must somehow reconcile 400 million years of failure to evolve a relatively modest innovation — growth on lignin — with a long list of spectacular innovations thought to have evolved in a fraction of that time. How can one mechanism have been at the same time so effective and so ineffective? That tension vanishes completely when the design perspective is adopted. Terrestrial animal life is crucially dependent on terrestrial plant life, which is crucially dependent on soil, which is crucially dependent on the gradual photo- and biodegradation of lignin.
In other words, the indigestibility of lignin is in the best interests of the ecosystem as a whole. As the paper explains,
We know that all complex terrestrial life depends on land plants and that land plants depend on soil. We also know that humus, the organic component of soil, is generated by the continual, gradual decomposition of plant material, and we know that lignin is what forces the decomposition to be gradual. Without lignin, the polysaccharide components of dead plant material would be consumed too rapidly for plant-supporting soil to exist, and life as we know it would not be possible. Only in a world with lignin can terrestial plant life have the rich diversity that we see, and without that diversity animal life as we know it could not exist.
Perhaps the oddest aspect of this is that Darwin’s theory is unable to make sense of a situation that otherwise makes perfect sense. If life is the product of intelligent design, it stands to reason that the whole design must be considered — not just the functions of molecules and cells and tissues and organs and organisms, but also the functions of the entire ecosystems.
What’s interesting is that the biodegradation of lignin can be accomplished by micro-organisms, including fungi (e.g. Hainal et al., 2012), who use it as a carbon source. In such cases, however, there is a net loss of energy, which ensures that the process is kept gradual. As the authors explain,
Typically several weeks are needed to achieve roughly 10% degradation of lignins below 1,000 daltons in molecular weight, and oxygen is always needed. In view of this, the answer that a Nature news article gave several years ago to the question “What can’t bacteria do?” still looks to be correct — they cannot metabolize lignin, because “the molecule is too large for most bacteria to handle, and its activation energy is too high.”
In the case of fungal degradation of lignin, the paper explains:
The degradation of lignin by white-rot fungi has some special and even strange features. Firstly, lignin is not degraded during fungal growth but only after nutrient depletion triggers secondary metabolism. This is strange since secondary metabolism is usually connected to biosynthetic reactions rather than degradative processes. Secondly, despite the fact that complete oxidation of lignin is highly exothermic, fungal degradation of lignin actually needs an energy source. It has been postulated that lignin degradation is too slow to serve as a source of metabolic energy […] Under optimal aerobic culture conditions, one gram of fungal mycelia degrades one gram of lignin in about 48 hours, consuming one gram of glucose in the process (as an energy source). Once glucose is depleted, lignin degradation ceases completely.
Now ask yourself: Is this the kind of coincidence one would expect to see under a Darwinian paradigm or under a design paradigm?
It is certainly surprising, on a Darwinian view, that over the course of 400 million years of evolution, no living organism has evolved the ability to metabolize lignin (despite the supposed occurrence of far more spectacular innovations in a fraction of that time). This makes perfect sense, however, under a design paradigm. As the authors put it, intelligent design “routinely takes the broad view and the long-term view, and because of this it alone makes sense of life.”