Looking for Laws to Make Darwinism Scientific
Science needs natural laws. Darwinian laws that have been put forward by evolutionists contain so many exceptions and complexities, they seem to have a bad case of physics envy.
- Coping with Cope’s Rule: Evolution tends to make animals larger over time – except when it makes them smaller. In Science,1 Kaustuv Roy lamented the perils of this principle that animals evolve toward largeness, known as Cope’s rule. It has some examples but plenty of exceptions. If Cope’s rule were a law of nature, wouldn’t we find lots of giants? “Instead, most species tend to be small to intermediate in size, with few in the smallest and largest size classes.”
- Bergmann’s suggestion: Maybe Cope’s rule is offset by a competing principle. This happens sometimes in physics when two forces compete with each other. Bergmann’s rule says that animals grow larger in colder climates. Polar bears grow larger than black bears, for instance. Again, this is too simplistic, Roy argues:
Translating these “rules” into predictions about trajectories of size evolution is not straightforward. If bigger really is better, then we should have a world full of giants, yet most species are small. Clearly there are costs to getting bigger, which prevent a runaway Cope’s rule. Such costs involve complex interactions among a multitude of factors including development time, population size, and patterns of resource use. In addition, the temperature-size rule [Bergmann’s rule] suggests that the external environment, which changes in a complex and nonlinear manner over geologic time, is also important in driving size evolution. So, not surprisingly, simple process-based models of size evolution (such as one based on energetics) have not been widely accepted.
As if that weren’t complex enough, “There is also the problem of scaling up from observations at the population level to macroevolutionary trends in size,” he said. It is unclear whether models built on samples from a few generations (living or extinct) will hold up “across geographically separated populations and macroevolutionary time.” The uncertainty about these “rules” of body size evolution make it difficult to quantify the apparent influence humans are having on large animals today.
- Extinction rules or rules going extinct? Three Turkish scientists brought up problems with measuring extinctions. There are no agreed-on measures of how “great” an extinction event was. Writing in PNAS,2 they said that even since Cuvier proposed multiple catastrophes, and on through the time of Lyell to the present, “it has remained controversial as to how completely and how fast those disappearances occurred,” they said. “Interpretations about the nature and origin of these fluctuations in the progression of life have long been bedeviled by uncertainties as to what constitutes a mass extinction and which mass extinction is ‘greater’ or ‘lesser’ than any other.” The fact that these authors proposed a quantitative scale highlights the fact that no one had done it successfully before. Here’s how they ended their discussion:
Great extinctions are generally less catastrophic than widely thought: they are generally Lyellian, only exceptionally Cuvierian. When they are Cuvierian, as the end-Cretaceous extinction so obviously was, and as the present one so alarmingly is, they stand out among the other, more mundane, Lyellian ones. It is not profitable to study extinctions in isolation, among few taxa, in few sections and in limited time frames. They are simply parts of one continuous evolution of the entire earth system and must be studied as such.
And yet, aside from the admitted uncertainties and complexities of defining an extinction event and measuring its magnitude, can there really be natural laws governing events as random and unpredictable as catastrophes?
- Know your limits: Evolutionists from UK and UC (University of California at Santa Cruz) pulled some reins on how much can be generalized from in vitro evolution models. Some scientists, for instance, study populations of E. coli in a Petri dish and watch what happens when bacteriophages invade. Can the results be generalized into laws of co-evolution?
Writing in Nature,3 the team began by asking, “Given the difficulty of testing evolutionary and ecological theory in situ, in vitro model systems are attractive alternatives; however, can we appraise whether an experimental result is particular to the in vitro model, and, if so, characterize the systems likely to behave differently and understand why?”
They optimistically proposed a mathematical model that was concordant with one experimental result. So far, so good, but can that be extended to other experiments? They provided several cases where outcomes could be very different depending on the host, the parasite, the resources, and the genetics of the system. Their explanation for different results in different conditions seemed convincing, but their ending paragraph seemed to suggest that a model for one experiment cannot easily be extrapolated to others without auxiliary hypotheses. These seems to make it difficult to establish any laws of co-evolution:
Given the above explanation, it is perhaps not surprising in retrospect that what is found for T7�E. coli interactions need not be true for other biologically viable modes of host-parasite co-evolution. These results show how appropriately framed mathematical models aligned with experimental analysis can obviate the need to presume typicality of one model within a class.
- Contingency vs Law: It would seem that contingency is the opposite of natural law. Attributing events to chance is about as explanatorily useful as saying “Stuff happens.” That’s about all that a team from the American Museum of Natural History was able to say, though, about the evolution of dinosaurs. Writing in Science, they found that the famous “evolutionary radiation” of the dinosaurs did not follow any rule of size trends, superiority, character evolution or morphological disparity. “The results strongly suggest that historical contingency, rather than prolonged competition or general ‘superiority,’ was the primary factor in the rise of dinosaurs.” Stuff just happened. Such a premise flies in the face of many a textbook and TV documentary.
The paper was summarized by PhysOrg, which titled its article, “Luck gave dinosaurs their edge.” Team member Steve Brusatte was quoted saying, “For a long time it was thought that there was something special about dinosaurs that helped them become more successful during the Triassic, the first 30 million years of their history, but this isn’t true.” In the AMNH press release, team member Michael Benton said, “Many people like to think that evolution is progressive: mammals are better than dinosaurs because they came later…. So it may be hard for us to accept that dinosaurs achieved their dominant position on earth largely by chance, just as mammals did when the dinosaurs were later wiped out by a meteorite strike.” Maybe the new phrase for Darwin should be “Survival of the luckiest.” But, then, if fitness cannot be correlated with evolutionary success, what becomes of any Darwinian claim to having established a new law of nature? What is natural selection selecting? What is survival of the fittest judging as fit?
- Lucky information: This list concludes with a reminder that David Deamer said this about the origin of the DNA code: “I think genetic information more or less came out of nowhere by chance assemblages of short polymers.” (See the 09/10/2008 entry.)
If evolutionary biology struggles with discovering natural laws, surely something as physical as geology should do better, right? Not so fast; in Science last week,4 Susan L. Brantley (Penn State) struggled with the complexities of determining the lifetime of something right under our feet: the soil. Soil is obviously important to humans for economic reasons. It also is easily available for study. But you would be surprised how many complicating factors there are when trying to calculate how fast it forms, how long it lasts, and how fast it erodes. Her opening paragraph only suggested the complexity of it all:
Soils constitute the topmost layer of the regolith, the blanket of loose rock material that covers Earth’s surface. An open system such as soil or regolith is sustainable, or in steady state, only when components such as rock particles are removed at the same rate they are replenished. However, soils are defined not only by rock particles but also by minerals, nutrients, organic matter, biota, and water. These entities–each characterized by lifetimes in regolith that vary from hundreds of millions of years to minutes–are often studied by scientists from different disciplines. If soils are to be maintained in a sustainable manner, scientists must develop models that cross these time scales to predict the effects of human impact.
Sure enough, each one of these ingredients of soil can increase or decrease at vastly different rates. Attempts to date a sample soil in Puerto Rico by cosmogenic nuclides has underscored the problem: how typical is it? A scientist needs to know the input rate, the erosion rate, the penetration depth and many other things which turn out to vary by several orders of magnitude in different soils. In Africa, for instance, the technique doesn’t work. And that is only one factor. If you study a soil based on its nitrogen input-output rate, or its water retention, or its minerals you can get vastly different results. “When scientists within a discipline study soils, they generally focus on one of these time scales while ignoring faster and slower processes,” she said. Can a scientist assume a sample is in a steady state? Whether any ecosystem reaches steady state, she said, is controversial: “If it is possible, steady state is a complex function of the extent and frequency of disturbances such as fires and insect infestations.” What other factors enter the equation? It appears that defining natural laws of soil evolution that will fit any meaningful set of diverse soils is unattainable. “For example, present-day and long-term denudation rates for catchments or soils have been shown to be equal across time scales in some cases, as required for sustainable soils,” she said, but added, “In other cases, the long-term and present-day denudation rates do not agree, perhaps because of variations in ecosystems, climate, glacial effects, extreme events, or human impact.” How, then, can humans predict what will happen? It’s kind of like debates about global warming: “Just as we use global climate models today to project future climate change, we will eventually be able to use global soil models to project future soil change,” she ended optimistically.
1. Kaustuv Roy, “Dynamics of Body Size Evolution,” Science, 12 September 2008: Vol. 321. no. 5895, pp. 1451-1452, DOI: 10.1126/science.1163097.
2. Sengor et al, “A scale of greatness and causal classification of mass extinctions: Implications for mechanisms,” Proceedings of the National Academy of Sciences USA, published online before print September 8, 2008, doi: 10.1073/pnas.0805482105.
3. Forde et al, “Understanding the limits to generalizability of experimental evolutionary models,” Nature 455, 220-223 (11 September 2008) | doi:10.1038/nature07152.
4. Susan L. Brantley, “Geology: Understanding Soil Time,” Science, 12 September 2008: Vol. 321. no. 5895, pp. 1454-1455, DOI: 10.1126/science.1161132.
In science it is fairly rare to reduce a phenomenon to simple, neat laws. Physics has arguably been the best example – you can write the physical laws of the universe in equations on a sheet of paper – but even there, complications and difficulties arise (see 06/30/2008, for instance). Maybe you’ve seen one of those science toys that pits gravity against magnetism: a pendulum wobbles chaotically as it tries to fall but hits magnetic repulsive forces. The laws of gravity and electromagnetism are easily expressed mathematically, but it would be a huge challenge to predict the path of the pendulum. How much more so when dealing with all the complex factors involved in ecology and evolution? Don’t use the comeback, Darwinists, of the “Law of Natural Selection.” Go re-read the entry on “Fitness for Dummies” from 10/29/2002.
One feels a bit of pity for the evolutionary biologist doing his or her best to capture nature’s exigencies in models, equations and natural laws. It seems a hopeless task. Valiantly they continue on, but the above examples highlight the quandary. One may never know all the factors that come to bear on a problem, or their relative influences, or their rates of action, or their interactions and feedbacks. Yet the NCSE and other pro-Darwin groups constantly parade the supposed priority of evolutionary theory over design or creation on the basis of its explanatory power with reference to natural laws. OK: show us the laws. Can they name any one evolutionary law or rule that is not plagued by exceptions, controversy and counter-claims? And when they have to admit that most evolution occurs without any apparent reason – the Stuff Happens Law – does that qualify as science? Honk if you find this defense convincing:
Why the Stuff Happens Law is Scientific
- It is reductive: all events can be reduced to this law.
- It makes predictions: Stuff will happen.
- It is universal: Stuff always happens.
- It is normative, not just descriptive: Given matter in motion, stuff must happen.
- It is falsifiable: If nothing happens, the law has been disproved.
- It is practical: If something happens, you know you will find stuff around.
- Corollaries can be derived from it: e.g., Stuff happens at the worst possible time, Bad stuff happens to good people, Murphy’s Law, etc.
Impressed? Darwin’s laws of nature are about as helpful to the understanding of nature as the Stuff Happens Law. Your science might be healthier with a bit of Cole’s Law (i.e., thinly sliced cabbage).