Evolution After the Fact
Many scientific theories are evaluated on their ability to make predictions. Good theories suggest experiments that lead a researcher to discover new things. In biology, however, “evolution” is a word often invoked as an after-market explanation for observations that emerged outside of the theory. Here are some recent examples:
- Ant farm: Science Daily reported on Smithsonian scientists who constructed an evolutionary tree after observing ants’ abilities to “farm” fungus for food. “By studying certain fungus-growing ants, which our study indicates are almost like ‘living fossils,’ we might be able to better understand steps involved in the evolution of ant agriculture,” one researcher said.
Living fossils might have been seen as evidence against evolution (10/13/2004). According to the evolutionary timetable, they represent organisms that have shown no evolution for tens or hundreds of millions of years. Somehow, despite that admission, the evidence was being used as support for evolution. The quotation indicates that if evolution has explanatory power in this case, it is in future tense.
- Mystery religion: The phrase “abominable mystery” seems synonymous with Darwin’s frustration at explaining the origin of flowering plants (01/30/2002, 12/21/2007). National Geographic admitted as much, saying, “The apparently sudden appearance of angiosperms in the fossil record confounded Darwin, who worried that it might pose a problem for his theory of evolution by natural selection.”
That admission, however, was the only expression of doubt about evolution in a story about “the world’s oldest plant-eating lizard.” Even though this “spectacular” fossil “challenges long-held views about lizard evolution,” the fact of lizard evolution was never in doubt. Ker Than explained that it was a choice between two evolutionary possibilities: “either the ancestral condition for lizard diet was not as restricted as once thought or that diet has been highly labile [easily changed] throughout lizard evolution.”
How this fossil solved the abominable mystery of flowering plants was not explained. “Thus the new fossil species, dubbed Kuwajimalla kagaensis, could indicate that angiosperms were already in existence and perhaps widespread millions of years earlier than had been thought, the researchers say.” Might that not count as evidence that flowering plants were created fully formed? Such an option was never in the cards: “Scientists have since uncovered fossils tracing the evolution of angiosperms from nonflowering plants, called gymnosperms.”
- Ancient mother: “They are separated by a vast ocean and by millions of years, but tiny prehistoric bones found on an Australian farm have been directly linked to a strange and secretive little animal that lives today in the southern rainforests of South America.” The observation is: a living animal that resembles a fossil animal. Science Daily wove this into a story about how this “Primitive Mouse-Like Creature May Be Ancestral Mother Of Australia’s Unusual Pouched Mammals.” PhysOrg echoed the tale, claiming, “The fossil ankle and ear bones of Djarthia make it clear that the Monito del Monte [the living animal] descends from a Djarthia-like ancestor, and so probably returned to South America from Australia before Gondwana broke up.”
- Hanging around: Spiders often hang upside down in their webs. What does this mean? Science Daily gave Darwin the microphone:
The great majority of land animals evolved to use the ground as the main support for their motion. Accordingly, they evolved legs capable of supporting the weight of their whole bodies, enabling them to move around with their heads above their feet. However, many spider species found it more convenient to literally turn their world upside down. They spend most of their lives hanging suspended by their legs, and ‘walk’ by swinging under the influence of gravity.
The article tells how researchers were “intrigued by this evolutionary phenomenon,” even though they had not watched any spiders evolve. “One of their focal questions was the evolutionary importance of ‘bridging’ — the technique many spiders use to move between remote plants by building their own silk bridges,” it said. Somehow they “discovered” evolution by watching live spiders: “We discovered that spiders that live upside-down have evolved disproportionately longer legs relative to ‘normal’ spiders, which enables them to move faster while bridging than while ‘normally walking’ on the ground.”
Again, both kinds of spiders are alive today, but “Now,” somehow “we have a much better understanding of how an animal shape should evolve when animals spent most of their lifetime hanging upside-down.” Yet people have observed living spiders for centuries without seeing evolution between them. Is it even clear which one evolved from the other? To the hanging spider, the walking spider looks upside-down.
A physicist was brought in to study the energetics of upside-down locomotion. Nowhere was there any mention, though, of an observable series of intermediates (perhaps spiders walking sideways) that would demonstrate evolution had occurred or was occurring. Nor was there any mention of how a spider finding it more “convenient” to hang around in an inverted world found a way to gather the random mutations required to allow natural selection to adapt its body for efficient upside-down mobility.
- Fuzzy logic: Observation: fuzzy fibers of cellulose (a protein) can sometimes be found in salt deposits. Conclusion: “Microscopic Fuzz May Be Best Evidence of Martians.” Yes, ladies and gentlemen, “If Martian life existed a few billion years ago, scientists think any plant-like microbes would have left behind a stringy fuzz of fibers.” Read all about it on Space.com.
Even though no life has ever been found on Mars, we already know that evolution will be the explanation. We can already envision Martian life cooking up cellulose like popcorn:
If a future Mars-bound robotic explorer seeks out signs of ancient life, [Jack] Griffith [U of North Carolina at Chapel Hill] said looking for cellulose in salt deposits peppered south of the planet’s equator would be the best places to start.
“Cellulose was one of the earliest polymers organisms made during their evolution, so it pops out as the most likely thing you’d find on Mars, if you found anything at all,” Griffith said. “Looking for it in salt deposits is probably a very good way to go.”
[Phil] Christensen [Arizona State U] said Martian salt deposits likely formed after briny pools of water on the planet’s surface ? a sun-bathed environment for photo-synthesizing organisms that may have made cellulose.
“The sun is an awfully nice source of energy to turn down in your evolution as a microbe,” Christensen said. “If we do find signs of life on Mars, I wouldn’t be at all surprised if it is plant-like in nature.”
In living organisms on earth, cellulose is manufactured by a group of complex molecular machines. They transcribe the recipe from the genetic code written in DNA, translate it into enzymes, and then weave the sugars into intricate chains (try the Wikipedia description for a taste of the complexity of the process). These scientists did not explain, nor did they even think to ask, how hopeful microbes wanting to green up a red planet could have figured this out.
- Demon drink: How did Asians become protected from alcoholism? Call Darwin: “That these populations turn out to be less prone to the ravages of demon rum,” explained Kenneth Kidd [Yale School of Medicine], ‘is just a serendipitous event’ of evolution.” So reported Science Daily. Since Asians are interfertile with American alcoholics, inter-species “evolution” does not demonstrate a Darwin-style Origin of Species.
- Your inner fish: Observation: selenium is toxic to humans but is necessary in trace amounts, or else serious diseases result. Explanation, according to PhysOrg: “Although this trace element is essential in the diet of humans, it seems that we have lost some of the need for selenium, which occurs in proteins and is transported in blood plasma, when our evolutionary ancestors left the oceans and evolved into mammals.”
The article continued without blinking an explanatory eye: “Selenium-containing proteins evolved in prehistoric times,” it said, and “We’ve found that the evolutionary change from fish to mammals was accompanied by a reduced use of proteins containing selenium.” The reporter seemed intent on inserting Darwinese (03/06/2008 into every sentence. “Some insects have also lost the need for selenium during the course of evolution.” The scientists linked humans’ minimum daily requirement to the “the evolved reduced utilization of selenium” that occurred since we ostensibly crawled out of the sea millions of years ago.
Each article above invoked evolution after the fact. But isn’t that an academic detail, now that evolution has been proven? “Darwin told us so,” announced a story April 1 on EurekAlert. No fooling: “UBC researcher shows natural selection speeds up speciation.”
You may have thought such a thing had been discovered a long time ago, but these researchers were announcing a first. “In the first experiment of its kind conducted in nature, a University of British Columbia evolutionary biologist has come up with strong evidence for one of Charles Darwin’s cornerstone ideas – adaptation to the environment accelerates the creation of new species.” They repeated their claim of priority: “As far as advancing Darwin’s theory that natural selection is a key driver of speciation, this is the first experiment of its kind done outside of a lab setting. The findings are exciting.”
Surely, this must be big news. What did Patrik Nosil find in a 200m x 200m parcel of chaparral of southern California? He gathered “walking stick” insects from one location and put them in another. He and his co-worker found that coloration patterns, such as a white line along the body, changed as they adapted to a new location. Then, the ones that could detoxify leaves of unfamiliar plants survived to “seal the deal” of speciation.
The dramatic tone of the claims led us to examine what was said in the original paper published in PLoS One.1 There, by contrast, Patrik Nosil and co-author Cristina Sandoval admitted that their work was extremely limited, and their conclusions much more tentative:
The findings suggest that selection on a greater number of niche dimensions promotes evolutionary divergence. Of course, replication of the data reported here is required before the robustness and generality of our findings can be known. This is especially the case because only a single species pair was examined.
Their collection methods (shaking a bush for 15 minutes, watching what kind of leaves an insect preferred, etc) and measurements of fitness (e.g., minute changes in coloration) also seemed highly subjective. Creationists might agree that the two species in the study had a common ancestor anyway. In few other sciences would such a limited study like this permit such far-reaching conclusions about all of life.
The paper also defended a contra-Darwin viewpoint, viz: “We stress that arguments for the existence of stages of divergence do not rely on strict gradualism” – they proposed, instead, a “niche dimensionality” hypothesis. That’s what was new about their experiment. It wasn’t natural selection per se they tested, but an ecology-based flavor of evolutionary theory that “has received almost no focused empirical attention, despite its potential for complementing more geographic and genetic hypotheses.”
All they recorded were small trends in coloration and behavioral changes. No new organs or beneficial structures were reported, nor did they discuss previously-reported problems about the phylogeny of walking sticks, such as the apparent re-evolution of wings three times (see 05/28/2003 and 01/16/2003), to say nothing of the origin of wings in the first place (04/02/2008). Another thing left unstated was whether the walking-stick descendants were still interfertile with their unexamined cousins, to prove that a new species had emerged (at least, according to the biological species definition of species as members of a population that can produce fertile offspring).
Most significantly, they failed to show whether any new genetic information emerged. Even Bible-believing creationists do not dispute that coloration differences and other “horizontal” sorting of traits can occur by natural selection within created kinds. This kind of natural selection can lead to dramatic differences, they say, such as donkeys and zebras, or mammoths and elephants.
As valuable as field experiments are, the procedures these scientists followed omitted some important tests. They did not repeat the experiment with other species or use controls. They failed to follow up and observe whether the insect progeny reverted to wild type after the artificial conditions were removed. The paper acknowledged, though, a number of additional factors that could have blurred the inferences they drew. (Also of note: father Darwin got no mention in their original paper.)
Nevertheless, the press release article announced this as a great vindication of Darwin’s theory of natural selection. Darwin, of course, extended his principle far beyond color changes in walking sticks. He developed it into a universal principle that produces humans from bacteria over time. Astrobiologists routinely extend natural selection even further, applying it as a universal natural law even alien life must obey.
Wherever life is found, one conclusion is sure to follow: Darwinian evolution will have been vindicated – after the fact.
1. Patrik Nosil and Cristina P. Sandoval, “Ecological Niche Dimensionality and the Evolutionary Diversification of Stick Insects,” Public Library of Science One, 3(4): e1907 doi:10.1371/journal.pone.0001907.
These articles, like building blocks of lie (03/19/2008), are typical of the daily Darwin fare fed to the public by the media. We’re collecting enough of them to build a monument to dupidity (03/13/2008 commentary).
Each article invoked evolutionary explanations for observations that were already “in the bag,” so to speak. In philosophy of science, explanatory inference can work for post-dicted observations as well as pre-dicted observations; the logic is the same. However, there is a built-in logical fallacy in prediction called “affirming the consequent.” It goes: p predicts q, q happens, therefore p explains q. The problem of underdetermination of theories by evidence shows that there are always other theories that could explain the evidence just as well. That is why Karl Popper repudiated prediction as having any value in scientific explanations. Instead, he proposed falsification as a test of a good theory. Historical studies of science show, however, that few scientists ever give up on a theory that has been falsified. W. V. Quine argued in 1951 that scientists are more likely to adjust strands at the periphery of their web of belief than abandon it because of anomalies.
These considerations are among many in 20th century philosophy of science that have undermined the simple faith that science is on a progressive path to the truth. Thomas Kuhn caused a furor in 1962 when he argued that scientists are blinded by the ruling paradigm in which they work. The paradigm, or explanatory viewpoint most widely accepted at the time, determines the questions worth asking, the scientific approach to answer them, and what counts as evidence. It even determines the concepts and language used to do science. Scientists, he said, do not work to falsify paradigms; they work to confirm them and thus receive affirmation from their peer group. Pursued to the extreme, his line of thinking decouples scientific practice from truth-seeking altogether, and reduces it to an absurdity: science is what scientists do. Though Kuhn didn’t go that far, some did. They doubted that science has any case for epistemic privilege over other avenues of investigation.
Some offer the rebuttal that science must be true because it works. This, however, is a pragmatic argument, not a logical argument. Even if a theory provides success (or satisfaction) at explanation, prediction, and control, that is no guarantee it is true. A look at history shows this. Civilizations throughout history, and modern science in recent Western history, have trusted in ideas that are now considered wrong, even though they provided their adherents at the time with remarkable degrees of success at explanation, prediction and control. Ptolemaic astronomy satisfied its believers for 1500 years, then Copernican, then Keplerian astronomy – but now we know that the planets do not move in ellipses (because a whole set of additional motions at higher levels precludes a closed loop). Newtonian mechanics for centuries represented the pinnacle of scientific truth – only to be doubted in the 20th century with the rise of relativity and quantum mechanics. String theory and dark energy continue to show that a comprehensive understanding of the basic structure of matter is lacking; how much more so for biology, where natural laws are hard to come by?
Exercise: Read this astronomy article on Space.com and ask how strong is the connection between the observations and the explanations offered.
The dust from Kuhn’s Structure of Scientific Revolutions has yet to settle, even if he overstated the case. His little book launched whole new university departments and fields of study. Researchers started putting science itself under the microscope. Some portrayed science as a cultural phenomenon, complete with its own sociology, rhetoric and history. Though the pendulum has swung back a bit toward “scientific realism” (the assumption that science does deal in fairly reliable accounts of external reality), it’s more from weariness of the science wars than any logical or epistemological victory.
Most philosophers and knowledgeable scientists today realize that scientists can no longer blithely assume that what they are doing is objective or has a necessary connection to truth or reality. Sociological, rhetorical, historical and political factors are non-trivial influences in what passes for science in a given era or culture. How strong are these influences? There is a broad spectrum of opinion, with no agreement.
If anything in science today fits the Kuhnian vision of “normal science” being an effort to force-fit observations to a consensus paradigm, it is Darwinism. Evolutionary biologists deceive themselves into thinking what they do is understand and explain reality by objective standards and methods (a position known as logical positivism or scientism). Their critics, looking in from the outside, are convinced the evolutionists have blinders on. From their vantage point outside the paradigm, evolutionists are simply putting a Darwinian shine on the observations, no matter what observations come along (12/17/2007 commentary). They are asking meaningless questions and giving self-reinforcing answers. Is this not obvious from the examples above? If so, any resolution to this impasse will require logical and rhetorical arguments as well as evidential arguments.
At the present, the Darwinians are controlling the rhetorical front from sheer clout over scientific institutions, schools, the courts and the media. That could change. A majority of the public is upset that only their side gets told. Darwinism has become a kind of world religion that, having gained ascendancy, no longer questions its assumptions. Worse, it imposes its paradigm on the world: both on the world of nature (demanding explanation in terms of the paradigm) and on the world of people (demanding compliance).
We have seen that the only requirement to explain anything these days is to say, “Darwin told us so.” Moreover, anyone who doubts the paradigm is labeled dangerous – not to the consensus, but to “science” itself! One has to go along to get along. Acceptance into the cult requires abandonment of all other explanatory systems, and allegiance to the Darwin Party statement of faith, encapsulated succinctly in their children’s song,
Darwin shoves me, this I know,
For the Origin tells me so.
Little use for right and wrong;
Weak ones die, but fit are strong.
Yes, fitness shoves me,
Yes, fitness shoves me,
Yes, fitness shoves me,
Survival tells me so.
Time for a scientific revolution? Join the rebellion.