Two papers in Science from last month claim to have observed and measured beneficial innovations that required multiple variations that were each unspecified and random. Natural selection (Darwin’s designer substitute) waited until these variations came together, then used them to improve the fitness of the organisms. Such multi-part innovations are called “composite traits” by Kathryn M. Elmer in her “Perspective” article about these two papers. Composite traits are defined as “sets of biological features that, when they come together, have a new synergy and function.” Has this demonstrated the power of neo-Darwinism to account for irreducibly complex systems, and organs of extreme perfection like eyes and wings? 

Elmer begins by narrowing chance to bestow the appearance of directionality to random variations:

Adaptation by natural selection cannot take any evolutionary path; it operates within the constraints of genetic variation and environmental context, with futures contingent on the past.

(A note in passing: this statement begs the question of neo-Darwinism, because it presumes past adaptations were caused by natural selection.)

Therefore, how new suites of traits arise is an enduring issue and is key to understanding the diversity of life. On pages 108 and 114 of this issue, Chomicki et al. and Stankowski et al., respectively, investigate two different cases of fascinating biological complexity that arose through convergent and convoluted evolutionary paths — one in carnivorous pitcher plants (Nepenthes gracilis and Nepenthes pervillei) and another in marine periwinkle snails (Littorina saxatilis). The studies use different approaches to reconstruct evolution to reveal how complex phenotypic traits arise in unexpected ways. The results advance understanding not only of the specific traits that are studied — feeding structures in plants and live-bearing (as opposed to egg-laying) in snails — but also how evolution in general might arrive at apparently unlikely combinations. [Emphasis added.]

When reading papers supporting evolution, I try to be as objective as possible. I give the authors the benefit of the doubt, presuming them to be honest seekers of the truth. I do not project onto them ulterior motives, realizing that most Darwinians have been taught only that perspective for their entire careers. I evaluate their evidence like I would listen to a polite salesman making his pitch. Only when all is said and done do I start asking questions. I’ll share some of those questions after we look at the two studies.

The Case of the Pitcher Plant Innovating Springboard Traps

Six scientists in the Chomicki et al. paper describe how three independent traits had to arise in combination for pitcher plants to build springboard traps — traps that fling prey into the pitchers where digestive juices await. There are many species of pitcher plants in the genus Nepenthes, but only two of them, they say, display this composite trait. Detailed inspection of 900 individual plants within 42 species revealed three physical requirements for the springboard traps to work: (1) horizontal lids, (2) pivot joints for the lids, and (3) slippery undersides of the lids that hinder prey from clinging to safety. The undersides of both Nepenthes gracilis and N. pervillei were found to be coated with microscopic pillars of wax that were very slippery, more so than the waxy coatings on the walls of the pitcher. 

Only these two species, the authors said, met these three requirements. When a raindrop strikes the top of the lid where a curious ant is exploring under the lid, the lid bounces and the prey is flung into the trap. They collected ants and let them crawl on and under the lid, then hit the lid with manually released water drops, filming the reaction with high-speed cameras. Do other species have this mechanism?

Unfortunately, we did not have permission to remove multiple lids per species from the botanical collections; therefore, we were unable to image multiple replicates for the other species in this study. Consequently, we did not include lid wax in the analysis of trait variability….

Additionally, all the species exhibited variability in lid angle and pivoting behavior, some of them buckling and twisting along with bouncing. It was not clear to me whether the other species were less successful at catching prey. 

The Case of the Snails Innovating Live Birth

In the second paper, Stankowski et al. evaluated periwinkle snails that inhabit coastlines of the Atlantic. Most species in the genus Littorina reproduce with eggs embedded in a jelly-like mass, but L. saxatilis gives birth to live young from a brood pouch. The authors claim viviparity (live birth) is advantageous for this species over oviparity (egg laying), as evidenced by its widespread extent compared to two oviparous species, L. compressa and L. arcana. The 13 researchers identified multiple gene families apparently upregulated in the species, and many of them seem related to reproduction. Again, they claim this to be composite trait achieved by natural selection, where multiple independent genes synergized to confer an adaptive benefit.

Time to Ask Questions

First, let’s establish that all these authors are invoking chance as a cause. They must because any appeals to intelligent causes are censored by the “rule” of methodological naturalism. Non-intelligent causes, therefore, include necessity and chance (see the Explanatory Filter diagram in The Design Inference, p. 245). Since nothing necessitates pitcher plants to build springboard traps, and since no natural law pushes snails to give live birth, chance is all that remains when mind-directed purposeful causes have been ruled out. 

For the pitcher plants, identifying chance as the preferred causal explanation is easy. The authors specifically state that the two springboarding species arrived at their configurations by a “spontaneous coincidence.” Judging the springboard trap as “beneficial” they generalize their findings: 

Notably, this spontaneous coincidence mechanism for the evolution of composite traits is applicable to any type of variation on which selection can act when beneficial combinations arise by chance.

The snail paper, though, does not overtly claim chance as a cause. It invokes positive natural selection, which begs the question at issue: is natural selection really a blind, undirected cause of adaptations? The authors repeatedly use the language of agency: selection “acts on” genes; it recruits” genetic loci and “purges” others when live-bearing has been selected; and “maintains” sets of alleles. Neil Thomas explains why this “art of concealment” hides the fact that chance is the only game in Darwinism. In the end, the Stankowski et al. admit that chance is all they’ve got in their toolkit:

We do not know which mutation caused the threshold from egg-laying to live-bearing to be crossed. Some potentiating mutations may have preceded live-bearing but were critical to its origin, and others may have refined live-bearing after it arose. Nevertheless, our results suggest that new functions evolved gradually through the recruitment of alleles at many loci rather than arising in a single evolutionary step.

Indeed, Elmer admits,

It is notable that in the era of big genome data, neither Chomicki et al. nor Stankowski et al. pinpoint the genetic variants that cause the traits they focus on.

So despite the metaphorical language of “refining” and “recruitment” here and there, it all boils down to random mutations. What caused the transition to live birth? After excluding all talk of agency, it was sheer dumb luck.

Much Ado

Next question: How novel were these changes? All pitcher plants already possess lids, hinges and wax that differ in minor ways. Existing pathways for wax synthesis, for instance, allow for easy modification, they admit:

Cuticular wax biosynthesis follows a stepwise pathway where C₂ building blocks are added to elongate fatty acid precursors and form very long-chain aliphatic compounds that can then be enzymatically modified into alcohols, esters, aldehydes, alkanes, and other wax compounds. Owing to this modular assembly process, shifts between major compound classes can be achieved relatively easily by redirecting substrate flux through different enzymatic pathways.

The degree of overlap between the species in the three design specifications for springboard traps strikes me as subjective. Is not each species successful in its own niche? Why haven’t the two springboarding species outcompeted all the others? Chomicki et al. cannot rule out that the capacity for springboard traps was already present in the phenotypic plasticity of Nepenthes, and that the features of the two springboarding species represent epigenetic modifications of existing genetic information:

The evolution of any trait is the result of a combination of natural selection, wherein traits are shaped by adaptive pressures and tend to change in a specific direction over time (determinism), and random events and processes, such as mutation or genetic drift (stochasticity), in the context of the evolutionary history (contingency) of the trait. Accordingly, composite traits may result from natural selection acting on multiple traits at once, random effects, or a combination of both. Here, we report evidence that a complex, composite trapping mechanism found in two carnivorous pitcher plant species likely evolved convergently through spontaneous coincidence of a new beneficial trait combination, facilitated by high stochastic phenotypic variation.

To me, the “springboard trap” feature seems trivial; it is certainly not on par with the origin of powered flight, vision, and mammalian live birth to which Elmer compares it.

The case of live birth in snails seems trickier but again looks trivial on closer inspection. Whether the embryos are embedded in a jelly-like mass or a brood pouch, they emerge as tiny baby snails. The “egg-laying” in the other species of Littorina is not like the complex egg-laying in birds.

Egg-layers have a gland that embeds fertilized eggs into a protective jelly. In the live-bearer, L. saxatilis, this structure has evolved into a brood pouch where embryos develop inside the mother. Live-bearing is the only taxonomic character that is diagnostic of L. saxatilis, because no other known trait differs consistently between the live-bearing and egg-laying individuals.

It’s noteworthy that the live-bearing species is virtually identical to other members of the genus except in this one respect. A Smithsonian article about Littorina says, “The taxonomy of this snail is one of the most confused of any mollusk, including 28 synonymous names and 31 varieties, resulting from its high morphological variability.”

The genes for jelly glands and brood pouches appear to have already existed within the genus Littorina. Stankowski et al. mention opportunities for gene flow, hybridization, and introgression — all of which represent the sharing of existing genetic information. The authors did not prove that anything new evolved. As with the pitcher plants, the differences could be due to epigenetic modifications within the snails’ capacity for phenotypic plasticity, and seem trivial, given that Smithsonian says the live-birthed snails are extremely tiny (half a millimeter), hardly different from hatchlings in the jelly-like mass.

Exaggerated Distinctions

Another question is whether these cases are strong enough to differentiate Darwinism from other views. Some design advocates accept common ancestry without the Darwinian mechanism. Even the most ardent young-earth creationists allow for extensive horizontal variations at the genus level, and sometimes up to the family level. The distinctive traits of these pitcher plants and snails, while interesting, hardly merit the celebrations given them by Elmer:

Highly complex organs or composite traits are sets of biological features that, when they come together, have a new synergy and function. As highlighted by Chomicki et al., an example of a composite trait is that of bird wings, which transformed from existing skin and forelimbs into new structures that enable flight. Other classic examples include animal eyes, for which many different parts evolved from different ancestral forms to operate together. How such complexity can coalesce has been a challenge to explain since the time ofDarwin. The stepwise changes in phenotypes over long times, involving many different forms and parts with complex genetic bases, make their existence seem vanishingly unlikely. Indeed, during the evolution of these composite traits, the intermediate states might not be beneficial or even functional, for example, as separate components or in disparate combinations. However, advances in quantitative and evolutionary genetics have shown that the combinations of traits and states that are beneficial for an organism can shift substantially and swiftly over time and space. Although it is challenging to predict, the history of selection and evolution can be highly flexible and variable under realistic scenarios.

Hidden within the triumphal speeches, the admissions of difficulty still existing after 165 years of the Darwinian revolution speak volumes. We are still told in 2024 that composite traits have been “a challenge to explain since the time of Darwin.” Elmer added, “The genetic means by which innovative new traits evolve have been hard to pin down in ecological model species.” “Key innovations are fundamental to biological diversification, but their genetic basis is poorly understood,” said Stankowski et al. And Chomicki et al. confess that “how [composite traits] evolve remains a puzzle.” And yet these papers expect readers to be persuaded by these examples that the full complexity of life from molecules to man (e.g., described in Your Designed Body) has succumbed to the causal power of natural selection.

That evolutionists go to such great lengths to celebrate trivial cases indicates to me that design advocates have nothing to fear as they continue making incursions into Darwin’s Fantasyland of chance. A new regime of causal adequacy is overdue. Let the design revolutionaries proceed with boldness, undeterred by the pops and snaps of miniature firecrackers with which evolutionists have mined the approach to the castle. Fantasyland can evolve into Tomorrowland, but only by intelligent design.