Saturday 26 October 2024
Yet further echoes of the Cambrian explosion.
Fossil Friday: An Extinct Animal Body Plan from the Cambrian Explosion
This Fossil Friday features Herpetogaster collinsi from the Middle Cambrian Burgess Shale in Canada. It is as an example of an extinct group of animals called Cambroernida, that originated in the Early Cambrian and disappeared in the Late Devonian.
Eldonia — The Medusa That Wasn’t
The Cambrian fauna of the famous Burgess Shale includes numerous enigmatic fossils that for a long time eluded any attempts by evolutionary scientists to place them in the tree of life. One of these fossils is Eldonia ludwigi, which was a soft-bodied animal with disc-shaped body, a coiled gut, and a ring of feeding tentacles around the oral opening. More than hundred years ago, Charles Walcott (1911) collected 550 specimens from the Burgess Shale and many more have meanwhile been found, including specimens from the Early Cambrian of Chengjiang in southwest China (Sun & Hou 1987, Chen et al. 1995, Zhu et al. 2002), the Middle Cambrian of Utah (Conway Morris & Robinson 1988) and Siberia (Friend 1995, Ivantsov 1998, Friend et al. 2002), and the Late Ordovician Erfoud sandstones of Morocco (Alessandrello & Bracchi 2003). Furthermore, seven other genera of eldoniids were described from different localities and strata. The latest fossil record is the putative eldoniid Paropsonema from the Upper Devonian of New York (Hagadorn & Allmon 2019), which was first described by Clarke (1900) as an echinoderm, which is an attribution that was still supported by Conway Morris (1993). However, the systematic affinities and lifestyle of eldoniids remained enigmatic. Because of the medusoid appearance some experts suggested an identification as cnidarian siphonophore or jellyfish (Madsen 1956, 1957, 1962, Lemche 1960, Seilacher 1961, Sun & Hou 1987), but the most favored alternative interpretations included an attribution to lophophorates (Dzik 1991, Chen et al. 1995, Dzik et al. 1997, Zhu et al. 2002) or to holothurian echinoderms (sea cucumbers) (Walcott 1911, Clark 1913, Durham 1974). Zhu et al. (2002) said that “the new anatomical information emphasize close phylogenetic relations with lophophorates (U-shaped intestine, circumoral tentacles and ectodermal, marginal accreted disc), though some features (e.g. dendritic tentacles, ventral pustules that may relate to reduced podia) do not exclude affinities with echinoderms.” Because of this strange and ambiguous combination of characters, Conway Morris & Robinson (1988) had concluded that “the higher taxonomic affinities of this genus are best regarded as uncertain”, but only a few years later Conway Morris (1993) considered eldoniids as pre-echinoderm deuterostomes (also see Friend 1995, Caron et al. 2010, and MacGabhann 2012), which happens to represent the currently preferred view (see below). Even the lifestyle of eldoniids was reconstructed very differently (see discussion in Caron et al. 2010): some scientists considered them as pelagic filter feeders (e.g., Clark 1913, Durham 1974, Chen et al. 1995, Zhu et al. 2002), while others re-interpreted them as sedentary benthic deposit feeders (Luo et al. 1999). Looks like there is not much we really know for sure about ancient life on Earth.
Herpetogaster — An “Alien” Life Form from Deep Time
Herpetogaster is another very strange fossil organism known from more than hundred specimens from the Middle Cambrian of British Columbia and Nevada as well as the Early Cambrian Chengjiang biota of China (Caron et al. 2010, Kimmig et al. 2019, Yang et al. 2020, 2023). It had a long and narrow stalk, a curved and segmented sac-like body, and pair of branched feeding tentacles around the apical mouth. Herpetogaster was about 3-4 cm long and was often found attached to fossil sponges. The quite similar genus Phlogites (= Cheungkongella) was originally described as urochordate (tunicate) by Shu et al. (2001), but re-interpreted as a tentaculate similar to entoprocts (Kamptozoa) by Chen et al. (2003) and Hou et al. (2006), and finally identified as a stem ambulacrarian by Caron et al. (2010) and Li et al. (2023). Shu et al. (2010) disagreed and still considered a tunicate affinity. These determinations seemingly jump between major groups of animals like in a wild guessing game.
Cambroernida — A Novel Animal Body Plan from the Paleozoic
Caron et al. (2010), who first described Herpetogaster collinsi from the Burgess Shale biota, already recognized that this organism likely represents a deuterostome animal, which they tentatively attributed to the stem group of hemichordates and echinoderms that are united in a clade called Ambulacraria. They also recognized that the enigmatic eldoniids, in spite of their discoidal shape, seem to be closely related to Herpetogaster and share a similar body plan. These animals are so distinct and so different from all other known animal phyla, that Caron et al. erected a new clade named Cambroernida to accommodate them. They did not formerly rank it as a new phylum, but it is very clear that this clade would deserve such a high rank in the taxonomic hierarchy as one of the numerous distinct body plans of bilaterian animals that originated in the Cambrian Explosion (see Bechly 2024).
To understand how weakly supported the phylogenetic and evolutionary hypotheses really are, it is worthwhile to quote from the discussion in Caron et al. (2010):
Arriving at a precise phylogenetic position for the cambroernids, therefore, has proved difficult. On balance a place amongst the tentaculate lophotrochozoans seems to be less persuasive. Given a place within the ecdysozoans is even less plausible, then the final possibility must be to look to the deuterostomes. Here, as noted the options revolve around a series of possibilities, including a stem- group echinoderm, a hemichordate or an ambulacrarian. Whilst this list of possibilities might seem to leave the matter largely unconstrained, it is important to stress that from a Cambrian perspective the morphological differences between these various alternatives were probably insignificant. If, for the sake of the argument, the position of the cambroernids does indeed lie near the branching point of the two main ambulacrarian clades that led ultimately to the echinoderms and hemichordates, then we should not be surprised that it seems reminiscent of both pterobranchs and pre-radial echinoderms. … Finally, if accepted as some sort of deuterostome then these fossils have some further interesting implications. … Whilst many of the evolutionary steps involved in this process are still hypothetical, we suggest that animals similar to Herpetogaster may, in terms of the fossil record, be our best current glimpse of a very primitive ambulacrarian.
This is a lot of uncertainty as shaky foundation for a house of cards of evolutionary speculations. It is likely the reason why, despite Caron et al.’s work, some other experts still think that “the taxonomic affinities of these groups remain uncertain” (Hagadorn & Allmon 2019), even though some others had readily excepted the cambroernid-hypothesis (MacGabhann 2012). The most recent work by Li et al. (2023) is a perfect example for the dubious evolutionary hypotheses built on such shaky assumptions. The latter author concluded that:
As Herpetogaster has been recovered at the base of the Ambulacrarian tree in recent phylogenies, a planktonic larval stage is suggested, which implies, that the last common ancestor of the Ambulacraria might have already had planktonic larvae or that such larvae developed multiple times within the Ambulacraria
Note the typical Darwinian gobbledygook with key words like “suggested” and “might,” combined with the anything goes approach of either the character is homologous or it developed multiple times. The real information content of such statements is basically zero.
Anyway, the cambroernid-hypothesis by Caron et al. has more recently been corroborated by Li et al. (2023), who analyzed the discoidal metazoan Rotadiscus grandis from the Early Cambrian Chengjiang biota, a putative eldoniid. According to these scientists, the results of their research implied that “key traits of extant forms, such as a post-anal region, gill bars, and a U-shaped gut, evolved through convergence.” Wait a moment and read this carefully again. It means nothing less than the following: characteristic similarities of one of the two major branches of metazoan animals (i.e., Protostomia and Deuterostomia) are not based on common descent but independently acquired. Furthermore, the scientists found “Rotadiscus exhibits a chimeric combination of ambulacrarian and chordate characters.” However, these chordate-like features (e.g., a serialized body) are not known from living hemichordates and echinoderms, implying secondary loss or another convergence. The more we know about the distribution of certain anatomical features in fossil organisms, the more the initially apparent congruent distribution of similarities among recent organisms evaporates as a mirage, an artifact of incomplete knowledge. In reality, many traits exhibit a highly incongruent pattern of similarities that do not easily align with a nested hierarchy that could be translated into a tree of life. One of the strongest arguments in favor of Darwinian evolution gets more and more dismantled, which totally vindicates the critique by Michael Denton that evolution is a theory in crisis, in spite of the desperate attempts of denialism by mainstream academia.
References
Alessandrello A & Bracchi G 2003. Eldonia berbera n. sp., a new species of the enigmatic genus Eldonia Walcott, 1911 from the Rawtheyan (Upper Ordovician) of little Atlas (Erfoud, Tafilalt, Morocco). Atti della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale in Milano 144(2), 337–358. https://biostor.org/reference/266993
Bechly G 2024. Fossil Friday: Discontinuities in the Fossil Record — A Problem for Neo-Darwinism. Evolution News May 10, 2024. https://evolutionnews.org/2024/05/fossil-friday-discontinuities-in-the-fossil-record-a-problem-for-neo-darwinism/
Caron J-B, Conway Morris S & Shu D 2010. Tentaculate Fossils from the Cambrian of Canada (British Columbia) and China (Yunnan) Interpreted as Primitive Deuterostomes. PLoS ONE 5(3): e9586, 1–13. DOI: https://doi.org/10.1371/journal.pone.0009586
Chen J-Y, Zhu M-Y & Zhou GQ 1995. The early Cambrian medusiform metazoan Eldonia from the Chengjiang Lagerstätte. Acta Palaeontologica Polonica 40(3), 213–244. https://www.app.pan.pl/archive/published/app40/app40-213.pdf
Chen J-Y, Huang D-Y, Peng Q-Q, Chi H-M, Wang X-Q & Feng M 2003. The first tunicate from the Early Cambrian of South China. PNAS 100(14), 8314–8318. DOI: https://doi.org/10.1073/pnas.1431177100
Clark AH 1913. Cambrian Holothurians. The American Naturalist 47(560), 488–507. https://www.jstor.org/stable/2455578
Clarke JM 1900. Paropsonema cryptophya, a peculiar echinoderm from the intumescens zone (Portage beds) of western New York. Bulletin of the New York State Museum 39(8), 172–178.
Conway Morris S 1993. The fossil record and the early evolution of the Metazoa. Nature 361(6409), 219–225. DOI: https://doi.org/10.1038/361219a0
Conway Morris S & Robinson RA 1988. More Soft-Bodied Animals and Algae from the Middle Cambrian of Utah and British Columbia. The University of Kansas Paleontological Contributions 122, 1–48. https://hdl.handle.net/1808/3691
Durham JW 1974. Systematic position of Eldonia ludwigi Walcott. Journal of Paleontology 48(4), 750–755. https://www.jstor.org/stable/1303225
Dzik J 1991. Is fossil evidence consistent with traditional views of the early metazoan phylogeny? pp. 47–56 in: Simonetta AM & Conway Morris S (eds). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge (UK), 296 pp.Dzik J, Zhao Y & Zhu M 1997. Mode of life of the Middle Cambrian eldonioid lophophorate Rotadiscus. Palaeontology 40(2), 385–396. https://www.palass.org/publications/palaeontology-journal/archive/40/2/article_pp385-396
Friend D. Paleobiology of Paleozoic medusiform stem group Echinoderms. Unpublished PhD thesis, University of Cambridge, Cambridge (UK), 178 pp.
Friend D, Zhuravlev AY & Solov’ev IA 2002. Middle Cambrian Eldonia from the Siberian Platform. Paleontological Journal 36(1), 20–24. https://repository.geologyscience.ru/handle/123456789/28936
Hagadorn JW & Allmon WD 2019. Paleobiology of a three-dimensionally preserved paropsonemid from the Devonian of New York. Palaeogeography, Palaeoclimatology, Palaeoecology 513, 208–214. DOI: https://doi.org/10.1016/j.palaeo.2018.08.007
Hou X-G, Bergström J, Ma X-Y & Zhao J 2006. The Lower Cambrian Phlogites Luo & Hu Re-Considered. GFF 128(1), 47–51. DOI: https://doi.org/10.1080/11035890601281047
Ivantsov AA 1998. The Richest of Sinsk Lagerstätten (Lower Cambrian, Siberian Platform). p. 10 in: Ahlberg P, Eriksson M & Olson I (eds). Abstracts of IV Field Conference of the Cambrian Stage Subdivision Working Group (Lund, Sweden, 24-31 August 1998).
Kimmig J, Meyer RC & Lieberman BS 2019. Herpetogaster from the early Cambrian of Nevada (Series 2, Stage 4) and its implications for the evolution of deuterostomes. Geological Magazine 156(1), 172–178. DOI: https://doi.org/10.1017/S0016756818000389
Lemche H 1960. A possible central place for Stenothecoides Resser, 1939 and Cambridium Horny, 1957 (Molluscs Monoplacophora) in invertebrate phylogeny. Reports of the International Geological Congress, XXl Session, Norden 22, 92–101.
Li Y, Dunn FS, Murdock DJE, Guo J, Rahman IA & Cong P 2023. Cambrian stem-group ambulacrarians and the nature of the ancestral deuterostome. Current Biology 33(12), 2359–2366. DOI: https://doi.org/10.1016/j.cub.2023.04.048
Luo H, Hu S, Chen L, Zhang S & Tao Y 1999. Early Cambrian Chengjiang fauna from Kunming region, China. Yunnan Science and Technology Press, Kunming, 162 pp.
Madsen FJ 1956. Eldonia, a Cambrian Siphonophore — formerly interpreted as a holoturian. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening i Københaven 118, 7–14MacGabhann BA 2012. A Solution to Darwin’s Dilemma: Differential Taphonomy of Palaeozoic and Ediacaran Non-Mineralised Discoidal Fossils. Earth and Ocean Sciences. PhD Thesis, National University of Ireland, Galway, xxix+338 pp. DOI: https://doi.org/10.13025/16034
Madsen FJ 1957. On Walcott’s supposed Cambrian holothurians. Journal of Paleontology 31(1), 281–282. https://www.jstor.org/stable/1300523
Madsen FJ 1962. The systematic position of the Middle Cambrian fossil Eldonia. Meddeleser fra Dansk Geologisk Forening 15, 87–89. https://2dgf.dk/xpdf/bull-1962-15-1-87-89.pdf
Seilacher A 1961. Holothurien im Hunsrückschiefer (Unter-Devon). Notizblatt des hessischen Landes-Amtes für Bodenforschung 89, 66–72. [In German] https://www.hlnug.de/fileadmin/shop/publikationen/geologie/notizblatt/Notizblatt%20des%20Hessischen%20Landesamtes%20für%20Bodenforschung%20Band%2089.pdf
Shu DG, Chen L, Han J & Zhang X-L 2001. An Early Cambrian tunicate from China. Nature 411(6836), 472–473. DOI: https://doi.org/10.1038/35078069
Shu D-G, Conway Morris S, Zhang Z-F & Han J 2010. The earliest history of the deuterostomes: the importance of the Chengjiang Fossil-Lagerstätte. Proceedings of the Royal Society B 277(1679), 165–174. DOI: https://doi.org/10.1098/rspb.2009.0646
Sun W-g & Hou X-g 1987. Early Cambrian medusae from Chengjiang, Yunnan, China. Acta Palaeontologica Sinica 26(3): 257–271. [In Chinese]
Walcott CD 1911. Middle Cambrian holothurians and medusae. Smithsonian Miscellaneous Collections 57(3), 41–68. https://repository.si.edu/handle/10088/23427
Yang X, Kimmig J, Lieberman BS & Peng S 2020. A new species of the deuterostome Herpetogaster from the early Cambrian Chengjiang biota of South China. The Science of Nature 107(5): 37, 1–8. DOI: https://doi.org/10.1007/s00114-020-01695-w
Yang X, Kimmig J, Schiffbauer JD & Peng S 2023. Herpetogaster collinsi from the Cambrian of China elucidates the dispersal and palaeogeographic distribution of early deuterostomes and the origin of the ambulacrarian larva”. PeerJ 11: e16385, 1–19. DOI: https://doi.org/10.7717/peerj.16385
Zhu MY, Zhao YL & Chen JY 2002. Revision of the Cambrian discoidal animals Stellostomites eumorphus and Pararotadiscus guizhouensis from South China. Geobios 35(2), 165–185. DOI: https://doi.org/10.1016/S0016-6995(02)00025-6
Friday 25 October 2024
Thursday 24 October 2024
Caterpillars eat Darwinian apologists' lunch?
“Notions” About Metamorphosis Fall Short of Scientific Explanations
The authors of a new paper on insect metamorphosis admit that its evolution is “poorly understood,” adding that “why this extreme lifestyle evolved is unclear.” Stated succinctly, they don’t know how it evolved; they don’t know why it evolved; they just know that it did evolve. With non-Darwinian explanations ruled out from the starting gate by the philosophical rule of methodological naturalism, what’s a Darwinian to do? Some of them came up with a notion.
Our work supports the notion that the holometabolous life history evolved to remove developmental constraints on fast growth, primarily under high mortality.
Dictionary.com gives five definitions for “notion”—
a general understanding; vague or imperfect conception or idea of something: a notion of how something should be done.
an opinion, view, or belief: That’s his notion, not mine.
conception or idea: his notion of democracy.
a fanciful or foolish idea; whim: She had a notion to swim in the winter.
an ingenious article, device, or contrivance; knickknack.
Science aspired to rise high above notions. For instance, in Leeuwenhoek’s day, people believed in spontaneous generation. The citizen scientist debunked that notion using the tools of observation, testing, and causal explanation. He observed the complete life cycle of ants, fleas, mussels, eels, and various insects, proving that all organisms had parents.
Notions have no place in scientific explanation. They may serve a pre-scientific purpose by suggesting a hypothesis to be tested but fall short of the demands of rigorous science. Notions (“small items displayed for sale”) belong in department stores, not universities.
Terms in Metamorphosis Science
Insect metamorphosis is best illustrated by the butterfly hatching from a chrysalis. This form of complete metamorphosis, in which the larval body plan is broken down and a new adult body plan is built, is called holometaboly. An adult butterfly hatches from its straitjacket with new wings, new limbs, a new proboscis, new sense organs, new reproductive organs, a new digestive system — a whole new organism built from the same genome.
In its documentary Metamorphosis: The Beauty and Design of Butterflies, Illustra Media compared the transformation of a caterpillar into a butterfly to a Model T driving into a garage and emerging as a helicopter, ready to fly, having been constructed out of all the disassembled parts of the car (see excerpt here). It’s no wonder that this kind of metamorphosis is “poorly understood” by Darwinians. Strictly speaking, holometaboly includes four stages in the life cycle of insects that undergo complete metamorphosis: egg, pupa, larva, and adult (also known as the imago). Over 50 percent of insects undergo holometaboly.
There’s a simpler form of metamorphosis known as hemimetaboly (incomplete metamorphosis) that might give a creative storyteller a steppingstone for support of his notion. This kind of life cycle, exemplified by grasshoppers, dragonflies, lice and many others, skips the pupa stage and goes from egg to nymph to imago. A few other insect orders are ametabolous(exhibiting slight or absent metamorphosis), growing in size from birth to adult. Only “primitive” wingless insects are ametabolous. Is there an evolutionary progression evident in these life cycles? That wasn’t clear to the authors of a new paper:
Holometaboly has fascinated students of natural history since Aristotle, yet the evolution of this extreme form of metamorphosis is puzzling: If decoupling different life stages is the key adaptation of metamorphosis, simpler forms of metamorphosis such as hemimetaboly should suffice. What is then the extra driver for the evolutionof complete metamorphosis?
The Notion Marketers
Four evolutionists from the Free University of Berlin and from Princeton published their notion in the Proceedings of the National Academy of Sciences. In the Significance statement of their paper titled, “Rapid growth and the evolution of complete metamorphosis in insects,” Manthey et al. boasted of the explanatory power of their notion.
More than half of all animal species are insects that undergo a dramatic rebuilding of their bodies, dubbed complete metamorphosis, as exemplified by the transition from a caterpillar through a pupa to a butterfly. Why this extreme lifestyle evolved is unclear. Here, by combining empirical data and mathematical modeling, we find that the holometabolous insects grow much faster than insects that do not show this extreme form of metamorphosis. This allows to first grow and then build the adult body, allowing for much faster growth.Fast growth is favorable under many ecological conditions such as competition and predation. This growth advantage reported here can almost certainly help to understand the huge diversification of the holometabolous insects.
The Abstract mentions the “notion” quoted earlier. But they didn’t leave it at the notion stage, a Darwinian might object. They tested the notion with empirical data and mathematical modeling, didn’t they? Well, let’s see.
The “Mother-May-I” Allow Notion
The essence of their notion is that complete metamorphosis allows the insect “to first grow and then build the adult body, allowing for much faster growth.” Stop right there! Are we to picture the magic hand of evolution, like a fairy godmother, granting permission to evolve? Does she tell the caterpillar entering a chrysalis, “You are now allowed, child, to build your adult butterfly body faster than you could before.” How does this make their explanation superior to a notion? Continuing this mini-fable, wouldn’t the caterpillar complain to the fairy godmother, “But how am I supposed to do that? I know how to die, dissolving all my existing parts, but where are the instructions for building wings and a proboscis and everything out of the debris? This chrysalis you gave me looks like a casket! How do I know I will get out the other side alive, let alone fly?”
In the Illustra film, this argument is stated more elegantly by Paul Nelson and Ann Gauger (see my earlier articles here and here). Unless there is a plan and a genetic program already in place to emerge from the chrysalis with wings and antennae and all the new body parts, the caterpillar, like the melted down Model T, is the end of the line. One cannot assume that “allowing” it to happen will make it happen. Yet Manthey et al. continue to use the Allow Notion:
Metamorphosis, the life-cycle discontinuity between larval and adult phenotypes, is found in the majority of animal taxa and is commonly explained as an adaptation that allows organisms to optimize their phenotypes to different habitats or diets.
A synonym for “allowing” is “enabling” good things to happen. Enable, like allow, personifies selection as a beneficent driver. They disguise this driver by embedding it in a mathematical model. This is evident in the following quote, where we notice they substitute “idea” for “notion” — the same fallacy.
We find that holometabolous insects have higher growth rates than hemimetabolous insects. This is consistent with the fastest reported growth rates in insects being reported for black soldier flies and burying beetles, both of which are holometabolous. Our mathematical model shows that in the presence of a trade-off between growth and differentiation, selection for fast growth results in the temporal decoupling of growth and differentiation and can result in the evolution of holometaboly. This effect is exacerbated under increasing risk of mortality.
Risk of mortality — recall the poor caterpillar worried about dying in the casket. Here comes the “enable” word; evolution will enable the caterpillar to come out alive as a butterfly.
Taken together, our findings are highly consistent with the idea that holometaboly enables insects to escape the developmental constraints imposed by a trade-off between growth and differentiation.
Twice they say their notions are “consistent with” some evidence. Correlation is not causation. Despite the whiz-bang math in their model, a model built with a notion confers no empirical adequacy on it. This is especially true when the model personifies the cause, contrary to the authors’ naturalistic worldview.
The “It Could Be Beneficial” Notion
A common flaw in evolutionary explanations is the assumption that a new trait or innovation might be beneficial. That doesn’t work except in hindsight. Because Darwinism lacks foresight, pointing to benefits of a trait today begs the question that it evolved yesterday. Natural selection cannot select what isn’t there. From the ancestor’s view before the innovation emerges, benefits can only arise by sheer dumb luck. It cannot say, “If I get this mutation, I will enjoy a benefit.”
How complete metamorphosis is related to the evolutionary success of the holometabolous insects, measured in terms of both species richness and habitat dominance, is poorly understood. One explanation is that once complete metamorphosis had evolved, the resulting higher modularity would enable higher evolvability, as for example shown by the high diversity of mouthparts in holometabolous insects. If, as we propose here, the decoupling of growth and differentiation has been the main driver for the evolution of complete metamorphosis, then any ecological situation where fast growth is beneficial would give holometabolous insects a significant competitive advantage over other organisms that display alternative forms of metamorphosis or no metamorphosis at all. The breaking of constraints on growth almost certainly provides an added evolutionary benefit to the other potential advantages provided by biphasic metamorphic life cycles.
Natural selection knows nothing of “potential advantages” that might accrue. Nothing in nature “evolves to” reach a potentially advantageous goal. Postdicting causation by observing existing benefits begs the question of natural selection. Why not consider that the benefits were designed into the original coding?
The Promissory Notion
For a beneficial trait to persist, it must be coded in genes. The authors never link their notion to genetic mutations being naturally selected. That part of the explanation, they say, is a job for future research. All they speculate is that their notion “can” or might work.
Our results do not make a statement about the developmental pathways that result in a larval and pupal stage of holometabolous insects but rather identify how selection can result in decoupling growth and differentiation. Bringing together the developmental and the adaptive evolution perspective on complete metamorphosis will be an important future challenge. This should allow for understanding genetic changes and their order that were required to result in this key innovation of the pupa.
Other Darwinians, they just suggested, are now “allowed” to explain how the benefits got coded in the genes. Others — not them — will bring the coveted “understanding.” With this promissory note, they tossed the hot potato of turning their notion into an explanation to others! But readers of a scientific paper expect understanding now. If it’s just a notion that might be explained later by others, why publish it?
Summary
Notions are beneath the dignity of science. They can serve as heuristics that lead to science, but they fall short of scientific explanations. An untested notion dies in its chrysalis and won’t fly. Weak papers like this getting published in major journals is one result of censorship of critiques from outside the Darwin Party.
Ezekiel chapter one New World Translation Study Bible
In the 30th year, on the fifth day of the fourth month, while I was among the exiled people+ by the river Cheʹbar,+ the heavens were opened and I began to see visions of God. 2 On the fifth day of the month—that is, in the fifth year of the exile of King Je·hoiʹa·chin+— 3 the word of JEHOVAH came to Ezekiel* son of Buʹzi the priest by the river Cheʹbar in the land of the Chal·deʹans.+ There the hand of JEHOVAH came upon him.+
4 As I was looking, I saw a tempestuous wind+ coming from the north, and there was a huge cloud and flashing fire*+ surrounded by a bright light, and from the midst of the fire was something that looked like electrum.*+ 5 Within it were what looked like four living creatures,+ and the appearance of each one was like that of a human. 6 Each one had four faces and four wings.+ 7 Their feet were straight, and the soles of their feet were like those of a calf, and they were shining like the glow of burnished copper.+ 8 They had human hands under their wings on all four sides, and the four of them had faces and wings. 9 Their wings were touching one another. They would not turn when they went; they would each go straight forward.+
10 Their faces had this appearance: Each of the four had a man’s face with a lion’s+ face on the right, a bull’s+ face on the left, and each of the four had an eagle’s+ face.+ 11 That is how their faces were. Their wings were spread out above them. Each had two wings that were touching one another and two wings covering their bodies.+
12 They would each go straight forward, going wherever the spirit would incline them to go.+ They would not turn as they went. 13 And the living creatures had the appearance of burning coals of fire, and something that looked like torches of bright fire was moving back and forth between the living creatures, and lightning was flashing out from the fire.+ 14 And when the living creatures would go forth and return, their movement had the appearance of flashes of lightning.
15 As I was watching the living creatures, I saw one wheel on the earth beside each of the living creatures with four faces.+ 16 The wheels and their structure appeared to glow like chrysʹo·lite, and the four of them looked alike. Their appearance and structure looked as though a wheel were within a wheel.* 17 When they moved, they could go in any of the four directions without turning as they went. 18 Their rims were so high that they inspired awe, and the rims of all four were full of eyes all around.+ 19 Whenever the living creatures moved, the wheels would move along with them, and when the living creatures were lifted up from the earth, the wheels would also be lifted up.+ 20 They would go where the spirit inclined them to go, wherever the spirit went. The wheels would be lifted up together with them, for the spirit operating on the living creatures* was also in the wheels. 21 When they moved, these would move; and when they stood still, these would stand still; and when they were lifted up from the earth, the wheels would be lifted up together with them, for the spirit operating on the living creatures was also in the wheels.
22 Over the heads of the living creatures was the likeness of an expanse that sparkled like awesome ice, stretched out above their heads.+ 23 Under the expanse their wings were straight,* one to the other. Each one had two wings for covering one side of their bodies and two for covering the other side. 24 When I heard the sound of their wings, it was like a sound of rushing waters, like the sound of the Almighty.+ When they moved, it was like the sound of an army. When they stood still, they would let their wings down.
25 There was a voice above the expanse over their heads. (When they stood still, they would let their wings down.) 26 Above the expanse that was over their heads was what looked like a sapphire stone,+ and it resembled a throne.+ Sitting on the throne up above was someone whose appearance resembled that of a human.+ 27 I saw something glowing like electrum+ that was like a fire radiating from what appeared to be his waist and upward; and from his waist down, I saw something that resembled fire.+ There was a brilliance all around him 28 like that of a rainbow+ in a cloud on a rainy day. That was how the surrounding brilliant light appeared. It was like the appearance of the glory of JEHOVAH.+ When I saw it, I fell facedown and began to hear the voice of someone speaking
Wednesday 23 October 2024
Tuesday 22 October 2024
Monday 21 October 2024
Sunday 20 October 2024
File under "well said" CXII
"Ask not for lighter burdens but for broader shoulders"
The Jewish Talmud
Saturday 19 October 2024
Friday 18 October 2024
Wednesday 16 October 2024
Tuesday 15 October 2024
Monday 14 October 2024
Sunday 13 October 2024
Saturday 12 October 2024
And even more of JEHOVAH'S Technology against Darwinism
New Research: Stuart Burgess Demonstrates the Exquisite Engineering of Human Limbs
In my last three articles (here, here, here), I described the research published by engineer and biomimetics expert Stuart Burgess on the exquisite design of vertebrate limbs. His analysis demonstrates why the similarities between vertebrate limbs is better explained by design than by common ancestry. In the journal Biomimetics, Burgess recently published another article, “How Multifunctioning Joints Produce Highly Agile Limbs in Animals with Lessons for Robotics,” that is featured on its cover. It further demonstrates that human limbs were designed.
Multifunctioning Limbs
The article explains how the multifunctional capacities of the human wrist, knee, and foot are optimized for the diverse motions that humans perform. It overturns claims that human limbs display poor design (here, here), and it provides positive evidence for design by demonstrating how our limbs represent the best construction possible to meet our needs.
Burgess describes how the ability of our limbs to perform multiple functions leads to their optimal performance for diverse tasks:
Multifunctionality is a very advantageous design feature because it reduces the number of subsystems and components and produces a compact design. Multifunctioning in joints leads to a high degree of compactness which then leads to a host of benefits such as low mass, low moment of inertia and low drag. It also leads to reduced energy demands and the ability to meet tight dimensional constraints. Multifunctioning joints also have the additional benefit that it often enables the animal or robot to perform multiple high-level functional tasks.
Required Fine Tuning
Burgess details how multifunctioning limbs must meet exacting engineering constraints in such features as integration, reconfiguring during movement, and miniaturization:
The parts of the knee joint are highly integrated, especially the meniscus in the way it surrounds the condyles. Joint locking and unlocking represents reconfiguration. To unlock the joint, the tibia is made to rotate internally by flexion muscles, especially the popliteus muscle behind the knee, as shown in Table 2. Like the wrist joint, there is miniaturisation in the sensors, nerves, blood vessels and lubrication system that helps to achieve compactness. The layout of the knee joint represents a unique solution where the layout performs multiple functions with multiple aspects of fine-tuning and integration.
Meeting the numerous constraints requires high levels of fine-tuning:
The requirements of multifunctioning are so exacting that fine-tuning of design is also generally required, such as the common centre of rotation in the wrist (Section 2), the geometry of the cruciate ligament 4-bar linkage in the knee (Section 3) and the precise alignment of the medial arch with the talus bone in the foot (Section 4). Therefore, it can be expected that fine-tuning is required for robotic multifunctioning joints. Indeed, this was the case for the three bioinspired designs presented in this paper for the wrist, knee and foot.
Challenge to Evolutionary Theory
Burgess describes why multifunctioning limbs are difficult to explain by evolution since they require irreducibly complex sets of components:
Complexity in biological systems is sometimes labelled as an emerging property. However, it is very difficult to explain how a multifunctioning system could emerge from an initially single-functioning system because the first single-functioning system would have to be one of the very few solutions that could lead to a later multifunctioning system. When discussing the origin of mechanical linkage mechanisms in animal joints, Muller has stated that it is very difficult to see how complex mechanical linkage systems can be developed in a bottom-up step-by-step process. Therefore, multifunctioning in biological systems such as limb joints presents a major challenge of irreducible complexity for evolutionary biologists.
Burgess’s research represents yet another nail in the coffin of the standard evolutionary model. It also further demonstrates how a design framework is required to understand the higher-level organization of animals.
Friday 11 October 2024
Yet another of the fossil record's many explosions
Fossil Friday: The Avalon Explosion and the Power of Maybe
This Fossil Friday features the 569-556-million-year-old frond-like fossil Charnia from Charnwood Forest in Leicestershire (UK), an example of the abrupt appearance of the so-called Ediacaran biota in the latest Precambrian. During this event, which has been called the Avalon Explosion (see Bechly 2024) and preceded the famous Cambrian Explosion, we find in three distinct assemblages the emergence of strange organisms that looked like aliens from a remote planet. They were very much unlike any of the organisms that roamed our planet after the Cambrian Explosion and certainly did not represent the ancestors of the Cambrian bilaterian animal phyla. The Ediacaran organisms generally exhibited a quilted body like an air mattress, a glide symmetry, a fractal growth pattern, and lacked any visible organs for feeding or locomotion or any internal structure. A genuine enigma for biologists and paleontologists.
A New Study
In a brand new study by Bowyer et al. (2024), three distinguished scientists from the University of Edinburgh analyzed the geological evidence for sea level changes (mainly changes in sedimentary rock volume as proxy), and compared them with the reconstructed biodiversity in terms of genus richness during different phases of the Ediacaran period, correlated according to a global age framework of high-precision radiometric datings. They found that “each successive rise of metazoan morphogroups that define the Avalon, White Sea, and Cambrian assemblages appears to coincide with global shallow marine oxygenation events at δ13Ccarb maxima, which precede major sea level transgressions” and concluded that “while the record of biodiversity is biased, early metazoan radiations and oxygenation events are linked to major sea level cycles.”
Well, that is certainly interesting, even though one should never forget that correlation does not imply causation. Therefore, the authors are to the point when they open their abstract with the admission that “the drivers of Ediacaran-Cambrian metazoan radiations remain unclear.” The press release for the study was much less prudent, with the pompous title “Sea level changes shaped early life on Earth, fossils show” (University of Edinburgh 2024). It quotes one of the authors with this statement: “Knowing what drives biodiversity is a fundamental piece of knowledge in the puzzle of life. I feel very privileged to have built upon decades of interdisciplinary global research, and contributed to a better understanding of the role that sea level plays in early animal evolution.” Did they?
Maybe, Possibly, It Might Be
Have you noticed the little qualifier “appears” in the first quote above? Here is something to think about: This supposedly very scientific article contains not fewer than 64 (!) times the words “may” or “might”, 20 times the word “possible,” 11 times the word “potential(ly),” 8 times the word “likely,” and 7 times the word “appears.” So, we are left with the take home message that this study maybe could possibly appear to potentially show that there might be some likely connection between sea level changes and biodiversity changes. However, even if this should indeed be the case, how did those sea level changes magically produce the new genetic information for the emergence of organisms with new body plans? Crickets — the article does not even mention the words “genetics’ or “genes” a single time.
Instead the authors simply suggest that “major transgressions would therefore both increase habitable shallow marine shelf area and also drive long-term increases in environmental oxygen levels, which culminated in the appearance of the Avalon, White Sea, and Cambrian assemblages.” As I have often said, these are at best describing necessary conditions for the appearance of new organisms but certainly not sufficient conditions. There is zero causal explanation for the astonishing culmination in the appearance of the totally new types of organisms that characterize these assemblages. The new study was published in the prestigious journal Science Advances, but did it really advance our understanding of the mechanisms responsible for the sudden origin of the Ediacaran biota? The answer must be a resounding no, not even a single bit. While evolutionary biology has no explanation even according to the authors themselves, intelligent design theory does uniquely provide a causally adequate explanation and therefore should be preferred over the blind acceptance of Darwinian magic as an imposed default explanation.
References
Bechly G 2024. Fossil Friday: Discontinuities in the Fossil Record — A Problem for Neo-Darwinism. Evolution News May 10, 2024. https://evolutionnews.org/2024/05/fossil-friday-discontinuities-in-the-fossil-record-a-problem-for-neo-darwinism/
Bowyer FT, Wood RA & Yilales M 2024. Sea level controls on Ediacaran-Cambrian animal radiations. Science Advances 10(31): eado6462, 1–21. DOI: https://doi.org/10.1126/sciadv.ado6462
University of Edinburgh 2024. Sea level changes shaped early life on Earth, fossils show. The University of Edinburgh News August 1, 2024. https://www.ed.ac.uk/news/2024/sea-level-changes-shaped-early-life-on-earth-fossi
Thursday 10 October 2024
Wednesday 9 October 2024
Tuesday 8 October 2024
And still more on JEHOVAH'S Primeval tech vs. Darwin
Kinesins: Nanoscale Molecular Motors, Each Built for a Purpose
Editor’s note: We are delighted to welcome biologist Dr. Jared Cochran as a new contributor.
Motors of any kind are a testament to intelligent design. While pondering motors, I went downstairs and asked my eight-year-old son, “What is the difference between a screwdriver and a power drill?” He promptly replied, “A screwdriver is something you turn with your hand. A drill is something you pull the trigger on and a motor turns it.” Isn’t that fascinating? Even at a young age, he is able to recognize similarities and differences in structure and function. He knew right away that both tools needed to move in order to function, and he correctly identified the difference in how the movement of each tool is achieved. Wow, it’s incredible how motors are engineered to accomplish specific tasks!
Consider the multitude of motors we encounter daily. From the simple motor that wiggles our fancy automatic toothbrush back-and-forth, to the complex motor that powers our vehicle as we commute to work. How about the motor that turns the carousel in our microwave, or the powerful electric motor that rotates an impeller at high speed to generate low pressure inside our vacuum cleaner. Linear actuators move our electric car seat forward, backward, up, and down. What about those sliding automatic doors at the grocery store (yes, my eight year old still pretends he is Luke Skywalker every time). These motors work in different ways because they have been designed for specific purposes…to get different types of work done. It is relatively easy for us to see these motors in action and appreciate their intricate design.
Biological Motors
What about the motors inside our cells that we can’t see with our eyes? Molecular motors are enzymes that use chemical energy to generate mechanical force and movement within cells. There are many different types of molecular motors, including cytoskeletal motors, rotary motors, nucleic acid motors, protein synthesis machinery, and dynamic biopolymers. These motors perform a wide range of tasks within cells: transport, cellular respiration, cell motility, nucleic acid manipulation, and cell division. These molecular motors are tiny (just a few nanometers long), and sophisticated experimental methodologies are required to be able to get a glimpse of their intricate design. A deep understanding of their chemistry, structure, and physics is crucial for comprehending the intricacies of these molecular motors and for unraveling diseases associated with their malfunction.
The Workhorse of the Cell
Inside our cells, we have long, string-like polymers (called microtubules) that function as roadways for molecular motors to walk on
Extensive research has focused on characterizing the structure and function of a group of proteins called kinesins (pronounced KY-knee-sons). Kinesins convert the chemical energy of ATP hydrolysis into directed mechanical movement along microtubules. Typically, kinesins are built with 1) a set of motor domains responsible for harnessing the energy from ATP and generating force, 2) a central stalk domain that holds the motor domains together, and 3) a tail domain with specialized functions for binding different cargo
Walkers, Hoppers, and More
What is amazing about kinesins is they all get their energy from the same place (ATP hydrolysis), but they seem to use it differently for different tasks inside the cell. Some kinesins are power walkers (like the one in the video above) — taking hundreds of steps along the microtubule before falling off. Others are hoppers — only taking a few steps before letting go of the track. Some kinesins walk forward, some walk backward, and some walk in both directions (trust me…this observation is still quite puzzling from a biophysical perspective). Other kinesins don’t walk at all, but somehow use their ATP energy to trigger the microtubule track to fall apart underneath them.
We have only skimmed the surface over the past four decades since the first kinesin motor was discovered in 1985. Are these differences in function a result of random haphazardness — stochastic tweaking of gene sequences to give infinitesimally small perturbations of amino acids within the motor to eventually (over billions and billions of years) produce a smorgasbord of elegant machines like the kinesin family? Many in the scientific community have faith in this hopeless Darwinian theory. Thankfully, there are a number of scientists who view the nanoscale world with wonder and are open to the idea that molecular machines reflect purpose and design. They see molecular motors as intelligently designed for a reason. These machines must function properly for cells to divide, for essential cargo to be delivered, for biochemical energy to be converted from chemical gradients into stored energy for metabolism, for the propulsion of a cell in a given direction to avoid danger. Studying their chemistry, structure, and physics is our joy and privilege. We have much to learn.
Monday 7 October 2024
The search for a place like home takes us to the jovian moon europa
Europa Clipper: The Moon Mission Making Waves
NASA is “following the water.” It is gearing up for a mission to one of Jupiter’s Galilean moons. The Europa Clipper spacecraft is set to launch on Thursday, October 10, and arrive at Jupiter in April 2030. During its 3.5-year mission, Clipper will perform up to 44 close flybys of Europa, getting as close as 16 miles from its icy surface. The spacecraft will study the moon’s chemistry, geology, and the characteristics of its hidden ocean. Astrobiologists hope this mission will help answer a couple of big questions in astrobiology: Could Europa’s ocean be habitable, and could it harbor life? Certainly, the recipe for life is more than “just add water,” but how much more?
Frozen Dreams: Europa’s Once-Hot Prospects for Life
For years, Europa has been seen as one of the most promising places to look for life beyond Earth. Its global ocean, containing twice as much water as all of Earth’s oceans combined, seems to some like it could be a perfect home for some form of extraterrestrial life.
Henry Dawson, from Washington University in St. Louis, isn’t so sure. He has been studying whether Europa’s seafloor could support the kind of geological activity that might make life possible. His team’s findings, presented at a recent meeting of the 55th Lunar and Planetary Science Conference, suggest that Europa’s ocean floor might be disappointingly inactive.1
On Earth, areas where tectonic plates meet on the seafloor can create hydrothermal vents. These vents spew out mineral-rich hot water that supports small communities of organisms. Astrobiologists have wondered if similar processes might occur on Europa, providing energy and nutrients for potential life forms
Rock Bottom: The Stagnant Reality of Europa’s Seafloor
Dawson’s team found that the forces acting on Europa’s seafloor are probably too weak to cause significant geological activity. The tidal forces from Jupiter that squeeze and stretch Europa aren’t strong enough to crack the seafloor rocks or cause fault lines to slip. This means there might not be any hydrothermal vents or other processes that could provide the chemical ingredients and energy needed for life.
The researchers also calculated that Europa’s “brittle layer” of rock could be anywhere from 30 to 180 kilometers thick — potentially much thicker than similar layers on Earth or even the Moon. This thick, strong layer of rock would make it even harder for any volcanic or tectonic activity to occur on the ocean floor.
Another problem is the lack of essential elements. While Europa’s ocean contains water, carbon, and possibly some phosphorus, it’s likely missing many other elements that life on Earth needs, like iron, calcium, and various metals. The ocean might be more like a stagnant pool than the dynamic, nutrient-rich environment scientists had hoped for.
This adds to the list of reasons to be skeptical about the prospects for life in Europa’s ocean that Jay Richards and I give in Chapter 5 of The Privileged Planet. Other challenges to Europan life we list include the ocean’s salt content, its variable volume over its history, and the pressure at its base.
Icy Moons: A Solar System-Wide Deep Freeze?
But Europa isn’t the only icy moon that’s caught the attention of astrobiologists. Saturn’s moon Enceladus has also been an object of interest (see, “Enceladus as a Habitability Test,” by David Coppedge). Like Europa, Enceladus has a subsurface ocean, but it also has something Europa doesn’t: active geysers shooting water into space. NASA’s Cassini spacecraft flew through these geysers and detected organic molecules, which got some people excited about the possibility of life there.
However, Dawson’s team also looked at Enceladus and other icy moons , including Titan (also covered by David Coppedge). They found that the tidal forces on these moons are probably not strong enough to cause significant geological activity either. This suggests that the challenges for life might be similar across many of the icy moons in our Solar System.
So why do we keep searching for life in these seemingly inhospitable places? It’s because many astrobiologists believe life only requires liquid water and a few other common compounds. Just let these chemical ingredients percolate long enough and out pops life.
Still, every time we study these distant worlds, we learn something new about planetary processes. This knowledge not only helps us understand other planets and moons but also gives us new insights into our own planet Earth. This research reminds us of how special and rare the conditions for life on Earth really are. It highlights the delicate balance of factors that allow life on our planet, from plate tectonics to our protective magnetic field.
In addition to NASA’s Europa Clipper, the European Space Agency is also planning a mission to Jupiter’s moons. The Jupiter Icy Moons Explorer (JUICE) was launched in April 2023 and is expected to reach Jupiter in 2031. It will study not only Europa but also Ganymede and Callisto, two other large moons of Jupiter that might have subsurface oceans.
These missions will use a variety of instruments to peer beneath the icy surfaces of these moons. They’ll measure the strength of the moons’ magnetic fields (which can tell us about the oceans beneath the ice), analyze the composition of their surfaces, and even sample particles ejected from Europa’s suspected plumes of water vapor.
References
Byrne, P. K., H. G. Dawson, C. Klimczak, P. V. Regensburger, S. D. Vance, M. Melwani Daswani, D. J. Hemingway et al. “Likely little to no geological activity on the Europan seafloor.” LPI Contributions 3040 (2024): 2780.
Sunday 6 October 2024
Romans Ch.2 NWTSB
2.1 Therefore you are inexcusable, O man, whoever you are,+ if you judge; for when you judge another, you condemn yourself, because you who judge practice the same things.+ 2 Now we know that God’s judgment is in harmony with truth, against those who practice such things.
3 But do you suppose, O man, that while you judge those who practice such things and yet you do them, you will escape the judgment of God? 4 Or do you despise the riches of his kindness+ and forbearance+ and patience,+ because you do not know that God in his kindness is trying to lead you to repentance?+ 5 But according to your stubbornness and your unrepentant heart, you are storing up wrath for yourself on the day of wrath and of the revealing of God’s righteous judgment.+ 6 And he will pay back to each one according to his works:+ 7 everlasting life to those who are seeking glory and honor and incorruptibleness+ by endurance in work that is good; 8 however, for those who are contentious and who disobey the truth but obey unrighteousness, there will be wrath and anger.+ 9 There will be tribulation and distress on every person who works what is harmful, on the Jew first and also on the Greek; 10 but glory and honor and peace for everyone who works what is good, for the Jew first+ and also for the Greek.+ 11 For there is no partiality with God.+
12 For all those who sinned without law will also perish without law;+ but all those who sinned under law will be judged by law.+ 13 For the hearers of law are not the ones righteous before God, but the doers of law will be declared righteous.+ 14 For when people of the nations, who do not have law,+ do by nature the things of the law, these people, although not having law, are a law to themselves. 15 They are the very ones who demonstrate the matter of the law to be written in their hearts, while their own thoughts they are being accused or even excused. 16 This will take place in the day when God through Christ Jesus judges the secret things of mankind,+ according to the good news I declare.
17 If, now, you are a Jew in name+ and rely on law and take pride in God, 18 and you know his will and approve of things that are excellent* because you are instructed out of the Law,+ 19 and you are convinced that you are a guide of the blind, a light for those in darkness, 20 a corrector of the unreasonable ones, a teacher of young children, and having the framework of the knowledge and of the truth in the Law— 21 do you, however, the one teaching someone else, not teach yourself?+ You, the one preaching, “Do not steal,”+ do you steal? 22 You, the one saying, “Do not commit adultery,”+ do you commit adultery? You, the one abhorring idols, do you rob temples? 23 You who take pride in law, do you dishonor God by your transgressing of the Law? 24 For “the name of God is being blasphemed among the nations because of you,” just as it is written.+
25 Circumcision+ is, in fact, of benefit only if you practice law;+ but if you are a transgressor of law, your circumcision has become uncircumcision. 26 If, therefore, an uncircumcised person+ keeps the righteous requirements of the Law, his uncircumcision will be counted as circumcision, will it not?+ 27 And the physically uncircumcised person will, by carrying out the Law, judge you who are a transgressor of law despite having its written code and circumcision. 28 For he is not a Jew who is one on the outside,+ nor is circumcision something on the outside, on the flesh.+ 29 But he is a Jew who is one on the inside,+ and his circumcision is that of the heart+ by spirit and not by a written code.+ That person’s praise comes from God, not from people.+
Be thankful for your shoulders' flawless design.
Is the Human Shoulder Badly Designed?
Editor’s note: We are saddened by the passing of our friend and colleague, the iconoclastic biologist Jonathan Wells. As a tribute, we are presenting some highlights from his work.
A few months ago, I fell and dislocated my left shoulder. My upper arm bone was put back in its socket the same day, but then I spent months in physical therapy to regain full function. In the process, I have learned a lot about an amazing joint that I previously took for granted.
The drawing below shows only part of the human shoulder’s anatomy. Not shown is the large deltoid muscle, which overlies the shoulder joint and connects the upper arm bone (humerus) to the collarbone (clavicle) and the shoulder blade (scapula). Also not shown is the trapezius muscle across the back, which connects the left and right scapulas. Both the deltoid and the trapezius play important roles in stabilizing the joint.
Image source: National Institute Of Arthritis And Musculoskeletal And Skin Diseases (NIAMS); SVG version by Angelito7, Public domain, via Wikimedia Commons
Anatomy of the Shoulder Joint
In the drawing, yellow indicates bone, red indicates muscle, blue indicates tendon, and purple indicates bursa (a fluid-filled cushion). The dashed black lines indicate the hidden ball-and-socket joint between the humerus and the scapula. Unlike the hip joint, in which the ball is deeper in the socket, the shoulder joint is more open. This means the shoulder joint is less stable than the hip joint, but it is also much more flexible. In fact, it is the most flexible joint in the human body.
The biceps muscle at the lower left gets its name from the fact that it has two heads. One attaches, through a tendon and a small bursa, near the top of the humerus. The other head attaches to the coracoid process, an extension of the scapula. The lower end of the biceps muscle is attached to the forearm. Although it is primarily involved in moving the forearm, its divided head helps to stabilize the shoulder joint.
Both the flexibility and stability of the shoulder joint are due primarily to the muscles of the “rotator cuff,” listed on the left side of the drawing. All four of the listed muscles stretch across the scapula and attach to the top of the humerus. For a 10-minute tutorial on the rotator cuff, see here. For a longer (20-minute) tutorial on the movements, bones, and muscles of the shoulder, see here.
The more I have learned about the shoulder joint, the more I have been impressed by its specified complexity, which points to intelligent design. Imagine my surprise when I came across a six-and-a-half-minute video claiming that the human shoulder is a “design disaster.” The video was made by Cheddar News, which describes itself as “the only news network focused on the next generation of innovators and decision-makers[.] Cheddar News is where forward thinkers go to learn about the people, ideas and innovations that are driving change and creating what’s next.”
am confident that a rigorous argument can be made for the intelligent design of the human shoulder. But that is not what I present here. In what follows, I examine the claims against design that are made in the Cheddar News video.
Proof that the Human Shoulder Is a Design Disaster?
The video’s producer is Natalia Ryzak, who has a master’s degree in journalism from Columbia University. At the beginning, Ryzak explains that “human shoulder blades tilt down and outwards, whereas chimps tilt up. Small variations like this are the reason humans have awful shoulders. And chimps, with whom we share nearly 99% of our DNA, don’t.” For that, Ryzak continues, “we can thank evolution — or more specifically, how we are outpacing it.”
But the tilt difference does not explain why the human shoulder is “awful.” If we spent most of our time swinging from tree branches, it might; but we don’t. And the claimed 99% similarity between human and chimp DNA has no bearing on the issue.
Ryzak goes on (from 0:47 to 0:59) to say:
Side effects of a human shoulder may include dislocation, separation, rotator cuff tears, bursitis, tendonitis, tendonosis, impingement syndrome, instability, arthritis, adhesive capsulitis (frozen shoulder), and fracture.
But these are not “side effects,” any more than getting a flat tire is a “side effect” of making an automobile. Or having a roof torn off by a tornado is a “side effect” of building a house. And these problems are not unique to humans: Chimps can also suffer from arthritis and fractures, among other things.
Enter Nathan Lents, professor of biology at the John Jay College of Criminal Justice in New York City. In 2015, Lents argued on his blog that the human eye is badly designed, primarily because “the vertebrate retina is wired in backwards.” Like Richard Dawkins and others before him, Lents based his claim on the fact that the light-sensing cells face away from the incoming light. But evidence published from the 1960s onward — and reported in standard textbooks — shows that this arrangement is far better than the one Lents favors.
Back to the video on “Why the Human Shoulder is a Design Disaster.” Lents says (at 1:30) that the shoulder is “more of a floating joint than any other joint in the body.” Ryzak explains that the outer layer of muscles (consisting of the deltoid and trapezius) is stronger than the inner layer (the rotator cuff). Then Lents continues (from 1:59), “Having such an overlapping meshwork of muscles, what you’re inviting is pinching, and tearing, as the orientation can shift.” Lents compares the shoulder joint to the hip joint, in which “the relationship of the hip to the leg is fairly fixed in place.”
So far, the video has summarized the structure of the shoulder and its difference from the hip. The shoulder is more flexible than the hip. Good thing, too, or we wouldn’t be able to perform many of the actions we do. Just watch an acrobat performing on the parallel bars. Or a baseball player pitching a fastball. Or an athlete swimming the butterfly.
But journalist Ryzak confidently concludes ex cathedra (starting at 2:19) that “we’ve proven to you just how cr*ppy our shoulders are.” How so? Ryzak doesn’t say. Instead she simply suggests going “back into the evolution part.”
Does Evolution Explain It All?
According to Lents (starting at 2:28), “In our quadrupedal ancestors, in our deep past, really we had four legs, they weren’t really arms, to speak of. When you think of a dog and a cat, they don’t have arms, they have legs. But they still have a shoulder joint, as we can think of it.”
Then Ryzak says, “Our shoulders evolved for a life in the trees, swinging and hanging out. Then we left the trees behind and began to stand upright. This freed our arms up for other purposes, like hunting and gathering.” So from four-legged animals that walked and ran on the ground, we get animals that spend some of their time on the ground but mostly swing from branches to branches in the trees. Then those animals “evolved” into animals that stood upright and used their arms for other purposes. This is the standard Darwinian narrative. But how, exactly, did four-legged animals on the ground evolve into two-armed animals that swung on tree branches, which then evolved into two-armed animals that stood upright on the ground? The video offers no explanation; only an imaginative story.
Lents continues (starting at 2:54), “We are partially adapted for throwing, which is… no other animal in our group of animals throws anything.” This is not true: Chimps can throw, though not as far or as accurately as humans. Indeed, they are infamous for flinging feces at visitors to zoos.
But that’s a minor detail. Lents goes on to say, “So we believe that throwing was a very strong evolutionary pressure as we began to hunt — throwing spears, thrusting as well, so thrusting and throwing are very specific kinds of motion. And that required that floating nature to our shoulder.” But “evolutionary pressure” just means that throwing favored the survival of early humans. It does not account for the origin of the human shoulder. As Darwinian biologists wrote in 1996, adaptations “concern the survival of the fittest, not the arrival of the fittest.”
So the claim that “we left the trees behind and began to stand upright” does not explain the remarkable anatomy of the human shoulder. After all, chimps leave the trees on a regular basis (though they don’t stand upright). Yet their shoulder anatomy has not changed.
The Problem and Its Solution
According to Lents (at 3:57), “Part of the problem in present-day humans is not so much a bad shoulder design but a mismatch between what our shoulder is designed to do and how we use it on a daily basis.” Of course, Lents doesn’t think the shoulder was intelligently designed. As a Darwinist, he believes that the shoulder evolved through accidental variations and survival of the fittest. And in our immediate ancestors, the shoulder was adapted (“designed”) to swing through trees.
Most of our modern activities are very different. Ryzak adds (starting at 4:16),
It might surprise you, but simply sitting at your desk is a major contributor to shoulder problems. When we hunch forward for days, hours, months, years on end, we end up causing unnecessary pulls and strains on our rotator cuff muscles. That can lead to injuries
Lents explains (starting at 5:20) that you can minimize shoulder problems by “changing the way you eat, changing the ways you use your body.” And, Ryzak adds (from 5:34 to 5:52), “pay attention to basic posture.” So after all the talk about bad design and evolutionary mismatch, the solution to our “design disaster” is for us to pay attention to diet, exercise, and posture.
I think I could have figured that out without all the anti-design rhetoric and Darwinian storytelling. Oh, and I would add: Be careful not to fall in such a way as to dislocate your shoulder.
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