Friday 24 March 2023

Waco revisited.

Ask not what your country should do for you?

the science concludes that that JEHOVAH may know a thing or two about engineering after all.

Peer-Reviewed Paper Answers Claims of “Bad Design” of the Human Foot/Ankle

Casey Luskin

In a peer-reviewed paper published in BIO-Complexity, Bristol University engineering professor Stuart Burgess explains “Why the Ankle-Foot Complex Is a Masterpiece of Engineering and a Rebuttal of ‘Bad Design’ Arguments.” Brian Miller has

previously Covered Professor Burgess’s arguments in a lecture, but those are framed as a response to arguments from ID-critics such as Jeremy DeSilva and Nathan Lents. Those critics claim that the human foot-ankle complex is sub-optimal because it reflects an unguided process where evolution attempted to convert a skeletal structure adapted for quadrupedal

locomotion to bipedalism. Burgess argues in response that the ankle-foot complex “show a very high degree of complexity and fine-tuning” and “masterful engineering.” Moreover, “Engineering insight reveals a close relationship between form and function in the ankle, a relationship seen in its multiple bones and the layout of those bones” and the “five midfoot bones are needed to form the optimal kinematic and structural interface between the hindfoot and forefoot.”

Burgess observes that many who have studied the foot without a preconceived bias have recognized its “excellent design.” He quotes Leonardo da Vinci who called the human foot “a masterpiece of engineering and a work of art,” and more modern researchers who observe the “nearly effortless human gait” or who note that various foot structures “work in perfect synchronisation” because it is “superbly constructed for ambulation.”

A Contrast with “Bad Design

In contrast, “bad design” proponents believe that most of the seven anklebones are pointless, poorly coordinated, and fundamentally a bad design because a “fused structure” would work better than “a joint with so many separate parts.” Burgess answers arguments that the ankle-foot performs poorly for bipedalism because it was originally evolved for quadrupedal locomotion by observing that such arguments “are based on circular reasoning and assumptions about what evolution could or could not do in the past.” He believes that “A better scientific approach to assessing the quality of design is to study the actual biomechanics and functions of the foot.”

Burgess observes that “The requirements for agile bipedal movement are extremely demanding.” After all, the foot must be “a compact multifunctioning precision device” which has to fulfill multiple requirements which are sometimes contradictory:

Act as a strong and stiff lever to propel the body forwards in walking and running. Joint movement is plantarflexion.

2. Act as a flexible platform to absorb shocks and adapt to uneven ground. Joint movements include dorsi-flexion, pronation, and supination.

3. Provide 3-point contact with the ground to allow standing on one or two legs and to enable controlled push-off from the ball of the feet. The control must involve fine adjustment of direction as well as power.

Difficult and Contradictory Demands

Yet Burgess further notes that “The requirements of a stiff lever and flexible platform are difficult to achieve because they are contradictory. To achieve these two requirements the foot must have stiffness and flexibility in just the right places. In addition, the foot must have the ability to adjust stiffness through precise control of muscles.” The foot is able to accomplish this because it “has three interconnecting flexible arches that perform multiple functions in particular three-point contact with the ground, stiff lever for take-off and flexibility for shock absorption.” Burgess notes how well-designed these arches are:

There are several features that maintain the integrity of the arches: (i) foot arches segmented like a Roman arch, which induces compressive forces, particularly the bone that forms the keystone to the arch; (ii) short ligaments that tie adjacent bones together; (iii) longer ligaments (like the spring ligament) that tie the arch across multiple bones; (iv) muscle-tendon groups that act like a sling, pulling the arches upwards; and (v) muscles that stiffen the arch.

He further notes that the bones of the midfoot allow it to perform five main sub-functions, including providing a “flexible transverse arch,” “Load bearing structure during pronation,” “Kinematic interfaces for pronation-supination,” “Structural interface for longitudinal loads,” and “Stiffening of the medial arch.”

Burgess also finds that “Another specialised design feature in the ankle-foot complex is the elastic hinge joints,” as some 17 of such joints allow “significant flexibility” in the foot and also aid in shock absorption. In fact, Burgess reports that these elastic hinge joints have at least five sub-functions, including “(i) flexibility; (ii) load-bearing; (iii) energy storage; (iv) failsafe design; and (v) ultra-low friction.”

Bad-design proponents have asked why there are paired bones at the bottom of the leg above the ankle instead of a single bone. Burgess notes there are good reasons for this as fibula is “well known to provide stability to the ankle joint” via “a type of linkage system with multiple bars.” He cites two specific advantages to having a fibula bone:

One advantage of the fibula is that it increases the moment arm (mechanical advantage) of muscles acting on the ankle-foot complex. A second advantage is that the fibula increases the attachment area for muscles and therefore allows more muscle to act on the joint.

Answering Bad Design

After providing this review of the engineering functions of the ankle-foot complex, Burgess is able to address claims that many foot and angle bones are functionless. In reality, “this paper has shown that all the bones of the ankle-foot complex have very important roles in the specialized design features. In particular, the five bones of the midfoot have multiple functions.” He also definitively shows that the fibula bone is necessary because it “provides essential stability to the ankle joint during pronation by forming a multi-bar linkage mechanism.” Burgess shows that a fused ankle structure would not function better because “It is well known in the medical field that ankle fusions lead to a degradation of ankle performance” and relative movement of ankle bones affords various functions, including shock absorption.

A major anti-design argument is that ankles are prone to sprains or other injuries, but Burgess notes that this confuses misuse with bad design:

The importance of this differentiation can be illustrated by analogy with a modern car. Most modern cars are well designed and very reliable when in good condition and used properly. However, despite the high quality of design, a modern car will fail if overloaded or neglected, or if it is simply very old. Therefore, when considering malfunctions in joints it is important to check why there was a malfunction. If the ankle-foot complex malfunctions due to overload, neglect, or health issues, this does not mean the design can be judged as bad.

Burgess ends with four conclusions:

There are four highly specialised design features in the ankle-foot complex

2. The ankle-foot complex is superior to human-engineered joints

3. Lents’s bad design arguments are contrary to scientific evidence

4. Engineering insight explains form and function

This last point is crucial because it shows that the very design and structure of the ankle-foot complex must exist to for it to perform its functions. According to Burgess, the system exhibits “very sophisticated engineering design.”

Pre-human powered flight v. Darwin.

Fossil Friday: The Abrupt Origin of Winged Insects

Gunter Bechly

This Fossil Friday features Lithomantis varius, a large fossil insect from the Carboniferous (Namurian) brickwork quarry of Hagen-Vorhalle in Germany, which is one of the most ancient fossil localities for winged insects and dates to about 318 million years ago. Lithomantis belongs to the winged insect order Paleodictyoptera, which only existed in the Palaeozoic era.

Insect wings are extremely complex structures that are highly adapted to their function Delitzschalan as flight organs. They have a fan-like plicated structure to give the wing surface stability; additionally they are enforced by a complex wing venation; the wing is also supplied with sensory hairs; and the wing base has a highly complex arrangement of articulatory plates to allow for sophisticated movement, enabled by an associated muscular and neural system.

According to Darwinism, the evolution of such a system would certainly have required a plethora of intermediate stages that brought this wonderful locomotory apparatus into being by an accumulation of many small changes over a long period of time. Since paleontologists have discovered thousands of fossil insects from the Paleozoic, we have certainly also found at least some of these transitional forms in the evolution of insect wings!? At least one? Nope, not a single one.

The oldest fossil winged insects belong the orders Palaeodictoptera (e.g., Delitzschala) and to the giant dragonfly order Meganisoptera, thus they were already equipped with the complete wing apparatus. There is not a single transitional form, so that the leading textbook on insect evolution, by Grimaldi & Engel (2005: 160), admitted: “An insect equivalent of an Archaeopteryx remains elusive but certainly existed.” Apparently, the engineering marvel of insect wings came into being abruptly rather than gradually, which is inexplicable with unguided evolution but quite expected with intelligent design.

Common sense has fallen?

Common sense re:Common ancestry?

Peer-Reviewed Paper Shows Vertebrate Embryonic Variation Contradicts Common Ancestry

Casey Luskin

Evolutionary biologists often argue that vertebrate embryos develop in highly similar manners, reflecting their common ancestry. But a peer-reviewed paper in BIO-Complexity, by David Swift (author of Evolution Under the Microscope), provides an insightful review on the subject. The Article is titled, “The Diverse Early Embryonic Development of Vertebrates and Implications Regarding Their Ancestry.” Swift shows that, despite common claims, vertebrates do not develop similarly, according to the predictions of evolution.

He opens by framing his thesis:

It is well known that the embryonic development of vertebrates from different classes (e.g., fish, reptiles, mammals) pass through a “phylotypic stage” when they look similar, and this apparent homology is widely seen as evidence of their common ancestry. However, despite their morphological similarities, and contrary to evolutionary expectations, the phylotypic stages of different vertebrate classes arise in radically diverse ways. This diversity clearly counters the superficial appearance of homology of the phylotypic stage, and the plain inference is that vertebrates have not evolved from a common vertebrate ancestor. The diversity extends through all stages of early development — including cleavage and formation of the blastula, gastrulation, neurulation, and formation of the gut and extraembryonic membranes.

Now intelligent design does not require common ancestry to be false, but even a guided form of common ancestry might lead to different predictions from strictly unguided descent with modification. Thus, Darwin and subsequent evolutionists such as Ernst Haeckel found embryology to be a crucial line of evidence supporting Darwin’s thesis. According to Swift, common ancestry predicts that vertebrate development should exhibit striking homologies. But more than that, “If common ancestry is the explanation for homologies, not only should homologous organs be derived from equivalent embryonic tissues (the cardinal criterion for homology) but they should also develop by comparable processes.”

Very Different Pathways

The crux of Swift’s thesis is that although vertebrate embryos do pass through a similar “phylotypic stage,” the pathways of development are very different:

[D]espite their morphological similarities and contrary to evolutionary expectations, the striking fact is that the “phylotypic stages” of different groups of vertebrates arise in remarkably diverse ways, even with key tissues such as the germ layers (see below) deriving from completely different early embryonic sources. These observations clearly refute the presumed evolutionary homology of the vertebrate phylotypic stage, and hence undermine the inference of common ancestry based on that supposed homology.

He reprints the “hourglass model” of vertebrate development and points out that this is merely an “observation” about development — not an explanation of how it arose:

From: Irie N, Satoh N, Kuratani S (2018) The phylum Vertebrata: A case for zoological recognition. Zoological Lett. 4(32):1–20. doi:10.1186/s40851-018-0114-y, under Creative Commons License

One of the key stages of development that leads to this similar “phylotypic stage” is gastrulation, which Swift notes is crucial because it establishes the basic body plan and “leads to the establishment of the germ layers — ectoderm, mesoderm and endoderm — from which all of the body’s tissues are derived.”

Differences in Vertebrate Development

Swift cites various specific differences in vertebrate development to make his case, especially in gastrulation. He predicts that “from an evolutionary perspective we would surely expect gastrulation to be ‘conserved’” but finds that “for almost all of the major classes of vertebrates” there are key differences in gastrulation, including “the mechanism of gastrulation is significantly different from any of the others,” and “the source tissues of the germ layers are different.”

After reviewing mechanisms of gastrulation in various vertebrate classes, Swift notes that “the wide variety of structures of the blastulas of different classes of vertebrate challenges the view that the resultant embryonic tissues can be considered equivalent or homologous.” Specifically, in different types of vertebrates different parts of the blastula ultimately become the embryo itself. He describes these differences as follows:

Chondrichthyans (lancelets): “It is a one-cell thick epithelial layer, forming the upper surface of the blastula.”

Teleosts (bony fish, e.g., zebrafish): “It is a multiple-cell layer, beneath the overlying enveloping layer.”

Amphibians: “It is the whole of the blastula, comprising the multilayered dome of the upper hemisphere and the mass of cells in the lower hemisphere.”

Reptiles and birds: “It is the upper surface of the blastula, comprising a single-cell thick epithelial layer, overlying the hypoblast.”

Placental mammals (e.g., primates): “It is part of the inner cell mass, within the outer trophoblast.”

He cites further differences between which cells become the endoderm and which become the mesoderm, noting:

in amniotes (reptiles, birds, mammals) cells that are internalized arise from a central area of the epiblast, i.e., the presumptive endoderm and mesoderm are surrounded by presumptive ectoderm; whereas

in anamniotes (chondrichthyans, teleosts, amphibians) the cells that internalize are from the edge of the epiblast, i.e., the presumptive endoderm and mesoderm surround the presumptive ectoderm.

Swift summarizes major differences in the mechanisms of gastrulation as follows:

Chondrichthyans: by cells rolling over a posterior overhang of the epiblast.

Teleosts: by involution around the edges of the epiblast as it spreads around the yolk.

Amphibians: by involution through an annular blastopore.

Reptiles: by involution through a canal-like blastopore.

Birds: by cells ingressing through a primitive streak, formation of the primitive streak being accompanied by growth of an underlying endoblast.

Placental mammals: by cells ingressing through a primitive streak.

Three Substantial Distinctions”

Swift thus finds that these diverse modes of development cannot be considered homologous:

In the light of these three substantial distinctions — the different overall structure of the blastulas, the different parts of the blastula that become the embryo, and the different relative positions of the presumptive ectoderm and mesoderm/endoderm in amniotes and anamniotes — there is no doubt that the tissues that become the embryo are not equivalent, and hence are far from being homologous across the various vertebrate classes.

According to Swift, these fundamental differences in early vertebrate mechanisms of development during gastrulation suggest that vertebrates do not share a common ancestry:

The straightforward conclusion to draw from this radical diversity of their early embryonic development is that it shows the vertebrates have not evolved from a common vertebrate ancestor. This conclusion can be avoided only if there are credible explanations for how such diversity of early development might have arisen from the development prevailing in a common ancestor (whether or not similar to present-day cephalochordates) in an evolutionary way, via changes that (i) had a realistic probability of occurring, (ii) maintained viability, and (iii) offered, in most cases, significant advantage that could be favored by natural selection.

Meeting these evolutionary requirements poses a great challenge, however. Swift quotes a prominent developmental biologist, Rudolf Raff, who wrote: “One might reasonably expect mechanisms of early development to be especially resistant to modification because all subsequent development derives from early processes.” Swift calls this a “commonsense conclusion” because the complexity of vertebrate development demands that many coordinated modifications would be required to fundamentally change how development proceeds. He thus finds that “because of the interdependence of the mechanisms that are involved, constructive changes to embryonic development must entail coordinated production of and/or changes to several genes, e.g., for transcription factors and the DNA sequences on which they act, which is prohibitively improbable.”

This leads to a “waiting time” problem where multiple coordinated change would be required to transition from one developmental regime to another, posing “a formidable challenge to supposed evolutionary scenarios” as generating these changes would be “generally far in excess of the time available.”

meditations of aservantofJEHOVAH

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