Intelligent Design Hoax News - How an 'Irreducibly Complex' System Evolved

Rove Beetle, Staphylinidae sp.

A beetle chemical defense gland offers clues about how complex organs evolve -- ScienceDaily

Rove beetles are a widespread family of beetles, comprising some 64,000 different, soil and leaf-litter dwelling species, many of which have interesting defensive organs for producing noxious chemicals that would normally have an unscrupulous Creationist fraud jumping up and down with glee - they appear to be irreducibly complex in that all components need to be present for the system to work.

What Creationist frauds, presented with these systems, do, is declare that such a system could not have evolved by Darwinian evolution which depends on an accumulation of small differences each of which conveys a benefit, since the entire evolutionary process would need to complete before any benefit became apparent. They then declare it to have been intelligently designed as is, by magic, because the probability of it arising as is, by chance in a single evolutionary event, is so low as to be indistinguishable from zero. The entire Intelligent [sic] Design industry is founded on just such a spurious argument, coupled with the implied false-dichotomy fallacy that if science can't explain something, "God did it!".

These beetles are fantastic models for understanding how new kinds of ecological relationships emerge during evolution through changes at the molecular, cellular, and behavioral levels. As part of this question, we're very interested in how rove beetles have pieced together these glandular structures in their abdomens, which are made of different cell types that work together. These structures are the embodiment of a major conundrum: how complex organs evolve that are often composed of many different cell types that appear to seamlessly cooperate with each other. How this cooperativity emerges during evolution is challenging to explain.

Joseph Parker, Senior author
Division of Biology and Biological Engineering
California Institute of Technology, Pasadena, CA, USA

Now, in an open access article published in CellPress, a group of scientists from the California Institute of Technology, Pasadena, CA, USA, which includes biologists and chemical engineers, have explained how one such organ evolved, and used it to illustrate the general principles behind the evolution of these complex organ systems.

The scientists used the rove beetle species, Dalotia coriaria, which has what is called a tergal gland in its abdomen that releases a cocktail made of two compound types: benzoquinones, which are highly toxic but solids on their own, and solvents, a fatty acid-derived blend of an alkane and three esters. The latter compounds by themselves are benign, but they weaponize the benzoquinones by dissolving them.

We were able to discover the biosynthetic pathways in each cell type and could then ask how these pathways were stitched together during evolution.

The beetle has recruited a major gene expression program from these ancient metabolic cell types and installed it into a patch of cuticle, creating a gland.

The solvent cells created a niche for a second cell type to produce the solid benzoquinones, which could dissolve in the alkane and esters. A highly toxic secretion emerged that massively raised the gland's adaptive value, locking the two cell types into a unit where they cooperate. In essence, a new organ emerged.

Joseph Parker

The group discovered that the tergal gland is composed of two cell types each with a specialised function: one that produces the benzoquinones and another that produces the solvents. The team first identified the novel enzyme pathways that produce these substances then used these findings to discover precursor pathways in older cell-types from elsewhere in the beetle's body. The cell type that produces the solvents was a hybrid of two other cells found in the beetle's exoskeleton that make and store lipids and produce pheromones.

The team also found that some of the chemicals have antimicrobial properties, suggesting that they may have evolved initially with these antibiotic properties which would have conveyed an adaptive advantage in the beetle's natural habitat of damp and decay.

The final stage in the evolution of the tergal gland would have been the co-evolution of the two cell types to produce a new organ, without, as Creationist frauds claim, magical intervention and new genetic information to code for a new organ. The organ evolved as a co-evolutionary process by exaptation of existing structures and metabolic pathways, and without an increase in genetic complexity, just as serious cell biologists think structures like the bacterial flagellum evolved.

And of course this refutes Creationist claims that evolution can't account for new taxons, which they define as 'macro-evolution' necessitating the evolution of new structures and organs, like the rove beetle's tergal gland, which they declare to be impossible.

In the abstract to their article in Cell, the authors say:

Graphic Abstract

Highlights

• A rove beetle defense gland reveals how evolution builds new organs
• Two secretory cell types work together, one making a solid toxin, the second a solvent
• New cellular functions evolved by combining ancient transcriptome modules and pathways
• Evolution of each cell type was shaped by adaptive coevolution between the cell types

Summary
How the functions of multicellular organs emerge from the underlying evolution of cell types is poorly understood. We deconstructed evolution of an organ novelty: a rove beetle gland that secretes a defensive cocktail. We show how gland function arose via assembly of two cell types that manufacture distinct compounds. One cell type, comprising a chemical reservoir within the abdomen, produces alkane and ester compounds. We demonstrate that this cell type is a hybrid of cuticle cells and ancient pheromone and adipocyte-like cells, executing its function via a mosaic of enzymes from each parental cell type. The second cell type synthesizes benzoquinones using a chimera of conserved cellular energy and cuticle formation pathways. We show that evolution of each cell type was shaped by coevolution between the two cell types, yielding a potent secretion that confers adaptive value. Our findings illustrate how cooperation between cell types arises, generating new, organ-level behaviors.

Brückner, Adrian; Badroos, Jean M.; Learsch, Robert W.; Yousefelahiyeh, Mina; Kitchen, Sheila A.; Parker, Joseph
Evolutionary assembly of cooperating cell types in an animal chemical defense system
Cell, Volume 184, Issue 25, 6138 - 6156.e28; DOI: 10.1016/j.cell.2021.11.014

Copyright: © 2021 CellPress, an imprint of Elsevier Inc.br>

It's hard to think of a better refutation of Intelligent [sic] Design Creationism than the above description of the evolution of an irreducibly complex organ, describing as it does how irreducible complexity can evolve by exaptation and co-evolution of pre-existing structures to give a new organ with a novel function, and also how a new organ can evolve by slow, Darwinian evolution, in other words by the self-same processes that Creationists call 'micro-evolution'.

It will be interesting to see how the frauds who lead the Creationist industry handle this piece of research, if they don't simply ignore it and try not to mention it in front of their credulous victims.

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