Phylogeny and diversity.
A chronogram of both Brassicales families (Upper) and Pierinae butterfly genera (Lower), showing species numbers and identification of clades in the adjacent table. A common temporal scale is provided between the two chronograms. The branches in the Brassicales phylogeny are colored to indicate the origin of indolic glucosinolates (purple), methionine derived glucosinolates (green), and novel structural elaborations to glucosinolates unique to the core Brassicaceae lineage (orange). Vertical dashed lines also indicate the origin of these novel chemical groups. Primary host–plant associations of various Pierinae lineages are similarly colored: orange (Brassicaceae), green (Capparaceae or Cleomaceae), orange-green (mixture of previous), purple (more basal Brassicales that synthesize indolic glucosinolates), blue (non-Brassicales feeding) and gray (unknown). The phylogenetic positions for the At-α and At-β WGDs are depicted with white diamond symbols, and significant net diversification rate shifts with red star symbols.
Source: Edgar, P.P, et al (2015)
While researching for my previous blog post about the unintelligent design in the horseradish flea beetle, I noticed I failed to write about this beautiful piece of research from 2015, despite having referenced it and wrote about the discovery in my popular book, Unintelligent Design: Refuting the Intelligent Design Hoax
I'm referring to the paper published in PNAS in June 2015, entitled The butterfly plant arms-race escalated by gene and genome duplications, now freely available under PNAS' open access option, the work of a large international team of scientists including biologists from The University of Missouri, Columbia, MO, USA, The Max Planck Institute for Chemical Ecology, Jena, Germany, and the Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK.
This work confirmed the conclusions made 50 years earlier by two now-renowned biologists, Peter Raven and Paul Erhlich, who introduced the concept of co-evolution, where two species influence the evolution of each other, by showing how gene duplication, and subsequent repurposing of the spare genes produced, was responsible for plants evolving a defence against the caterpillars of butterflies and how, beginning about the same time as the extinction of the large dinosaurs in the mass extinction at the KT boundary, this gave rise over several million years to the co-evolutionary diversification of brassica-eating butterfly species and the brassicas, in an ultimately pointless arms race. Raven and Erhlich had even used the brassicales and cabbage butterflies as examples (A case of a prediction of the Theory of Evolution being proved correct, 50 years later!)
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The result of this arms race was the tangy taste we call mustard, produced by glucosinolates - chemicals which are toxic to butterfly caterpillars and other leaf-eating insects - the large number of brassicales and a large number of brassica-eating butterflies.
The blunder by Creationism's putative intelligent [sic] designer, if you believe that nonsense, is that it apparently thought it was good design to create species to eat the leaves of plants, then redesign the plants to prevent them being eaten, then redesign the plant-eating insects to overcome the toxins intended to stop them eating the plants. An example there of the designer's right hand not knowing what its left hand was doing!
As a piece of design, designing problems to be solved then treating the solutions as more problems to be solved, ad infinitum, would be breathtakingly stupid even for a human designer, let alone an omniscient one who should have foreseen the consequences of the arms race it was having with itself, scrapped its bad designs and started again when it realised what it had done.
The apparent fact that it allowed it to continue for several million years, adding more layers of complexity at each wasteful escalation of the arms races and never thought to scrap it and start again shows that the 'designer' was neither intelligent nor good at design. Needless complexity and prolific waste are both characteristics of bad design, or more precisely no design at all, since two of the hallmarks of good design are minimal complexity and minimal waste. A world with the inbuilt flaws of needless complexity and avoidable waste cannot conceivably be the work of a perfect designer.
The paper in question can be read in PNAS:
We found the genetic evidence for an arms race between plants like mustards, cabbage and broccoli and insects like cabbage butterflies. These plants duplicated their genome and those multiple copies of genes evolved new traits like these chemical defenses and then cabbage butterflies responded by evolving new ways to fight against them.
Seeing the variation in the detoxification mechanisms among species and their gene copies gave us important evolutionary insights.
We found that the origin of brand-new chemicals in the plant arose through gene duplications that encode novel functions rather than single mutations. Given sufficient amounts of time the insects repeatedly developed counter defenses and adaptations to these new plant defenses.
Professor Chris Pires
Researcher and associate professor of biological sciences
College of Arts and Sciences
Bond Life Sciences Center
Missouri University, Columbus, MO, USA.
Researcher and associate professor of biological sciences
College of Arts and Sciences
Bond Life Sciences Center
Missouri University, Columbus, MO, USA.
Seeing the variation in the detoxification mechanisms among species and their gene copies gave us important evolutionary insights.
Hanna Heidel-Fischer, Co-lead author
Max Plank Institute for Chemical Ecology, Jena, Germany.
Max Plank Institute for Chemical Ecology, Jena, Germany.
We found that the origin of brand-new chemicals in the plant arose through gene duplications that encode novel functions rather than single mutations. Given sufficient amounts of time the insects repeatedly developed counter defenses and adaptations to these new plant defenses.
Pat Edger, Co-lead author
Missouri University, Columbia, MO, USA
Missouri University, Columbia, MO, USA
SignificanceIt is papers like this that utterly refute the childish notion of intelligent design by a magic designer, as well as much else of Creationist dogma. Not only does it show that whatever the 'design' process was, it had no intelligence, no foresight and no plan. It also shows that the Creationist claim that no new information can arise by mutation, and their latest ploy - the idiotic claim that all mutations are devolutionary and thus support some notional idea of a perfect creation a few thousand years ago (© 2019 Michael J Behe/Discovery Institute) is fraudulent and aimed at scientifically and biologically ignorant fools.
This research uncovers the mechanisms of an ancient arms race between butterflies and plants, seen today in countless gardens as caterpillars of cabbage butterflies that devour cabbage crop varieties. Nearly 90 million years ago, the ancestors of Brassica (mustards, cabbage) and related plants developed a chemical defense called glucosinolates. While very toxic to most insects, humans experience glucosinolates as the sharp taste in wasabi, horseradish and mustard. Here we report that this triggered a chemical arms race that escalated in complexity over time. By investigating the evolutionary histories of these plants and insects, we found that major increases in chemical defense complexity were followed by butterflies evolving countertactics to allow them to continue to attack and feed on the plants.
Abstract
Coevolutionary interactions are thought to have spurred the evolution of key innovations and driven the diversification of much of life on Earth. However, the genetic and evolutionary basis of the innovations that facilitate such interactions remains poorly understood. We examined the coevolutionary interactions between plants (Brassicales) and butterflies (Pieridae), and uncovered evidence for an escalating evolutionary arms-race. Although gradual changes in trait complexity appear to have been facilitated by allelic turnover, key innovations are associated with gene and genome duplications. Furthermore, we show that the origins of both chemical defenses and of molecular counter adaptations were associated with shifts in diversification rates during the arms-race. These findings provide an important connection between the origins of biodiversity, coevolution, and the role of gene and genome duplications as a substrate for novel traits.
Edger, Patrick P.; Heidel-Fischer, Hanna M.; Bekaert, Michaël; Rota, Jadranka; Glöckner, Gernot; Platts, Adrian E.; Heckel, David G.; Der, Joshua P.; Wafula, Eric K.; Tang, Michelle; Hofberger, Johannes A.; Smithson, Ann; Hall, Jocelyn C.; Blanchette, Matthieu; Bureau, Thomas E.; Wright, Stephen I.; dePamphilis, Claude W.; Eric Schranz, M.; Barker, Michael S.; Conant, Gavin C.; Wahlberg, Niklas; Vogel, Heiko; Pires, J. Chris; Wheat, Christopher W.
The butterfly plant arms-race escalated by gene and genome duplications
Proceedings of the National Academy of Sciences
Jul 2015, 112 (27) 8362-8366; DOI: 10.1073/pnas.1503926112
Copyright: © 2015 National Academy of Sciences
Freely available online through the PNAS open access option.
The refutation of Creationism is abundantly available in the details of biology, if only one takes the trouble to look at it objectively. The reason plants produce the mustard flavour that we use as a condiment is testament to the creative power of the natural evolutionary process and against the childish notion of magic creation and a magic man in the sky directing things.
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