Duf et al. Evo Edu Outreach (2020) 13:9 https://doi.org/10.1186/s12052-020-00124-w Evolution: Education and Outreach REVIEW ARTICLE Open Access Dissent with modifcation: how postcreationism’s claim of hyperrapid speciation opposes yet embraces evolutionary theory R. Joel Duf1* , Thomas R. Beatman2 and David S. MacMillan III3 Abstract The development of creationism to its multiple modern forms has been made possible in part by its appropriation and misuse of mainstream scientifc terms. Here we illustrate how anti-evolutionary advocates have redefned the terms macroevolution and microevolution to advance their view of the origins of biological diversity. We identify and describe an ideological movement within modern young-earth creationism we call postcreationism, those that have embraced a hyperrapid speciation model of the origin of biological diversity. Postcreationism is demonstrated with specifc examples from young-earth creationist publications and Ark Encounter creationist theme park, with takea- ways for addressing these ideas in evolutionary biology education. Keywords: Young-earth creationism, Creationist, Macroevolution, Microevolution, Evolution, Natural selection, Postcreationism, Ark Encounter Introduction of living things, including humans, on earth were inde- Young-earth creationism, also known variously as literal- pendently created at about the same time as the earth. day creationism, literal creationism, or creation science, In their description of natural history, the supernatural is a movement dedicated to providing purportedly scien- creation of lifeforms precipitated today’s diverse bio- tifc support for a particular literal reading of the Biblical sphere, as the originally-created populations diversifed book of Genesis. Teir reading of Genesis and subsequent into modern species. While the scale of this alleged post- attempts to gather evidence in support of their view puts creation diversifcation has changed over time, the cur- them at odds with the scientifc consensus on common rent claim is that the original created populations served descent and deep time. As such, Young-earth creationists as independent common ancestors of entire taxonomic (YECs) are the leading anti-evolutionary voices in North families (Belknap and Chafey 2019), though in some America (Chin and Buckland 2011). cases represent at ancestry of greater or lower taxonomic Despite abundant evidence that the planet is billions of ranks. In recent years, attempts to promote the validity years old and that all living organisms share a common of their explanatory models have led to YECs increasingly ancestor, YECs assert that the earth was formed super- accepting the conventional mechanisms of biological naturally less than 10,000 years ago and that all forms evolution and broad common ancestry, departing from the comparative animus toward common ancestry exhib- ited by earlier generations of creationists. *Correspondence: [email protected] Here we provide an introduction to a new-wave cre- 1 Department of Biology, University of Akron, Akron, OH 44325-3908, USA ationist viewpoint which has quietly spread through Full list of author information is available at the end of the article the insular world of young-earth creationism. We will © The Author(s) 2020. 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The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/publi cdoma in/ zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Duf et al. Evo Edu Outreach (2020) 13:9 Page 2 of 16 demonstrate that the modern YEC approach to descent Unfortunately, this continued debate within modern with modifcation and common ancestry has become biology, coupled with the inherent ambiguity in the def- in some ways more similar to the modern evolutionary nitions of these terms, can be used to perpetuate public synthesis than YECs wish to acknowledge, often with- misconceptions about evolutionary theory (Novick et al. out any awareness among the movement’s lay followers. 2014). Tis has led some biologists such as Bergstrom As a means of introducing the reader to this new- and Dugatkin (2016), who have written a general evolu- wave of young-earth creationism and how it has taken tionary biology textbook, to encourage broad avoidance root, we begin by illustrating how creationists have of terms like “microevolution” and “macroevolution” misappropriated the terms microevolution and mac- rather than permitting confusion. However, the contin- roevolution in advancing their alternative theory of the ued use of these terms by biologists and their aggressive origin of species. In creationist-specifc journals and appropriation by YECs has made public misunderstand- popular literature, YECs make organized and concerted ing unavoidable. attempts to synonymize the term ‘macroevolution’ with Due to the lack of consensus defnitions and willing- the broader scientifc consensus on deep time and uni- ness to broadly oversimplify in their representations of versal common descent. Teir goal in this is to bifurcate biological processes, the terms “microevolution” and their lay audience’s understanding of biology, creating “macroevolution” are used by YECs at the popular level the impression that there are “microevolutionary pro- to promote their own views. In their popular messaging, cesses” which are somehow diferent from or unrelated YECs present and discuss these terms with the implicit to the rest of evolutionary biology. By targeted use of representation that they are providing accepted, well- these terms, they are able to insist to their followers established defnitions and distinctions from within that they reject broad evolutionary theory as “macro- mainstream science: evolution” while quietly appropriating the conventional “Evolutionists [the YEC term for those who under- mechanisms of biological evolution as “microevolution” stand and accept evolutionary theory] assume that wherever it suits them. the small, horizontal microevolutionary changes In contrast, the understanding of these terms within (which are observed) lead to large, vertical macro- the mainstream scientifc community does not feature evolutionary changes (which are never observed)” the qualitative distinction claimed by creationists. While (Morris 1996). there are no universally-held defnitions for all these terms, Box 1 provides defnitions from a few popular “Tere is, in fact, no known relationship between so- sources of evolutionary terminology. Most biologists called microevolution and macroevolution.” (Men- agree that microevolution can be broadly identifed ton 1994). as the small, gradual changes to heritable alleles which take place within populations, such as natural selection, genetic drift, mutation, and gene fow via migration. In “[M]acroevolution is not observable, repeatable, or refutable and thus does not qualify as either a scien- contrast, macroevolution is understood to reference evolutionary change taking place at or above the level of tifc fact or theory.” (Menton 1993). the species, involving the compounded efects of micro- Te third quote from Menton above illustrates the evolutionary processes. underlying argument they seek to promote by bifurcating Tere is, of course, considerable debate among biolo- microevolution and macroevolution. As demonstrated by gists about macroevolutionary processes. Diferences of Fig. 1, YECs argue that “observable and repeatable” herit- opinion among evolutionary biologists emerge readily ability in biology are merely examples of microevolution, when navigating the relationships of microevolutionary while the mainstream proposal of “macroevolution” is an processes to macroevolutionary patterns, including the unsupported, illegitimate theory which runs counter to efects of mass extinctions, adaptive radiation, conver- observable facts. gent evolution, coevolution, and punctuated evolution Tis purported distinction between “microevolu- (Allmon 1994; Grantham 1995; Stanley 1979). In some tion” and “macroevolution” mirrors a greater rhetorical cases, evolutionary biologists have debated whether mac- approach favored by YECs. Tis approach divides felds roevolution merely constitutes multiple compounded of scientifc inquiry using distorted forms of “operational rounds of microevolution or represents a greater phe- science” and “historical science” (Geisler and Ander- nomenon (Erwin 2000). Tese disputes, however, over- son 1987) so as to provide a framework for their denial lay a universal consensus that “macroevolution” as a of numerous scientifc consensuses. Other examples of descriptor refers to changes that occur above the level of YECs partitioning of felds of inquiry include treating