© Cedarville University International Conference on Creationism. The views expressed in this publication are those of the author(s) and do not necessarily represent those of Cedarville University. Carter, R.W. 2023. Genealogical vs phylogenetic mutation rates. In J.H. Whitmore (editor), Proceedings of the Ninth International Conference on Creationism, pp. 168-180. Cedarville, Ohio: Cedarville University International Conference on Creationism. GENEALOGICAL VS PHYLOGENETIC MUTATION RATES: ANSWERING A CHALLENGE Robert W. Carter, Creation Ministries International, P.O. Box 350, Powder Springs, GA 30127 USA r.carter@creation.com ABSTRACT There is a discrepancy between the mutation rate we can measure today and the rate at which evolution is supposed to have proceeded. The former is sometimes called the genealogical mutation rate, for it is obtained by comparing individuals whom we know to be related. The latter is sometimes called the phylogenetic mutation rate. It is generally calculated by counting the fixed differences between two species and dividing by the estimated time since their common ancestor. Genealogical mutation rates are several orders of magnitude faster than phylogenetic estimates. This causes problems for the evolutionary model. For example, using the genealogical method would place Y Chromosome Adam and Mitochondrial Eve well within the biblical time frame. The evolutionary community often uses appeals to natural selection, genetic drift, or theoretically low mutation rates to explain away the discrepancy. In this study, the population modeling software Mendel’s Accountant and simple statistics were used to show that these explanations do not work. The genealogical mutation rate is, in fact, a serious challenge to evolutionary theory. KEY WORDS phylogeny, genealogy, mutation, Y Chromosome Adam, Mitochondrial Eve, natural selection, genetic drift I. INTRODUCTION The fact that genealogical estimates yield much faster mutation rates than phylogenetic estimates has been known for many years (Wieland 1998, 2006). Evolutionists generally claim the dilemma is irrelevant or easily solved (c.f., Carter 2021), for a variety of reasons which will be explained below. Even so, the issue continues to pop up in evolutionary writing (e.g., Connell et al. 2022). When estimating things like the time to a most recent common ancestor (TMRCA), they almost universally use the phylogenetic mutation rate. This is obtained by dividing the number of differences separating two species by the assumed time since their last common ancestor (Mishmar et al. 2003). At least, this is what is generally presented. Occasionally, a study will use known archaeological points to fix the tree in time. The dating of such events is generally based on radiometric methods. This has been attempted for mitochondria (Friedlaender et al. 2005) as well as Y chromosomes. In fact, the most significant Y chromosome studies used the peopling of the Americas as a fixed reference point, calling it a “sanity check”. This exact phrase was used in the main paper that contributed the Y chromosome data to the 1000 Genomes Project (Poznik et al. 2016), as well as in an earlier paper by a different group of authors (Behar et al. 2012). While discussing this, Carter et al. (2018) stated, “Clearly, they are prepared to reject measured mutation rates in favor of evolutionary assumptions if the measured rates turn out to be too high.” Phylogenetic methods (whether based on archaeology, radiometric dating, or something else) generally yield mitochondrial mutation rates on the order of 10-8 mutations per site per year. Given a 16,569nt genome and a ~30-yr generation time, that amounts to approximately 1 mitochondrial mutation every 200 generations. This is not actually the ‘mutation’ rate. Instead, it is the substitution rate, or the rate at which new mutations replace the original genetic variant across the entire population. On the other hand, the genealogical mutation rate is a better estimate of the real-time mutation rate (after subtracting lethal mutations). The phylogenetic mutation rate is clearly influenced by evolutionary assumptions, but the genealogical rate is not completely free of them either. Since the error rate in large sequencing databases is on the same order of magnitude as the expected mutation rate, the data must be highly filtered before any mutation rate estimates can be made. Earlier genetic databases had so many errors that much of the data were unusable (Carter et al. 2008), but quality control has improved. Still, the intrinsic error rate complicates all calculations. Among creationists, Jeanson has done the most work on this (see Jeanson and Holland 2020) and we are indebted to the detailed analyses of this subject that he pioneered. During data filtering, it is highly likely that many real mutations are removed, which would lower the genealogical mutation rate. Even so, the rates are still far too high, meaning that Mitochondrial Eve and Y Chromosome Adam would be placed too recently in time for the evolutionary model. In their study on the mitochondrial mutation rate in Daphnia pulex, Xu et al. (2012) said: “Despite the great utility of mitochondrial DNA (mtDNA) sequence data in population genetics and phylogenetics, key parameters describing the process of mitochondrial mutation (e.g., the rate and spectrum of mutational change) are based on few direct estimates. Furthermore, the variation in the mtDNA mutation process within species or between 9th 2023 Carter, R.W. 2023. Genealogical vs phylogenetic mutation rates: Answering a challenge. In J.H. Whitmore (editor), Proceedings of the Ninth International Conference on Creationism, pp. 168180. Cedarville, Ohio: Cedarville University International Conference on Creationism.
RkJQdWJsaXNoZXIy MTM4ODY=