The Proceedings of the Ninth International Conference on Creationism (2023)

have remained constant across all genealogies, all populations, all time, and all environments (Carter 2021). Claims have been made that identical mitochondria have been found in individuals that lived fully 8,000 years apart (Hublin et al. 2020). This seems preposterous, based on what we know about mitochondrial mutation rates, but they did find two individuals with identical mtDNA who did not live at the same time. The rate of fixation is also strongly affected by population size (Cabrera 2020). In fact, demographic changes have a much greater effect than selection, and both sides in the creation-evolution debate agree that the human population has undergone dramatic changes in size, both in the long term and locally. It seems logical that the probability of transmission of a new mutation should be similar to the probability of fixation for that mutation. Each measurement approaches 1/(2N) in stable populations. In fluctuating populations, however, the rate of fixation can be proportionally higher (in shrinking populations) or lower (in growing populations). On the other hand, Nabholz et al. (2009) called the mitochondrial molecular clock “erratic”. Studying birds, they discovered that the mutation rate in the mitochondrial cytochrome b gene was highly variable among different species. They concluded by saying, “Mitochondrial data tell nothing about species population sizes, and strongly depart the molecular clock assumption.” Översti and Palo (2022) also demonstrated differential mutation rates among various human mitochondrial lineages. Likewise, since only a few hundred mutations separate the men on the Y chromosome family tree (Carter et al. 2018), a Y chromosome mutation rate on the order of 1–3 per generation (Jeanson and Holland 2020) would place Y Chromosome Adam only a few hundred generations ago, squarely in the biblical ballpark. While we do not know the actual Y chromosome mutation rate, even low-resolution tandem repeats in Y chromosome data have been used to differentiate father and son in over one quarter of sequenced father-son pairs (Ballantyne et al. 2014). Clearly, the mutation rate is quite high. Similar to the case for mtDNA, Ding et al. (2021) showed quite clearly that different branches on the Y chromosome family tree have accumulated significantly different numbers of mutations in the same amount of time (Fig. 1). Carter et al. (2018) drew the exact same conclusions a few years earlier (Fig. 2). Ding et al. also showed that the Y chromosome mutation rate in cell cultures derived from the men in their study also comported to the branch lengths on the tree. In other words, intrinsic genetic factors influence the mutation rate. One cannot assume the rate is the same among all men without factoring in the rest of the genome, and we do not yet know how to do that. There are also questions about where to put the ‘root’ for phylogenetic calculations. “Using prior knowledge” Poznik et al. (2016) placed the founding human Y chromosome at the midpoint between two deeply rooting African Y chromosome lineages. Applying ‘sanity checks’ and unspecified ‘prior knowledge’ to critical scientific analyses does not build confidence in the mind of the reader. Even so, the evolutionary mtDNA and Y chromosome roots are still within the range of explanations when using known genealogical mutation rates. One additional factor that complicates these estimates is something Carter (2019b) called “patriarchal drive”. This deals with the excess genetic load very old people would be adding to the population if they had children in the early post-Flood years. In short, the inner branches on the Y chromosome tree (and possibly the mtDNA tree) were created all at once. This reduces the number of generational steps from the middle of the tree (ancestors) to the branch tips (living people). Thus, the genealogical rate was probably faster in the past, so using a modern average rate is a conservative approach that favors evolutionary history. Natural Selection There are two main objections evolutionists employ when trying to discount genealogical mutation rates: natural selection and genetic drift. There are problems with each argument. First, there is no Figure 2. The average distance (+ 1 SD) from each Y chromosome group ancestor to the founding member of the group, after Carter, Lee, and Sanford (2018). CARTER Genealogical vs. phylogenetic mutation rates 2023 ICC 170

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