The Proceedings of the Eighth International Conference on Creationism (2018)

to accomplish the same thing, however we sought to be consistent with the biblical account, which seems to require moderately rapid population growth after Adam and Eve, a single-generation bottleneck at the time of the Flood, and moderately rapid population rebound after the flood (Carter and Hardy 2015). When we combined mutational alleles with designed alleles (starting at 25%), with the two primary bottlenecks, we saw that the designed alleles substantially drifted toward lower allele frequencies, while the mutational alleles drifted substantially toward higher allele frequencies, effectively filling the gap (Figure 6b). When we added a blend of two or more types of designed allele pairs (for example, one type starting with an initial allele frequency of 25%, another type starting with an initial allele frequency of 50%), we found our distributions could be fine-tuned to align with the actually observed allele distribution (Figure 7). In summary, modeling a heterozygous Adam and Eve brings us a very long way toward reconciling a literal Adam and Eve with the observed allele frequencies. In this model, the primary factors that shape the allele frequency distribution included: a) the number and duration of bottlenecks; b) the ratio of the designed alleles in different frequency classes; and c) the ratio of designed alleles versus mutational alleles. By modulating these variables, we were able to discover parameter settings that produce allele frequency distributions that plot as smooth curves and closely approximate the actually observed biological allele frequency distributions. We may be able to enhance the current distribution further by: a) adjusting the ratio of mutational alleles versus designed alleles; b) simulating a growth pause after the Babel event; and c) simulating an episode of accelerated mutation accumulation in the first 25–50 generations after the flood. 2. Adam and Eve were created with internal designed diversity, combined with various demographic forces other than classical genetic drift. We believe that we must eventually factor in forces such as selective sweeps and differential sub-population expansions to make our simulations more biologically realistic. Genetic drift is really just a type of diffusion and is quite impotent in changing allele frequencies except in very small populations or over very deep time. It is a passive and slow process. Most drift models (including ours) assume all alleles are neutral, that there is essentially no selection, and that the global population has perfectly random mating. Yet there are various other forces that are much more effective in shifting allele frequencies, and in much less time. These other factors consist of numerous active processes such as selective sweeps, migration/invasion, explosive lineage expansions, lineage extinctions, and other fast-acting population events. We used selective sweeps as just one example to illustrate non-drift alternatives that can change allele frequencies rapidly (Figure 5). A series of powerful selective sweeps can clearly help fill “the gap”. One reason why designed diversity makes so much sense is that it enables very rapid adaptation to local conditions. The biblical mandate to “fill the earth” (i.e., fill all the environmental niches in the earth), seems to imply rapid adaptive population fragmentation. Therefore, it would be reasonable to have a limited class of designed alleles on hand that could rapidly respond to natural selection. Designed alleles represent the most effective and the most rapid way to cause selection-driven adaptation. This is because no extended “waiting time” is required. All the required genetic variants are present from the first generation, and are already present at high frequency, enabling very rapid selective progress. There is no need to wait for just the right set of mutations to arise serendipitously and then slowly move from allelic near-extinction to allelic fixation. Furthermore, such designed variants would already exist as fully functional linkage sets at high frequency. This amplifies the rate of selective progress and so allows for extremely rapid adaptation. Given a pair of high-impact alleles, one allele will typically be more adaptive in one habitat than the other, so the frequency of that allele would increase rapidly toward fixation in that habitat. At the same time, in that habitat the corresponding minor allele would be moving toward a frequency of zero. As these high-impact pairs are driven toward the far left or far right of our plots, they will carry with them countless nearly-neutral variants that happen to be linked. This is what is called a “selective sweep”. Those variants that will be carried along will include both designed alleles and mutational alleles. In less than 200 generations we observe smooth allele distributions when we simulated this scenario (Figure 5). Given only mutational alleles, selective sweeps would be expected to be very rare. This is because beneficial mutations are very rare, and because mutations that are strongly-beneficial are vanishingly rare. However, given designed alleles, selective sweeps (and all other types of adaptive selection) should be very common, and should respond to selection very rapidly. This is because designed alleles would be very abundant from the first generation (no waiting time), they would be created at relatively high frequencies, and for every designed allele pair both variants would have a designed purpose, one favored over the other, depending on habitat. Lastly, designed alleles of this type would naturally be designed to work in coordination each other, constituting functional linkage blocks, and constituting desirable poly-genic (quantitative) traits. We used selective sweeps as our example because they are rapid demographic shifts that can be easily demonstrated using numerical simulation. However, we are not yet able to simulate other important demographic factors that could very rapidly change allele frequencies. Looking backwards in human history, we see a long series of explosive human expansions, along with genocides and shrinkages. It is obvious that all people living today are the descendants of the lucky lineages that survived, as the vast majority of all lineages go extinct (Helgason et al. 2003; Rohde et al. 2004). Therefore, the frequencies of many human alleles must have diminished over time, even as the alleles of other historical populations surged forward. These types of population dynamics could rapidly amplify many of the countless un-plotted rare mutational alleles, moving them from the invisible 0–1% histogram bin into the 1–15% histogram bins. We have primarily compared our simulated results with the actual allele distributions of the autosomal chr22. But we also generated the actual allele distributions of chrY and chrM. These distributions are striking in that these two chromosomes are very different in their nature, yet both of their distributions are very similar. They both Sanford et al. ◀ Designed genetic diversity in Adam and Eve ▶ 2018 ICC 212