Species were designed to change, part 2
Speciation and the limits of change
Published: 22 July 2021 (GMT+10)
In part 1 of this article, we saw how God designed life with a large amount of information, up front. Some of this was in the form of genetic diversity and some was in the form of latent information that could arise through the process of recombination. We also saw that he foreknew the effects of mutation and incorporated this into His design. God was not caught by surprise here. He knew.
We will now broaden this discussion to include population-level changes that lead to the rise of new species. But first, we must define what a species is. This is not easy to do, and many different definitions exist. Basically, if a group of organisms breeds ‘true to type’ we call that a species. The problem is that many ‘species’ can interbreed, producing hybrids. Worse, in the fossil record we see skeletons of all sorts of deceased organisms, yet we know nothing about which ones could have interbred. In the end, the word species is just a term of convenience. For example, it is helpful to separate the North American cardinal (Cardinalis cardinalis) from the pyrrhuloxia (or desert cardinal, Cardinalis sinuatus), even if they share a lot of physical features, have identical songs, and can interbreed.
The easiest definition to understand is the ‘biological species concept’. Basically, if two organisms can successfully breed (i.e., not make sterile hybrids), they belong to the same species. If they can’t, they are separate species. Yet, the lines between ‘species’ are often quite blurry. This is perhaps not unexpected in the creation model. If you take a group of organisms from a single created kind and spread them out across the earth, it is not hard to imagine each of the resulting subpopulations changing in different ways while maintaining the ability to interbreed with other subpopulations.
Many, many ‘species’ can interbreed. In fact, there are multiple examples of species from different genera and even from different families1 being able to successfully interbreed. Therefore they belong to the same biological species by definition. Yet, just because two things cannot interbreed today does not mean they do not belong to the same biblical kind. We have to take each case separately and study it in detail.
Given the pluripotent baranomes (see part 1) God put into His creation, with a rich diversity of genes, we would naturally expect rapid diversification. As that diversity was slowly lost, mutated, and pigeonholed into discrete species, the rate of change should have slowed over time. However, hybridization can lead to a burst of change because mixing the genes of two species partially restores the original diversity. Evolutionists have been slow to realize how much hybridization among species has always existed.2 In fact, they are now saying that new species often arise due to hybridization.3 Of course, they are putting a much longer timescale on these events, but what is clear is that standing variation is a rich source of rapid change and the rise of new phenotypes.
Speciation can be driven by reproductive incompatibility, but it can also be driven by mate choice. In songbirds, the females will often choose to mate with a male that has a song very similar to her father’s. In the nest, he imprinted a specific song into her mind. Likewise, the males will grow up singing the song they heard their father sing. Cross-species mating can sometimes occur if the nests of two songbird species are too close together. In this case, one male can imprint his song onto the babies in the other nest. In a long-term study of Galápagos finches, the team of Peter and Rosemary Grant noticed that a strange bird had arrived on the small island of Daphne Major. He was himself a hybrid of a medium ground finch (Geospiza fortis) and a common cactus finch (Geospiza scandens). He was larger than any of the other closely related finches on the island but managed to mate with a G. fortis female and raise a clutch of eggs. One of those birds flew off to mate with another G. fortis individual, but every other bird mated with a sibling.4 There are not a lot of these birds, but they have been on that island for over three decades. They are genetically and morphologically different from any other species on the island, and they sing a different song. In short, we saw the rise of a new species, through hybridization.
Frequent hybridization among species caught the evolutionists flat-footed. They resisted the thought for many years because it did not fit well with the whole evolution concept. If species can mingle, and if species have been around for a very long time, giving them plenty of time to ‘mingle’, why do discrete species even exist? Perhaps they don’t.
As we saw above, there are things that happen on the population level that can affect the way organisms look and act. For example, if you take a population and divide it into subgroups, each little group might not carry all the genes in the original population. Yet, the future individuals born into those subpopulations can only carry the genes of their sires. This is called the founder effect. If the founders of the subpopulation carried more “tall” genes, or “yellow” genes, or “fast” genes than average, the resulting subpopulation would be different. We would expect such a thing to be in play in many of the biblical kinds as they were spreading out on the earth after the Flood.
Think about any post-Flood kind (dogs, bears, birds, or whatever). As they travel further away from where the Ark came to rest, they would have to cross rivers, mountain ranges, and deserts. It would become more and more difficult to interact with other members of the original population. Given founder effects, the appearance of mutations unique to each subpopulation, genetic drift removing genetic diversity at random, and things like that, the different groups would quickly change. This easily explains how the pair of the Ursid created kind on the Ark could give rise to grizzlies, brown bears, black bears, sun bears, polar bears, and the extinct cave bear and short-faced bear. We don’t need evolution to explain speciation. All we need is an initially high genetic diversity, a way to scramble that diversity, and the isolation of subpopulations. The rise of unique phenotypes after isolation is called allopatric speciation, and mountainous regions (such as Ararat!) are well known for it. Actually, many types of bears can still interbreed, such as the grizzly and polar bears having a pizzly cub together, so all bears are really a single biological species, by definition.
As an aside, we see a similar process for humans, but it was delayed by a century. That is, humans disobeyed God’s command to fill the earth and intentionally stayed gather in one place (Babel). God confused their languages to force them to spread out in the days of Peleg. They were divided into small, isolated subpopulations. This is largely responsible for the small differences between ‘races’. But no speciation has occurred—all humans (including Neanderthals and Denisovans) are or were interfertile, so are one species, by definition. We started off as one group and there has been considerable mixing throughout history, so people can often share things like blood groups and Y-chromosomes with people of supposedly very different races. Thus, ‘inter-racial’ organ transplants are more common than many people might assume. Why? Because you can be more similar to a person from another ‘race’ than to people from your own.
How fast does change happen?
It seems reasonable that change would have happened more quickly in the past. Thus, when Darwin observed small changes in some species over a few years, he was witnessing the end game. He drew grand conclusions from a very limited sampling in time. Had he considered what God would have initially created, perhaps he would have come up with a different theory (but perhaps not, for religious reasons).
Once living things exist, they can change. Fine. But, as the species derived from each original kind aged, they lost some of that original, good, God-created diversity and started to accumulate mutations. Because of this, it is like modern species are poised on the edge of a knife. You cannot change them too much without killing them. Their ancestors were more robust than the inbred, high-mutation-load individuals that exist today. Plus, due to the way species adapt to different environmental niches, genetic pigeonholing happens. Natural selection doesn’t create genes, but instead culls them. Once they go down one path, they can no longer hop to another. They are stuck. Change is (mostly) a one-way street.
Do we believe in ‘hyperevolution’, as some evolutionists claim, dutifully followed by old-earth compromisers like Hugh Ross? Not at all. There are a lot of species in the world, and each land-based species derives from only a few representatives on the Ark. If we have to account for the rise of millions of species in just a few thousand years, it sure sounds like we are talking about evolution, right?
Actually, no. We do not have to account for much change at all. It depends on where you draw the line. First of all, we do not have to account for anything but the nephesh chayyah that were on the Ark, which generally equate to the land-based vertebrates (i.e. mammals, reptiles, and birds). Thus, it does not matter how many species of beetles are in the world. Yet, for the animals on the Ark, we would have a major problem if kind = species. But what if we draw the line at the family level? Of the 151 mammalian families, for example, some have upward of 400 species, but most have less than 20.5 The families with more species tend to include the smaller species, with high reproduction rates, short generation times, and large populations (in other words, the ones with more opportunities for speciation processes to operate). We have had 4,500 years of post-Flood history to account for within-kind speciation. Even a modest speciation rate can account for the numbers of species we see, especially if the kind can divide into two species, which divides into four, etc. Just because a subpopulation split off from the main population does not mean it cannot split again and again, especially in those early years. I fully expect that the rate of speciation has slowed down over time.
How much change is allowed?
The next question we must face is one of magnitude. Given pluripotent baranomes and several thousand years of individual and population-level changes, how much ‘change’ can we get? Clearly, there is a limit. God may have engineered things to dynamically adapt to new environments, but we have only so much time for mutation, selection, drift, and recombination. We also have limits to the design itself. An organism cannot exceed its design constraints, or it perishes.
Some creationists have pushed for much more potential change than we are comfortable with. For example, Dr Kurt Wise once wrote:
Finally, some of the animals which are aquatic or marine today may not have been aquatic at the time of the Flood. The marine and sea otters, for example, are members of the mustelid (weasel) family and their aquatic character is likely to have been revealed after the Flood. The whales might turn out to be another example. Only when including the legged archaeocetes (and/or possibly the terrestrial order Acreodi) do the whales have a fossil record continuous with the Flood. Vestigial legs and hips in modern whales confirm legged ancestors of the whales existed only a short time ago. It is possible that the purely marine cetaceans of the present were derived from semi-aquatic or even terrestrial ancestors as well.6
Whales came off the Ark? At face value, this seems preposterous. There is nothing seriously wrong with thinking that the legless lizards once had legs, and the same goes for snakes. There is no problem thinking that wingless beetles once had perfectly functioning wings, or that blind cave creatures had sighted ancestors. In fact, there are all sorts of examples of loss that we can cite.
But whales can’t be explained just by leg loss. In any case, the so-called vestigial legs are not what is often claimed in modern whales, and in the extinct whale Basilosaurus they appeared to be reproductive claspers. The evolutionary ancestors of whales could not nurse their young underwater. Their breathing and eating systems were still connected. They would have had no need for those strange mouth plates that baleen whales use to filter out krill from the water. They would not have had the ability to echolocate. There are entire suits of morphological and behavioural changes that are necessary to explain whales.
Modern whales are also found in the fossil record. There is debate among creationists about where to locate the Flood/post-Flood boundary. If the boundary is high up, whales died in the Flood, so they did not come from any animal on the Ark. If the boundary is lower, there is still not much room for the evolution of whales from land animals because whales are found about half-way between today and the end of the Cretaceous, where some creationists put the Flood/post-Flood boundary. This would require an incredible amount of change in a very small amount of time. We are not talking about cat-like lions and cat-like tigers arising from a cat-like ancestor.
The amount of change allowed in the creation model is an interesting question. In some ways, it is still an open question. Yet, the line must be drawn somewhere. Generally, if the proposed changes necessarily involves the appearance of brand new features that would have been useless to the original organism (i.e. a land-based predator with baleen instead of teeth), it is almost certainly excluded from consideration. If, however, it can be shown that the information for the new features could have been coded into the original baranome (either directly or in latent form), or if it could have arisen through the destructive process of mutation, then the resulting changes might be allowed in the creation model.
God is the master engineer. He did not just create life; He designed life to robustly respond to the environment. He overdesigned living things so that they could withstand, so far, thousands of years of mutational accumulation. His designs were holistic, in that He accounted for what each kind would need in the future. He built redundancy in the genomes to ward off the effects of decay, but He also designed specific aspects of the genome to change via mutation.
On the last page of Origin of Species, Charles Darwin wrote, “There is grandeur in this view of life,” referring to his claim that all life evolved from primitive ancestors.7 How wrong he was! Our God, however, is an amazing, fantastic, super-intelligent, all powerful, and omniscient Creator.
Consider the words of Paul:
“For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him. And he is before all things, and in him all things hold together.” (Colossians 1:16–17)
There is grandeur in that view of life.
References and notes
- For example, a hybrid between an American paddlefish (family Polyodontidae) and a Russian sturgeon (family Acipenseridae). Kály, J. and 12 others, Hybridization of Russian sturgeon (Acipenser gueldenstaedtii, Brandt and Ratzeberg, 1833) and American paddlefish (Polyodon spathula, Walbaum 1792) and evaluation of their progeny, Genes 11(7):753, 6 Jul 2020; Sarfati, J., Startling sturddlefish, Creation 43(1):17, 2020. Return to text.
- Pennisi, E., Shaking up the tree of life. Science 354(6314):817–821. Return to text.
- Pennisi, E., Hybrids spawned Lake Victoria’s rich fish diversity. Science 361(6402):539. Return to text.
- Lamichhaney, S. et al., Rapid hybrid speciation in Darwin’s finches, Science 359(6372):224–228, 2018. Return to text.
- Jeanson, N.T., Mitochondrial DNA clocks imply linear speciation rates within “kinds”, Answers Research Journal 8:273–304, 2015. Return to text.
- Wise, K.P., Mammal Kinds—how many were on the Ark? in: Wood, T.C. and Garner, P.A. (Eds.), Genesis Kinds: Creationism and the Origin of Species, Wipf & Stock, Eugene, Oregon, p. 143, 2009. Return to text.
- Darwin, C., On the Origin of Species, 6th edition, John Murray, London, 1871. Return to text.