The word ‘select’ is an interesting word. As soon as someone uses this word, forcing listeners, including a speaker, himself assume one thing. “Cannot take all”. The presupposition of this word is ‘there are multiple options but cannot take all. Someone needs to decide’. The other words like this are ‘chose’ and ‘pick’. On most occasions, ‘chose’ and ‘select’ are interchangeable. ‘Pick’ has a wider meaning than ‘chose’ and ‘select’ but it includes them. Once someone uses these words, asking the questions like “are there more options?”, “it looks no option”, “all options look same” or “can I take all?” is getting difficult if you are educated adults. Kids are generally less constraint by common sense, and they are honest with their demands. They can ask these questions outside of presupposition. On the other hand, their parents may get embarrassed because of their common sense.
The second part of presupposition of ‘select’ is “someone decides”. ‘Natural selection’ is the word invented by Charles Darwin. Before him, someone was the God in the Western Christian world. Something appears selected or chosen, but no one knows who did that and how did that. Those were often interpreted as the God did that. Instead of ‘the God’, Darwin envisioned ‘nature’ did. He saw the world as struggles of survival. An environment is the field of competition. All species struggle for their survival. Competition selects a winner. No God is needed.
I assume several reasons that Darwin’s view was accepted relatively smoothly by the society, compared to other radical ideas like Galileo. One is that he is a British belonging to the British scientific community. Less dictatorship from the Catholic church authority, unlike in the mainland Europe. Second is the presence of the strong supporter, Thomas Huxley. Third, the timing. Industrial revolution and development of capitalism. The situation favoured Darwin’s view to justify the socio-economic activity at that time. Of course, there were many arguments in the early days. In the early 20th century, Mendel’s work was rediscovered, and population genetics was emerged. After that, people, including scientists, considered as Darwin’s view was scientifically validated. Since then, some minor modifications were applied. But the basic Darwin’s view of evolution, ‘natural selection’ stays holding as correct. This is one of exceptional scientific theories lasting more than a century.
I was not an exception. I have been thinking that Darwin’s view is right, until recently. Indeed, I can agree that ‘natural selection’ happens. However, I think that ‘natural selection’ does nothing for making a new species, ‘speciation’ but only works for extinction. To make ‘natural selection’ work, we need to think a niche (i.e. available resource). In addition, the essence of ‘natural selection’ is ‘competition’, not the God. To make ‘competition’ work, common rules and interests need to be set between the two competing two species. Without common rules and interests, no competition happens.
The presupposition of ‘natural selection’ is two holds. The niche is limited and there are common rules and interests. In my view ‘natural selection’ only works within one species. Within the species, everyone eats same things. My food can be others. There is a rule to find mating partners. My partner can be others. The availability of resource (i.e. food and reproductive partners) is limited. The rule should be followed if you want to reproduce with partners. Cheaters may occasionally be present but importantly, the cheaters also rely on the assumption that others follow the rule. Thus, even the cheaters are not completely outside of the rule. Because there is the rule to follow, it is possible to make the evaluation matrix for individual fitness. The matrix does not need to be one dimension but should be limited dimensions. Everyone plays the same game with the same rule. Thus, comparison is possible as well as competition. Herbert Spencer phrased this as “survival of the fittest”. The process appears to select fitter individuals in a group that plays over the limited resource under the common rules and interests.
Darwin thought that the environment sets the rule. When the environment changes, the rule will be changed in the same game. When one species spread in two distinct environmental areas geographically separated, the rules and fitness matrix in each area are different each other. The selection criteria will become different. In the neo-Darwinian theory, this is the beginning of speciation. However, from here, the neo-Darwinian theory becomes vague. Somehow at some point, one species become two by reproductive isolation. A new game diversifies from the original one. The best ones are selected in each distinct environment and eventually they play incompatible games.
Reproductive isolation is a very important concept to understand ‘speciation’. A species can be defined as a group of individual organisms sharing a pool of genetic information. Everyone inherits own genetic information for the phenotypic competition. Everyone can contribute to the genetic pool for its descendent. Reproductive isolation means two distinct genetic pools are created, no mixing between the two. This is the essential foundation of speciation. Without this, the two genetic pools in two distinct environments can be mixed back again. In the current neo-Darwinian theory, three main possibilities of reproductive isolation have been proposed. 1. Separating reproductive environments. The strictest reproductive isolation can be achieved if two species become impossible to meet, called geographical isolation. No physical contact between the two. Without this extreme separation, two distinct limited mating seasons would also work. 2. Incompatibility of male/female genitalia. Two species physically cannot mate. 3. Offspring inviability and sterility.
Something less known at the time of Darwin and the early 20th century is meiotic block. The third possibility. Darwin noticed the reproductive problem of hybrids. He knew hybrids’ sterility from breeders of various domesticated animals and plants. Some crossing of two species cannot produce off-spring at all. Even off-spring is produced, they are often sterile. He mentioned this in his book. However, it was impossible to dig deeper at that time (i.e. well before genetics, genes and DNA were discovered). Importantly, this reproductive fitness is independent from the individual fitness. Even hybrids have much better individual fitness, they have no way to produce their off spring. Darwin noticed it but could not go deeper. Subsequent people ignored that, and focused something they could deal with in mathematics, ‘natural selection’.
Why do the hybrids become infertile? Because during gametogenesis (the process leading formation of sperm/oocytes), the germ cells need to go through meiosis. Diploid cells become haploid gametes. The first step of meiosis is a pair of two homologous chromosomes find each other to align them. This is easy to say but hard to do. In humans, we have 48 chromosomes. Imagine as you are one of them and need to find your partner from other 47 chromosomes! Some mechanisms have been proposed but I’m not fully convinced by them yet. Interestingly, if there is too much difference between the pair, they do not align. The consequence is no meiosis; thus the individual becomes sterile. The positional differences like translocation and inversion are sufficient to block meiosis without massive difference in their sequence. In my knowledge it is unknown how much difference is tolerated. Some translocation and inversion are permitted but others reduce the fertility.
Richard Goldschmidt is a German scientist having strong background in genetics, morphology, epigenetics and development. He was a colleague of Hans Spemann and Otto Warburg at Berlin. He has extensive own studies on seasonal polymorphism, sexual dimorphism, and cytogenesis. In addition, I believe, the exposure of the novel concept at that time, developmental induction, from the work by Spemann and Mangold. Goldschmidt proposed a highly controversial view of evolution in his book “the material basis of evolution” in 1940. He separated the evolution into two classes, micro- and macro evolution. Microevolution happens within a species or subspecies as Darwin suggested. In modern term, ‘genetic drift’. However, macroevolution, like speciation and the emergence of a new phylum, class and family, happens sudden as reproductive isolation based on chromosomal rearrangement. Amazingly, he realized that similar morphological differences can be caused by epigenetically (based on environmental polymorphism and sexual dimorphism), genetically (mutations) and chromosomal pattern differences (distinct species). Furthermore, he recognized two distinct species having very similar morphology have distinct chromosomal patterns. He proposed that chromosomal pattern differences are the critical essential event to separate two species. Those chromosomal pattern difference can cause massive changes in morphology and physiology or no change at all. If the change modifies the early process of development, its impact in morphology will be large and cover the entire organismal level (i.e. body-plan). If the change modifies the later one, the impact is more restricted. In addition, the change in developmental processes of the area and timing would also modify their morphology. These two concepts are now called heterotrophy and heterochrony. Goldschmidt proposed all these without knowing what the gene and DNA are. Since at publication in 1940 to his death in 1958, his idea was completely disregarded, and he has been treated as an outcast scientist. For me, his idea was amazingly insightful and predicted various things correctly. Simply his idea was too early. 80 years after his book, his idea is still not appreciated. However, I think that he was correct in the most of his views (if not all).
I simply ask the readers to imagine if reproductive isolation happens at first before selection. Then, two genetic pools cannot mix anymore. This means no competition of reproductive partners. At beginning, the genetic pool size of a new species would be an extremely small compared to the original species. I think there are only two possibilities for permitting the survival of the new very minor individuals. One is having much better fitness than the original one in the same game. This would be a quite tough battle. Second is to start playing a completely different game that no old one has played. In case of food, the new one eats something uneatable for the original one. Something not recognized as food for the original species. The other possibility is the new one can tolerate in hotter/colder habitats. The one does not need to be better in fitness but simply move to the area where the old one cannot use. The point is the resource need for the new one is different from the resource for the original one. The niche can be expanded, no need of competition.
Many people cannot easily escape from the concept of ‘natural selection’. For example, Lions and Cheetahs, both eat Gazelles. People conceive this as both are a winner of competition, and they also compete each other. I do not think they are competing each other. Because they use different strategies to hunt Gazelles, the individuals within the Gazelle group they hunt are different. Like dumb ones are eaten by Lions but slow ones by Cheetahs (I just made up!). Their food resource is not overlapping. However, if the Gazelle population shrinks, their resource would start overlapping. If this happens, the competition gets initiated. However, I still do not think they are competing each other. The eatable food repertoire of individual species is unique. None is 100% identical each other. What often happens and looks competing is that one species eats something uneatable for the other but this is the upstream resource for the second species, like raw and ripe. One can eat raw but the other can only eat ripe fruits, for example. The survival resource for the second one has a higher risk. The competition within the second species happens if the resource decreases but not between the two. We often see this as invasive species taking over original local species. Often strong invasive species eat everything thus has a competitive advantage. I think they are not a fair competition at all but unfair take-over. They start taking the resource before the resource becomes usable for the original ones.
Competition does not create something new. Selection is always the consequence of competition. On the other hand, each species looks well adopted its own environment. Some explain this as the consequence of ‘natural selection’. As Goldschmidt mentioned, many traits can be modulated by epigenetics, genetics and chromosomal repatterning. If the difference is observed within one species, likely due to ‘natural selection’ or ‘genetic drift’. However, if they are two distinct species, I see the same thing in an opposite way. The main reason that they look fit to their environment is because they could occupy that niche when no one previously occupied. In other words, they gain the unique property first and then this property permits to fill the new niche where no one usable. The niche was not a usable niche before this new species emerge. Once a new species is established, ‘natural selection’ can start after the new niche reaches at a limit. After all, ‘natural selection’ is always the event within one species who play the same game with the same rule. A new species is established because they can set a new game without competing the previous ones. The niche (available resource) is not limited but keeps expanding. The new species is a game creator. A couple of scholars like Masatoshi Nei and Stuart Kauffman pointed this possibility but have not been widely appreciated.
Languages allow us to communicate with others. However, once we use certain words, sometimes other plausible possibilities are eliminated. ‘Selection’ is only possible if a niche is limited, and two species play the same game. When the niche can be expandable, ‘selection’ becomes an illusion. This is the essence of my essay. Current living species had successfully found their own open niche at their infancy. That is why they exist now and look well adopted. No preexisting species cares the emergence of a new species because they take an open niche that is not a valuable resource for them.
We observe something very similar in the current global economy. The size of the economy keeps getting bigger and new niches emerge. Some products were extinct, not because of losers of competition, but because of take-over due to unfair game changers who do not follow the original rule and invent a new game. For example, mobile pagers, blackberry and smartphones. The primary function of these products is the wireless connection between two people. However, no one would see them as the same. The new ones always have unfair additional functions and convenience. The battle between them is not a competition and but a take-over. In a unique small niche where all products are forced to take the same rule (e.g. imagine in a hospital), mobile pagers might be able to compete to others. When the niche gets limited and a common rule is set, a competition will be inevitable.
Innovation is the game changer that expands the niche and changes the rules. Innovation will expand the niche where no one previously attempts to use and no one previously recognizes any value. Making something new by ‘natural selection’ is an illusion after all. When a new species comes to the world, no competition but expanding the niche. But when the niche shrinks or overlaps with others, and competition starts. ‘Natural selection’ only works for elimination of the ones that could not change themselves to adopt the new game.
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