The evolutionary theory continues to be a vocal point for debate between the intelligent design supporters and their evolutionist opponents. The Greatest Show on Earth by Richard Dawkins (2010) represents an attempt to put forth an accessible and comprehensive message to the general public on the scientific status of the evolutionary theory and its implications. Given great relevance of the issues raised by Dawkins, it is necessary to dwell on some of them, with subsequent conclusions derived.
- Artificial selection, natural selection, and intelligent design: common features and divergences
Dawkins tries to connect the reader’s experiences with his overall argument by appealing to the common-sense examples from daily life. In this case, following Darwin himself, he compares the phenomena of artificial and natural selection, with the former being represented by a generally familiar practice of domestication (Dawkins, 2010, p.27).
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Dawkins refers to an “astonishing” power of the breeder to modify, or “sculpt” the gene pool of the respective animal or plant species. (2010, pp.28-29). He describes Mendelian insights on the importance of gene pools and gene variations for the individual animals and plants’ hereditary traits transmission. In wild nature, the decrease and/or increase in gene frequency is largely dependent on natural barriers and physical distances; however, in the case of domestic animals’ breeding, the role of such barriers are played by deliberate restrictions on cross-pedigree miscegenation instituted by human breeders (Dawkins, 2010, pp. 33).
Thus artificial selection may be operationally defined as a method of selective production of desired genetic characteristics. This selection may proceed through either simple controlled mating among the animals of specified breed, or by purposeful crossbreeding and the inheritance of major genetic mutations, supervised by the breeders (Dawkins, 2010, pp. 34-36). For instance, in reviewing the domestic dogs’ artificial selection history, Dawkins refers to Huxley’s (1942) observations on the impact of the breeders’ efforts on the genetic inheritance of different body parts’ growth rates in domestic dogs. In this way, widely diverse breeds of the same species have been selectively bred, ranging from the pug to the borzoi (Dawkins, 2010, p.36). R. Coppinger & L. Coppinger’s (2001) findings referred to by Dawkins likewise testify to the great importance of the breeders’ selection choices in shaping the majority of modern dog breeds.
Therefore, natural selection process may be regarded as a random-based prototype for the same processes implemented in the course of artificial selection. The main distinction between artificial and natural selection, therefore, lies in the absence of a deliberate choosing agent in the latter case, as the preservation and passing-on of attractive genes is carried out by randomized survival-or-failure natural mechanism (Dawkins, 2010, p.62). The survivors in natural struggle for life resources are sure to replicate their genes in the successive population, thereby passing their genes on “making superior [natural] equipment for survival and reproduction” on their progeny (Dawkins, 2010, p.63). The angler fish example mentioned by Dawkins may serve as introduction in the complexities of natural selection, with those angler fish that possess longer and more prominent ilicium (i.e. a rudiment fin emitting natural light) to lure their prey being more likely to transfer and spread their genes across the total gene pool of the species (Williams, 1992, p.77-78).
In contrast, intelligent design assumptions and theories proceed from the rejection of an idea of randomized natural selection. Instead, the proponents of the intelligent design notion assert that the Neo-Darwinist evolutionist theory cannot account for unusual behavioral modifications leading to qualitatively new biological changes (as in the aforementioned case of the angler fish’s transition from chasing the prey to luring it by light; Thomas, 2011, p. 268). The intelligent design theorists and supporters view the process of species’ changes in the course of biological history as guided by the intelligent development principle, usually characterized as some form of the divine or the absolute. While the minority of intelligent designers may view biological transformations as directly supervised by this ‘designer’, the majority thereof accept conventional scientific explanations for biological processes’ causes, yet assert the existence of certain hidden reasons behind them (Thomas, 2011).
Thus, the intelligent design theories basically attribute the qualities of a choosing agent to nature, extrapolating methods and motivations guiding human selection breeders in artificial selection processes. While this explanation for the intelligent design theories’ development helps conceptualize its appeal to the public, it is still unfalsifiable (i.e. may not be either verified or rejected; DeWitt, 2010), and thus cannot be compared to natural selection theories.
- Evolutionary theory and temporal sequence of the species
The famous observation of Dawkins on evolutionary scientists as “detectives who come late to the scene of a crime” (2010, p.85) is directly connected with the peculiarities of time sequence measurements in paleontology and evolutionary biology. Several types of time sequence measurements are described by Dawkins. Generally they may range from the short-range ones (tree rings and carbon-14 half-life analysis measurement) to long-range radioactive clocks such as the one based on potassium-40 to argon-40 radioactive decay (a potassium/argon clock; Dawkins, 2010, pp.96-104).
While dendrochronology and carbon dating may be used to identify shorter time sequences (within the range of dozens of thousands years), radioactive clocks based on estimation of the respective isotopes’ half-life in igneous rocks are considered by Dawkins to enable the researchers to trace the temporal sequence of the species the remains whereof are found at the same geological layer with these igneous rocks (Dawkins, 2010, pp. 99-101). By identifying respective geological strata of sedentary rocks, it is then possible to use a potassium/argon or a similar radioactive clock to pinpoint the time (within the limits of an appropriate statistical error) of the fossil deposits found in these strata. For instance, while it was known for a long time that Devonian geological period was followed by Carboniferous one, it was only with the introduction of radioactive time measurement that the exact time frames for both periods could be established (Dawkins, 2010, p.101).
Therefore, the process of a species’ time sequence attribution essentially consists of two stages: that of locating the fossils representative of this species in the appropriate sedentary rocks layer (thus establishing a qualitative temporal sequence), and then using radioactive isotope analysis to identify the approximate time period that has lapsed between the present time and the fossil’s depositing. Thus both the approximate sequence of prevalent species (i.e. from trilobites to modern mammals) and the temporal eras they thrived in may be determined by scientists.
- Evidence for continuing speciation
One of the main claims offered by the creationists as a response to evolutionary theorists is that the new species’ differentiation (also known as speciation) supposedly ceased to occur after the act of creation. Dawkins goes to great lengths in dispelling such concepts, using the evidence of the speciation processes that either occurred as recently as several centuries ago or are observed in biological laboratories at the moment.
Of particular interest is the example of rapid speciation among cichlid fishes of Lake Malawi and Lake Victoria that took place in recent geological period (i.e. less than 17,000 years ago in the case of Lake Victoria and supposedly after the late 18th century in the case of Lake Malawi; Dawkins, 2010, p.267). Here the isolated species of cichlid fishes evolved in a peculiar ecosystem, acquiring genetic characteristics sharply differentiating them from their former mother species. In particular, the case of Lake Malawi cichlid fishes demonstrates how the new species may emerge in the relatively insignificant amount of time if the specimens from mother species are isolated from the latter’s main genetic pool and confront unique environmental challenges.
Similarly, the case of Galapagos Islands, with their species of animals that appear to have diverged from their continental mother species relatively recently, demonstrates the potential for rapid speciation presented by geographical isolation factors (Dawkins, 2010, pp.260-262). In addition, Dawkins refers to Coyne & Orr’s (2004) authoritative research on speciation, with the focus on biogeographical factors influencing this form of evolutionary process. The evidence presented therein further corroborates the idea of continuing speciation, thus offering an additional argument in favor of evolutionary theory.
- Evolutionary mistakes’ correction
Dawkins’s notion of evolution “correcting an initial ‘mistake’ or historical relic by post hoc compensation or tweaking” (2010, p.341) may be taken as a reference to various secondary adaptations of the species evolving in the course of major changes in their environmental situation. The very example of dolphin’s altered nostril apparatus, presented by Dawkins in the same paragraph, makes it certain that evolution continuously ‘builds’ on the previous foundations of a species, instead of changing its physiological structure from scratch. In Dawkins’s judgment, if nature were an intelligent designer, in case of dolphins, it would “abolish lungs and go for gills” without bothering for introducing subsequent minor tweaks and improvements, or changing the whole species from terrestrial to aquatic-adapted (Dawkins, 2010, p.341).
Other examples presented by Dawkins to this end include whales possessing rudimental pelvic girdle and hind legs bones; sirenians (dugongs and manatees) that are equipped with double diaphragm and special buoyancy mechanism; ostriches, penguins and other wingless birds that either lacked fly capacity from the very outset (kiwis) or lost it in the course of the species’ evolution; and various species of blind animals (Dawkins, 2010, pp.341-355). All these species had to tweak themselves from their original physiological structure in the course of naturally selected adaptation to their new surroundings. Thus they were far from being ‘perfectly designed’ in the first place.
Moreover, the species that are supposedly well adapted to their present surroundings may be characterized by significant ‘research flaws’, prompting Dawkins to use a term ‘unintelligent design’ to denote these instances of evolutionary deficiencies (Dawkins, 2010, p.368). In particular, such a feature of the mammals’ nervous system as recurrent laryngeal nerve is considered by Dawkins to be a significant natural selection failure, with one of its branches charting a distinctively irrational path of going through chest and near one of major arteries back to the neck, and only then to its original destination (Dawkins, 2010, p.356). This phenomenon clearly contradicts the notion of a rationally designed human (and animal) body, contributing to Dawkins’s defense of a randomized natural selection’s actuality.
- Dawkins’s impact on my understanding of evolutionary theory
On reading the book under consideration, I have become much better acquainted with various aspects and intricacies of modern evolutionary biology. While previously I have a rather crude idea of the relationship between Darwinist natural selection theory and modern synthetic evolution theory that incorporates the insights of genetics, now I am able to grasp the importance of genetic heritage factors in evolutionary process. The discussion of speciation issues has been likewise of enormous assistance, as it helped me visualize the evolutionary processes that are still ongoing in our current natural world.
Furthermore, Dawkins’s passionate yet good-intentional defense of his scientific convictions accorded him a great deal of respect in my eyes. I believe that such individuals as Dawkins may contribute a lot to the public understanding of complicated scientific issues, dispelling common misconceptions and prejudices connected therewith.
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