15 Answers to John Rennie and Scientific American’s Nonsense--Argument #11
||Bert Thompson, Ph.D.
Brad Harrub, Ph.D.
11. [Creationists suggest that] natural selection might explain microevolution, but it cannot explain the origin of new species and higher orders of life.
Mr. Rennie wrote:
Evolutionary biologists have written extensively about how natural selection could produce new species. For instance, in the model called allopatry, developed by Ernst Mayr of Harvard University, if a population of organisms were isolated from the rest of its species by geographical boundaries, it might be subjected to different selective pressures. Changes would accumulate in the isolated population. If those changes became so significant that the splinter group could not or routinely would not breed with the original stock, then the splinter group would be reproductively isolated and on its way toward becoming a new species (2002, 287:82, emp. in orig.).
In section 2 of this review, we dealt at great length with the concept of natural selection, and so we will not repeat that information here. But we would like to point out that Mr. Rennie has done nothing more than create and then tear down a “straw man” in a feeble-but-failed attempt to make his own position look better. Creationists have no problem whatsoever with the creation of a species. As creationist Bill Hoesch correctly pointed out:
A new population of creatures that has lost its will or ability to reproduce with its parent population (i.e., a new species) is no problem for the creationist. It would represent a loss of function, not a gain. Such change does nothing to establish the truth of macroevolution, for the traits that typify the new population were also a part of the original gene pool. Nothing new is created, in other words (2002).
Furthermore, the definition of a biological species is controversial at best, and poorly understood at worst. In his 2001 seminal work, What Evolution Is, Ernst Mayr—arguably the most eminent taxonomist in the world—plainly admitted as much when he wrote:
Obviously one cannot study the origin of gaps between species unless one understands what species are. But naturalists have had a terrible time trying to reach a consensus on this point. In their writings this is referred to as “the species problem.” Even at present there is not yet unanimity on the definition of species (p. 163, emp. added).
Mayr then went on to note:
Taxonomists finally came to the conclusion that they had to develop a new species concept, not based on difference but on some other criterion. Their new concept was based on two observations: (1) species are composed of populations, and (2) populations are conspecific if they successfully interbreed with each other. This reasoning resulted in the so-called biological species concept (BSC): “Species are groups of interbreeding natural populations that are reproductively isolated from other such groups” (p. 166, emp. and parenthetical item in orig.; see also Gee, 1999, p. 124).
Geneticist Theodosius Dobzhansky echoed the widely accepted definition of a species when he said that a species is “a group of individuals fully fertile inter se [among themselves—BT/BH], but barred from interbreeding with other similar groups by its physiological properties (producing either incompatibility of parents, or sterility of the hybrids, or both)” [see Schwartz, 1999, pp. 285-286, parenthetical item in orig.]. In his 2001 book, The Evolutionists: The Struggle for Darwin’s Soul, Richard Morris commented:
The most common definition of the term “species” is this: a population that is reproductively isolated from other, related species. If two populations do not interbreed or do not produce fertile offspring when they do, they are said to be distinct species (p. 40).
In his 2002 book, From Genesis to Genetics, evolutionist John A. Moore stated:
Thus, the individuals of a species are usually part of a single potentially interbreeding unit, usually do not interbreed with individuals of another species, are usually distinguishable on the basis of external characteristics and behavior patterns, and are usually found in a restricted geographic area where all individuals can, in theory, meet all other individuals of the same interbreeding unit (p. 134, emp. in orig.).
Why the hedging? The reason is that in “real life,” species do not fall into neatly nested categories. Dogs, jackals, coyotes, wolves, hyenas, and dingoes are all separate, distinct species. But they also frequently can interbreed—which they should not be able to do if the above definitions are legitimate. In fact, Moore alluded to this very fact when he said:
On the other hand, the ability of two populations to interbreed under natural conditions does not mean that they are always recognized as a single species. A notable example is lions and tigers. They can be crossed in captivity, and depending on the direction of the cross, the offspring are ligers (male lion and female tiger) or tiglons (male tiger and female lion) [p. 134, parenthetical items in orig.].
In his book, In Search of Deep Time, Henry Gee made a fascinating observation along these same lines. Read carefully.
To classical thinkers, the concept of species was not at all problematic. Each species was represented by an archetype, represented by a collection of more or less varied instances. Whether Dalmatian or Doberman, retriver or Rottweiler, a dog is a dog because it is an instance of an archetype. A dog will always be different from a wolf, say, or a jackal, which will have their own distinct archetypes.
But if variation is the substrate of evolution, and if the individuals and populations that constitute a species can vary so much that they can evolve by infinitesimal stages into other species, it becomes very difficult to define a species in such an unequivocal way, based solely on the appearance of the individuals within it. If species do not change, a dog is a dog no matter how strange an individual dog might look. But if species can change, it is possible that some dogs represent evolutionary stages between dogs and other things, such as wolves or jackals. Defining what is meant by “dog” in that sense becomes difficult, and sometimes arbitrary (1999, p. 124).
Species do change. Creationists and evolutionists both agree on that point. Evolutionists suggest, however, as did Moore, that “if species can change, it is possible that some dogs represent evolutionary stages between dogs and other things, such as wolves or jackals.” Creationists, on the other hand, suggest that the original dog family very likely may have included the potential for producing the more than 200 different breeds of domestic dogs, the Australian dingoes, coyotes, wolves, jackals, foxes, and maybe even hyenas, even though these animals now are classified as different species. As Walter Kaiser commented:
God created the basic forms of life called min [kind—BT/BH] which can be classified according to modern biologists and zoologists as sometimes species, sometimes genus, sometimes family or order. This gives no support to the classical evolutionist view which requires developments across kingdom, phyla, and classes (1980, 1:503-504).
Natural selection works to weed out the unfit, true. But there certainly is nothing inherent in the concept to empower it to produce a genus, a family, a class, or an order. When pressed, even evolutionists admit as much.