7. The change or trait must not affect an individual's reproductive ability. If there is no reproduction, there is no natural selection, hence no Darwinian Evolution.
Not true With the ambiguity in the definitions of the concept of species notwithstanding, even when species have diverged, reproduction between species is still possible. Only when sufficient genetic differences between two species have grown wide enough, that is, a wide enough divergence down the evolutionary path, is reproduction prohibitive. The assertion that H. sapiens (and/or H. sapiens sapiens) could not have interbred with H. erectus, because they are different species is invalid. If they could have produced fertile offspring, then they weren't really different species. These fairly common misconceptions proceed from a misunderstanding of the 'biological species concept', which makes species distinctions based on fertility. There is NO criterion that says (as is commonly believed) that if two populations can interbreed they are the SAME species. There is NO criterion that says that two distinct species CAN'T interbreed. Consider the example of wolves, coyotes and dogs: three distinct species that can interbreed. In fact, all species of the genus Canis can mate and produce fertile offspring. The word species, however, is sometimes used simply as a name for a morphologically distinguishable form. This is especially true in paleontology, in which a single evolving lineage (gene pool) may be assigned several names for successive, phenotypically different forms. For example, Homo erectus and Homo sapiens are names for different, distinguishable stages in the same evolving lineage. They are chrono-species, rather than separate biological species. The two species names do not imply that speciation (bifurcation into two gene pools) occurred: in fact it probably did not in this case. Genetic studies have shown, erectus could interbreed with sapiens: Note, however, that some people also say erectus was a distinct taxon. In fact, Rightmire, a recognized expert on erectus, says (The Evolution of Homo Erectus, Cambridge, 1990) they were a distinct species It is interesting to see why there is disagreement on the subject. Wolpoff, and others, compare the early African and Asian skulls with the most modern ones and show that there was an increase in cranial capacity, and a morphological tendency toward some sapiens characteristics. BUT, those recent skulls are the very ones are hybrid specimens! Rightmire excludes the late, Southeast Asian skulls from Ngandong for very good reasons, and shows that the rest of the series reveals no statistically significant development toward becoming modern human. That is even with including later, African skulls that show some interbreeding with sapiens radiating out of Eurasia. When you get up to the recent African material, which shows significant sapiens influence, the afrocentrists claim those aren't erectus, but 'early sapiens'. For instance, they call the Herto skulls H. sapiens idaltu. A final consideration is the distinguishing characteristics that differentiate the various Homo species. If they were separated by potentially incompatible mutations, then there might have been diminished fertility between those species. However, it appears they have been distinguished by neoteny: ancestral forms were succeeded by juvenilized versions of themselves. While the effects of neoteny (such as increased intelligence, delayed maturation, progressive gracilization, and a diminution of some ancestral-adult characteristics) may be profound, the genetic changes are subtle. There seems to be little or no impediment to fertility, as the new type must have been fertile with the parent species in order to survive. Accordingly, the entire genus Homo has probably been inter-fertile, just as the genus Canis is. On Fri, Aug 3, 2012 at 8:27 AM, Jojo Jaro <jth...@hotmail.com> wrote: > ** > Hello gang, > > In honor of my bet with Terry, this is my first post on the Fallacies of > Darwinian Evolution. Before I continue, I would like to lay the ground > work and define a few basic terms that we will be using in my series of > posts. Hopefully, people read this post so that I do not have to redefine > my terms repeatedly. I do hope Jed engages me in a Debate between > Darwinian Evolution and Intelligent Design. Maybe I'll learn something. I > hope that if you decide to engage in this discussion, that you would keep > the exchange civil. I will not initiate an Ad hominem attack unless > attacked first. Let's discuss your ideas and why you absolutely believe in > Darwinian Evolution and I'll discuss my belief in Intelligent Design. But > if you want to exchange insults, I can surely accomodate you. > > What is Darwinian Evolution? > > Darwinian Evolution is the theory of evolution espoused by Charles Darwin > in his book "The Origin of Species". Later he wrote "The Descent of Man" > specifically to address man's evolution from lower life forms. The basic > Tenet of Darwinian Evolution is a random mutation process that results in > "features" that allow an individual animal or plant life to survive a > stress in its environment. When it survives, it passes down this "Trait" > to its progeny thereby allowing its progeny to successfully live in this > new stressful environment thereby passing this trait down to its progeny > also. The trait enables the individual to survive hence the term "Survival > of the Fittest", or "Natural Selection". Darwin then takes this idea of > Natural Selection one step further and hypothesizes that this natural > selection process is the means by which variouis species emerge. Hence > species A mutates, survives, passes on its traits, then after several > generations. becomes another species B - hence the term "The origin of > Species". The nature or origin or mechanism of the mutation was unknown > to Darwin. DNA was not discovered in his lifetime. > > Darwinian Evolution presupposes that the mutation or the change is small, > and the mutation process in passed down only via the mechanism of natural > selection. In other words, a new trait must not be so complex and the > change so huge as to cause people to suspect that there might be some > directed process, or an Intelligence causing the change; other than > natural selection that would cause the change. In other words, Darwinian > Evolution says that it is impossible to evolve a complex organ like a fully > developed human eye in a single generation. The development of a complex > organ must take place slowly, one minor change at a time, one minor change > per generation. This also implies that the minor changes must be > commulative, or additive. One small minor change within each generation > that adds up generation after generation until it becomes an organ as > complex as an eye. > > Darwinian Evolution implies the following: > > 1. The change must be small and minor and slow in an individual. The > mutation results in a small change or small feature. If the change is big, > there must be some other mechanism or directed Intelligence behind that > change. Darwin recognized this and said so in his book. > > 2. The change or the new trait or feature must confer to that individual > a survival advantage. Otherwise, that useful trait will simply die with > that individual. A trait that may be useful but does not confer a survival > advantage is a trait that does not result in natural selection hence > Darwinian Evolution is NOT in operation here. > > 3. The trait must not cause any impairment or susceptibility to the > individual. In other words, a trait that confer an increased survival > advantage but also causes an increased susceptibility to some other > stress will not result in natural selection. For example, a trait that > results in an individual to survive a drought in food must not make that > same individual be more susceptible to Cold weather. If it does, the > chances of the trait being sucessfully passed down commulatively generation > after generation is minimized and the survival of that individual will not > be any better statistically compared to another individual without that > mutated trait. > > 4. The trait or change must be permanent. In other words, the change > must not revert back or disappear once the stress is removed. If it does, > it will not be additive and hence can not result in a complex organ like an > eye. This will result in natural selection only for a few generations and > then that advantage dissappears and other individuals can compete again > which will result in a dilution of that trait in the general population. > > 5. Each successive additive change must confer a survival advantage each > and every step until a complex organ results. To illustrate, lets say it > takes 5 steps to develop an eye. Change A, Change B, Change C, Change D > and Change E results in a fully developed eye. (I am using only 5 steps to > simplify the discussion. In reality, the steps required to develop a human > eye requires billions of steps.) Change A must confer a survival > advantage to the individual. An additive change B is added to change A > that results in his children having a survival advantage also. Change C is > added and must also confer a survival advantage to his grandchildren. > Change D must also confer a survival advantage to his great grandchildren > and change E results in a fully developed eye conferring a survival > advantage also. Each additive change must confer a survival advantage for > natural selection to work. If only one step in the chain does not confer a > sruvival advantage, the entire series of changes previous to the change > could be lost when that individual does not outperform the rest of the > population. All the hard work and useful changes will simply be diluted in > the population again. Natural selection is broken and a complex organ can > not develop. > > 6. The evolution process occurs and operates over many generations. An > evolution or mutation that occurs in one individual is NOT Darwinian > Evolution, since no Natural selection is in operation. > > 7. The change or trait must not affect an individual's reproductive > ability. If there is no reproduction, there is no natural selection, hence > no Darwinian Evolution. > > 8. The change must have a random mechanism. If the cause of the change > is not random, that evolution is NOT Darwinian Evolution by definition. > > 9. Natural Selection is the only mechanism that will differentiate one > change from another change. In other words, within an individual we can > not say a change is useful or not, until it enables that individual to have > a survival advantage. Hence, natural selection operates between > generations, not within a single generation. There is not natural > selection process within a generation or within an individual. Natural > selection can not be invoked within a generation to explain what mutation > is useful and what is not useful. A process that operates within a > generation is NOT natural selection. A process that does not confer a > survival advantage is NOT natural selection. Survival is the criteria for > natural selection. An individual has no mechanism wherein it can decide > which change to retain or to not retain. The change is retained and acts > only if the individual survives. I can not emphasize this enough. > > 10. The change must enable the individual to "outsurvive" other > individuals in his group. It is not enough to merely allow the individual > to survive, but it must cause that individual to "outsurvive" others. If > it is not outsurviving other individuals, the change will merely get > diluted in the gene pool and lost. > > > In the next post, I will define the difference between Microevolution (aka > Adaptation) and Macroevolution (aka Darwinian Evolution). > > > Enjoy > > Jojo > > >
