sexta-feira, 9 de março de 2012
Evolution, micro and macroevolution, the big scene...
Speciation, what is it?
"...Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or "cladogenesis," as opposed to "anagenesis" or "phyletic evolution" occurring within lineages. Whether genetic drift is a minor or major contributor to speciation is the subject matter of much ongoing discussion...": http://en.wikipedia.org/wiki/Speciation
There are four geographic modes of speciation in nature, based on the extent to which speciating populations are geographically isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry or laboratory experiments. Observed examples of each kind of speciation are provided throughout.
The following link from a website shows just how difficult it is to talk about “speciation”, when defining a species or what a species is supposed to be, is by itself a hard task…http://www.mansfield.ohio-state.edu/~sabedon/biol1515.htm
“…So what is the best way to define a species?
Most scientists feel that the biological species concept should be kept, but with some qualifications. It can only be used with living species, and cannot always be applied to species that do not live in the same place. The real test applies to species that have the potential to interbreed…” http://www.globalchange.umich.edu/globalchange1/current/lectures/speciation/speciation.html
What?! If we define it this way that what would an hybrid be? A mule could be considered a new species? But a mule can’t reproduce and make other mules like mom, specially (let me be ironic here) because they could turn out looking like dad…
The article goes on…
“…Prezygotic isolating mechanisms
Ecological isolation: Species occupy different habitats. The lion and tiger overlapped in India until 150 years ago, but the lion lived in open grassland and the tiger in forest. Consequently, the two species did not hybridize in nature (although they sometimes do in zoos)…”
If tough similar a tiger and a lioness dot not interbreed in nature but in zoos, where their natural behaviors are conditioned, coarcted by unnatural circumstances why would, like some scientists say these days, a hominid ancestor hybridize with an ape? Yes…they do say it… http://www.livescience.com/783-human-chimp-ancestors-interbred.html
With other female hominids around why on Earth would a male hominid mate with a chimpanzee ancestor? It would be as strange as it would be in nature to see a lioness “falling in love” with a tiger all of a sudden…
Of course you might say that there have always been perverts capable of having sex or raping just about any creature, but there is one small detail that is missing there: if human rapes a monkey he is still human…homo sapiens. If any offspring comes out the genes would eventually “clear up” de mistake, the “accident” in few generations not configuring a speciation because the offspring would still live and breed with monkeys as “life goes on“…
“…Speciation as a Gradual Process
Our understanding of speciation arising from reproductive isolation and the gradual evolution of reproductive isolating mechanisms should help us to appreciate why the biological species concept, and the test of reproductive isolation, may sometimes fail.
If speciation is a gradual process, species may not yet be fully separated. A continuum must exist from species that are in the process of splitting into two, to species that are fully formed. Surely we only expect the latter to behave as "good species."
Alternative Models of Species Formation -- Hybridization and Polyploidy
In plants, new, reproductively isolated species may arise instantaneously, due to multiplication of the entire complement of chromosomes by a process known as polyploidy. This may occur as a result of hybridization, combining the chromosome sets from two parent species in a hybrid individual. If such hybrids turn out to be well adapted to environmental conditions, hybridization is a mechanism that produces new species.
Even if hybrids are unable to undergo sexual reproduction because their chromosomes do not sort out properly in meiosis, they may reproduce vegetatively…” : this might be true for a plant but a little difficult for a mammal with unique characteristics.
Unless you force it: “… The second type of hybrid consists of crosses between populations, breeds or cultivars within a single species. This meaning is often used in plant and animal breeding, where hybrids are commonly produced and selected because they have desirable characteristics not found or inconsistently present in the parent individuals or populations. This flow of genetic material between populations or races is often called hybridization…number of conditions exist that limit the success of hybridization, the most obvious is great genetic diversity between most species. But in animals and plants that are more closely related hybridization barriers can include morphological differences, differing times of fertility, mating behaviors and cues, physiological rejection of sperm cells or the developing embryo. In plants, barriers to hybridization include blooming period differences, different pollinator vectors, inhibition of pollen tube growth, somatoplastic sterility, cytoplasmic-genic male sterility and structural differences of the chromosomes…”
Other interesting approaches: “…Let's now look at the talkorigins site and study the article titled "Observed Instances of Speciation" of one species evolving into a "new" and "distinct" species. The article is broken into five parts: 1. Acknowledgments, 2. Definitions, 3. Context, 4. How to tell if speciation has occurred, and finally, 5. "Observed instances of speciation."
The writer begins Part 5 with, "Observed Instances of Speciation. The following are several examples of observations of speciation."3 However, at the beginning of the article he gives an important qualification. He says, "Part 5 describes a number of observed speciation events and several experiments which (in my opinion) failed to produce speciation." Huh? His evidence for observed speciation doesn't exist? So if they aren't examples of "observed speciation," why are they listed as "Observed Instances of Speciation." It's because there isn't any. He even pleads for evidence: "If you know of observations that I should include, let me know and I will chase down the reference, read it and modify the file."4 Here is one example he gives of speciation that he says isn't an example of speciation:
"The Russian cytologist Karpchenko (1927, 1928) crossed the radish, Raphanus sativus, with the cabbage, Brassica oleracea."5 The scientist crossed a radish with a cabbage. He crossed two vegetables. This is given as an example of observed speciation of one species evolving into another species. No wonder the author disassociates himself with this "evidence." This has nothing to do with evolution. Crossing different types of vegetables is common and is done with fruit, dogs, beetles, worms, bacteria, and cats. Remember the Encyclopedia Britannica definition of "speciation" is "the formation of new and distinct species in the course of evolution." There is no new species when a vegetable produces a vegetable. There is no speciation. This is just another example of evolutionary smoke and mirrors to deceive the simple.
But Talkorigins has more evidence, in another article titled: "Some More Observed Speciation Events."6 This is written by James Meritt. He says,
"Someone writes: I have a friend who says since we have never seen a species actually split into two different species during recorded history that he has trouble believing in the theory of evolution. Is this bogus and have humans seen animals bred into different species? (The various highly bred English dogs come to mind but I suppose this would be easier to find in vegetation. Corn, wheat strains? Donkeys and mules? ) This is bogus. We've seen it happen naturally without our tampering with the process."
Then he gives examples of this observable evidence of speciation:
"Three species of wildflowers called goatsbeards were introduced to the United States from Europe shortly after the turn of the century. Within a few decades their populations expanded and began to encounter one another in the American West. Whenever mixed populations occurred, the specied interbred (hybridizing) producing sterile hybrid offspring. Suddenly, in the late forties two new species of goatsbeard appeared near Pullman, Washington. Although the new species were similar in appearance to the hybrids, they produced fertile offspring. The evolutionary process had created a separate species that could reproduce but not mate with the goatsbeard plants from which it had evolved."
He points to an experiment from the 1940's in which a windflowers produced wildflowers that "were similar in appearance to the hybrids." They were still wildflowers. Once again no evolution has taken place. There is no new species. Remember that speciation is "the formation of new and distinct species in the course of evolution." Speciation has never been observed…” http://www.pulltheplugonatheism.com/art18.shtml
And it is not just me saying, it is even a website on evolutionism news…
There you can read this on speciation: “…Theoretically, reproductive barriers arise when geographically separated populations diverge genetically. But Coyne describes five "cases of real-time speciation" that involve a different mechanism: chromosome doubling, or "polyploidy."43 This usually follows hybridization between two existing plant species. Most hybrids are sterile because their mismatched chromosomes can't separate properly to produce fertile pollen and ovaries; occasionally, however, the chromosomes in a hybrid spontaneously double, producing two perfectly matched sets and making reproduction possible.
The result is a fertile plant that is reproductively isolated from the two parents -- a new species, according to the BSC.
But speciation by polyploidy ("secondary speciation") has been observed only in plants. It does not provide evidence for Darwin's theory that species originate through natural selection, nor for the neo-Darwinian theory of speciation by geographic separation and genetic divergence. Indeed, according to evolutionary biologist Douglas J. Futuyma, polyploidy "does not confer major new morphological characteristics... [and] does not cause the evolution of new genera" or higher levels in the biological hierarchy…So secondary speciation does not solve Darwin's problem. Only primary speciation -- the splitting of one species into two by natural selection -- would be capable of producing the branching-tree pattern of Darwinian evolution. But no one has ever observed primary speciation. Evolution's smoking gun has never been found…”
“…"speciation would require a new creature so different as to be unable to breed with its parent species. This has never been observed in the lab or in the fossil record." Im must add here that even two birds. male and female, in a cage all alone, no other choices for mates, can still refuse to mate with each other and even bite each other initially tough hormones will or might come to plea for both to mate.
Speciation HAS been observed in the laboratory, regarding fossil records- they are not the best methods by which to determine if speciation has occurred or not. For speciation to occur, you don't need to be so different from the parent species…”
The Mariana Mallard was, perhaps hastily, considered at first an extremely rare example of non vegetal (therefore mammal) example of speciation but…
“…After Salvadori, most taxonomists, such as Dean Amadon and Ernst Mayr, considered it a subspecies of the Mallard. Yoshimaro Yamashina examined those specimens in Japanese museums in 1948, and decided that the Mariana Mallard was an example of hybrid speciation, and was descended from the Mallard and the Pacific Black Duck's Palau subspecies (Anas superciliosa pelewensis). However, no molecular genetic evidence is available to support this hypothesis. Some scientists, such as Jean Delacour, have considered the Mariana Mallard a simple hybrid, so it was absent from Delacour's four-volume monograph on the ducks and from the IUCN Red List. If Yamashina's hypothesis is correct, the Mariana Mallard would have presumably evolved into near species status in only about ten thousand years.
Neither Mariana Mallards nor their progenitor species are known from fossils on the Marianas, casting into doubt the assumption that a resident Black Duck population had been long established on the islands. However, most rock shelters and caves on the Marianas were obliterated in the 1944 Battle of Guam. A species of flightless duck is known from a prehistoric bone found on Rota in 1994; was apparently not closely related to the Mariana Mallard…” http://en.wikipedia.org/wiki/Mariana_Mallard
The Madeira island mice… “…
Amusing article: 500 years and they are still mice. Where is the speedometer? And, what part of those mice are no longer mice?…” http://evolutionlist.blogspot.com/2006/11/island-mice-may-evolve-faster-from-one.html
In few words, a participant in this blog said it all: the so called speciation of the Madeira island mice did not turn the mice into anything else but a mice… It is almost the same as saying that an island where all men and women have big hears no longer have men and women but a new species… they are still man and women. If mankind divides itself in different races are those races different species or still human beings? Human beings they are off course. So where is the big loop in 500 years? A couple of genetic mutations and/or well succeeded adaptations turned mice into something else? Was it as easy as an ape turning into a human being as we know it today, or homo sapiens?
But of course there are new developments in the island mice controversy:
“…The chromosomal radiation of the house mouse in the island of Madeira most likely involved a human-mediated colonization event followed by within-island geographical isolation and recurrent episodes of genetic drift. The genetic signature of such processes was assessed by an allozyme analysis of the chromosomal races from Madeira. No trace of a decrease in diversity was observed suggesting the possibility of large founder or bottleneck sizes, multiple introductions and/or a high post-colonization expansion rate. The Madeira populations were more closely related to those of Portugal than to other continental regions, in agreement with the documented human colonization of the island. Such a Portuguese origin contrasts with a study indicating a north European source of the mitochondrial haplotypes present in the Madeira mice. This apparent discrepancy may be resolved if not one but two colonization events took place, an initial north European introduction followed by a later one from Portugal. Asymmetrical reproduction between these mice would have resulted in a maternal north European signature with a nuclear Portuguese genome. The extensive chromosomal divergence of the races in Madeira is expected to contribute to their genic divergence. However, there was no significant correlation between chromosomal and allozyme distances. This low apparent chromosomal impact on genic differentiation may be related to the short time since the onset of karyotypic divergence, as the strength of the chromosomal barrier will become significant only at later stages…” http://www.nature.com/hdy/journal/v99/n4/full/6801021a.html
There is even a legend supporting it…
There is also a romantic tale of two lovers, Robert Machim and Anna d'Arfet, during the reign of King Edward III of England, who, fleeing from England to France in 1346, were driven off their course by a violent storm. Their ship crashed along the coast of an island, that may have been Madeira; later, this story would be used in the naming of Machico, whose name was transliterated from the name of the boy in the tale, in memory of the young lovers…Madeira was re-discovered by Portuguese sailors in the service of Infante D. Henrique (Henry the Navigator) in 1419, and settled after 1420. The archipelago is considered to be the first territorial discovery of the exploratory period of the Portuguese Age of Discovery.”
(Correspondence: Dr J Britton-Davidian, Institut des Sciences de l'Evolution, UMR 5554, Laboratoire Génétique et Environnement, CC65, Université Montpellier II, 34095 Montpellier Cedex 5, France. E-mail: email@example.com)
So what could have happened would be something like the heat in Africa did for the africans: their skin is black to protect from hard sun. But they are still human…the nose is human, the mouth, the eyes, everything: that is of course something that all human races have in common: made at God’s resemblance? So God allowed the “initial model” to evolve or did God create all races just as they are today?
Is adapting really changing?
“…But creationists point out that the biblical ‘kind’ is larger than one of today’s ‘species.’ Each of the original kinds was created with a vast amount of information. God made sure that the original creatures had enough variety in their genetic information so that their descendants could adapt to a wide variety of environments.
Based on the biblical criterion for kinds, creationists have made several deductions about the modern descendants of the original creations. They deduce, for example, that as long as two modern creatures can hybridize with true fertilization, the two creatures are descended from the same kind.3 Also, if two creatures can hybridize with the same third creature, they are all members of the same kind.4 The hybridization criterion is a valid operational definition, which could in principle enable researchers to list all the kinds. The implication is one-way—hybridization is evidence that two creatures are the same kind, but it does not necessarily follow that if hybridization cannot occur then they are not members of the same kind (failure to hybridize could be due to degenerative mutations). After all, there are couples who can’t have children, and we don’t classify them as a different species, let alone a different kind…”
Some put it in a very amusing point of view:
“…Noor looked at the fruit flies Drosophila pseudoobscura and D. persimilis. In the lab, he can get a female D. pseudoobscura to mate and produce some fertile offspring with a male D. persimilis. Out in the world, however, it doesn’t happen—she hates his smell, his song, his mating dance.
So here’s the idea you’ve been patiently waiting for: let’s simply say that dog breeds are different species. Take two that Coyne highlights for their differences—the 180-pound English Mastiff and the two-pound Chihuahua. They’re both considered members of Canis lupus familiaris, and in principle artificial insemination could produce some sort of mix or possibly an exploding Chihuahua. But face it, the only shot a male Chihuahua has with a female Mastiff involves rock climbing or spelunking equipment…” : http://www.scientificamerican.com/article.cfm?id=an-immodest-proposal
This particular link sort of resumes it all:
I read an article a while back where they found a skull that pushed it back to 1 m, but you know that has to go through scrutiny. Did anyone else read that? Who knows for sure?
I think it goes back to gamila's issue also--what is a species? Theoretically, couldn't a chimp and another ape cross breed and "speciate." Sorry I just have a problem with the mechanics of the speciation theory, when it comes to the creation of entirely new orders of organisms. I have no problem with speciation within families of organisms. This kind of "speciation" is observable.
If two populations separate, there would have to be a mass simultaneous mutation in the population to root out the originals and create another family or order of organisms. Or EVEN if you have only a male and female who get separated from the pack geographically, think of the process that would ensue in order to produce a new order. If one mutates with a dominant trait, then the recessive trait will still show in the offspring, and as modern mutations would still be around. They would have to keep separating over and over again as if there was an unseen breeder in charge, and then would we have an entirely different phylum one day?
But we are merely similar to apes, like a goat to a deer.
“…The Miracle of Man
Today, four out of ten Americans find it difficult to believe that humans are related to the apes. Why is this so? Compare yourself to a chimpanzee. Man is intelligent, naked and highly sexual – a species apart from his alleged primate relatives.
This may be an intuitive observation but it is actually supported by scientific study. In 1911, the anthropologist Sir Arthur Keith listed the anatomical characteristics peculiar to each of the primate species, calling them ‘generic characters’ which set each apart from the others. His results were as follows: gorilla 75; chimpanzee 109; orangutan 113; gibbon 116; man 312. Keith thus showed scientifically that mankind was nearly three times more distinctive than any other ape.
Another scientist to take this approach was the British zoologist Desmond Morris. In his book, The Naked Ape, Desmond Morris highlighted the amazing mystery of mankind’s ‘missing hair’:
Functionally, we are stark naked and our skin is fully exposed to the outside world. This state of affairs still has to be explained, regardless of how many tiny hairs we can count under a magnifying lens.
Desmond Morris contrasted Homo sapiens with 4,237 species of mammals, the vast majority of which were hairy or partly haired. The only non-hairy species were those which lived underground (and thus kept warm without hair), species which were aquatic (and benefited from streamlining), and armoured species such as the armadillo (where hair would clearly be superfluous). Morris commented:
The naked ape [man] stands alone, marked off by his nudity from all the thousands of hairy, shaggy or furry land-dwelling mammalian species... if the hair has to go, then clearly there must be a powerful reason for abolishing it.
Darwinism has yet to produce a satisfactory answer as to how and why man lost his hair. Many imaginative theories have been suggested, but so far no-one has come up with a really acceptable explanation. The one conclusion that can perhaps be drawn, based on the principle of gradiented change, is that man spent a long time evolving, either in a very hot environment or in water…”
Other intelligent arguments here:http://www.bibliotecapleyades.net/ciencia/esp_ciencia_life03.htm
But the recent findings say we did not evolve from apes after all. It was on science magazine:
“…Human exceptionalism received a boost today with the news that human beings apparently did not evolve from apes. From the story:
The skeleton of an early human who lived 4.4 million years ago shows that humans did not evolve from chimpanzee-like ancestors, researchers reported on Thursday. Instead, the missing link — the common ancestor of both humans and modern apes — was different from both, and apes have evolved just as much as humans have from that common ancestor, they said. The researchers stressed that “Ardi” may now be the oldest known hominid, but she was not the missing link. “At 4.4 million years ago we found something pretty close to it,” said Tim White of the University of California
Berkeley, who helped lead the research team.
Here’s how the matter was put in another report about the story:
Researchers concluded that both the human branch and the ape branch of the family tree have evolved significantly from its common ancestor, and chimps can no longer be thought of as a “proxy” for that common ancestor.
I bring this up because some Darwinsists and other assorted materialists have attacked human exceptionalism on the basis that our supposed emergence from the great apes and/or our genetic closeness means that we should not think of ourselves as distinctive. I never thought that was in the least persuasive. What matters is what we are now, not what might have been millions of years ago or how we got here. But this report concludes that our common ancestry–still undiscovered–is thrown even further back–with apparently no direct lineage of human beings arising from apes.
It looks like the anti-human exceptionalists will have to go back to the drawing board.
Some very good features on forcing apes into men here too: http://www.gennet.org/facts/metro19.html
“…Move over, Lucy. And kiss the missing link goodbye. Scientists today announced the discovery of the oldest fossil skeleton of a human ancestor. The find reveals that our forebears underwent a previously unknown stage of evolution more than a million years before Lucy, the iconic early human ancestor specimen that walked the Earth 3.2 million years ago.
"All of a sudden you've got fingers and toes and arms and legs and heads and teeth," said Tim White of the University of California, Berkeley, who co-directed the work with Berhane Asfaw, a paleoanthropologist and former director of the National Museum of Ethiopia, and Giday WoldeGabriel, a geologist at Los Alamos National Laboratory in New Mexico.
"That allows you to do something you can't do with isolated specimens," White said. "It allows you to do biology." http://news.nationalgeographic.com/news/2009/10/091001-oldest-human-skeleton-ardi-missing-link-chimps-ardipithecus-ramidus.html
“…The basic issue is this: Despite the fact that human/ape genetic similarities are often overstated, YES, in many instances it is true that humans and chimps have very high levels of genetic similarity. Does this functional genetic similarity bolster neo-Darwinian evolution and human/ape common ancestry? Not at all. In fact, we could have predicted these similarities without any knowledge of Darwinian evolution simply by observing that humans have similar body plans to apes. If similar morphology implies similar genetics, then we could predict these high levels of similarities without even thinking about considerations pertaining to common ancestry.
But there's another important point to consider: Functional morphological and genetic similarities between humans and apes could be the result of common design just as much as common descent. That's a good principle to keep in mind as you investigate this issue: functional biological similarity is explained by common design just as well as it's explained by common descent. (In fact, in some cases--such as extreme convergent evolution--such similarity is explained much better by common design.)…”:
Recent Genetic Research Shows Chimps More Distant From Humans, Neanderthals Closer:
Research published in Nature over the past few months is showing a much greater genetic distance between humans and chimps than previously thought, while revealing a closer one between humans and Neanderthals.
A Nature paper from January, 2010 titled, "Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content," found that Y chromosomes in humans and chimps "differ radically in sequence structure and gene content," showing "extraordinary divergence" where "wholesale renovation is the paramount theme." Of course, the paper attributes these dramatic genetic changes to "rapid evolution during the past 6â€‰million years…Textbooks often depict Neanderthals as primitive, bungling brutes with a vaguely human-like form (see above)--an attempt to instill the ape-to-human icon in students. But as Time Magazine reported in 1999, there's increasing evidence showing that this evolutionary interpretation was wrong, and Neanderthals were essentially "all just people":
Convergent evolution: “…Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.
The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are similar in construction, due to the physical constraints imposed upon wing shape. Similarity can also be explained by shared ancestry. Wings were modified from limbs, as evidenced by their bone structure.
Traits arising through convergent evolution are termed analogous structures, in contrast to homologous structures, which have a common origin. Bat and pterosaur wings are an example of analogous structures, while the bat wing is homologous to human and other mammal forearms, sharing an ancestral state despite serving different functions. Similarity in species of different ancestry that is the result of convergent evolution is called homoplasy. The opposite of convergent evolution is divergent evolution, whereby related species evolve different traits. On a molecular level, this can happen due to random mutation unrelated to adaptive changes; see long branch attraction. Convergent evolution is similar to, but distinguishable from, the phenomena of evolutionary relay and parallel evolution. Evolutionary relay describes how independent species acquire similar characteristics through their evolution in similar ecosystems at different times—for example the dorsal fins of extinct ichthyosaurs and sharks…” : http://en.wikipedia.org/wiki/Convergent_evolution
Now there is a theory that could explain a lot… why foxes look like dogs, or many rodents look alike, and many cetaceans look alike etc, etc… similar, and yet, no common ancestor. And yet is also a scientific theory.
Human intervention in genetics is not speciation…
“…Dobzhansky’s Fruit Flies
Isaak continues: “The origin of new species by evolution has also been observed, both in the laboratory and in the wild...” He then directs us to:
the work of Theodosius Dobzhansky et al. (involving the deliberate, radiation-induced mutation of fruit flies in the laboratory), and
the “Observed Instances of Speciation” FAQ in the talk.origins archives.
As for Dobzhansky’s fruit fly experiments, it should be pointed out that an example of a laboratory-induced physiological change in a specimen—even though it involves genetic change—can hardly be considered proof that NATURAL evolution occurs, since the change did not take place without the deliberate, intelligence-driven activity of man.
Furthermore, a genetic, mutational change alone, while it may qualify (in a broad sense) as evolution (“micro-evolution”), does not demonstrate evolution per se: Evolution does not require mere change, but progressive change (i.e., from simple to complex, from one organism to another organism—an increase in both quantity and quality of genetic information).
In Dobzhansky’s work, numerous varieties resulted from radiation bombardment: fruit flies with extra wings, fruit flies with no wings, fruit flies with huge wings, fruit flies with tiny wings... In the end, however, they were all ... fruit flies! Dobzhansky meddled with the genetic code of an organism and effected changes on the organism’s offspring. Nearly all of the changes were detrimental to survival, and none of them resulted in an advantage over other fruit flies.
The “Observed Instances FAQ”
As for the “Observed Instances of Speciation” FAQ (the reading of which is encouraged by this writer), after one goes to the trouble of digesting all the preliminary verbiage, all the “speciation” examples given fall into one of two categories:
“new” species that are “new” to man, but whose “newness” remains equivocal in light of observed genetic “variation” vs. genetic “change” (as discussed above), and/or because a species of unknown age is being observed by man for the first time.
“new” species whose appearance was deliberately and artificially brought about by the efforts of intelligent human manipulation, and whose status as new “species” remain unequivocally consequential to laboratory experiments rather than natural processes.
In neither of the above examples cited by Isaak was the natural (i.e., unaided) generation of a new species accomplished or observed, in which an unequivocally “new” trait was obtained (i.e., new genetic information created) and carried forward within a population of organisms. In other words, these are not examples of macro-evolutionary speciation—they are examples of human discovery and/or genetic manipulation and/or natural genetic recombination. They serve to confirm the observable nature of genetic variation, while saying absolutely nothing in support of Darwinian “macro-evolution,” which postulates not just variations within a type of organism but the emergence of entirely new organisms.
Definitions of “species” and (therefore) “speciation” remain many and varied, and by most modern definitions, certain changes within organism populations do indeed qualify as “speciation events”—yet even after many decades of study, there remains no solid evidence that an increase in both quality and quantity of genetic information (as required for a macro-evolutionary speciation event) has happened or could happen…”
"..Confirmation:Speciation of numerous plants, both angiosperms and ferns (such as hemp nettle, primrose, radish and cabbage, and various fern species) has been seen via hybridization and polyploidization since the early 20th century. Several speciation events in plants have been observed that did not involve hybridization or polyploidization (such as maize and S. malheurensis).
Some of the most studied organisms in all of genetics are the Drosophila species, which are commonly known as fruitflies. Many Drosophila speciation events have been extensively documented since the seventies. Speciation in Drosophila has occurred by spatial separation, by habitat specialization in the same location, by change in courtship behavior, by disruptive natural selection, and by bottlenecking populations (founder-flush experiments), among other mechanisms.
Several speciation events have also been seen in laboratory populations of houseflies, gall former flies, apple maggot flies, flour beetles, Nereis acuminata (a worm), mosquitoes, and various other insects. Green algae and bacteria have been classified as speciated due to change from unicellularity to multicellularity and due to morphological changes from short rods to long rods, all the result of selection pressures.
Speciation has also been observed in mammals. Six instances of speciation in house mice on Madeira within the past 500 years have been the consequence of only geographic isolation, genetic drift, and chromosomal fusions. A single chromosomal fusion is the sole major genomic difference between humans and chimps, and some of these Madeiran mice…“ allready discussed…“have survived nine fusions in the past 500 years (Britton-Davidian et al. 2000).
More detail and many references are given in the Observed Instances of Speciation FAQ: (http://www.talkorigins.org/faqs/faq-speciation.html)
Fish have also been involved but in debunked ways:
“…Capturing the eye of a potential mate is the first step in propagating a species. But can the way a female sees males of a certain color lead a single species of fish to split into two?
A study published this week in Nature suggests two species of cichlid fish -- one red and one blue -- may have arisen from the female mating preference for males she is best able to see.
"We've wanted since Darwin to understand how species originate," said Karen Carleton, a biologist at the University of Maryland and co-author of the study. "This is one of first times we've been able to understand from the molecular level to the fish to the environment to get the whole picture."
Researchers have long believed that geographic isolation was the primary force behind the evolution of a single species into two reproductively incompatible groups, yet, as lead author and evolutionary biologist Ole Seehausen, found in Lake Victoria in eastern Africa, the red and blue cichlids were separated by as little as 15 meters of water…” So the female chooses the best male, as we all females do in nature…and suddenly choosing the best mate, in a lab, on top of it all (unnatural circumstances) becomes speciation? Weird…
Read more: Red fish, blue fish, speciation? - The Scientist - Magazine of the Life Sciences http://www.the-scientist.com/blog/display/55065/#ixzz1og92Vbfu
Another website says that mutations are crucial in speciation https://homes.bio.psu.edu/.../nei/.../NeiNozawaGBE%202011.pdf?...
Another says the path from single mutation to reproductive isolation in speciation may not be immediately obvious but a technique by Andrew Greenberg can show it. And yet another says “…Mutations are very rare. They hardly ever occur in the natural world…” so how could the allegedly so many biodiversity resulting could come out of it?
Conclusions (my summary and opinions):
Adaptation therefore should be not only slow but mostly with small, tiny changes that do not mean a major loop into a different species to the point of looking as different, nevertheless, as humans and chimps.
“…Spontaneous mutations are very rare, and advantageous mutations are even rarer…” http://en.wikipedia.org/wiki/Randomness and http://en.wikipedia.org/wiki/Natural_selection
That can be seen in some occurring human syndromes and diseases. So why does an ape evolves to human as speciation for better in this context?
What you see in “speciations” or speciations (according to whatever you believe in…) occurred in species outside labs (no human intervention) are small not drastic changes sometimes even in something as simple as the color of a feather or patron, or eye. Basically you look at that species of fish or bird and see only a small turn away from the allegedly original species.
The fruit flies are still fruit flies even if they get 5 pairs of wings, a whale or shrimp is still a whale or shrimp when it decides (free will for all creatures) to start eating something else or prefers something else.
A good example is a documentary I saw that showed how a fish eating bird found a technique to catch fish…he observed that when people gave bread to the fish in the park they slightly came up to get it. So he started catching bread from people not to eat it but to throw it to the fish and catch the fish. Did he become a new species? He might get good and abundant offspring and get fat and get lots of girlfriend and teach his art to the offspring but that offspring will still be a very similar, very close, not too different species from this particular individual that generate them.
Animals think, they are smart and have their own personality and free will (given by God? Could be…)
You can see it here: http://www.sciencemeetsreligion.org/evolution/speciation.php
But keep in mind what was said previously on species categorization: still a problem for biologists and taxonomists… many still debate the beginning let alone the conclusions.
We have seen here how the man/ape common ape like ancestor is far from being consensual or certain. Far from it , recent discoveries show that our DNA is not that close, that humans have distinctive features and how the loosing of hair or other humane features are far from being logical evolution / beneficial adaptation features. Apart from intelligence or language the rest seems rather random just as many mutations are. In fact the brain and language ability as in fact been pointed out has debunking ape like common ancestry for it would take such a big loop.
Big loops are not common in nature, speciation either. Science and nature have laws that rule by common events, that repeat often and regularly in such ways that calling speciation an explanation for human evolution would be to take the exception from the rule to explain the normal / natural, it would be to grab to the exceptional to explain the general and raise it , and state it as the general law ...
Many frauds, half truths, theories latter debunked, have been used to take skeletons findings and claim them as the new answer to the so called missing link approach. But the truth is that the missing link is missing and resemblance is not enough to explain macroevolution: a fox resembles a dog, same as a deer’s muzzle resembles that of a goat (mouth mostly), a prairie dog resembles a lot of different rodents and so on. Many monkeys might have gone extinct.
Some skeletons like that of “Ardi” showed that human like features are older than usually assumed and some species of monkeys have long legs too (in Borneo for example) and others have some teeth like that of humans, so taking a part a skeleton with a tooth and say: “this is it!” is highly giddy.
The genetic pool must be wide of course or there would not be enough variability and a Creator could have predicted, as intelligent force that He is, the need to slight adaptations in order to be stronger, healthier, more resistant but that is part of a dynamic natural world, or should I say: dynamic intelligent plan?
Fossil records are not very conclusive in terms of macroevolution to the point that it is still controversial by many.
“…This is the core question about the TE. Micro-evolution is a proven fact, and cannot be denied. It also does not conflict with the Genesis creation account. Macro-evolution however does. Despite the so often seen allegation of evolutionists, Macro-evolution has not been proved to be true. It remains a theory, based on faith…”: http://elshamah.heavenforum.org/t80-has-macro-evolution-been-proved-observed
“…Using Microevolution As Evidence
Most of the "evidence" for evolution (and some of their "evidence" is nothing but the use tricky definitions) comes from microevolution or point mutations. For example, Darwin never observed evolution, he only observed microevolution. As another example, the peppered moth, which is in almost every biology book, is an example of microevolution. It is no different than two people having different colored hair.
Neither microevolution, nor point mutations (e.g. a bacteria developing a resistance to a drug) have anything to do with creating new genetic information, including new genes. Creating new genetic information, including new gene complexes, is a requirement for true evolution (this is true macroevolution) and has never been observed in the lab or in nature - only by assumption (i.e. if you assume it is true, you cannot claim you have proven it is true) or wishful thinking (which is total nonsense). Logic should travel from truth down to assumptions, not from assumptions up to truth…”: http://www.mathematicsofevolution.com/ChaptersMath/Chapter_220__Debate_Tactics__.html
And I’m not saying macroevolution does not exist, the world as a whole evolves, even the climate is evolving unfortunately mostly by mankind’s fault.
The rest has not been well established yet.
You might be thinking that I based myself only in creationist website or books for my opinions expressed here , but check it out first because in many cases it is better (at least it was, for me) to avoid biased or not impartial websites. But also, creationist websites are not quite that biased or partial as you may think, read this:
“…Why should a Christian ministry maintain a list of arguments creationists should avoid? As a ministry, we want to honor God and represent Christ well when we defend His Word. This means using honest, intellectually sound arguments that are based in Scripture, logic, and scientific research. Because there are so many good arguments for a recent creation (which the Bible clearly teaches), we have no need to grasp at straws—arguments using questionable logic and tenuous or no evidence. Answers in Genesis is not willing to distort evidence or resort to bad logic to defend the Bible.
Furthermore, there is little harm in avoiding questionable arguments—or, at least, stating that certain interpretations of evidence are doubtful—since there are plenty of valid arguments with well-documented evidences against molecules-to-man evolution, atheism, and the like. Using bad arguments allows evolutionists to easily “refute” creationists by sidestepping the actual case for biblical creation. Even one instance of using a faulty argument can lead someone to write off creationism as pseudoscientific and dismiss creationists as shoddy researchers—or charlatans!
A final reason for avoiding flawed arguments is that it leads to faulty thinking…”
Stick around for new posts. Cheers.
Publicada por Patrícia à(s) 20:45