Posted on 10/28/2009 7:34:50 PM PDT by GodGunsGuts
Where have I presented an Argumentum ad Hominem ?
Here ya go:
Some of the best examples of speciation are examples of diversification on archipelagos. These provide clear contexts of allopatry and hence provide the extrinsic barrier to gene exchange from the source (usually mainland) population.
The most famous are the Galapagos Islands. The islands are young (some ~ 1 million years), have a volcanic origin providing an opportunity for new arrivals to “radiate” into open niches and the islands are quite distant from the mainland. This isolation and context of primary succession (e.g., development of a flora and fauna on a “clean slate”) will allow for a random element in community composition. Irrespective of genetic consequences of the founding event, subsequent evolution of species quite likely will be under dramatically different selective regime than those in the source population.
Darwin’s Finches. Morphological and genetic studies indicate that they are derived from single ancestral finch, i.e., are monophyletic. There has been dramatic specialization in ecological roles, each species having distinct morphologies and associated food items (beak size and shape associated with seed size, grub feeding, tool use, etc.). Classic examples of different distributions of beak depths: difference between means is greater between species when they occur on the same island than when they occur alone on different islands (see figure below).
Often cited as a clear indication that competition played a role in the adaptive radiation of the finches. There are obvious alternative hypotheses to explain these patterns: populations on different island differ by these amounts as a consequence of drift; different islands have different plants, insects (food items in general) thus the differences are a result of food, not competitors). As P.R. Grant concludes in Ecology and Evolution of Darwin’s Finches, Princeton Univ. Press, 1985, patterns of differentiation and speciation are a combined effect of adaptation to different flora/food and adaptive responses to competitors. The issue of different plants/food on different islands just shifts the question to another trophic level: how did the different islands come to be different in these species.
Another evolutionary paradigm: the Hawaiian islands. Again the islands are young (< 5 million years old), have a volcanic origin and an interesting one: convection currents in the earth’s mantle generate a “hot spot” where volcanic activity occurs above. The pacific plate moves northwest over this spot so the islands’ geographical location is related to their age (Kauai in the north west is ~ 5 million years old; Hawaii [the big island] in the southeast is ~ 500,000 years old and still active).
Hawaiian Drosophila show remarkable patterns of colonization and speciation. At least 700 species of Drosophilids on Hawaiian islands. Not just typical little fruit flies either: large body size, dramatic “picture wing” species, some with “hammer-head” shaped heads. Banding patterns of polytene chromosomes allows phylogeny reconstruction: these and other data show that patterns of colonization are from older to younger islands (flies on Hawaii are derived from ancestors on Maui). Most species are found only on one island (high levels of endemism; more later in Biogeography). This implies that most new colonization events have lead to speciation events! This observation lead Hampton Carson to propose the founder-flush model of speciation.
African cichlid fishes are another remarkable case of “explosive speciation” (the Hawaiian Drosophila of the fish world). Geology and geography again plays an important role. African rift lakes: great fresh-water lakes in east Africa. Formed recently: < 1 million years old. Lake Victoria colonized by one (??) founder 200,000 years ago(??) now has ~ 200 species of fish!. Recent study (Meyer et al. 1990, Nature vol. 347, pg. 550 and see pg. 512) used mitochondrial DNA to show that the species in the lake are indeed monophyletic and that there is very little sequence divergence between species: confirms short time span. But there has been remarkable evolution of morphological, ecological and behavioral variation in these fish: algae grazers, snail crushers, plankton feeders, paedophages (clamp onto the mouth of a fish brooding her young in her mouth and force her to spit out here young into the mouth of the attacker), one fish (in Lake Malawi) plucks the eyes out of other fish as food. All this diversity in 200,000 years with very little genetic differentiation.
Another set of important examples of speciation are those that are believed to have speciated as a result of isolation in Pleistocene refugia. Glacial advances and retreats during the Pleistocene epoch acted as vicariance events in areas where glaciers were present (Wisconsin ice sheet). Dramatic evidence of this is in the North American bird fauna and the clear faunal break between the east and west, e.g., wood warblers; Peterson’s field guides have an Eastern and Western edition).
Climatic changes associated with the glacial advances and retreats altered habitats in the tropics resulting in “islands” of habitat that fluctuated in size and geographic location, leading to fragmentation of distributions and contribution to speciation. Believed to one explanation for patterns of speciation in the Amazon. Also a possible explanation for the Larus ring species complex: genus Larus (seagulls) fragmented in Siberia during the Pleistocene. Diverged populations of Larus argentatus (herring gull) colonized eastern Siberia, across the Bering straits, across North America, Iceland and back to Northern Europe becoming increasingly diverged at each step. Hybrid zones exist between successive populations but the ends of the ring are reproductively isolated implying that speciation has gone to completion (an example of geographic speciation)
http://biomed.brown.edu/Courses/BIO48/23.Cases.HTML
I think you guys are playing semantics here. I told metmom earlier that the term species is a man made term. It is just used to classify. Wolves, dogs and foxes are all different species of dogs. Just because a scientist LABELED them as different species, that doesn’t make them different animals. So speciation HAS occurred.
What they need to prove evolution is something like “genusiation” (made up term). IOW, they need an example of an animal jumping it’s genus not it’s species. In fact they claim that animals have even jumped their class.
Of course to this evolutionist all this is “proven” by the fact that a wolf can be domesticated and bred into a different “species” of dog.
ping to 123
As I think you mentioned on an earlier post, Evolution is now defined as any genetic change at all. Well, we can easily see genetic change (red-haired children, blue eyes, etc.). Therefore, from the standpoint of an Evolutionist, Evolution has been proven right before your very eyes.
As you say, the required proof must be shown on a much broader level. I maintain that evolutionists cannot show meaningful speciation even within canines -- wolf-dog hybrids are not uncommon. We can say we're dealing with different species, but they can still breed.
I agree with the notion that demonstrating reptiles turning into mammals is the level at which Evolution needs to be demonstrated. It works in "theory", but rather than evidence, all we have are assumptions and guesswork.
Evolutionists have a lot of faith, but they come up short on proof.
Your questions show a basic misconception, and lack of education regarding the evolutionary theory. There is no example of a lizard turning into a dog. The evolutionary theory shows that a lizard and a dog share a common ancestor in the distant past.
The current evidence shows that the divergence between reptiles and mammals happened about 195 million years ago.
I dunno? Are you taking one of my generalizations out of context and making it personal? Did I call you a name or defame your character?
“It has become clear that the horizontal transfer of genetic information is pervasive .... Evolution of bacterial chromosomes by gene loss and acquisition”
This is from another link...
I wasn’t willing to pay $30 to look at the whole thing but above is a quote from the paper. There is a whole section on the effects of gene loss.
“Your questions show a basic misconception, and lack of education regarding the evolutionary theory.”
I understand evolutionary theory just fine. It was a generalization. My point was that in and evolutionary timeline, a mammal came from a reptile. That is a leap of taxonomy ORDER.
With speciation, it proves that a dog can have ALOT of variability. Evolutionist have extrapolated that all the way up to ORDER. Speciation isn’t proof of evolution as much as evolutionist would like it to be and as much as they try to contort it to be.
Examples please.
What empirical evidence do you have to show otherwise?
Define any change as *evolution* and any difference as a *species* and you can prove anything.
The kind of change evos propose must have occurred to produce the variety of life on this planet has only been deduced from their interpretation of the spotty fossil record.
Extrapolation is a philosophical consideration, not a fact established by the use of the scientific method.
“The evolutionary theory shows that a lizard and a dog share a common ancestor in the distant past.”
Where is your empirical evidence to support this assertion? ;)
You responded with a cut a paste from a document that indicates that there was indeed a Muller that offered Stalin, or at least promoted the idea of eugenics to Stalin.
A link to the short-cut pdf, which opens in "google docs" which one and all can see is most likely to be the same source that you copied and pasted from (but failed yourself to provide a link to, even as you complain);Herman J. Muller's 1936 letter to Stalin, from The Mankind Quarterly 43(3), Spring 2003 pp 305-318
So the answer is yes, this IS the same Herman J. Muller that you quoted in your post #18
underlining for emphasis my own
Not only was this apparently the same Muller, but it also demonstrates where the logical outcome of strictly materialist thinking leads. It did lead to "eugenics" in Muller's case, although he pitched the idea as a positive, in that it could be used to "help improve" the human race, or in the case of his pitch, at least the Soviet Socialists portion of humanity.
Maybe Lysenco and Lamarck did us all an accidental favor!
It’s interesting that for all the attempts by scientists to produce change in creatures, they still can’t produce by intent the kind of change that they claim must have happened by accident to support the ToE.
You want us to unprove an unproven assumption.
Variations.
1. Variations exist with in all populations.
2. Some of that variation is heritable
3. Base pair sequences are encoded in a set of self-replicating molecules that form templates for making proteins.
4. Combinations of genes that did not previously exist may arise via “Crossing over”
During meiosis, which alters the sequence of base pair on a chromosome.
5. Copying errors (mutations) can also arise; because the self-replication process is of imperfect (although high) fidelity; these mutations also increase the range of combinations of alleles in a gene pool.
6. These recombination’s and errors produce a tendency for successfully increasing genetic divergence radiating outward from the initial state of the population.
Selection
7. Some of the heritable variations have an influence on the number of offspring able to reproduce in turn, including traits that affect mating opportunities, or survival prospects for either individuals or close relatives.
8. Characteristics which tend to increase the number of an organisms offspring that are able to reproduce in turn; tend to become more common over generations and diffuse through a population; those that tend to decrease such prospects tend to become rarer.
9. Unrepresentative samplings which alters the relative frequency of the various alleles can occur in populations for reasons other than survival / reproduction advantages, a process known as” genetic drift”.
10. Migration of individuals from one population to another can lead to changes in the relative frequencies of alleles in the “recipient” population.
Speciation
11. Populations of a single species that live in different environments are exposed to different conditions that can “favor” different traits. These environmental differences can cause two populations to accumulate divergent suites of characteristics.
12. A new species develops (often initiated by temporary environmental factors such as a period of geographic isolation) when sub-population acquires characteristics, which promote or guarantee reproductive isolation from the alternative population, limiting the diffusion of variations thereafter.
Sufficiency
13. The combination of these effects tends to increase diversity of initially similar life forms over time.
14. Over the time frame from the late Hadean to the present, this becomes sufficient to explain both the diversity within and similarities between the forms of life observed on earth, including both living forms directly observed in the present, and extinct form indirectly observed from the fossil record.
That’s what Evolution IS! If you have a problem with Evolution you have a problem with one or more of these fourteen points. Which one is it? Provide any evidence of any of the points that are incorrect.
While the origins of life are a question of interest to evolutionary biologist and frequently studied in conjunction with researchers from other fields such as geochemistry and organic chemistry, the core of evolutionary theory itself does not rest on a foundation that requires any knowledge about the origins of life on earth. It is primarily concerned with the change and diversification of life after the origins of the earliest living things – although there is not yet a consensus as to how to distinguish “living” from “non-living”
Evolution does NOT indicate that all variations are explained this way; that there are no other mechanisms by which variations may arise, be passed, or become prevalent; or that there is no other way life diversifies. Any and all of these may be valid topics for conjecture…but without evidence, they aren’t science.
Other peoples opinions presented in the form of quotes are not evidence against the theory of evolution. They are merely opinions, and all people have opinions, which turn out to be false. So lets stick to the facts.
Lol! I love how Ira keeps making bold assertions and then asking us to prove they aren’t true.
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