New species are merely variations within species, or hybrids of the type similar to when horses and donkeys mate to produce mules. No new genetic information is created, and the supposed "new" species were examples like this one:
“5.3.1 Drosophila paulistorum. Dobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972). "
These new species barely deserve commenting on. Dobshansky's "speciation right before our eyes" were still Drosophila, still fruit flies. They started out as fruit flies and they ended up as fruit flies and were, like many of Boxhorn's examples, sterile, thus having little or no value in evolutionary reproductive terms.
In another of Boxhorn’s experiments on fruit flies "55 virgin males and 55 virgin females of both ebony body mutant flies and vestigial wing mutant flies (220 flies total) were put into a jar and allowed to mate for 20 hours"! Whew! (Boxhorn did not personally carry out the experiment. I can imagine it would be a little hard on the eyes. How anyone figured out that they were virgins in the first place should have won a Nobel Prize) This experiment was done to examine the courtship behavior of mutant fruit flies, since Boxhorn believed that one of the distinctions of a species was determined by how attracted certain members of the opposite sex were to each other. Perhaps this meant that ugly fruit flies were of a different species than handsome ones.
The first two examples of speciation in Boxhorn’s FAQ were the experiments of de Vries (1905) and Digby (1912) on the Primrose plant, but as long ago as 1922 the magazine Science reported: "Twenty years ago de Vries made what looked like a promising attempt to supply this (evidence for new species appearing among natural offspring) as far as Oenothera [Primrose] is concerned . . .but in application to that phenomenon the theory of mutation falls. We see novel forms appearing, but they are no new species of Oenothera. For that which comes out is no new creation." (Science, Jan. 20, 1922; from an address by Professor William Bateson addressing a group of scientists in Toronto)
So talk.origins is still using an experiment for evidence for evolution that was rejected by the scientific community as long ago as 1922
From here: The Darwin Papers
I took a look at that website. The following snippet caught my eye. It does not fill me with confidence:
Even by evolutionists' own admission, this theory does not have one shred of evidence to support it. Ted Holden has written: "It is a pure pseudo-science seeking to explain and actually be proved by a lack of evidence rather than by evidence (all the missing intermediate fossils). Similarly, Cotton Mather claimed that the fact that nobody had ever seen or heard a witch was proof they were there (if you could see or hear them, they wouldn't be witches...)”Holden further wrote: ...
This is a gross misrepresentation. Rejection by one person (Bateson) does not count as "rejected by the scientific community". One dissent does not a consensus make -- and the "scientific community" is a community of consensus.
I can't find any details on the reason for Bateson's dissent, but it's probably significant that Bateson was a strong advocate of the "saltation" hypothesis of evolution ("hopeful monsters"), which has long been discredited. As such, it seems likely that he rejected the example on ideological grounds because, like DittoJed2, he had a personal overestimate about how "big" a speciation event would have to look.
If anything, you have it backwards -- it's Bateson's paradigm which has been "rejected by the scientific community".
"Our doubts are not as to the truth or reality of evolution, but as to the origins of species, a technial, almost domestic problem. Any day that mystery may be solved. The discoveries of the last twenty-five years enable us for the first time to discuss these questions intelligently and on a basis of fact. That synthesis will follow on analysis, we do not and cannot doubt."
(Any mistakes in transcription are mine.)
That's where new species arise, but not what they are. By the dawn of the age of exploration, the human race had spread around the globe. The varying environments and the isolation of various subgroups from the rest of the gene pool had produced the beginnings of speciation processes that would eventually have gone to completion had we not re-discovered each other and re-connected all the gene pools. Now we're basically re-melding.
Thus, up to a somewhat blurry point, the process is reversible. Put in barriers to gene-mixing, differences arise. Take out the barriers, re-mixing can occur. (But in nature, it doesn't always. Sometimes the process once started simply runs away because of sexual selection pressures or a lack of situational viability of hybrid types.)
... or hybrids of the type similar to when horses and donkeys mate to produce mules.
The product (a mule) of horse-donkey hybridization is not a new species. It's not even fertile. (It's a useful farm animal combining some of the better points and skipping some of the drawbacks of its parent species.) You misinterpret the significance of the situation. That horses and donkeys are cross-fertile but produce sterile offspring is a sign that speciation has already occurred and relatively recently.
Despite all the similarities between the species and the near-compatibility that allows the production of mules, there is no way for horse and donkey populations to re-meld in the way humans are doing. They are on the other side of the speciation barrier and will go their separate ways now.