First of all, this article has been written to counter the following article that appears on Talk.Origins Archives.
It is entitled Observed Instances of Speciation.
The beginning of this article is slow reading with very little or no evidence so I've decided to exclude that
portion from my page. You may read it at the site linked above if you like. The below evidences presented are examples
of speciation. Speciation is what happens when one species produces another. I will show that the below evidences
can not and should not be used to support evolution. (Because the original article was so long, this article has been divided into several parts.) The portions
written in Bold are excerpts from Joeseph Boxhorn's article.
5.0 Observed Instances of Speciation The following are several examples of observations of speciation.
5.1 Speciations Involving Polyploidy, Hybridization or Hybridization Followed by Polyploidization.
5.1.1 Plants (See also the discussion in de Wet 1971).
22.214.171.124 Evening Primrose (Oenothera gigas)
While studying the genetics of the evening primrose, Oenothera lamarckiana, de Vries (1905) found an unusual variant among his plants. O. lamarckiana
has a chromosome number of 2N = 14. The variant had a chromosome number of 2N = 28. He found that he was unable to breed this variant with O.
lamarckiana. He named this new species O. gigas.
This is a case in which a genetic "fluke" occured, giving the new plant twice as many chromosomes than was needed.
There was no mutation of the chromosomes and no other genetic mutations.
Recently, my use of the word fluke was called into question. What was meant is that this is an
example of an EVOLUTIONARY EVENT, but not EVOLUTION. What the heck am I talking about? You should read about the difference here.
126.96.36.199 Kew Primrose (Primula kewensis)
Digby (1912) crossed the primrose species Primula verticillata and P. floribunda to produce a sterile hybrid. Polyploidization occurred in a few of these
plants to produce fertile offspring. The new species was named P. kewensis. Newton and Pellew (1929) note that spontaneous hybrids of P. verticillata
and P. floribunda set tetraploid seed on at least three occasions. These happened in 1905, 1923 and 1926.
First of all, you will notice that the original attempts at crossing these two plants produced a new plant that was incapable of reproduction.
Secondly, you will notice that on three occasions the new plants were capable of reproduction. Once again, this is caused by a combination of genes and not
a mutation there-of.
Owenby (1950) demonstrated that two species in this genus were produced by polyploidization from hybrids. He showed that Tragopogon miscellus
found in a colony in Moscow, Idaho was produced by hybridization of T. dubius and T. pratensis. He also showed that T. mirus found in a colony near
Pullman, Washington was produced by hybridization of T. dubius and T. porrifolius. Evidence from chloroplast DNA suggests that T. mirus has
originated independently by hybridization in eastern Washington and western Idaho at least three times (Soltis and Soltis 1989). The same study also
shows multiple origins for T. micellus.
I would like to know just how the scientists knew that the species arose three times. This is not the point, however. The point is that, if it arose
three times, then it was obviously the product of cross pollenation. A simple mixing of the chromosomes occured, however, no chromosomal or genetic mutations occured.
The Russian cytologist Karpchenko (1927, 1928) crossed the radish, Raphanus sativus, with the cabbage, Brassica oleracea. Despite the fact that the
plants were in different genera, he got a sterile hybrid. Some unreduced gametes were formed in the hybrids. This allowed for the production of seed.
Plants grown from the seeds were interfertile with each other. They were not interfertile with either parental species. Unfortunately the new plant
(genus Raphanobrassica) had the foliage of a radish and the root of a cabbage.
The "evolution" of this new plant (which is just another example of chromosomes being crossed) was a genetic failure. The new species was incapable
of reproducing within it's species, but was capable of reproducing with radishes and cabbages. Simple proof that it is nothing more than different combinations of chromosomes.
188.8.131.52 Hemp Nettle (Galeopsis tetrahit)
A species of hemp nettle, Galeopsis tetrahit, was hypothesized to be the result of a natural hybridization of two other species, G. pubescens and G.
speciosa (Muntzing 1932). The two species were crossed. The hybrids matched G. tetrahit in both visible features and chromosome morphology.
Let me explain what the author is saying here. He is saying that scientists thought that this plant came from the hybridization of two other species.
They performed the experiment and the result LOOKED like the plant they were trying to get, but was not the plant they were trying to get.
184.108.40.206 Madia citrigracilis
Along similar lines, Clausen et al. (1945) hypothesized that Madia citrigracilis was a hexaploid hybrid of M. gracilis and M. citriodora As evidence they
noted that the species have gametic chromosome numbers of n = 24, 16 and 8 respectively. Crossing M. gracilis and M. citriodora resulted in a highly
sterile triploid with n = 24. The chromosomes formed almost no bivalents during meiosis. Artificially doubling the chromosome number using colchecine
produced a hexaploid hybrid which closely resembled M. citrigracilis and was fertile.
Hooah! (pronounced: HU ah) I hope I wasn't the only one to catch that! This is even better evidence against evolution than the last one!
Let me once again explain. Once again, scientists believed that this plant was the result of hybridization between two others. They attempted to duplicate this.
Here are the results: The result was a plant that had the right no. of chromosomes, but was completely sterile (incapable of reproducing itself). Because this experiment
was a failure, the scientists played around with the plant's chromosomes and doubled the number. This was done artificially because it would not occur naturally in their
experiments. The new product was fertile and LOOKED like the plant they wanted, but was not. Never mind the fact that it had twice as many chromosomes as it was supposed to.
It makes me wonder why they even bothered to perform the experiment in the first place if they were just going to alter the results to make it appear as evidence of evolution.
Frandsen (1943, 1947) was able to do this same sort of recreation of species in the genus Brassica (cabbage, etc.). His experiments showed that B.
carinata (n = 17) may be recreated by hybridizing B. nigra (n = 8) and B. oleracea, B. juncea (n = 18) may be recreated by hybridizing B. nigra and B.
campestris (n = 10), and B. napus (n = 19) may be recreated by hybridizing B. oleracea and B. campestris.
I fail to see how this experiment was at all like the last. Is the author trying to say that the original experiments were failures and required
tampering to produce the expected results? We already know that hybrids can be formed in nature. So what?
220.127.116.11 Maidenhair Fern (Adiantum pedatum)
Rabe and Haufler (1992) found a naturally occurring diploid sporophyte of maidenhair fern which produced unreduced (2N) spores. These spores
resulted from a failure of the paired chromosomes to dissociate during the first division of meiosis. The spores germinated normally and grew into diploid
gametophytes. These did not appear to produce antheridia. Nonetheless, a subsequent generation of tetraploid sporophytes was produced. When grown
in the lab, the tetraploid sporophytes appear to be less vigorous than the normal diploid sporo- phytes. The 4N individuals were found near Baldwin City,
Big words got used here, so I'll focus on the second to last sentence. The lab results yeilded inferior sporophytes, as can be seen in the statement: "appear to be
less vigorous than the normal." I do not understand why these results are claims of proof for evolution if they did not yeild EXACTLY the correct results. If this was a case
of evolution, then the result should have been more efficient and not less.
18.104.22.168 Woodsia Fern (Woodsia abbeae)
Woodsia abbeae was described as a hybrid of W. cathcariana and W. ilvensis (Butters 1941). Plants of this hybrid normally produce abortive sporangia
containing inviable spores. In 1944 Butters found a W. abbeae plant near Grand Portage, Minn. that had one fertile frond (Butters and Tryon 1948). The
apical portion of this frond had fertile sporangia. Spores from this frond germinated and grew into prothallia. About six months after germination
sporophytes were produced. They survived for about one year. Based on cytological evidence, Butters and Tryon concluded that the frond that
produced the viable spores had gone tetraploid. They made no statement as to whether the sporophytes grown produced viable spores.
How many times are we going to see examples of chromosomal combinations? Chromosomal combinations also cause some women to be sterile, but this is not a result
of evolution. Now look at the final statement. If the sporophytes had grown to become viable spores, it would have been shouted from the roof tops because a new species
would have arisen. Because it was not mentioned, I find it rather safe to say that the resulting plants were also sterile.
5.1.2 Animals Speciation through hybridization and/or polyploidy has long been considered much less important in animals than in plants [[[refs.]]]. A
number of reviews suggest that this view may be mistaken. (Lokki and Saura 1980; Bullini and Nascetti 1990; Vrijenhoek 1994). Bullini and Nasceti
(1990) review chromosomal and genetic evidence that suggest that speciation through hybridization may occur in a number of insect species, including
walking sticks, grasshoppers, blackflies and cucurlionid beetles. Lokki and Saura (1980) discuss the role of polyploidy in insect evolution. Vrijenhoek
(1994) reviews the literature on parthenogenesis and hybridogenesis in fish. I will tackle this topic in greater depth in the next version of this document.
5.2 Speciations in Plant Species not Involving Hybridization or Polyploidy
5.2.1 Stephanomeira malheurensis Gottlieb (1973) documented the speciation of Stephanomeira malheurensis. He found a single small population (< 250
plants) among a much larger population (> 25,000 plants) of S. exigua in Harney Co., Oregon. Both species are diploid and have the same number of
chromosomes (N = 8). S. exigua is an obligate outcrosser exhibiting sporophytic self-incompatibility. S. malheurensis exhibits no self- incompatibility
and self-pollinates. Though the two species look very similar, Gottlieb was able to document morphological differences in five characters plus
chromosomal differences. F1 hybrids between the species produces only 50% of the seeds and 24% of the pollen that conspecific crosses produced. F2
hybrids showed various developmental abnormalities.
What's your point? You found a bunch of plants surrounded by different plants. The two were similar. Why does that mean that one evolved from the other?
If one really did arise from the other, then it was probably the product of mixed up chromosomal combinations like the other instances. I would be cautious, even saying
this, because there is no lab documentation suggesting that the two were ever, in any way, related.
5.2.2 Maize (Zea mays) Pasterniani (1969) produced almost complete reproductive isolation between two varieties of maize. The varieties were
distinguishable by seed color, white versus yellow. Other genetic markers allowed him to identify hybrids. The two varieties were planted in a common
field. Any plant's nearest neighbors were always plants of the other strain. Selection was applied against hybridization by using only those ears of corn
that showed a low degree of hybridi- zation as the source of the next years seed. Only parental type kernels from these ears were planted. The strength
of selection was increased each year. In the first year, only ears with less than 30% intercrossed seed were used. In the fifth year, only ears with less
than 1% intercrossed seed were used. After five years the average percentage of intercrossed matings dropped from 35.8% to 4.9% in the white strain
and from 46.7% to 3.4% in the yellow strain.
Another example of chromosome combinations. Just as some combinations will give you blue eyes and others will give you brown, chromosome combinations in corn
will give you the same effect in kernels. What you see in this experiment is a filtering of the traits. Just as two blue eyed parents are more likely to produce
blue eyed children, corn of a specific color will be more likely to produce offspring of that color. After enough time of filtering, the undesirable traits will fade away,
BUT never completely disappear.
5.2.3 Speciation as a Result of Selection for Tolerance to a Toxin: Yellow Monkey Flower (Mimulus guttatus) At reasonably low concentrations, copper is
toxic to many plant species. Several plants have been seen to develop a tolerance to this metal (Macnair 1981). Macnair and Christie (1983) used this to
examine the genetic basis of a postmating isolating mechanism in yellow monkey flower. When they crossed plants from the copper tolerant
"Copperopolis" population with plants from the nontolerant "Cerig" population, they found that many of the hybrids were inviable. During early growth,
just after the four leaf stage, the leaves of many of the hybrids turned yellow and became necrotic. Death followed this. This was seen only in hybrids
between the two populations. Through mapping studies, the authors were able to show that the copper tolerance gene and the gene responsible for
hybrid inviability were either the same gene or were very tightly linked. These results suggest that reproductive isolation may require changes in only a
small number of genes.
Just as certain chromosomal combinations may cause a couple to produce still born offspring, chromosomal combinations between these two plants
caused MANY (but not all) of the hybrids to die. If the two genes were truly linked, then the article should have read: "the leaves of ALL hybrids turned yellow and became
necrotic." The fact that it did not read as such is proof that the genes are highly incompatible, but not completely incompatible as some offspring survived. This is a prime
example of an author trying to swing something to look the way he wants it.
Also, many huamans can build up tolerances to certain chemicals that others can't. This is not
evolution so neither should the plant's tolerance to copper be considered one. I would also wonder this: if the copper tolerant plants lived in a cuprous environment, then would
the spores, or whatever was used to create the hybrids, contain copper itself? If so, this would explain why some of the product plants died and others didn't. Those who were tolerant
survived and those who weren't didn't.
That's it for this page. Click Here for part two of this article.