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9. has been observed,

* 9a. in the field

In the genus Tragopogon (a plant genus consisting mostly of diploids), two new species (T. mirus and T. miscellus) have evolved within the past 50-60 years. The new species are allopolyploid descendants of two separate diploid parent species.

Here is how this speciation occurred. The new species were formed when one diploid species fertilised a different diploid species and produced a tetraploid offspring. This tetraploid offspring could not fertilize or be fertilised by either of its two parent species types. It is reproductively isolated, the very definition of a species.

Mammals:

Rapid speciation of the Faeroe Island house mouse occurred less than 250 years after humans brought it to the island. Species identification in this case was based on morphology, since breeding experiments could not be performed with the parent stock . (S. Stanley, Macroevolution: Pattern and Process, San Francisco: W. H. Freeman & Company, 1979, p. 41)

Birds:

During a series of natural catastrophes, the Galapagos island finch- species Geospitza fortis developed a larger beak, necessary for consuming a variety of seed unaffected by the ravages. This was a new phenotype never observed before, made manifest i n just a few years time.

* 9b. in the laboratory

Plants:

In 1905, while studying the genetics of the evening primrose, Oenothera lamarckiana, H. De Vries discovered among his plants a variant having a different chromosome number. He was unable to breed this variant with O. lamarckiana. He named the new species O. gigas. (De Vries, Species and Varieties, Their Origin By Mutation, 1905)

In 1973, L. D. Gottlieb documented the speciation of Stephanomeira malheurensis from a large population of S. exigua in Harney County, Oregon. He was able to document morphological differences in five characteristics plus chromosomal differences. Attempts at crossbreeding these plants produced hybrids having either scant seeds and pollen, or developmental abnormalities. (American Journal of Botany 60, pp. 545-553)

After five years of selective crossbreeding, E. Pasterniani in 1969 produced almost complete reproductive isolation between two varieties of corn. The species were distinguishable by seed color, white versus yellow. Other genetic markers allowed him to identify hybrids, which were not used for future breeding. (Zea mays L. Evolution 23, pp. 534547)

Insects:

There is a lot of literature about speciation in fruit flies and house flies. Different experiments have been carried out to examine separately the effects of natural selection and genetic drift. See, for example, J. Ringo, et. al, "An experiment testing two hypotheses of speciation," The American Naturalist (1989) 126, pp. 642661, or A. B. Soans, et. al, "Evolution of reproductive isolation in allopatric and sympatric populations," The American Naturalist (1974) 108, pp. 117- 124.

Tropical fish:

The question can be asked, is the sex ratio then just a non-adaptive consequence of the independent assortment of X and Y chromosomes in male sperm? Or, is the ratio adaptive and Mendelian assortment an adaptive trait that has evolved?

The authors of a recent paper put this to the test by studying the Atlantic silverside fish Menidia menidia . This fish has an unusual life cycle in that, during the early months of the year mostly female offspring are produced. In the summer months mostly males are produced. The bias in the sex of the offspring is induced by the water temperature. Female offspring are produced while the water is cold, males while it is warm. The sex ratio across the whole year balances out to 0.5. This sex bias is caused by temperature dependent sex determination, not temperature dependent sex mortality. In other words cold water makes baby female fish form, it doesn't kill male baby fish. The same embryo could be male or female depending on the temperature it is raised at (i.e. Mendelian segregation does not influence the sex ratio in this species.)

The authors captured hundreds of these fish and maintained them in aquaria for five to six years. Some aquaria were maintained at low temperatures, others at high temperatures. In the low temp aquaria, the populations began with mostly females. The sex ratio, for example, in one low temp tank was 0.70 (70% female) In the high temperature aquaria, the populations began with mostly males. In one of the low tanks the sex ratio was 0.18. Both of these, given the population sizes, are significantly different than 0.50.

As the experiment progressed, the sex ratios changed from the highly skewed initial conditions. In all the populations the sex ratios converged on 0.5. The trajectory of the sex ratios converging on 0.5 differed between many of the tanks. In one tank, the next and all subsequent generations were at an 0.5 sex ration. In another, it slowly converged upon 0.5. In yet another it reached 0.5, then overshot slightly, then returned. This indicates that a sex ratio of 0.5 is somehow adaptive be cause the fish evolved from a skewed ratio to a balanced ratio. Since chromosome assortment does not determine sex in these fish (temperature does), the only explanation for their convergence to 0.5 is natural selection favoured fish that produced an abnormal amount of the minority sex. (If males are lacking, any fish that produces male fish will contribute more than average to the gene pool).

This is a frequency-dependent kind of selection. As the sex ratio approaches 0.5, fish who produce a disproportionate amount of either sex will contribute less than average to the gene pool.

Finally, notice that evolution has occurred. The experiment started with populations of fish that produced skewed sex ratios and ended with populations that produced balanced sex ratios. Since the environment was held constant, the change in the populations was therefore genetic. In other words, the gene pool changed over time. This is the definition of evolution.

Conover and Voorhees, 1990, Evolution of a Balanced Sex Ratio by Frequency-Dependent Selection in a Fish, Science 250: p.1556-1558

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Originally posted by Ricky
Welcome Peptide. I must first say, very originial arguments, I for one haven't heard of either.

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However you must be careful, out of this will surely come the, "Thats microevolution, not macroevolution" argument which I think we are all too familiar with.

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4. Phanerozoic extinctions

4.1. The Big Five
Analyses of past extinctions rely upon the fossil record to provide information on the appearance of new species (speciation) and their decline towards extinction. At a species level the fossil record is fragmentary and thus only higher taxa such as families can be used for analytical purposes. The fossil record left by terrestrial species is less complete than for marine because terrestrial environments are more destructive, and those marine species with hard shells have left the most complete record of all. It is these abundant, widespread shelly invertebrates, for example Ammonites (Figure 2), which provide palaeontologists with the data used to investigate past extinction rates.

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Fossils are not sorted according to hydrodynamic principles. Ammonites, which are buoyant organisms similar to the chambered nautilus, are found only in deep strata. Turtles, which are rather dense, are found in middle and upper strata. Brachiopods are very similar to clams in size and shape, but brachiopods are found mostly in lower strata than clams. Most fossil-bearing strata contain fossils of various sizes and shapes. Some species are found in wide ranges, while others are found only in thin layers within those ranges. Hydrologic sorting can explain none of this.

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The Real Poop on the Global Flood
by Glenn R. Morton
copyright G. R. Morton 2002

This may be freely reproduced so long as no changes to the text are made nor any monetary charges required. One may freely link to this page.
Young-earth creationism is faced with many difficulties in explaining the real world. One more item which it can't explain is the existence of dried and petrified turtle poop (coprolite, in scientific terms). Young-earth creationists believe that the geologic record is the result of a major catastrophe in which everything (or nearly everything) was deposited within a single year. That leaves certain difficulties.

Consider the turtle coprolite shown below which is from Betsiboka, Madagascar.
#65532;
This coprolite, from my personal fossil collection, was deposited by a turtle in Eocene rocks. Geology says these rocks are 38-55 million years old. The coprolite today is rock-hard and has no smell. It is the mineralized poop from an Eocene turtle. How do we know it is turtle poop? Because even today, in Betsiboka, Madagascar where this was found, turtles come ashore to lay their eggs, they leave such

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Finally, at 1800 K water would not exist as liquid.

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Originally posted by Ricky

From the Flood Math link:

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Finally, at 1800 K water would not exist as liquid.

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I could just see the argument, "God raised the boiling point of water."

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Originally posted by Dave W.

Well, how strange. tksgurl is absolutely correct when she says "this debate is over before it starts."

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