I was graciously invited to participate in these forums by VenomShocker, who happens to attend the same Pentecostal Church that I do. VenomShocker and I met at the University of Alberta, where he sat in on a Creationism class I took.
The professor I studied under for both of my Creationism classes is Dr. Denis Lamoureux, who not only has his divinity degree but two doctorates. One is in biology and one is in dentistry. His experience and insight has only added to a part-time advocation ive had on this topic; he has formally debated Michael Behe and Philip Johnson and has personal friendships with many of the Young Earth Creationists. This introduction to his experiences with these pioneers has been very valuable. You really get a sense of what the forefront of the movement is, and where it will proceed in the future.
My background is one steeped not only in the physical but also the historical sciences. Add a passion for religious studies and philosophy, and this seems to be the topic that draws me in. Enough preamble though, let's dig in.
I've done a quick review of the evolution conversations here. Speciation (and or the lack of it) seems to be one of the foundations of Jonathan's skepticism with evolution.
Speciation deals with reproductive isolation. Jonathan (or do you prefer VenomShocker, just let me know) is not completely sold on the idea of habitat, behavioural, or temporal isolation being speciation. He asked me on the phone personally for examples of Mechanical and Gametic Isolation or Postzygotic barriers.
For the less technically inclined, these are examples of speciation where:
a) Can't reproduce due to anatomic differences
B) Can't reproduce due to gamete incompatibility
c) The hybrid zygote doesnt produce a fertile adult (and that this is a result of observed, and not assumed, speciation)
What does this rule out?
Horses and donkeys creating mules. This speciation was not observed, and is only assumed. This inference only holds weight if you have examples of postzygotic barriers developing empirically.
Postzygotic Barrier Example:
Lab Rat Worm: Nereis acuminata. 6 pairs of worms are taken from Long Beach, where they go to Woods Hole Oceanographic Institute. 20 years later, they go back to the beach, and find two species of worms there. They cross the Woods Hole worms with the two species found there. The goal was to determine which species the Woods Hole worms were. To their surprise, the worm, which upon all inspection was the same to P2 and only slightly different than P1, was unable to produce offspring that survived until adulthood. Isolated cause was a small difference in karyotype. P1 and P2 crosses survived measurably decently (75%+).
**Weinberg, J. R., et al., Evolution 46: 1214-1220.**
Mechanical Isolation Example:
Erebia rossii and Erebia disa. These are Alpine butterflies that are genetically very similar, sharing 99.8% coding DNA. However, they have genital organs that are different enough that breeding cannot occur. Examples of attempted matings have been observed, yet no successful copulations have been. THE MOLECULAR STUDY OF BIOLOGICAL EVOLUTION, Chapter 3, pp. 46-59 (F. Ayala, Ed.), Sinauer Associates, Inc., Sunderland, Massachusetts; EVOLUTION WITHIN POPULATIONS, Ann. Mo. Bot. Garden 63: 248-261
Gamete Isolation Example: (Polyploidy provides 50-60 similar examples, this is probably the best imo)
Tragopogon mirus and Tragopogon miscellus. These are tetraploid hybrids of tragopogon pratensis and Tragopogon porrifolius. Differences in the plant stigma (From chromosomal differences) prevent pollinization. References are innumerable.
But as we speak, this argument is really becoming moot. The largest Creationist organization in the world, Answers in Genesis (Answersingenesis.com) has implicitly folded any argument against speciation. In fact, they now incorporate it into their Young Earth theory to defend the wide variety of species seen on Earth. Source: http://www.answersingenesis.org/home/area/...aq/dont_use.asp
Hope this clears up any confusion on speciation of these kinds not occurring.
Edited by Matthew_28_28, 12 June 2004 - 10:27 PM.