Vinegar said:
Evolution requires (to keep it simple) four things: (1) DNA, (2) Reproduction, (3) Useful changes (mutations) in the DNA that is passed down the generations through reproduction, and (4) Change in the interactions between organisms and their environment. All of these four things can be directly observed, existing and happening now, all about us. No-one (even "creation scientists")denies that.
This is what is required for
natural selection. Evolution could happen if organisms inherited acquired characteristics. Evolution is descent with modification. Natural selection is mechanism of modification that gives the designs in plants and animals.
You could have modification, and do, by pure chance. Genetic drift is that. Genetic drift only really works in
very small populations -- less than 6 breeding pairs.
The most significant event in evolution is speciation - this is when one species of organism develops from another species, due to the accumulation of useful mutations in the genome.
Vinegar, I hate to mar an excellent attempt to explain evolution with what may seem to be nit-picking, but it isn't.
There are several significant events in evolution. Speciation comes in two forms:
1. Anagenesis. This is when one
population transforms over time into a population that is different enough from the original as to be designated a new species. This is your first example of short and long beaked birds over time.
2. Cladogenesis. This is when a small, isolated
population faces a different environment and transforms to a population having different traits from the original. But the original still exists. So now you have two species where there was one. This is your example of birds on the other side of the mountain.
Both of these happen due to natural selection. So, the signficant event is the acquisition of new designs that are new traits. You used long beaks instead of short ones.
Evolutionary theory does not say that at some point, a knuckle-dragging ape gave birth to a fully-formed human baby. That is just a dumb story told to try to make evolution look ridiculous.
Well said. Actually, it is creationism. Which shows you how ridiculous creationism is.
Speciation is not just speculation, either. It has in fact been observed, in some plants, bacteria and insects, which breed fast enough for enough mutations to mount up for speciation to occur, within the professional lifetime of a modern scientist.
And in some vertebrates:
1. N Barton Ecology: the rapid origin of reproductive isolation Science 290:462-463, Oct. 20, 2000.
www.sciencemag.org/cgi/content/full/290/5491/462 Natural selection of reproductive isolation observed in two cases. Full papers are: AP Hendry, JK Wenburg, P Bentzen, EC Volk, TP Quinn, Rapid evolution of reproductive isolation in the wild: evidence from introduced salmon. Science 290: 516-519, Oct. 20, 2000. and M Higgie, S Chenoweth, MWBlows, Natural selection and the reinforcement of mate recognition. Science290: 519-521, Oct. 20, 2000
2. G Vogel, African elephant species splits in two. Science 293: 1414, Aug. 24, 2001.
www.sciencemag.org/cgi/content/full/293/5534/1414
3. C Vila` , P Savolainen, JE. Maldonado, IR. Amorim, JE. Rice, RL. Honeycutt, KA. Crandall, JLundeberg, RK. Wayne, Multiple and Ancient Origins of the Domestic Dog Science 276: 1687-1689, 13 JUNE 1997. Dogs no longer one species but 4 according to the genetics.
http://www.idir.net/~wolf2dog/wayne1.htm
4. Barrowclough, George F.. Speciation and Geographic Variation in Black-tailed Gnatcatchers. (book reviews) The Condor. V94. P555(2) May, 1992
5. Kluger, Jeffrey. Go fish. Rapid fish speciation in African lakes. Discover. V13. P18(1) March, 1992.
Formation of five new species of cichlid fishes which formed since they were isolated from the parent stock, Lake Nagubago. (These fish have complex mating rituals and different coloration.) See also Mayr, E., 1970. _Populations, Species, and Evolution_, Massachusetts, Harvard University Press. p. 348
6. Genus _Rattus_ currently consists of 137 species [1,2] and is known to have
originally developed in Indonesia and Malaysia during and prior to the Middle
Ages[3].
[1] T. Yosida. Cytogenetics of the Black Rat. University Park Press, Baltimore, 1980.
[2] D. Morris. The Mammals. Hodder and Stoughton, London, 1965.
[3] G. H. H. Tate. "Some Muridae of the Indo-Australian region," Bull. Amer. Museum Nat. Hist. 72: 501-728, 1963.
7. Stanley, S., 1979. _Macroevolution: Pattern and Process_, San Francisco,
W.H. Freeman and Company. p. 41
Rapid speciation of the Faeroe Island house mouse, which occurred in less than 250 years after man brought the creature to the island.