How does evolution happen?

[lucaspa]

StubbornMule asked this in another thread. Since he is a "newbie" he probably hasn't seen all the threads yet.

Biological evolution (the one we are talking about) encompasses changes in populations of organisms over generations.

As Arkikay pointed out, this happens mainly thru two mechanisms:

1. Natural selection

2. Genetic drift.

Of these natural selection is by far the most important. NS is responsible for all the designs in biological organisms. In fact, NS is an algorithm to get design. That means that NS is a series of steps that, if followed by an idiot without thinking, is guaranteed to give the result. In this case the result of the algorithm of NS is design.

Now, if you want to go into more detail as to how evoution happens, feel free to ask whatever specific questions you have.

 

[The Archangel Aethariel]

Biological evolution (the one we are talking about) encompasses changes in populations of organisms over generations.

As Arkikay pointed out, this happens mainly thru two mechanisms:

1. Natural selection

2. Genetic drift.

Of these natural selection is by far the most important. NS is responsible for all the designs in biological organisms. In fact, NS is an algorithm to get design. That means that NS is a series of steps that, if followed by an idiot without thinking, is guaranteed to give the result. In this case the result of the algorithm of NS is design.

Now, if you want to go into more detail as to how evoution happens, feel free to ask whatever specific questions you have.

I wouldn't necessarily say "...natural selection is by far the most important. NS is responsible for all the designs in biological organisms." There is still a great deal of debate regarding the Neutral Theory, which in the words of its architect, Motoo Kimura, predicts that:

"...the great majority of evolutionary mutant substitutions at the molecular level are caused by random fixation, through sampling drift, of selectively neutral (i.e., selectively equivalent) mutants under continued mutation pressure."

(Lewin 99)

In fact, evidence gathered since the theory's proposition in the 1960s has indicated that it is in some degree accurate-- in particular, observed mutation rate data has strongly supported the Neutral Theory. (Lewin 101) While it is hard to say exactly to what degree the two theories combine, it is clear that the truth of the matter lies somewhere in the middle, far from either extreme, where neither selection nor fixation are "by far the most important."

While I hesitate to emphasize the importance that chance fixation plays in evolution with creationists lurking to misinterpret me, it seems accuracy is the most important factor. After all, no point in convincing a creationist that evolution really does function, only to have them find out about this stuff later and think we lied to 'em. Just a minor quibble.

1. Patterns in Evolution, Lewin, 1996.

~AA

 

[Shimmerstar]

Evolution is like life itself. If you stuff everything up enough, something is bound to make sense.

 

[Michali]

Evolution is like life itself. If you stuff everything up enough, something is bound to make sense.

Rather- If you stuff everything up enough, something is bound to fall through.

edit- I just figured out your name "lucaspa" after reading your bio.

 

[lucaspa]

I wouldn't necessarily say "...natural selection is by far the most important. NS is responsible for all the designs in biological organisms." There is still a great deal of debate regarding the Neutral Theory, which in the words of its architect, Motoo Kimura, predicts that:

(Lewin 99)

In fact, evidence gathered since the theory's proposition in the 1960s has indicated that it is in some degree accurate-- in particular, observed mutation rate data has strongly supported the Neutral Theory. (Lewin 101) While it is hard to say exactly to what degree the two theories combine, it is clear that the truth of the matter lies somewhere in the middle, far from either extreme, where neither selection nor fixation are "by far the most important."

Lewin is talking about mutation rates. And yes, most mutations are "neutral" in that the changes either don't affect the protein at all (get same amino acid) or are apparently neutral to selection. However, that is a far cry from saying that characteristics result from chance fixation. There are two "Neutral Theories". This is one. However, by its very nature, the neutral theory discussed here can't produce designs. To be selectively neutral means that both alleles are equally good at the job. You can't get design that way.

Dawkins demolishes the Neutral Theory in The Blind Watchmaker.

Now, Kimura had another Neutral Theory. In this one speciation was caused by a mutation that produced reproductive isolation between populations and then selection worked on the two populations to diverge them in characteristics. This has absolutely been falsified by the data. Reproductive isolation is a result of changing characteristics that in turn are a result of natural selection.

While I hesitate to emphasize the importance that chance fixation plays in evolution with creationists lurking to misinterpret me, it seems accuracy is the most important factor.

The problem is that chance fixation doesn't work on a population size larger than about 10 breeding individuals. The chances of chance fixation become just too small and it takes way too long.

Mathematics. Futuyma page 393
Kimura and then Li and Gauer derived the probability of an allele being fixed in the population. The probability of fixation of an allele A2 where the fitness of the genotypes are: A1A1 = 1, A1A2 = 1 +s, and A2A2 = 1 +2s is:
P = 1 - e^2Nsq/1 - e^-4Nq where e = the base of natural logarithms = 2.718, N = effective population size, s = selection coefficient, and q = the initial frequency of the allele in the population. For a mutation, q = 1/2N
Where s = 0 (genetic drift) then the equation reduces to P = 1/2N. The influence on fixation is obvious. Double the population and you halve the probability. Any N > 50 really reduces P.

For instance, if N = 1,000 then P = 0.0005 by genetic drift.

However, if you have N = 1,000 and the selective advantage is small at s = 0.01 and A2 is a mutation so that its initial frequency is 1/2000, then P = 0.02. That is 40 times the probability of fixation by chance alone. And that is a small s. Most s are 0.1 or above.

Now you see why I said genetic drift is unimportant.


Now, you can also look at this as a neutral mutation has a 0.5 probability of eventually being fixed. That is, it will eventually either be totally removed from the population or be fixed. This is where Kimura bases his hopes. However, now we get to look at time frames. Shoot! That info is at home!

I'll get back to you but I've done this before. It turns out that the time required to get fixation in a decently sized population (>1,000) is so long that it exceeds by an order of magnitude the average lifespan of a species. IOW, there simply isn't enough time for the neutral mutation to become fixed by pure chance.

 

[Jet Black]

edit- I just figured out your name "lucaspa" after reading your bio.

but then we have a new enigma... what does A stand for? I suspect something like Andrew, but I live in hope that his parents were fans of greek classics and A is for Agamemnon or something really cool like that

 

[lucaspa]

but then we have a new enigma... what does A stand for? I suspect something like Andrew, but I live in hope that his parents were fans of greek classics and A is for Agamemnon or something really cool like that

Hopes dashed!

 

[The Archangel Aethariel]

Oh, hell, my entire post got erased somehow. To recap briefly:

Thanks for the information luscapa, very interesting. I haven't really read much on evolutionary biology besides Dawkin's The Selfish Gene and the Lewin text I cited-- in the latter, the Neutral Theory is given a much more favourable shine than your information suggests that it ought recieve. Sorry for attempting to correct you-- I was both unaware of your expertise in the area, and I was eager to actually use the new information I learned in one of my recent classes. (The Lewin book was one of the primary texts for my recent advanced seminar in philosophy of biology.) To clarify, is 'Mathematics' the title of the Futuyama text you're citing, or was that merely a header in your post? I would be interested in reading the actual analysis in full, because Lewin gives a much more favourable appraisal of the theory. Also, is the study you cited more recent than the 1996 publishing date of the Lewin book, or does my book just contain bad information?

~AA

 

[pureone]

Lucaspa Oeloasquan
hmmm...

 

[lucaspa]

Oh, hell, my entire post got erased somehow. To recap briefly:

Thanks for the information luscapa, very interesting. I haven't really read much on evolutionary biology besides Dawkin's The Selfish Gene and the Lewin text I cited-- in the latter, the Neutral Theory is given a much more favourable shine than your information suggests that it ought recieve. Sorry for attempting to correct you-- I was both unaware of your expertise in the area, and I was eager to actually use the new information I learned in one of my recent classes. (The Lewin book was one of the primary texts for my recent advanced seminar in philosophy of biology.) To clarify, is 'Mathematics' the title of the Futuyama text you're citing, or was that merely a header in your post? I would be interested in reading the actual analysis in full, because Lewin gives a much more favourable appraisal of the theory. Also, is the study you cited more recent than the 1996 publishing date of the Lewin book, or does my book just contain bad information?

~AA

The "Mathematics" was just a heading. The discussion is from Douglas Futuyma's Evolutionary Biology, 1998. The dates aren't that different.

Archangel, I think we are talking about apples and oranges here. Lewin is noting that the huge amount of variation in populations does indeed support Kimura's contention that most mutations are neutral in regards to selection. However, it is a leap from that to say the Neutral Theory of evolution is supported.

Kimura's Neutral Theory is that at least half the mutations that eventually become fixed must do so by drift -- pure chance. That doesn't look likely given the equations that Kimura himself developed!

And neutral mutations, by definition, can't be adaptations (design). If they were adaptations, they would be under selection and their fixation not due to pure chance.

In small populations, under 10 breeding individuals, there is a better chance that neutral or even slightly deleterious mutations can be fixed by chance. This would be genetic drift.

The calculations are:
N = 1,000 individuals and A is deleterious and and s = -0.001, then P = 0.00004. This will increase if N is very small.

That's not a very high probability, but it would get larger if you decrease N in the larger equation I gave you.

 

[Vargatron]

WHO cares how elotution happened...The fact is, is that it did and we are here now....Yea it would be nice to know, but seeing that everything is based on Cause and Effect, Infinite Regress is an inescapable fact....and if you disagree...then you are denying the very essance of being human...therefore you are not!

 

[Michali]

There are many who care how it happened. It is, as you say, our essence to being human.

 

[Jet Black]

WHO cares how elotution happened...The fact is, is that it did and we are here now....Yea it would be nice to know, but seeing that everything is based on Cause and Effect, Infinite Regress is an inescapable fact....and if you disagree...then you are denying the very essance of being human...therefore you are not!

this is the most abysmal sequence of "logical conclusions" I have ever seen.

 

[Vargatron]

I said, if you can learn how to read...that the concept of Infinite regress is human essance...that is if you even know what Infinite regress means...

 

[LorentzHA]

Lucaspa-

Hello, could you help me out? I was explaining to a friend this weekend about Evolution. My friend was telling me that he agrees there have been Micro-adaptation (he ref. birds beaks) but he said there has never been been evidence of Macro Evolution. I told him that one cannot exist without the other. I also said that Macro Evolution IS a series of Micro Evolution(s). I also gave him a few links that you gave us on transitionals. Am I off base, Regarding Macro? He said one species has never evolved into another!! Can you help me, please? BTW-My friend has a science background like I do (but like mine a BS) but only knows the basics (like I do). BUT he has a flair towards creationism-if that helps at all. I felt like the blind leading the blind. -LorentzHA

 

[lucaspa]

WHO cares how elotution happened...The fact is, is that it did and we are here now....Yea it would be nice to know, but seeing that everything is based on Cause and Effect, Infinite Regress is an inescapable fact....and if you disagree...then you are denying the very essance of being human...therefore you are not!

Not everything is strictly cause and effect. Basically, the universe is indeterminant. And evolution is the perfect system for converting an indeterminant event at the quantum level to macroscopic levels. Think about it: mutations are copying mistakes in the DNA at the quantum level -- atoms and electrons. After all, picking the right base to bind to the complementary base (adenine to thymine and guanosine to cytosine) is based on electrons and those are quantum particles. So, have a quantum event that changes a which base binds and you have a mutation. Thru embryonic development that quantum event is transformed to a macroscopic organism.

Also, we want to know how the designs in biological organisms happen. This has great implications for how we view the universe. Prior to Darwin, the dominant philosophy was a top-down philosophy where deity sat on top, made intelligence and made design, design made order, and order made chaos.

We have turned that view upside down. Now chaos leads to order -- including life, order makes design thru natural selection, and natural selection also makes intelligence as part of design.

Try reading Daniel Dennett's Darwin's Dangerous Idea. Darwinism is really a "universal acid" that transforms how we look at the world.

 

[Jet Black]

well there are numerous hings like the transitional fosils and ERVs which cannot be explained any other way. ERVs and transposons are a good bet imo.

 

[lucaspa]

Lucaspa-

Hello, could you help me out? I was explaining to a friend this weekend about Evolution. My friend was telling me that he agrees there have been Micro-adaptation (he ref. birds beaks) but he said there has never been been evidence of Macro Evolution. I told him that one cannot exist without the other. I also said that Macro Evolution IS a series of Micro Evolution(s). I also gave him a few links that you gave us on transitionals. Am I off base, Regarding Macro? He said one species has never evolved into another!! Can you help me, please? BTW-My friend has a science background like I do (but like mine a BS) but only knows the basics (like I do). BUT he has a flair towards creationism-if that helps at all. I felt like the blind leading the blind. -LorentzHA

What your friend is thinking about when he says "micro" and 'bird beaks" is that the mean size of the beaks of Galapagos finches increased in drought years and then decreased again in wet years. So he is saying there is not directional selection long enough to produce "permanent" changes in the characteristics of organisms. With me so far?

However, he is wrong on a couple of counts:
1. Even in the Grant study on the Galapagos finches, when the beaks decreased in size they did not go back to the exact shape before the increase in size. IOW, yes the size of the beaks was smaller again, but they were not the same beaks. The proportions of length, width, and height had changed even tho the overall size was similar.

2. Directional change that did not reverse have been documented. Here are just three examples out of literally thousands:
1. Case, TJ, Natural selection out on a limb. Nature, 387: 15-16,May 1, 1997. Original paper in the same issue, pp. 70-73 (below). Discusses natural selection in the wild where lizards were introduced tovarious islands in the Bahamas. Length of limbs varied according to the plant life present on the islands. JB Losos, KI Warhelt, TW Schoener, Adaptive differentiation folowing experimental island colonization in Anolis lizards. Nature, 387: 70-73,1997 (May 1)
2. Reznick, DN, Shaw, FH, Rodd, FH, and Shaw, RG. Evaluationof the rate of evolution in natural populations of guppies (Poeciliareticulata). Science 275:1934-1937, 1997. The lay article isPredatory-free guppies take an evolutionary leap forward, pg 1880.
4. Macnair, M. R. 1981. Tolerance of higher plants to toxic materials.In: J. A. Bishop and L. M. Cook (eds.). Genetic consequences of man made change. Pp.177-297. Academic Press, New York.

Now, macroevolution is speciation. Because in nature species is all there is. All our "higher" taxa are simply groups of species. So, once you have speciation you have macroevolution. Now, speciation in sexually reproducing organisms is reproductive isolation. That is, the two populations don't interbreed or if they do they don't produce fully fertile offspring. The offspring from two separate populations (species) are hybrids.

Below is a partial list of observed speciation that I have gathered. It is by no means complete. But it is extensive enough to shatter that "one species has never evolved to another" claim.

General
1. M Nei and J Zhang, Evolution: molecular origin of species. Science 282: 1428-1429, Nov. 20, 1998. Primary article is: CT Ting, SC Tsaur, ML We, and CE Wu, A rapidly evolving homeobox at the site of a hybrid sterility gene. Science 282: 1501-1504, Nov. 20, 1998. As the title implies, has found the genes that actually change during reproductive isolation.
2. M Turelli, The causes of Haldane's rule. Science 282: 889-891, Oct.30, 1998. Haldane's rule describes a phase every population goes thru during speciation: production of inviable and sterile hybrids. Haldane's rule states "When in the F1 [first generation] offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterozygous [heterogemetic; XY, XO, or ZW] sex."Two leading explanations are fast-male and dominance. Both get supported. X-linked incompatibilities would affect heterozygous gender more because only one gene."
3. Barton, N. H., J. S. Jones and J. Mallet. 1988. No barriers to speciation. Nature. 336:13-14.
4. Baum, D. 1992. Phylogenetic species concepts. Trends in Ecology and Evolution. 7:1-3.
5. Rice, W. R. 1985. Disruptive selection on habitat preference and the evolution of reproductive isolation: an exploratory experiment. Evolution. 39:645-646.
6. Ringo, J., D. Wood, R. Rockwell, and H. Dowse. 1989. An experiment testing two hypotheses of speciation. The American Naturalist. 126:642-661.
7. Schluter, D. and L. M. Nagel. 1995. Parallel speciation by natural selection. American Naturalist. 146:292-301.
8. Callaghan, C. A. 1987. Instances of observed speciation. The American Biology Teacher. 49:3436.
9. Cracraft, J. 1989. Speciation and its ontology: the empirical consequences of alternative species concepts for understanding patterns and processes of differentiation. In Otte, E. and J. A. Endler [eds.] Speciation and its consequences. Sinauer Associates, Sunderland, MA. pp. 28-59.
10. Callaghan, C. A. 1987. Instances of observed speciation. The American Biology
Teacher. 49:3436.
Speciation in Insects
1. G Kilias, SN Alahiotis, and M Pelecanos. A multifactorial genetic investigation of speciation theory using drosophila melanogaster Evolution 34:730-737, 1980. Got new species of fruit flies in the lab after 5 years on different diets and temperatures. Also confirmation of natural selection in the process. Lots of references to other studies that saw speciation.
2. JM Thoday, Disruptive selection. Proc. Royal Soc. London B. 182: 109-143, 1972.
Lots of references in this one to other speciation.
3. KF Koopman, Natural selection for reproductive isolation between Drosophila pseudobscura and Drosophila persimilis. Evolution 4: 135-148, 1950. Using artificial mixed poulations of D. pseudoobscura and D. persimilis, it has been possible to show,over a period of several generations, a very rapid increase in the amount of reproductive isolation between the species as a result of natural selection.
4. LE Hurd and RM Eisenberg, Divergent selection for geotactic response and evolution of reproductive isolation in sympatric and allopatric populations of houseflies. American Naturalist 109: 353-358, 1975.
5. Coyne, Jerry A. Orr, H. Allen. Patterns of speciation in Drosophila. Evolution. V43. P362(20) March, 1989.
6. Dobzhansky and Pavlovsky, 1957 An incipient species of Drosophila, Nature 23: 289- 292.
7. Ahearn, J. N. 1980. Evolution of behavioral reproductive isolation in a laboratory stock of Drosophila silvestris. Experientia. 36:63-64.
8. 10. Breeuwer, J. A. J. and J. H. Werren. 1990. Microorganisms associated with chromosome destruction and reproductive isolation between two insect species. Nature. 346:558-560.
9. Powell, J. R. 1978. The founder-flush speciation theory: an experimental approach. Evolution. 32:465-474.
10. Dodd, D. M. B. and J. R. Powell. 1985. Founder-flush speciation: an update of experimental results with Drosophila. Evolution 39:1388-1392. 37. Dobzhansky, T. 1951. Genetics and the origin of species (3rd edition). Columbia University Press, New York.
11. Dobzhansky, T. and O. Pavlovsky. 1971. Experimentally created incipient species of Drosophila. Nature. 230:289-292.
12. Dobzhansky, T. 1972. Species of Drosophila: new excitement in an old field. Science. 177:664-669.
13. Dodd, D. M. B. 1989. Reproductive isolation as a consequence of adaptive divergence in Drosophila melanogaster. Evolution 43:1308-1311.
14. de Oliveira, A. K. and A. R. Cordeiro. 1980. Adaptation of Drosophila willistoni experimental populations to extreme pH medium. II. Development of incipient reproductive isolation. Heredity. 44:123-130.15. 29. Rice, W. R. and G. W. Salt. 1988. Speciation via disruptive selection on habitat preference: experimental evidence. The American Naturalist. 131:911-917.
30. Rice, W. R. and G. W. Salt. 1990. The evolution of reproductive isolation as a correlated character under sympatric conditions: experimental evidence. Evolution. 44:1140-1152.
31. del Solar, E. 1966. Sexual isolation caused by selection for positive and negative phototaxis and geotaxis in Drosophila pseudoobscura. Proceedings of the National Academy of Sciences (US). 56:484-487.
32. Weinberg, J. R., V. R. Starczak and P. Jora. 1992. Evidence for rapid speciation following a founder event in the laboratory. Evolution. 46:1214-1220.
33. V Morell, Earth's unbounded beetlemania explained. Science 281:501-503, July 24, 1998. Evolution explains the 330,000 odd beetlespecies. Exploitation of newly evolved flowering plants.
34. B Wuethrich, Speciation: Mexican pairs show geography's role. Science 285: 1190, Aug. 20, 1999. Discusses allopatric speciation. Debate with ecological speciation on which is most prevalent.
Speciation in Plants
1. Speciation in action Science 72:700-701, 1996 A great laboratory study of the evolution of a hybrid plant species. Scientists did it in the lab, but the genetic data says it happened the same way in nature.
2. Hybrid speciation in peonies http://www.pnas.org/cgi/content/full/061288698v1#B1
3. http://www.holysmoke.org/new-species.htm new species of groundsel by hybridization
4. Butters, F. K. 1941. Hybrid Woodsias in Minnesota. Amer. Fern. J. 31:15-21.
5. Butters, F. K. and R. M. Tryon, jr. 1948. A fertile mutant of a Woodsia hybrid. American Journal of Botany. 35:138.
6. Toxic Tailings and Tolerant Grass by RE Cook in Natural History, 90(3): 28-38, 1981 discusses selection pressure of grasses growing on mine tailings that are rich in toxic heavy metals. "When wind borne pollen carrying nontolerant genes crosses the border [between prairie and tailings] and fertilizes the gametes of tolerant females, the resultant offspring show a range of tolerances. The movement of genes from the pasture to the mine would, therefore, tend to dilute the tolerance level of seedlings. Only fully tolerant individuals survive to reproduce, however. This selective mortality, which eliminates variants, counteracts the dilution and molds a toatally tolerant population. The pasture and mine populations evolve distinctive adaptations because selective factors are dominant over the homogenizing influence of foreign genes."
7. Clausen, J., D. D. Keck and W. M. Hiesey. 1945. Experimental studies on the nature of species. II. Plant evolution through amphiploidy and autoploidy, with examples from the Madiinae. Carnegie Institute Washington Publication, 564:1-174.
8. Cronquist, A. 1988. The evolution and classification of flowering plants (2nd edition). The New York Botanical Garden, Bronx, NY.
9. P. H. Raven, R. F. Evert, S. E. Eichorn, Biology of Plants (Worth, New York,ed. 6, 1999).
10. M. Ownbey, Am. J. Bot. 37, 487 (1950).
11. M. Ownbey and G. D. McCollum, Am. J. Bot. 40, 788 (1953).
12. S. J. Novak, D. E. Soltis, P. S. Soltis, Am. J. Bot. 78, 1586 (1991).
13. P. S. Soltis, G. M. Plunkett, S. J. Novak, D. E. Soltis, Am. J. Bot. 82,1329 (1995).
14. Digby, L. 1912. The cytology of Primula kewensis and of other related Primula hybrids. Ann. Bot. 26:357-388.
15. Owenby, M. 1950. Natural hybridization and amphiploidy in the genus Tragopogon. Am. J. Bot. 37:487-499.
16. Pasterniani, E. 1969. Selection for reproductive isolation between two populations of maize, Zea mays L. Evolution. 23:534-547.
Speciation in microorganisms
1. Canine parovirus, a lethal disease of dogs, evolved from feline parovirus in the 1970s.
2. Budd, A. F. and B. D. Mishler. 1990. Species and evolution in clonal organisms -- a summary and discussion. Systematic Botany 15:166-171.
3. Bullini, L. and G. Nascetti. 1990. Speciation by hybridization in phasmids and other insects. Canadian Journal of Zoology. 68:1747-1760.
4. Boraas, M. E. 1983. Predator induced evolution in chemostat culture. EOS. Transactions of the American Geophysical Union. 64:1102.
5. Brock, T. D. and M. T. Madigan. 1988. Biology of Microorganisms (5th edition). Prentice Hall, Englewood, NJ.
6. Castenholz, R. W. 1992. Species usage, concept, and evolution in the cyanobacteria (blue-green algae). Journal of Phycology 28:737-745.
7. Boraas, M. E. The speciation of algal clusters by flagellate predation. EOS. Transactions of the American Geophysical Union. 64:1102.
8. Castenholz, R. W. 1992. Speciation, usage, concept, and evolution in the cyanobacteria (blue-green algae). Journal of Phycology 28:737-745.
9. Shikano, S., L. S. Luckinbill and Y. Kurihara. 1990. Changes of traits in a bacterial population associated with protozoal predation. Microbial Ecology. 20:75-84.
New Genus
1. Muntzig, A, Triticale Results and Problems, Parey, Berlin, 1979. Describes whole new *genus* of plants, Triticosecale, of several species, formed by artificial selection. These plants are important in agriculture.
Invertebrate not insect
1. ME Heliberg, DP Balch, K Roy, Climate-driven range expansion and morphological evolution in a marine gastropod. Science 292: 1707-1710, June1, 2001. Documents mrorphological change due to disruptive selection over time. Northerna and southern populations of A spirata off California from Pleistocene to present.
2. Weinberg, J. R., V. R. Starczak and P. Jora. 1992. Evidence for rapid speciation following a founder event with a polychaete worm. . Evolution. 46:1214-1220.

 

[lucaspa]

This didn't fit in the previous post:
Vertebrate Speciation
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.
Speciation in the Fossil Record
1. Paleontological documentation of speciation in cenozoic molluscs from Turkana basin. Williamson, PG, Nature 293:437-443, 1981. Excellent study of "gradual" evolution in an extremely find fossil record.
2. A trilobite odyssey. Niles Eldredge and Michelle J. Eldredge. Natural History 81:53-59, 1972. A discussion of "gradual" evolution of trilobites in one small area and then migration and replacement over a wide area. Is lay discussion of punctuated equilibria, and does not overthrow Darwinian gradual change of form. Describes transitionals

 

[Jet Black]

woah, Lucaspa just exploded