Since you keep repeating this blatant lie, it’s time to break out the ordnance to demolish your bullshit. Given the post count limit enforced here, this will be a multi-part exposition.
However, before moving on to the heavy artillery, I’ll provide a brief exposition of the biological species concept, which is applicable here. The biological species concept is a population concept (as indeed are many other evolutionary concepts), and can be summarised as follows …
A population comprises a species, when:
[1] All members thereof (bar occasional mutants) are reproductively interfertile with other members of the population;
[2] All members thereof (again, bar occasional mutants), when mating, produce offspring that satisfy [1] above.
This provides the foundation for understanding speciation processes. I’ll describe a simple case thereof, while noting that more complex cases, such as ring species, also exist, which properly deserve their own complete post.
The simplest case of speciation occurs when the population undergoes a split for some reason, resulting in two new populations, both sharing the same ancestors, but between which gene flow has ceased. That split can arise as a result of the emergence of a physical barrier, or a behavioural barrier, and instances of both are documented in the relevant literature (more on this later). Once that barrier exists, and gene flow between the two separated populations ceases, the populations start to diverge from each other genetically, and it’s possible for the astute to model this process by spending time writing the relevant code to simulate the process.
Among the genes that exhibit divergence in this respect, are the genes belonging to the Major Histocompatibility Complex family. These genes are responsible for such processes as the immune response, tissue typing, and compatibility of egg and sperm (the fertillin genes governing this last process are part of the MHC family), and these genes have been documented as undergoing mutational change at a rapid rate compared to many other organismal genes.
So, when a population is split into two, for whatever reason, the two populations begin diverging from each other, and that divergence encompasses the MHC gene family, including those all-important fertillin genes. The moment that divergence reaches the point where criterion [1] or [2] above fails to be met, a speciation event has occurred. While the fertillin genes are obvious candidates for this process, there exist other genes that are implicated in the speciation process, and have been documented in the literature as exerting the requisite effect.
Having provided a simple exposition of one operating mechanism (covering some of the others would require me to write a book exceeding 1,000 pages in length), it’s now time to look at the literature, which includes the following papers:
A Model For Divergent Allopatric Speciation Of Polyploid Pteridophytes Resulting From Silencing Of Duplicate-Gene Expression by Charles R.E. Werth and Michael D. Windham, American Naturalist, 137(4): 515-526 (April 1991) - DEVELOPMENT OF A MODEL TO MATCH OBSERVED SPECIATION IN NATURE
A Molecular Reexamination Of Diploid Hybrid Speciation Of Solanum raphanifolium by David M. Spooner, Kenneth. J. Sytsma and James F. Smith, Evolution, 45(3): 757-764 - DOCUMENTATION OF AN OBSERVED SPECIATION EVENT
A Mouse Speciation Gene Encodes A Meiotic Histone H3 Methyltransferase by Ondrej mihola, Zdenek Trachtulec, Cestmir Vlcek, John C. Scimenti and Jiri Forejt, Science, 323: 350-351 (16th January 2009) - DETERMINING THE FUNCTION OF A GENE DIRECTLY IMPLICATED IN SPECIATION AND FAILURE OF INTERFERTILITY BETWEEN DIVERGING POPULATIONS
A Rapidly Evolving MYB-Related Protein Causes Species Isolation In Drosophila by Daniel A. Barbash, Dominic F. Siino, Arron M. Tarone and John Roote, Proceedings of the National Academy of Sciences of the USA, 110(9): 5302-5307 (29th April 2003) - DETERMINING THE BEHAVIOUR OF A GENE DIRECTLY IMPLICATED IN SPECIATION AND FAILURE OF INTERFERTILITY BETWEEN DIVERGING POPULATIONS
A Screen For Recessive Speciation Genes Expressed In The Gametes Of F1 Hybrid Yeast by Duncan Greig, Public Library of Science Genetics, 3(2): e21 (February 2007) - Determining the presence of speciation genes in a primitive eukaryote, and the roles of any genes thus located
Adaptive Divergence And The Evolution Of Reproductive Isolation In The Wild: An Empirical Demonstration Using Introduced Sockeye Salmon by Andrew P. Hendry, Genetics, 112-113: 515-534 (2001) - DIRECT EXPERIMENTAL TEST OF REPRODUCTIVE ISOLATION AND ITS ROLE IN SPECIATION EVENTS
Adaptive Evolution And Explosive Speciation: The Cichlid Fish Model by Thomas D. Kocher, Nature Reviews Genetics, 5: 288-298 (April 2004) - DISCUSSION OF METHODS OF EMPIRICAL DEMONSTRATION OF SPECIATION INCLUDING MOLECULAR ANALYSES
Chromosomal Rearrangements And Speciation by Loren H. Rieseberg, TRENDS In Ecology & Evolution, 16(7): 351-358 (July 2001) - determination of the input that chromosomal rearrangements may have upon speciation evnets
Chromosome Evolution, Phylogeny, And Speciation Of Rock Wallabies by G. B. Sharman, R. L. Close and G. M. Maynes, Australian Journal of Zoology, 37(2-4): 351-363 (1991) - DOCUMENTATION OF OBSERVED SPECIATION IN NATURE
Evidence For Rapid Speciation Following A Founder Event In The Laboratory by James R. Weinberg Victoria R. Starczak and Danielle Jörg, Evolution 46: 1214-1220 (15th January 1992) - EXPERIMENTAL GENERATION OF A SPECIATION EVENT IN THE LABORATORY
Evolutionary Theory And Process Of Active Speciation And Adaptive Radiation In Subterranean Mole Rats, Spalax ehrenbergi Superspecies, In Israel by E. Nevo, Evolutionary Biology, 25: 1-125 - DOCUMENTATION OF OBSERVED SPECIATION IN NATURE
Experimentally Created Incipient Species Of Drosophila by Theodosius Dobzhansky & Olga Pavlovsky, Nature 230: 289 - 292 (2nd April 1971) - EXPERIMENTAL GENERATION OF A SPECIATION EVENT IN THE LABORATORY
Founder-Flush Speciation On Drosophila pseudoobscura: A Large Scale Experiment by Agustí Galiana, Andrés Moya and Francisco J. Alaya, Evolution 47: 432-444 (1993) EXPERIMENTAL GENERATION OF A SPECIATION EVENT IN THE LABORATORY
Gene Duplication And Speciation In Drosophila: Evidence From The Odysseus Locus by Chau-Ti Ting, Shun-Chern Tsaur, Sha Sun, William E. Browne, Yung-Chia Chen, Nipam H. Patel and Chung-I Wu, Proceedings of the National Academy of Sciences of the USA, 101(33): 12232-12235 (17th August 2004) - EMPIRICAL ANALYSIS OF THE ROLE OF A DEFINED SPECIATION GENE AND DUPLICATION THEREOF IN SPECIATION EVENTS
Gene Transfer, Speciation, And The Evolution Of Bacterial Genomes by Jeffrey G. Lawrence, Current Opinion in Microbiology, 2(5): 519-523 (October 1999) - determining the role of horizontal gene transfer in the development of new bacterial serotypes
Genes And Speciation by Chung-I Wu, Journal of Evolutionary Biology, 14: 889-891 (2001) - development of a rigorous theory of reproductive isolation taking into account incomplete interfertility failure events
Hybrid Lethal Systems In The Drosophila melanogaster Species Complex. II. The Zygotic Hybrid Rescue (Zhr) Gene Of Drosophila melanogaster by Kyoichi Sawamura, Masa-Toshi Yamamoto and Takao K. Watanabe, Genetics, 133: 307-313 (February 1993) - EMPIRICAL DETERMINATION OF THE ROLE OF A NAMED SPECIATION GENE IN SPECIFIC LIVING ORGANISMS
Hybridisation And Adaptive Radiation by Ole Seehausen, TRENDS In Ecology & Evolution, 19(4): 198-207 (April 2004) - development of a rigorous theory underpinning hybrid speciation and SPECIFICATION OF EMPIRICAL TESTS OF THAT THEORY
Incipient Speciation By Sexual Isolation in Drosophila: Concurrent Evolution At Multiple Loci by Chau-Ti Ting, Aya Takahashi and Chung-I Wu, Proceedings of the National Academy of Sciences of the USA, 98(12): 6709-6713 (5th June 2001) - EMPIRICAL DEMONSTRATION OF THE EXISTENCE OF GENES GOVERNING MALE MATING SUCCESS AND FEMALE MATING PREFERENCE LEADING TO SEXUAL SELECTION AND SPECIATION
Laboratory Experiments On Speciation: What Have We Learned In 40 Years? by William R. Rice and Ellen E. Hostert, Evolution, 47(6):1637-1653 (December 1993) - review of speciation literature and determination of the validity of reproductive isolation as a speciation mechanism
Models Of Evolution Of Rperoductive Isolation by Masatoshi Nei, Takeo Maruyama and Chung-I Wu, Genetics, 103: 557-559 (March 1983) - DIRECT EMPIRICAL TEST OF MODELS OF REPRODUCTIVE ISOLATION, AND ESTABLISHMENT OF CORRELATION WITH REAL WORLD DATA
Phylogenetics And Speciation by Timothy G. Barraclough and Sean Nee, TRENDS in Ecology & Evolution, [b]16(7): 391-399 (July 2001) - Determination of rigorous methods for using phylogenetic analyses to establish speciation events
Pollen-Mediated Introgression And Hybrid Speciation In Louisiana Irises by Michael L. Arnold, Cindy M. Buckner and Jonathan J. Robinson, Proceedings of the National Academy of Sciences of the USA, 88(4): 1398-1402 (February 1991) - OBSERVATION OF A SPECIATION EVENT IN NATURE
Premating Isolation Is Determined by Larval Rearing Substrates in Cactophilic Drosophila mojavensis. IV. Correlated Responses In Behavioral Isolation To Artificial Selection On A Life-History Trait by William J. Etges, The American Naturalist, 152(1): 129-144 (July 1998) - DIRECT EMPIRICAL TEST OF BEHAVIOURAL ISOLATION AS A MECHANISM DRIVING SPECIATION
Rapid Evolution Of Postzygotic Reproductive Isolation In Stalk-Eyed Flies by Sarah J. Christianson, John G. Swallow and Gerald S. Wilkinson, Evolution, 59(4): 849-857 (12th January 2005) - DIRECT EMPIRICAL TEST AND MOLECULAR ANALYSIS OF SEXUAL SELECTION AND HYBRID STERILITY AS MECHANISMS DRIVING SPECIATION
Reproductive Isolation As A Consequence Of Adaptive Divergence In Drosophila pseudoobscura by Diane M. B. Dodd, Evolution, 43(6): 1308-1311 (September 1989) - DIRECT EXPERIMENTAL TEST OF ALLOPATRIC SPECIATION MECHANISMS, which, if continued for a sufficient period of time, will result in an observable speciation event
Role Of Gene Interactions In Hybrid Speciation: Evidence From Ancient And Experimental Hybrids by Loren H. Rieseberg, Barry Sinervo, C. Randall Linder, Mark C. Ungerer and Dulce M. Arias, Science, 272: 741-745 (3rd May 1996) - DIRECT EXPERIMENTAL TESTS OF HYPOTHESES REGARDING HYBRID SPECIATION
Searching For Speciation Genes by Roger Butlin and Michael G. Ritchie, Nature, 412: 31-33 (5th July 2001) - DIRECT EMPIRICAL SEARCH FOR GENES IMPLICATED IN SPECIATION EVENTS
Selfish Operons And Speciation By Gene Transfer by Jeffrey G. Lawrence, Trends in Microbiology, 5(9): 355-359 (September 1997) - EMPIRICAL DETERMINATION OF MECHANISMS FOR DEVELOPMENT OF NEW BACTERIAL SEROTYPES
Sex-Related Genes, Directional Sexual Selection, And Speciation by Alberto Civetta and Rama S. Singh, Molecular & Biological Evolution, 15(7): 901-909 (1998) - EMPIRICAL DETERMINATION OF THE SHAPING OF GENES IMPLICATED IN SPECIATION VIA SEXUAL SELECTION
Sexual Selection, Reproductive Isolation And The Genic View Of Speciation by J. J. M. Van Alphen and Ole Seehausen, Journal of Evolutionary Biology, 14: 874-875 (2001) - application of known speciation mechanisms to the Lake Victoria superflock of Cichlid fishes
Speciation Along Environmental Gradients by Michael Doebeli and Ulf Dieckmann, Nature, 421: 259-264 (16th January 2003) - determination of the effects of environmental pressures upon the outcome of speciation events
Speciation And The Evolution Of Gamete Recognition Genes: Pattern And Process by S. R. Palumbi, Heredity, 102: 66-76 (2009) - determination of the role of gamete recognition genes in speciation events, and their rapid evolution in segregated populations
Speciation By Hybridisation In Heliconius Butterflies by Jesús Mavárez, Camilo A. Salazar, Eldredge Bermingham, Christian Salcedo, Chris D. Jiggins and Mauricio Linares, Nature, 441: 868-871 (15th June 2006) - DETERMINATION OF A SPECIATION EVENT IN NATURE, FOLLOWED BY LABOARTORY REPRODUCTION OF THAT SPECIATION EVENT, AND CONFIRMATION THAT THE LABORATORY INDIVIDUALS ARE INTERFERTILE WITH THE WILD TYPE INDIVIDUALS
Speciation By Hybridization In Phasmids And Other Insects By Luciano Bullini and Guiseppe Nascetti, Canadian Journal of Zoology 68(8): 1747-1760 (1990) - OBSERVATION OF A SPECIATION EVENT IN NATURE
Speciation By Postzygotic Isolation: Forces, Genes And Molecules by H. Allen Orr and Daven C. Presgraves, Bioessays, 22(12): 1085-1094 (2000) - EMPIRICAL DETERMINATION OF THE EXISTENCE OF SPECIATION GENES AND THEIR ROLE IN INTERFERTILITY FAILURE BETWEEN SEGREGATED POPULATIONS
Speciation Genes by H. Allen Orr, John P. Masly and Daven C. Presgraves, Current Opinion in Genetics & Development, 14: 675-679 (2004) - DETERMINATION OF THE EXISTENCE OF SPECIATION GENES AND THEIR SUSCEPTIBILITY TO DARWINIAN SELECTION
Speciation, Hybrid Zones And Phylogeography - Or Seeing Genes In Space And Time by Godfrey M. Hewitt, Molecular Ecology, 10: 537-549 (2001) - review of origins of speciation theory, current developments, and application to past and present speciation events
Speciation By Habitat Specialisation: The Evolution Of Reproductive Isolation As A Correlated Character by William R. Rice, Evolutionary Ecology, 1: 301-314 (1987) - LINKING OF SPECIATION EVENTS TO NICHE MOBILITY AND ADAPTATION FOR NEW NICHES
The Evolution Of Asymmetry In Sexual Isolation: A Model And Test Case by Stevan J. Arnold, Paul A. Verrell and Stephen G. Tilley, Evolution, 50(3): 1024-1033 (June 1996) - DEVELOPMENT OF AN EXTENDED MODEL OF SEXUAL SELECTION FOLLOWED BY EMPIRICAL TEST OF THAT MODEL AND DETERMINATION OF CORRELATION WITH A REAL WORLD POPULATION DIVERGENCE EVENT
The Evolution Of Reproductive Isolation Through Sexual Conflict by Oliver Y. Martin and David J. Hosken, Nature,423: 979-982 (26th June 2003) - DIRECT EXPERIMENTAL TEST OF SEXUAL CONFLICT AS A DRIVER OF SPECIATION
The Evolutionary Genetics Of Speciation by Jerry A. Coyne and H. Allen Orr, Philosophical Transactions of the Royal Society of London Part B, 353: 287-305 (1998) review of recent advances in speciation theory and empirical results
The Genetic Basis Of Reproductive Isolation: Insights From Drosophila by H. Allen Orr, Proceedings of the National Academy of Sciences of the USA, 102 supplement 1: 6522-6526 (3rd May 2005) - review of work on speciation genes and the empirical determination of their roles
The Genic View Of The Process Of Speciation by Chung-I Wu, Journal of Evolutionary Biology, 14: 851-865 (2001) - review of theory of speciation including renewed insights into Darwin’s own early view of the topic, and how this correlates to a hitherto unforeseen extent with modern genetic results
The Gibbons Speciation Mechanism by S. Ramadevon and M. A. B. Deaken, Journal of Theoretical Biology, 145(4): 447-456 (1991) - DEVELOPMENT OF A MODEL ACCOUNTING FOR OBSERVED INSTANCES OF SPECIATION
The Phylogeny Of Closely Related Species As Revealed By The Genealogy Of A Speciation Gene, Odysseus by Chau-Ti Ting, Shun-Chern Tsaur and Chung-I Wu, Proceedings of the National Academy of Sciences of the USA, 97(10): 5313-5316 (9th May 2000) - EXPERIMENTAL VERIFICATION OF A PREDICTION ABOUT SPECIATION MECHANISMS AT THE MOLECULAR LEVEL
The Population Genetics Of Speciation: The Evolution Of Hybrid Incompatibilities by H. Allen Orr, Genetics, 139: 1805-1813 (April 1995) - development of a gene-based model for speciation and the implications of the results obtained from that model for speciation research
The Theory Of Speciation Via The Founder Principle by Alan R. Templeton, Genetics, 94:1011-1038 (April 1980) - development of a model for founder speciation, and DIRECT EXPERIMENTAL TEST of that model by applying it to a real world organism
What Does Drosophila Genetics Tell Us About Speciation? by James Mallet, TRENDS in Ecology & Evolution, 21(7): 386-393 (July 2006) - Comparison of Drosophila data with data from other organisms to produce a more complete picture of speciation mechanics
Part 1 ends here. Part 2 follows shortly.