Similar species share similar genes

The only figure in Darwin’s book, The Origin of Species, showed how he envisioned species branching off of one another. Similar species have a relatively recent common ancestor and have had limited time to diverge from each other. This means that their genes should be similar. Entirely new genes, for instance, would not have enough time to evolve. As François Jacob explained in an influential paper from 1977, “The probability that a functional protein would appear de novo by random association of amino acids is practically zero.” (Jacob) Any newly created gene would have to arise from a duplication and modification of a pre-existing gene. (Zhou et. al.; Ohno) But such a new gene would retain significant similarity to its progenitor gene. Indeed, for decades evolutionists have cited minor genetic differences between similar species as a confirmation of this important prediction. (Berra, 20; Futuyma, 50; Johnson and Raven, 287; Jukes, 120; Mayr, 35)
 
But this prediction has been falsified as many unexpected genetic differences have been discovered amongst a wide range of allied species. (Pilcher) As much as a third of the genes in a given species may be unique, and even different variants within the same species have large numbers of genes unique to each variant. Different variants of the Escherichia coli bacteria, for instance, each have hundreds of unique genes. (Daubin and Ochman)
 
Significant genetic differences were also found between different fruit fly species. Thousands of genes showed up missing in many of the species, and some genes showed up in only a single species. (Levine et. al.) As one science writer put it, “an astonishing 12 per cent of recently evolved genes in fruit flies appear to have evolved from scratch.” (Le Page) These novel genes must have evolved over a few million years, a time period previously considered to allow only for minor genetic changes. (Begun et. al.; Chen et. al., 2007)
 
Initially some evolutionists thought these surprising results would be resolved when more genomes were analyzed. They predicted that similar copies of these genes would be found in other species. But instead each new genome has revealed yet more novel genes. (Curtis et. al.; Marsden et. al.; Pilcher)
 
Next evolutionists thought that these rapidly-evolving unique genes must not code for functional or important proteins. But again, many of the unique proteins were in fact found to play essential roles. (Chen, Zhang and Long 1010; Daubin and Ochman; Pilcher) As one researcher explained, “This goes against the textbooks, which say the genes encoding essential functions were created in ancient times.” (Pilcher)
 
References
 
Begun, D., H. Lindfors, A. Kern, C. Jones. 2007. “Evidence for de novo evolution of testis-expressed genes in the Drosophila yakuba/Drosophila erecta clade.” Genetics 176:1131-1137.
 
Berra, Tim. 1990. Evolution and the Myth of Creationism. Stanford: Stanford University Press.
 
Chen, S., H. Cheng, D. Barbash, H. Yang. 2007. “Evolution of hydra, a recently evolved testis-expressed gene with nine alternative first exons in Drosophila melanogaster.” PLoS Genetics 3.
 
Chen, S., Y. Zhang, M. Long. 2010. “New Genes in Drosophila Quickly Become Essential.” Science 330:1682-1685.
 
Curtis, B., et. al. 2012. “Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs.” Nature 492:59-65.
 
Daubin, V., H. Ochman. 2004. “Bacterial genomes as new gene homes: The genealogy of ORFans in E. coli.” Genome Research 14:1036-1042.
 
Futuyma, Douglas. 1982. Science on Trial: The Case for Evolution. New York: Pantheon Books.
 
Jacob, François. 1977. “Evolution and tinkering.” Science 196:1161-1166.
 
Johnson, G., P. Raven. 2004. Biology. New York: Holt, Rinehart and Winston.
 
Jukes, Thomas. 1983. “Molecular evidence for evolution” in: Scientists Confront Creationism, ed. Laurie Godfrey. New York: W. W. Norton.
 
Le Page, M. 2008. “Recipes for life: How genes evolve.” New Scientist, November 24.
 
Levine, M., C. Jones, A. Kern, H. Lindfors, D. Begun. 2006. “Novel genes derived from noncoding DNA in Drosophila melanogaster are frequently X-linked and exhibit testis-biased expression.” Proceedings of the National Academy of Sciences 103: 9935-9939.
 
Marsden, R. et. al. 2006. “Comprehensive genome analysis of 203 genomes provides structural genomics with new insights into protein family space.” Nucleic Acids Research 34:1066-1080.
 
Mayr, Ernst. 2001. What Evolution Is. New York: Basic Books.
 
Ohno, Susumu. 1970. Evolution by Gene Duplication. Heidelberg: Springer.
 
Pilcher, Helen. 2013. “All Alone.” NewScientist January 19.

Zhou, Q., G. Zhang, Y. Zhang, et. al. 2008. “On the origin of new genes in Drosophila.” Genome Research 18:1446-1455.