necessary condition, acknowledging that observed speciation events among Drosophila fruitflies had been shown to cut off hybridization. Marsh also originated "discontinuity systematics", the idea that there are boundaries between different animals that cannot be crossed with the consequence that there would be discontinuities in the history of life and limits to common ancestry. Baraminology In 1990, Kurt Wise introduced baraminology as an adaptation of Marsh's and Walter ReMine's ideas that was more in keeping with young Earth creationism. Wise advocated using the Bible as a source of systematic data. Baraminology and its associated concepts have been criticized by scientists and creationists for lacking formal structure. Consequently, in 2003 Wise and other creationists proposed a refined baramin concept in the hope of developing a broader creationist model of biology. Alan Gishlick, reviewing the work of baraminologists in 2006, found it to be surprisingly rigorous and internally consistent, but concluded that the methods did not work. Walter ReMine specified four groupings: holobaramins, monobaramins, apobaramins, and polybaramins. These are, respectively, all things of one kind; some things of the same kind; groups of kinds; and any mixed grouping of things. These groups correspond to the concepts of holophyly, monophyly, paraphyly, and polyphyly used in cladistics. Methods Baraminology employs many of the same methods used in evolutionary systematics, including cladistics and Analysis of Pattern (ANOPA). However, instead of identifying continuity between groups of organisms based on shared similarities, baraminology uses these methods to search for morphological and genetic gaps between groups. Baraminologists have also developed their own creationist systematics software, known as BDIST, to measure distance between groups. Criticism The methods of baraminology are not universally accepted among young-Earth creationists. Other creationists have criticized these methods as having the same problems as traditional cladistics, as well as for occasionally producing results that they feel contradict the Bible. Baraminology has been heavily criticized for its lack of rigorous tests and post-study rejection of data to make it better fit the desired findings. By denying general common descent, it tends to produce inconsistent results that also conflict with evidence discovered by biology. Created kinds have been compared to other attempts at "alternate research" to produce artificial pseudoscientific "evidence" that support preconceived conclusions, similarly to how advocacy was done by the tobacco industry. The US National Academy of Sciences and numerous other scientific and scholarly organizations recognize creation science as pseudoscience. Some techniques employed in Baraminology have