In this article, the topic of Two-empire system will be addressed from different perspectives and approaches. Two-empire system is a topic of great relevance in today's society, which has generated great debate and interest in various areas of study. Throughout these pages, its implications, impact and possible solutions will be analyzed, with the aim of offering a comprehensive and complete vision of Two-empire system. Both the positive aspects and the challenges it represents will be examined, providing the reader with a wide range of information that allows them to fully understand this topic and form an informed opinion about it.
Biological classification system
The two-empire system (two-superkingdom system) was the top-level biological classification system in general use before the establishment of the three-domain system. It classified cellular life into Prokaryota and Eukaryota as either "empires" or "superkingdoms". When the three-domain system was introduced, some biologists preferred the two-superkingdom system, claiming that the three-domain system overemphasized the division between Archaea and Bacteria. However, given the current state of knowledge and the rapid progress in biological scientific advancement, especially due to genetic analyses, that view has all but vanished.
Some prominent scientists, such as the late Thomas Cavalier-Smith, still hold and held to the two-empire system. The late Ernst Mayr, one of the 20th century's leading evolutionary biologists, wrote dismissively of the three-domain system, "I cannot see any merit at all in a three empire cladification." Additionally, the scientist Radhey Gupta argues for a return to the two-empire system, claiming that the primary division within prokaryotes should be among those surrounded by a single membrane (monoderm), including gram-positive bacteria and archaebacteria, and those with an inner and outer cell membrane (diderm), including gram-negative bacteria.
^Gupta, Radhey S (1998). "Life's Third Domain (Archaea): An Established Fact or an Endangered Paradigm?". Theoretical Population Biology. 54 (2): 91–104. doi:10.1006/tpbi.1998.1376. PMID9733652.
^Linnaeus, C. (1735). Systemae Naturae, sive regna tria naturae, systematics proposita per classes, ordines, genera & species.
^Haeckel, E. (1866). Generelle Morphologie der Organismen. Reimer, Berlin.