TY - JOUR
T1 - United theory of biological evolution
T2 - Disaster-forced evolution through Supernova, radioactive ash fall-outs, genome instability, and mass extinctions
AU - Ebisuzaki, Toshikazu
AU - Maruyama, Shigenori
N1 - Funding Information:
TE thanks Dr. Y. Ishimine for his comments on the volcanic eruptions. This work was supported by Grants-in-Aid for Scientific Research ( 23224012 ) from the Japanese Ministry of Education, Science, Sports, Technology, and Culture . In order to complete this interdisciplinary-based (geological, biological, and astrophysics) investigation, we poured through countless papers, and thus express sincere thanks to all the efforts of the librarians in Japan who have supplied us with copies of papers through Interlibrary Copy Order Service. We thank Dr. James Dohm for the improvement of English.
Publisher Copyright:
© 2014, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. All rights reserved.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - We present the disaster-forced biological evolution model as a general framework that includes Darwinian "phylogenic gradualism", Eldredge-Gould's "punctuated equilibrium", mass extinctions, and allopatric, parapatric, and sympatric speciation. It describes how reproductive isolation of organisms is established through global disasters due to supernova encounters and local disasters due to radioactive volcanic ash fall-outs by continental alkaline volcanism. Our new evolution model uniquely highlights three major factors of disaster-forced speciation: enhanced mutation rate by higher natural radiation level, smaller population size, and shrunken habitat size (i.e., isolation among the individual populations). We developed a mathematical model describing speciation of a half-isolated group from a parental group, taking into account the population size (Ne), immigration rate (m), and mutation rate (μ). The model gives a quantitative estimate of the speciation, which is consistent with the observations of speciation speed. For example, the speciation takes at least 105 generations, if mutation rate is less than 10-3 per generation per individual. This result is consistent with the previous studies, in which μ is assumed to be 10-3-10-5. On the other hand, the speciation is much faster (less than 105 generations) for the case that μ is as large as 0.1 in parapatric conditions (m < μ). Even a sympatric (m ∼ 1) speciation can occur within 103 generations, if mutation rate is very high (μ ∼ 1 mutation per individual per generation), and if Ne < 20-30. Such a high mutation rate is possible during global disasters due to supernova encounters and local disasters due to radioactive ash fall-outs. They raise natural radiation level by a factor of 100-1000. Such rapid speciation events can also contribute to macro-evolution during mass extinction events, such as observed during the Cambrian explosion of biodiversity. A similar rapid speciation (though in a much smaller scale) also has been undergoing in cichlid fishes and great African apes in the last several tens of thousand years in the current African rift valley, including the origin of humankind due to the radioactive ash fall-outs by continental alkaline volcanism.
AB - We present the disaster-forced biological evolution model as a general framework that includes Darwinian "phylogenic gradualism", Eldredge-Gould's "punctuated equilibrium", mass extinctions, and allopatric, parapatric, and sympatric speciation. It describes how reproductive isolation of organisms is established through global disasters due to supernova encounters and local disasters due to radioactive volcanic ash fall-outs by continental alkaline volcanism. Our new evolution model uniquely highlights three major factors of disaster-forced speciation: enhanced mutation rate by higher natural radiation level, smaller population size, and shrunken habitat size (i.e., isolation among the individual populations). We developed a mathematical model describing speciation of a half-isolated group from a parental group, taking into account the population size (Ne), immigration rate (m), and mutation rate (μ). The model gives a quantitative estimate of the speciation, which is consistent with the observations of speciation speed. For example, the speciation takes at least 105 generations, if mutation rate is less than 10-3 per generation per individual. This result is consistent with the previous studies, in which μ is assumed to be 10-3-10-5. On the other hand, the speciation is much faster (less than 105 generations) for the case that μ is as large as 0.1 in parapatric conditions (m < μ). Even a sympatric (m ∼ 1) speciation can occur within 103 generations, if mutation rate is very high (μ ∼ 1 mutation per individual per generation), and if Ne < 20-30. Such a high mutation rate is possible during global disasters due to supernova encounters and local disasters due to radioactive ash fall-outs. They raise natural radiation level by a factor of 100-1000. Such rapid speciation events can also contribute to macro-evolution during mass extinction events, such as observed during the Cambrian explosion of biodiversity. A similar rapid speciation (though in a much smaller scale) also has been undergoing in cichlid fishes and great African apes in the last several tens of thousand years in the current African rift valley, including the origin of humankind due to the radioactive ash fall-outs by continental alkaline volcanism.
KW - Cambrian explosion
KW - Cichlid
KW - Continental alkaline volcanism
KW - Great African ape
KW - Speciation
KW - Supernova encounter
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U2 - 10.1016/j.gsf.2014.04.009
DO - 10.1016/j.gsf.2014.04.009
M3 - Article
AN - SCOPUS:84918594777
VL - 6
SP - 103
EP - 119
JO - Geoscience Frontiers
JF - Geoscience Frontiers
SN - 1674-9871
IS - 1
ER -