On the dependence of speciation rates on species abundance and characteristic population size

Journal of biosciences

Anastassia M Makarieva1¹  Victor G Gorshkov¹ 

[1] Theoretical Physics Division, Petersburg Nuclear Physics Institute, 188300, Gatchina, St.-Petersburg, Russia$$

关键词: Extinction;    fixation;    molecular clock;    neutral theory;    population size;    species duration;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

The question of the potential importance for speciation of large/small population sizes remains open. We compare speciation rates in twelve major taxonomic groups that differ by twenty orders of magnitude in characteristic species abundance (global population number). It is observed that the twenty orders of magnitude’s difference in species abundances scales to less than two orders of magnitude’s difference in speciation rates. As far as species abundance largely determines the rate of generation of intraspecific endogenous genetic variation, the result obtained suggests that the latter rate is not a limiting factor for speciation. Furthermore, the observed approximate constancy of speciation rates in different taxa cannot be accounted for by assuming a neutral or nearly neutral molecular clock in subdivided populations. Neutral fixation is only relevant in sufficiently small populations with 4𝑁𝑒 𝜈 < 1, which appears an unrealistic condition for many taxa of the smaller organisms. Further research is clearly needed to reveal the mechanisms that could equate the evolutionary pace in taxa with dramatically different population sizes.

【 授权许可】

Unknown