scholarly journals Axiomatic-deductive theory of competition of complete competitors: coexistence, exclusion and neutrality in one model

2020 ◽  
Author(s):  
Lev V. Kalmykov ◽  
Vyacheslav L. Kalmykov
Keyword(s):  
Artificial Intelligence ◽  
Competitive Exclusion ◽  
Ecosystem Dynamics ◽  
Exclusion Principle ◽  
Single Individual ◽  
Competing Species ◽  
Competitive Exclusion Principle ◽  
Cooperative Effects ◽  
Initial Location ◽  
Individual Based Modeling

AbstractBackgroundThe long-standing contradiction between formulations of the competitive exclusion principle and natural diversity of trophically similar species is known as the biodiversity paradox. Earlier we found that coexistence of complete competitors is possible despite 100% difference in competitiveness, but only under certain conditions – at their moderate propagation and at the particular initial location of individuals. Here we verify a hypothesis that completely competing species with aggressive propagation may coexist with less than 100% difference in competitiveness regardless of random initial location of competing individuals in ecosystem.MethodsWe investigate a role of competitiveness differences in coexistence of two completely competing species by individual-based modeling based on a transparent artificial intelligence. We propose and investigate an individual-based model of ecosystem dynamics supplemented by a probabilistic determination of the competitiveness of competing individuals without cooperative effects and with cooperative effects based on the numerical superiority of individuals of the species.ResultsWe have found that two aggressively propagating complete competitors can stably coexist, despite one species has some advantage in competitiveness over the other and all other characteristics of the species are equal. The found competitive coexistence occurred regardless of the initial random location of individuals in the ecosystem. When colonization of a free habitat started from a single individual of each species, then the complete competitors coexisted up to 31% of their difference in competitiveness. And when on initial stage half of the territory was probabilistically occupied, the complete competitors coexisted up to 22% of their difference in competitiveness. In the experiments with cooperative dependence on the numerical superiority of individuals of the species complete competitors stably co-existed despite 10% difference in basic competitiveness.DiscussionThe results additionally support our earlier reformulation of the competitive exclusion principle. Besides that, we revealed classical cases of competitive exclusion and “neutrality”. Our approach unifies models of competitive exclusion (“niche”), neutrality and coexistence of complete competitors in one theory. Our individual-based modeling of a complex system based on a transparent artificial intelligence opens up great prospects for a variety of theoretical and applied fields.

scholarly journals Coexistence of complete competitors with fitness inequality

2017 ◽  
Author(s):  
Lev Kalmykov ◽  
Vyacheslav Kalmykov
Keyword(s):  
Competitive Exclusion ◽  
Initial Conditions ◽  
Exclusion Principle ◽  
Single Individual ◽  
Competing Species ◽  
Competitive Exclusion Principle ◽  
Trade Offs ◽  
Initial Stage ◽  
Initial Location ◽  
Rigorous Model

There was a long standing contradiction between formulations of the competitive exclusion principle and natural species richness, which is known as the biodiversity paradox. Here we investigate a role of fitness differences in coexistence of two completely competing species using individual-based cellular automata. According to the classical formulations of the competitive exclusion principle such coexistence is impossible. Earlier we found that coexistence of complete competitors is possible with a 100% difference in fitness, but only under certain initial conditions. Here we verify a hypothesis that completely competing species may coexist with less than 100% difference in fitness regardless of different initial location of competing individuals in the ecosystem. We have found a new fact that two aggressively propagating complete competitors can stably coexist in one limited, stable and homogeneous habitat, when one species has some advantage in fitness over the other and all other characteristics of the species are equal, in particular any trade-offs and cooperations are absent. This fact is established theoretically on the rigorous model. The found competitive coexistence occurred regardless of the initial location of individuals in the ecosystem. When colonization of free habitat started from a single individual of each species, then the complete competitors coexisted up to 31% of their difference in fitness. And when on initial stage half of the territory was probabilistically occupied, the complete competitors coexisted up to 22% of their difference in fitness. These results additionally support our reformulation of the competitive exclusion principle, which we consider as resolving of the biodiversity paradox.

Ecological Theory and the Superfluous Niche

2019 ◽  
Vol 47 (1) ◽  
pp. 105-123
Author(s):  
James Justus ◽  
Keyword(s):  
Competitive Exclusion ◽  
Ecological Theory ◽  
Character Displacement ◽  
Exclusion Principle ◽  
Limiting Similarity ◽  
Competitive Exclusion Principle ◽  
Ecological Equivalence

Perhaps no concept has been thought more important to ecological theorizing than the niche. Without it, technically sophisticated and well-regarded accounts of character displacement, ecological equivalence, limiting similarity, and others would seemingly never have been developed. The niche is also widely considered the centerpiece of the best candidate for a distinctively ecological law, the competitive exclusion principle. But the incongruous array and imprecise character of proposed definitions of the concept square poorly with its apparent scientific centrality. I argue this definitional diversity and imprecision reflects a problematic conceptual indeterminacy that challenges its putative indispensability in ecology.

The distribution and behavior of Peromyscus maniculatus gracilis and Peromyscus leucopus noveboracensis (Rodentia: Cricetidae) in a southeastern Ontario woodlot

1970 ◽  
Vol 48 (6) ◽  
pp. 1187-1199 ◽  
Author(s):  
Donald A. Smith ◽  
S. Wayne Speller
Keyword(s):  
Competitive Exclusion ◽  
Peromyscus Leucopus ◽  
Population Characteristics ◽  
Exclusion Principle ◽  
Dense Population ◽  
Competitive Exclusion Principle ◽  
Upland Forest ◽  
Live Trapping ◽  
Tree Holes ◽  
And Behavior

P. m. gracilis and P. l. noveboracensis are sympatric in southeastern Ontario and some adjacent areas. Similar in appearance, food and breeding habits, and frequently cohabiting certain forests, they may occupy identical niches, contrary to the competitive exclusion principle. A 12-week summer live-trapping study in a woodlot containing upland, mixed, and cedar forest associations showed that although most of their population characteristics were similar, their local distributions, densities, and certain behaviors differed. Noveboracensis inhabited upland forest but avoided mixed and cedar forest associations apparently because suitable refuges were lacking. The less dense population of gracilis was ubiquitous; gracilis and noveboracensis cohabited the upland forest. On release from traps noveboracensis sometimes 'froze' before darting in a zigzag manner to nearby cover, and ran up trees significantly more than gracilis, which usually ran instantly, rapidly, and directly to a more distant ground refuge. Low densities of both species reduced competition for available food and refuges. This may have facilitated cohabitation in the upland forest where differential use of ground- and tree-holes also contributed to reduction of competition and thus to compatibility. Coexistence may be transitory there; with denser populations, potential competition might be minimized by emigration of the more exploratory gracilis.

Sign in / Sign up

Export Citation Format

Share Document