scholarly journals Cryptic Population Dynamics: Rapid Evolution Masks Trophic Interactions

PLoS Biology ◽  
2007 ◽  
Vol 5 (9) ◽  
pp. e235 ◽  
Author(s):  
Takehito Yoshida ◽  
Stephen P Ellner ◽  
Laura E Jones ◽  
Brendan J. M Bohannan ◽  
Richard E Lenski ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Trophic Interactions ◽  
Rapid Evolution

scholarly journals Rapid evolution leads to differential population dynamics and top-down control in resurrectedDaphniapopulations

2017 ◽  
Vol 11 (1) ◽  
pp. 96-111 ◽  
Author(s):  
Eyerusalem Goitom ◽  
Laurens J. Kilsdonk ◽  
Kristien Brans ◽  
Mieke Jansen ◽  
Pieter Lemmens ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Rapid Evolution ◽  
Top Down

scholarly journals Warming can destabilise predator-prey interactions by shifting the functional response from Type III to Type II

2018 ◽  
Author(s):  
Uriah Daugaard ◽  
Owen Petchey ◽  
Frank Pennekamp
Keyword(s):  
Population Dynamics ◽  
Functional Response ◽  
Conversion Efficiency ◽  
Trophic Interactions ◽  
Clearance Rate ◽  
Temperature Effects ◽  
Type Ii ◽  
Predator Prey ◽  
Type Iii ◽  
Population Dynamic Model

The potential for climate change and temperature shifts to affect community stability remains relatively unknown. One mechanism by which temperature may affect stability is by altering trophic interactions. The functional response quantifies the per capita resource consumption by the consumer as a function of resource abundance and is a suitable framework for the description of nonlinear trophic interactions. We studied the effect of temperature on a ciliate predator-prey pair (Spathidium sp. and Dexiostoma campylum) by estimating warming effects on the functional response and on the associated conversion efficiency of the predator. We recorded prey and predator dynamics over 24 hours and at three temperature levels (15, 20 and 25 C). To these data we fitted a population dynamic model including the predator functional response, such that the functional response parameters (space clearance rate, handling time, and density dependence of space clearance rate) were estimated for each temperature separately. To evaluate the ecological significance of temperature effects on the functional response parameters we simulated predator-prey population dynamics. We considered the predator-prey system to be destabilised, if the prey was driven extinct by the predator. Effects of increased temperature included a transition of the functional response from a Type III to a Type II and an increase of the conversion efficiency of the predator. The simulated population dynamics showed a destabilisation of the system with warming, with greater risk of prey extinction at higher temperatures likely caused by the transition from a Type III to a Type II functional response. Warming-induced shifts from a Type III to II are not commonly considered in modelling studies that investigate how population dynamics respond to warming. Future studies should investigate the mechanism and generality of the effect we observed and simulate temperature effects in complex food webs including shifts in the type of the functional response as well as consider the possibility of a temperature dependent conversion efficiency.

scholarly journals Effects of rapid evolution on species coexistence

2019 ◽  
Vol 116 (6) ◽  
pp. 2112-2117 ◽  
Author(s):  
Simon P. Hart ◽  
Martin M. Turcotte ◽  
Jonathan M. Levine
Keyword(s):  
Population Dynamics ◽  
Species Diversity ◽  
Interspecific Competition ◽  
Species Coexistence ◽  
Rapid Evolution ◽  
Empirical Work ◽  
Niche Differentiation ◽  
Ecological Communities ◽  
Competing Species ◽  
Ecological Processes

Increasing evidence for rapid evolution suggests that the maintenance of species diversity in ecological communities may be influenced by more than purely ecological processes. Classic theory shows that interspecific competition may select for traits that increase niche differentiation, weakening competition and thus promoting species coexistence. While empirical work has demonstrated trait evolution in response to competition, if and how evolution affects the dynamics of the competing species—the key step for completing the required eco-evolutionary feedback—has been difficult to resolve. Here, we show that evolution in response to interspecific competition feeds back to change the course of competitive population dynamics of aquatic plant species over 10–15 generations in the field. By manipulating selection imposed by heterospecific competitors in experimental ponds, we demonstrate that (i) interspecific competition drives rapid genotypic change, and (ii) this evolutionary change in one competitor, while not changing the coexistence outcome, causes the population trajectories of the two competing species to converge. In contrast to the common expectation that interspecific competition should drive the evolution of niche differentiation, our results suggest that genotypic evolution resulted in phenotypic changes that altered population dynamics by affecting the competitive hierarchy. This result is consistent with theory suggesting that competition for essential resources can limit opportunities for the evolution of niche differentiation. Our finding that rapid evolution regulates the dynamics of competing species suggests that ecosystems may rely on continuous feedbacks between ecology and evolution to maintain species diversity.

scholarly journals Rapid Evolution of a Sexual Reproduction Gene in Centric Diatoms of the Genus Thalassiosira

2001 ◽  
Vol 67 (8) ◽  
pp. 3501-3513 ◽  
Author(s):  
E. Virginia Armbrust ◽  
H. M. Galindo
Keyword(s):  
Population Dynamics ◽  
Sexual Reproduction ◽  
Related Species ◽  
Rapid Evolution ◽  
Sequence Divergence ◽  
Thalassiosira Pseudonana ◽  
Centric Diatom ◽  
Additional Species ◽  
Gamete Recognition ◽  
The Impact

ABSTRACT Sexual reproduction is commonly assumed to occur in the vast majority of diatoms due to the intimate association of this process with cell size control. Surprisingly, however, little is known about the impact of sexual events on diatom population dynamics. TheSig1 gene is strongly upregulated during sexual reproduction in the centric diatom Thalassiosira weissflogii and has been hypothesized to encode a protein involved in gamete recognition. In the present study, degenerate PCR primers were designed and used to amplify a portion ofSig1 from three closely related species in the cosmopolitan genus Thalassiosira, Thalassiosira oceanica, Thalassiosira guillardii, andThalassiosira pseudonana. Identification ofSig1 in these three additional species facilitated development of this gene as a molecular marker for diatom sexual events. Examination of the new sequences indicated that multiple copies of Sig1 are probably present in the genome. Moreover, compared to the housekeeping geneβ -tubulin, the Sig1genes of isolates of T. weissflogii collected from different regions of the Atlantic and Pacific oceans displayed high levels of divergence. The Sig1 genes of the four closely related Thalassiosira species also displayed high levels of sequence divergence compared to the levels observed with a second gene, Fcp, probably explaining why Sig1could not be amplified from more distantly related species. The high levels of sequence divergence both within and between species suggest that Sig1 is rapidly evolving in a manner reminiscent of the manner observed in other genes that encode gamete recognition proteins. A simple model is presented for Sig1 evolution and the implications of such a rapidly evolving sexual reproduction gene for diatom speciation and population dynamics.

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