Adaptive evolution and explosive speciation: the cichlid fish model

2004 ◽  
Vol 5 (4) ◽  
pp. 288-298 ◽  
Author(s):  
Thomas D. Kocher
Keyword(s):  
Adaptive Evolution ◽  
Cichlid Fish ◽  
Fish Model ◽  
Explosive Speciation

scholarly journals The Adaptive Radiation of Cichlid Fish in Lake Tanganyika: A Morphological Perspective

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Tetsumi Takahashi ◽  
Stephan Koblmüller
Keyword(s):  
East Africa ◽  
Adaptive Radiation ◽  
Lake Tanganyika ◽  
Cichlid Fish ◽  
Ancient Lakes ◽  
Species Assemblage ◽  
Cichlid Species ◽  
Morphological Studies ◽  
Rapid Speciation ◽  
Explosive Speciation

Lake Tanganyika is the oldest of the Great Ancient Lakes in the East Africa. This lake harbours about 250 species of cichlid fish, which are highly diverse in terms of morphology, behaviour, and ecology. Lake Tanganyika's cichlid diversity has evolved through explosive speciation and is treated as a textbook example of adaptive radiation, the rapid differentiation of a single ancestor into an array of species that differ in traits used to exploit their environments and resources. To elucidate the processes and mechanisms underlying the rapid speciation and adaptive radiation of Lake Tanganyika's cichlid species assemblage it is important to integrate evidence from several lines of research. Great efforts have been, are, and certainly will be taken to solve the mystery of how so many cichlid species evolved in so little time. In the present review, we summarize morphological studies that relate to the adaptive radiation of Lake Tanganyika's cichlids and highlight their importance for understanding the process of adaptive radiation.

scholarly journals Secondary contact seeds phenotypic novelty in cichlid fishes

2015 ◽  
Vol 282 (1798) ◽  
pp. 20142272 ◽  
Author(s):  
Paul Nichols ◽  
Martin J. Genner ◽  
Cock van Oosterhout ◽  
Alan Smith ◽  
Paul Parsons ◽  
...  
Keyword(s):  
Adaptive Evolution ◽  
Natural Populations ◽  
Cichlid Fish ◽  
Single Species ◽  
Secondary Contact ◽  
Isolated Populations ◽  
In The Wild ◽  
Genetic Novelty ◽  
Genomic Introgression ◽  
Phenotypic Novelty

Theory proposes that genomic admixture between formerly reproductively isolated populations can generate phenotypic novelty for selection to act upon. Secondary contact may therefore be a significant promoter of phenotypic novelty that allows species to overcome environmental challenges and adapt to novel environments, including during adaptive radiation. To date, this has largely been considered from the perspective of interspecific hybridization at contact zones. However, it is also possible that this process occurs more commonly between natural populations of a single species, and thus its importance in adaptive evolution may have been underestimated. In this study, we tested the consequences of genomic introgression during apparent secondary contact between phenotypically similar lineages of the riverine cichlid fish Astatotilapia calliptera . We provide population genetic evidence of a secondary contact zone in the wild, and then demonstrate using mate-choice experiments that both lineages can reproduce together successfully in laboratory conditions. Finally, we show that genomically admixed individuals display extreme phenotypes not observed in the parental lineages. Collectively, the evidence shows that secondary contact can drive the evolution of phenotypic novelty, suggesting that pulses of secondary contact may repeatedly seed genetic novelty, which when coupled with ecological opportunity could promote rapid adaptive evolution in natural circumstances.

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