Related Experiment Video
Updated: Jun 8, 2026
06:36
Incremental Temperature Changes for Maximal Breeding and Spawning in Astyanax mexicanus
Published on: February 14, 2021
Temporal diversification of Central American cichlids
C Darrin Hulsey1, Phillip R Hollingsworth, James A Fordyce
1Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA. chulsey@utk.edu
BMC Evolutionary Biology
|September 16, 2010
Summary
Heroine cichlids in Central America did not experience an early burst of diversification after invasion. Instead, these fish diversified at a consistent rate throughout their evolutionary history.
Area of Science:
- Evolutionary biology
- Ichthyology
- Speciation research
Background:
- Cichlid fishes are prime examples of adaptive radiation.
- Adaptive radiation is characterized by rapid diversification following environmental invasion.
- Heroine cichlids are a species-rich group found in Central America.
Purpose of the Study:
- To investigate if Heroine cichlids underwent a diversification burst upon invading Central America.
- To determine if ecological opportunity influenced early diversification rates in this group.
- To test the hypothesis of an 'early burst' of speciation in cichlid adaptive radiation.
Main Methods:
- Phylogenetic reconstruction of Heroine cichlids.
- Analysis of lineage accumulation patterns using pure-birth models.
- Simulations incorporating incomplete taxon sampling and node truncation.
Main Results:
- Phylogenetic analyses did not support a significant deviation from a constant diversification rate.
- Incomplete taxon sampling did not obscure evidence for an early burst.
- Node truncation analyses further weakened support for an early diversification surge.
Conclusions:
- Heroine cichlids did not experience a diversification burst after invading Central America.
- Diversification in this group occurred at a constant rate throughout their history.
- The 'early burst' model of adaptive radiation may not apply universally to all cichlid radiations.
Related Concept Videos
02:29Hybrid Zones
Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.Gene flow and natural selection are evolutionary mechanisms that shape the outcome of a hybrid zone. Gene flow...
01:07Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
01:31Formation of Species
Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.Allopatric SpeciationIn allopatric speciation, gene flow between two populations of the same species is prevented by a geographic barrier, like...
02:16Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms...
01:54Convergent Evolution
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...
02:39Gene Flow
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.