Related Experiment Video
Updated: Jun 16, 2026
06:48
Assessing Intertidal Populations of the Invasive European Green Crab
Published on: September 16, 2020
Adaptive radiations: competition rules for Galápagos gastropods
Paul M Richards1, Angus Davison
1Institute of Genetics, School of Biology, University of Nottingham, Nottingham NG7 2RD, UK. plxpr5@nottingham.ac.uk
Current Biology : CB
|February 16, 2010
Summary
Galápagos land snails seized unique opportunities on new islands. Competition and diverse resources drove their adaptive radiation, allowing for evolutionary innovation.
Area of Science:
- Evolutionary biology
- Ecology
- Island biogeography
Background:
- New islands offer unique ecological settings for speciation.
- Adaptive radiation is a key process in evolutionary diversification.
- Galápagos land snails provide a model system for studying evolutionary processes.
Purpose of the Study:
- To investigate the factors driving adaptive radiation in Galápagos land snails.
- To understand the role of competition and resource diversity in evolutionary innovation.
Main Methods:
- Phylogenetic analysis of Galápagos land snail species.
- Ecological niche modeling to assess resource availability.
- Comparative analysis of shell morphology and habitat.
Main Results:
- Evidence of two distinct periods of adaptive radiation in Galápagos land snails.
- Competition and high resource diversity were identified as key drivers.
- Snails exhibited significant morphological and ecological divergence.
Conclusions:
- Galápagos land snails experienced recurrent opportunities for adaptive radiation.
- Environmental factors, including competition and resource availability, shaped their evolutionary trajectories.
- This study highlights the dynamic interplay between ecological opportunity and evolutionary diversification.
Related Concept Videos
02:34Competition
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.Intraspecific competition, which occurs between individuals of the same species, serves as a natural mechanism for regulating population size. Too much...
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...
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.
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
01:46Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
02:55The Evidence for Evolution
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.