scholarly journals Evidence for determinism in species diversification and contingency in phenotypic evolution during adaptive radiation

2012 ◽  
Vol 279 (1748) ◽  
pp. 4817-4826 ◽  
Author(s):  
Frank T. Burbrink ◽  
Xin Chen ◽  
Edward A. Myers ◽  
Matthew C. Brandley ◽  
R. Alexander Pyron
Keyword(s):  
Adaptive Radiation ◽  
New World ◽  
Morphological Evolution ◽  
Rapid Change ◽  
Phenotypic Evolution ◽  
Late Oligocene ◽  
Species Diversification ◽  
Continental Scale ◽  
Phenotypic Diversification ◽  
Time Periods

Adaptive radiation (AR) theory predicts that groups sharing the same source of ecological opportunity (EO) will experience deterministic species diversification and morphological evolution. Thus, deterministic ecological and morphological evolution should be correlated with deterministic patterns in the tempo and mode of speciation for groups in similar habitats and time periods. We test this hypothesis using well-sampled phylogenies of four squamate groups that colonized the New World (NW) in the Late Oligocene. We use both standard and coalescent models to assess species diversification, as well as likelihood models to examine morphological evolution. All squamate groups show similar early pulses of speciation, as well as diversity-dependent ecological limits on clade size at a continental scale. In contrast, processes of morphological evolution are not easily predictable and do not show similar pulses of early and rapid change. Patterns of morphological and species diversification thus appear uncoupled across these groups. This indicates that the processes that drive diversification and disparification are not mechanistically linked, even among similar groups of taxa experiencing the same sources of EO. It also suggests that processes of phenotypic diversification cannot be predicted solely from the existence of an AR or knowledge of the process of diversification.

scholarly journals Iterative adaptive radiations of fossil canids show no evidence for diversity-dependent trait evolution

2015 ◽  
Vol 112 (16) ◽  
pp. 4897-4902 ◽  
Author(s):  
Graham J. Slater
Keyword(s):  
Adaptive Radiation ◽  
Morphological Evolution ◽  
Empirical Support ◽  
Phenotypic Evolution ◽  
Ecological Opportunity ◽  
Radiation Theory ◽  
Molar Teeth ◽  
Adaptive Radiations ◽  
Adaptive Peak ◽  
Adaptive Zone

A long-standing hypothesis in adaptive radiation theory is that ecological opportunity constrains rates of phenotypic evolution, generating a burst of morphological disparity early in clade history. Empirical support for the early burst model is rare in comparative data, however. One possible reason for this lack of support is that most phylogenetic tests have focused on extant clades, neglecting information from fossil taxa. Here, I test for the expected signature of adaptive radiation using the outstanding 40-My fossil record of North American canids. Models implying time- and diversity-dependent rates of morphological evolution are strongly rejected for two ecologically important traits, body size and grinding area of the molar teeth. Instead, Ornstein–Uhlenbeck processes implying repeated, and sometimes rapid, attraction to distinct dietary adaptive peaks receive substantial support. Diversity-dependent rates of morphological evolution seem uncommon in clades, such as canids, that exhibit a pattern of replicated adaptive radiation. Instead, these clades might best be thought of as deterministic radiations in constrained Simpsonian subzones of a major adaptive zone. Support for adaptive peak models may be diagnostic of subzonal radiations. It remains to be seen whether early burst or ecological opportunity models can explain broader adaptive radiations, such as the evolution of higher taxa.

scholarly journals Toxin expression in snake venom evolves rapidly with constant shifts in evolutionary rates

2020 ◽  
Vol 287 (1926) ◽  
pp. 20200613 ◽  
Author(s):  
Agneesh Barua ◽  
Alexander S. Mikheyev
Keyword(s):  
Snake Venom ◽  
Adaptive Radiation ◽  
Prey Capture ◽  
Phenotypic Evolution ◽  
Venomous Snake ◽  
Rates Of Evolution ◽  
Key Innovation ◽  
Venom Evolution ◽  
Phenotypic Diversification ◽  
Key Innovations

Key innovations provide ecological opportunity by enabling access to new resources, colonization of new environments, and are associated with adaptive radiation. The most well-known pattern associated with adaptive radiation is an early burst of phenotypic diversification. Venoms facilitate prey capture and are widely believed to be key innovations leading to adaptive radiation. However, few studies have estimated their evolutionary rate dynamics. Here, we test for patterns of adaptive evolution in venom gene expression data from 52 venomous snake species. By identifying shifts in tempo and mode of evolution along with models of phenotypic evolution, we show that snake venom exhibits the macroevolutionary dynamics expected of key innovations. Namely, all toxin families undergo shifts in their rates of evolution, likely in response to changes in adaptive optima. Furthermore, we show that rapid-pulsed evolution modelled as a Lévy process better fits snake venom evolution than conventional early burst or Ornstein–Uhlenbeck models. While our results support the idea of snake venom being a key innovation, the innovation of venom chemistry lacks clear mechanisms that would lead to reproductive isolation and thus adaptive radiation. Therefore, the extent to which venom directly influences the diversification process is still a matter of contention.

scholarly journals Biomechanical trade-offs bias rates of evolution in the feeding apparatus of fishes

2011 ◽  
Vol 279 (1732) ◽  
pp. 1287-1292 ◽  
Author(s):  
Roi Holzman ◽  
David C. Collar ◽  
Samantha A. Price ◽  
C. Darrin Hulsey ◽  
Robert C. Thomson ◽  
...  
Keyword(s):  
Genetic Factors ◽  
Morphological Evolution ◽  
The Body ◽  
Body Parts ◽  
Phenotypic Evolution ◽  
Genetic Constraints ◽  
Functional Systems ◽  
Rates Of Evolution ◽  
Trade Offs

Morphological diversification does not proceed evenly across the organism. Some body parts tend to evolve at higher rates than others, and these rate biases are often attributed to sexual and natural selection or to genetic constraints. We hypothesized that variation in the rates of morphological evolution among body parts could also be related to the performance consequences of the functional systems that make up the body. Specifically, we tested the widely held expectation that the rate of evolution for a trait is negatively correlated with the strength of biomechanical trade-offs to which it is exposed. We quantified the magnitude of trade-offs acting on the morphological components of three feeding-related functional systems in four radiations of teleost fishes. After accounting for differences in the rates of morphological evolution between radiations, we found that traits that contribute more to performance trade-offs tend to evolve more rapidly, contrary to the prediction. While ecological and genetic factors are known to have strong effects on rates of phenotypic evolution, this study highlights the role of the biomechanical architecture of functional systems in biasing the rates and direction of trait evolution.

scholarly journals Intraspecific adaptive radiation: Competition, ecological opportunity, and phenotypic diversification within species

Evolution ◽  
2017 ◽  
Vol 71 (10) ◽  
pp. 2496-2509 ◽  
Author(s):  
Nicholas A. Levis ◽  
Ryan A. Martin ◽  
Kerry A. O'Donnell ◽  
David W. Pfennig
Keyword(s):  
Adaptive Radiation ◽  
Ecological Opportunity ◽  
Phenotypic Diversification

scholarly journals Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous–Palaeogene mass extinction

2016 ◽  
Vol 283 (1833) ◽  
pp. 20153026 ◽  
Author(s):  
Thomas John Dixon Halliday ◽  
Paul Upchurch ◽  
Anjali Goswami
Keyword(s):  
Phylogenetic Analysis ◽  
Adaptive Radiation ◽  
Mass Extinction ◽  
Fossil Record ◽  
Morphological Evolution ◽  
Placental Mammal ◽  
Stochastic Methods ◽  
Ecological Niches ◽  
Evolutionary Radiation ◽  
Quantitative Analyses

The effect of the Cretaceous–Palaeogene (K–Pg) mass extinction on the evolution of many groups, including placental mammals, has been hotly debated. The fossil record suggests a sudden adaptive radiation of placentals immediately after the event, but several recent quantitative analyses have reconstructed no significant increase in either clade origination rates or rates of character evolution in the Palaeocene. Here we use stochastic methods to date a recent phylogenetic analysis of Cretaceous and Palaeocene mammals and show that Placentalia likely originated in the Late Cretaceous, but that most intraordinal diversification occurred during the earliest Palaeocene. This analysis reconstructs fewer than 10 placental mammal lineages crossing the K–Pg boundary. Moreover, we show that rates of morphological evolution in the 5 Myr interval immediately after the K–Pg mass extinction are three times higher than background rates during the Cretaceous. These results suggest that the K–Pg mass extinction had a marked impact on placental mammal diversification, supporting the view that an evolutionary radiation occurred as placental lineages invaded new ecological niches during the Early Palaeocene.

The Intellectual Challenge of Morphological Evolution: A Case for Variational Structuralism

2014 ◽  
Author(s):  
Günter P. Wagner
Keyword(s):  
Developmental Biology ◽  
Evolutionary Biology ◽  
Morphological Evolution ◽  
Evolutionary Developmental Biology ◽  
Phenotypic Evolution ◽  
Developmental Variation ◽  
Core Idea ◽  
Intellectual Challenge

This chapter explores variational structuralism, whose core idea is that organisms and their parts play causal roles in shaping the patterns of phenotypic evolution. Drawing on the work of pioneers such as Ron Amundson, it discusses the conceptual incompatibilities between two styles of thinking in evolutionary biology: functionalism and structuralism. It proceeds by explaining the meaning of developmental types and structuralist concepts arising from macromolecular studies. It also examines facts and ideas about bodies, Rupert Riedl's theory of the “immitatory epigenotype,” and Neil Shubin and Pere Alberch's developmental interpretation of tetrapod limbs. Finally, it looks at the emergence of molecular structuralism and the enigma of developmental variation. The chapter argues that typology naturally emerged from the facts of evolutionary developmental biology and that it would be seriously problematic to try to avoid it.

scholarly journals The signature of competition in ecomorphological traits across the avian radiation

2020 ◽  
Vol 287 (1938) ◽  
pp. 20201585
Author(s):  
A. M. Chira ◽  
C. R. Cooney ◽  
J. A. Bright ◽  
E. J. R. Capp ◽  
E. C. Hughes ◽  
...  
Keyword(s):  
Species Interactions ◽  
Biological Diversity ◽  
Phenotypic Evolution ◽  
Shared Resources ◽  
Deep Time ◽  
Extant Species ◽  
Phenotypic Diversification ◽  
Best Fit

Competition for shared resources represents a fundamental driver of biological diversity. However, the tempo and mode of phenotypic evolution in deep-time has been predominantly investigated using trait evolutionary models which assume that lineages evolve independently from each other. Consequently, the role of species interactions in driving macroevolutionary dynamics remains poorly understood. Here, we quantify the prevalence for signatures of competition between related species in the evolution of ecomorphological traits across the bird radiation. We find that mechanistic trait models accounting for the effect of species interactions on phenotypic divergence provide the best fit for the data on at least one trait axis in 27 out of 59 clades ranging between 21 and 195 species. Where it occurs, the signature of competition generally coincides with positive species diversity-dependence, driven by the accumulation of lineages with similar ecologies, and we find scarce evidence for trait-dependent or negative diversity-dependent phenotypic evolution. Overall, our results suggest that the footprint of interspecific competition is often eroded in long-term patterns of phenotypic diversification, and that other selection pressures may predominantly shape ecomorphological diversity among extant species at macroevolutionary scales.

scholarly journals Replaying the tape of life in the twenty-first century

2015 ◽  
Vol 5 (6) ◽  
pp. 20150057 ◽  
Author(s):  
Virginie Orgogozo
Keyword(s):  
Experimental Evolution ◽  
First Century ◽  
Phenotypic Evolution ◽  
Phenotypic Differences ◽  
Diverse Species ◽  
Evolution Of Life ◽  
Long Time ◽  
Time Periods ◽  
Living Organisms ◽  
Life On Earth

Should the tape of life be replayed, would it produce similar living beings? A classical answer has long been ‘no’, but accumulating data are now challenging this view. Repeatability in experimental evolution, in phenotypic evolution of diverse species and in the genes underlying phenotypic evolution indicates that despite unpredictability at the level of basic evolutionary processes (such as apparition of mutations), a certain kind of predictability can emerge at higher levels over long time periods. For instance, a survey of the alleles described in the literature that cause non-deleterious phenotypic differences among animals, plants and yeasts indicates that similar phenotypes have often evolved in distinct taxa through independent mutations in the same genes. Does this mean that the range of possibilities for evolution is limited? Does this mean that we can predict the outcomes of a replayed tape of life? Imagining other possible paths for evolution runs into four important issues: (i) resolving the influence of contingency, (ii) imagining living organisms that are different from the ones we know, (iii) finding the relevant concepts for predicting evolution, and (iv) estimating the probability of occurrence for complex evolutionary events that occurred only once during the evolution of life on earth.

scholarly journals Coevolution is linked with phenotypic diversification but not speciation in avian brood parasites

2015 ◽  
Vol 282 (1821) ◽  
pp. 20152056 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Egg Size ◽  
Biological Diversity ◽  
Phenotypic Diversity ◽  
Arms Race ◽  
Phenotypic Evolution ◽  
Brood Parasites ◽  
Parasitic Species ◽  
Extinction Rates ◽  
Rates Of Evolution ◽  
Phenotypic Diversification

Coevolution is often invoked as an engine of biological diversity. Avian brood parasites and their hosts provide one of the best-known examples of coevolution. Brood parasites lay their eggs in the nests of other species, selecting for host defences and reciprocal counteradaptations in parasites. In theory, this arms race should promote increased rates of speciation and phenotypic evolution. Here, we use recently developed methods to test whether the three largest avian brood parasitic lineages show changes in rates of phenotypic diversity and speciation relative to non-parasitic lineages. Our results challenge the accepted paradigm, and show that there is little consistent evidence that lineages of brood parasites have higher speciation or extinction rates than non-parasitic species. However, we provide the first evidence that the evolution of brood parasitic behaviour may affect rates of evolution in morphological traits associated with parasitism. Specifically, egg size and the colour and pattern of plumage have evolved up to nine times faster in parasitic than in non-parasitic cuckoos. Moreover, cuckoo clades of parasitic species that are sympatric (and share similar host genera) exhibit higher rates of phenotypic evolution. This supports the idea that competition for hosts may be linked to the high phenotypic diversity found in parasitic cuckoos.

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