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If Creationism qualified as a scientific theory, and was taken seriously by scientists working in the field, it would be the real 'theory in crisis', and would have been so ever since Darwin and Wallace explained biodiversity as a process not requiring intelligent agency, back in 1859 - hence the hysteria, disinformation and anti-science rhetoric of its proponents who make a living off the fears and superstitions of ignorant people and need them to stay that way.
In this paper, the scientists set out to reconstruct the evolutionary history of a group of lizards familiar to anyone who has holidayed in the Mediterranean area of Southern Europe and North Africa - the green and wall lizards.
The lizards are from two genera, the Lacerta and Timon. Being biologists the scientists looked at the factors that cause evolutionary diversification - environmental and ecological change and how these dynamic changes related to the genetic and phenotypic changes in the lizards.
As the University of Barcelona news release explains:
The evolutionary clade and biodiversity of green lizards of the genera Lacerta and Timon — reptiles common in the Mediterranean basin and surrounding areas of the European continent, North Africa and Asia — have never been studied in detail from the perspective of historical biogeography. Now, a paper published in the Journal of Biogeography presents a new scenario for deciphering the potential evolutionary processes that have acted — separately or together — to give rise to the biodiversity of species in this group in Mediterranean ecosystems.Sadly, the published paper in the Journal of Biogeography is behind an expensive paywall but the authors give details of their aims, methods, results and main conclusions in the abstract.
The study is led by the researcher Antigoni Kaliontzopoulou, from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona. Teams from the National Museum of Natural Sciences (MNCN-CSIC), the University of Vigo and the University of Porto (Portugal), among other institutions, are also participating.
The hidden history of the evolution of green lizards
Today, green lizard populations are threatened by numerous factors: the destruction and fragmentation of their natural habitat; the disappearance of traditional agricultural practices; the use of pesticides; the increase in cat populations in humanised areas; climate change, and, in addition, the fatal accidents they suffer in roads. However, although there are indications that some populations are in population decline, the International Union for Conservation of Nature (IUCN) has not yet listed these reptiles as endangered species.
According to previous studies, the evolution of the green lizard group was the result of a combination of evolution and the conservatism of ecological niches.…but the relative role of geological history and niche dynamics had not yet been tested.
Such inferences usually focus on a single aspect of diversification: either cladogenesis, geographic dynamics, climatic niche properties or phenotypic trait evolution. Our study is innovative in bringing together evidence that has allowed us to contrast hypotheses about different potential evolutionary processes that might act separately or in combination to shape species diversity in the Mediterranean hotspot
As a whole, the group has diversified in a relatively steady rhythm, without changes in lineage diversification rates associated to major climatic events of the Mediterranean region, and without an apparent link to functional morphological or climatic niche divergence”, says Kaliontzopolou. “Rather, the colonization of previously empty areas rather promoted the diversification of new lineages through their isolation from their relatives and was facilitated, in some groups, by an increased tolerance to lower temperatures.
Our study provides evidence of a combined role of higher-scale niche conservatism and rapid niche evolution underlying the evolutionary history of this lizard clade around the Mediterranean.
In Mediterranean ecosystems, instead, it seems that lineage diversification is rather driven by geological events and through allopatric divergence after the colonization of new environments. In such environments, morphological divergence seems to occur in much more recent times and within already diversified groups, possibly as a response to ecological-scale events or processes such as sexual selection, not investigated in our study.
Antigoni Kaliontzopoulou, co-author
Department of Evolutionary Biology
Ecology and Environmental Sciences, and Biodiversity Research Institute (IRBio)
Universitat de Barcelona, Barcelona, Catalonia, Spain.
The new study combines cutting-edge analytical tools to study the evolution of phenotypes and the biogeographic history of green lizard phylogeny, and to infer their relative contribution to species diversification. The team links high-temporal resolution biogeographic models, which integrate for the first time comprehensive data on changes in terrestrial ecosystem configuration and connectivity in the Mediterranean to assess the importance of dispersal and vicariance in determining historical range dynamics.
Specifically, the team implemented phenotypic modelling of phylogenies to identify changes in the evolutionary rate of morphological diversity and the climatic niches occupied. This information was then combined with a series of trait-dependent diversification analyses to establish how the diversification of the lineage group had been shaped.
The study provides evidence that, when all existing diversity is considered, the biogeographic history of this emblematic group of Mediterranean lizards is the result of a combination of range expansions associated with dispersal events —probably dependent on geographic distance— and rapid evolution of ecological niche characteristics within a specific clade.
A recurring pattern in Mediterranean ecosystems
All indications are that the evolutionary history of green lizards was dominated by biogeographical episodes of long-distance dispersal into previously empty areas, modulated by the allopatric divergence process. These processes are also accompanied by the mechanism of ecological niche conservatism, occasionally interrupted by events of local evolution and adaptation of climatic niches, but with no signs of connection to morphological evolution.
This seems to be established as a recurrent pattern in Mediterranean ecosystems, with several examples accumulating to support the idea that while niche conservatism is a common mechanism favoring the buildup of diversity, transition away from hotspots is related to events of accelerated niche evolution. Furthermore, diversification in functional morphology does not emerge as a key component of the diversification process of green lizards.
This contrasts with other biogeographic areas — perhaps with more stable climatic conditions such as the tropics — where structural niche partitioning is an important process of lineage diversification.
AbstractSo, once again we have a research paper in which biologists demonstrate no doubts whatsoever that the TOE is the fundamental explanation for biodiversity, in this case the relationships and distribution of clades of lizards in the Mediterranean basin and, in doing so, show that the dynamics of climate change and ecological development map accurately onto the genotypic and phenotypic changes which occurred during the allopatric speciation of these reptiles. The evolution of these lizards is the result of the interplay between environmental changes, and genotype changes on which the changing environment was able to exert selection pressure - just like the TOE says.
Aim
The contributions of historical biogeography, morphology and climatic niche evolution in shaping species diversification have been typically examined separately. To fill this gap, we assessed the relative role of geologic history, environment and phenotypic trait evolution in lineage diversification of green lizards in the Mediterranean biodiversity hotspot.
Location
Eurasia and North Africa.
Taxon
Green lizards (genera Timon and Lacerta).
Methods
For all green lizard lineages, we characterized distributional ranges and external morphological traits across discrete biogeographical areas, occupied macro-habitats and climatic niches using environmental variables that represent average and extreme climatic conditions. To assess the contribution of geographical factors in shaping diversity patterns, we evaluated the fit of 24 biogeographical models. We used BAMM and estimated phylogenetic signal to assess the rates of lineage diversification and of phenotypic and climatic niche evolution, and to determine whether these processes occurred steadily or at specific time periods as a response to palaeogeological or palaeoclimatic events. Finally, we tested for associations between phenotypic traits and lineage diversification using trait-dependent diversification analyses (QuaSSE, ES-sim and STRAPP).
Results
Biogeographical analyses favoured a dispersal–vicariance model explaining speciation patterns in green lizards, including jump dispersal and constrained dispersal by geographical distance. Lineages accumulated gradually towards the present, with minor divergence in morphological traits and conservatism of climatic niches. In contrast, in the Lacerta agilis lineage, niche evolution may have allowed expansion towards colder environments. Morphological and climatic niche evolution were uncoupled from diversification rates.
Main Conclusions
Biogeographical processes largely explain the constant lineage diversification of green lizards in the Mediterranean Basin since the Miocene, followed by gradual phenotypic divergence unrelated to cladogenesis. Climatic niche conservatism promoted the accumulation of lineages within the Mediterranean, except for L. agilis, where climatic niche evolution might underpin its range spread towards higher latitudes.
Enriquez-Urzelai, U., Martínez-Freiría, F., Freitas, I., Perera, A., Martínez-Solano, Í., Salvi, D., Velo-Antón, G., & Kaliontzopoulou, A. (2022).
Allopatric speciation, niche conservatism and gradual phenotypic change in the evolution of European green lizards.
Journal of Biogeography, 00, 1– 13. DOI: 10.1111/jbi.14497
© 2022 John Wiley & Sons, Inc.
Reprinted under the terms of the Copyright, Designs and Patents Act 1988, s60.
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