scholarly journals Cope's rule and the adaptive landscape of dinosaur body size evolution

Palaeontology ◽  
2017 ◽  
Vol 61 (1) ◽  
pp. 13-48 ◽  
Author(s):  
Roger B. J. Benson ◽  
Gene Hunt ◽  
Matthew T. Carrano ◽  
Nicolás Campione
2018 ◽  
Vol 49 (1) ◽  
pp. 379-408 ◽  
Author(s):  
Roger B.J. Benson

Dinosaurs were large-bodied land animals of the Mesozoic that gave rise to birds. They played a fundamental role in structuring Jurassic–Cretaceous ecosystems and had physiology, growth, and reproductive biology unlike those of extant animals. These features have made them targets of theoretical macroecology. Dinosaurs achieved substantial structural diversity, and their fossil record documents the evolutionary assembly of the avian body plan. Phylogeny-based research has allowed new insights into dinosaur macroevolution, including the adaptive landscape of their body size evolution, patterns of species diversification, and the origins of birds and bird-like traits. Nevertheless, much remains unknown due to incompleteness of the fossil record at both local and global scales. This presents major challenges at the frontier of paleobiological research regarding tests of macroecological hypotheses and the effects of dinosaur biology, ecology, and life history on their macroevolution.


2020 ◽  
Vol 287 (1918) ◽  
pp. 20192615 ◽  
Author(s):  
Michael D. Burns ◽  
Devin D. Bloom

Migratory animals respond to environmental heterogeneity by predictably moving long distances in their lifetime. Migration has evolved repeatedly in animals, and many adaptations are found across the tree of life that increase migration efficiency. Life-history theory predicts that migratory species should evolve a larger body size than non-migratory species, and some empirical studies have shown this pattern. A recent study analysed the evolution of body size between diadromous and non-diadromous shads, herrings, anchovies and allies, finding that species evolved larger body sizes when adapting to a diadromous lifestyle. It remains unknown whether different fish clades adapt to migration similarly. We used an adaptive landscape framework to explore body size evolution for over 4500 migratory and non-migratory species of ray-finned fishes. By fitting models of macroevolution, we show that migratory species are evolving towards a body size that is larger than non-migratory species. Furthermore, we find that migratory lineages evolve towards their optimal body size more rapidly than non-migratory lineages, indicating body size is a key adaption for migratory fishes. Our results show, for the first time, that the largest vertebrate radiation on the planet exhibited strong evolutionary determinism when adapting to a migratory lifestyle.


PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e34654 ◽  
Author(s):  
Jorge Avaria-Llautureo ◽  
Cristián E. Hernández ◽  
Dusan Boric-Bargetto ◽  
Cristian B. Canales-Aguirre ◽  
Bryan Morales-Pallero ◽  
...  

Author(s):  
Jorge Avaria-Llautureo ◽  
Cristián E. Hernández ◽  
Dusan Boric-Bargetto ◽  
Cristian B. Canales-Aguirre ◽  
Bryan Morales-Pallero ◽  
...  

2018 ◽  
Author(s):  
Pedro L. Godoy ◽  
Roger B. J. Benson ◽  
Mario Bronzati ◽  
Richard J. Butler

AbstractBackgroundLittle is known about the long-term patterns of body size evolution in Crocodylomorpha, the > 200-million-year-old group that includes living crocodylians and their extinct relatives. Extant crocodylians are mostly large-bodied (3–7 m) predators. However, extinct crocodylomorphs exhibit a wider range of phenotypes, and many of the earliest taxa were much smaller (< 1.2 m). This suggests a pattern of size increase through time that could be caused by multi-lineage evolutionary trends of size increase or by selective extinction of small-bodied species. In this study, we characterise patterns of crocodylomorph body size evolution using a model fitting-approach (with cranial measurements serving as proxies). We also estimate body size disparity through time and quantitatively test hypotheses of biotic and abiotic factors as potential drivers of crocodylomorph body size evolution.ResultsCrocodylomorphs reached an early peak in body size disparity during the Late Jurassic, and underwent essentially continually decreases in disparity since then. A multi-peak Ornstein-Uhlenbeck model outperforms all other evolutionary models fitted to our data (including both uniform and non-uniform), indicating that the macroevolutionary dynamics of crocodylomorph body size are better described within the concept of an adaptive landscape, with most body size variation emerging after shifts to new macroevolutionary regimes (analogous to adaptive zones). We did not find support for a consistent evolutionary trend towards larger sizes among lineages (i.e., Cope’s rule), or strong correlations of body size with climate. Instead, the intermediate to large body sizes of some crocodylomorphs are better explained by group-specific adaptations. In particular, the evolution of a more aquatic lifestyle (especially marine) correlates with increases in average body size, though not without exceptions.ConclusionsShifts between macroevolutionary regimes provide a better explanation of crocodylomorph body size evolution than do climatic factors, suggesting a central role for lineage-specific adaptations rather than climatic forcing. Shifts leading to larger body sizes occurred in most aquatic and semi-aquatic groups. This, combined with extinctions of groups occupying smaller body size regimes (particularly during the Late Cretaceous and Cenozoic), gave rise to the upward-shifted body size distribution of extant crocodylomorphs compared to their smaller-bodied terrestrial ancestors.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Pedro L. Godoy ◽  
Roger B. J. Benson ◽  
Mario Bronzati ◽  
Richard J. Butler

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