scholarly journals The influence of juvenile dinosaurs on community structure and diversity

Science ◽  
2021 ◽  
Vol 371 (6532) ◽  
pp. 941-944
Author(s):  
Katlin Schroeder ◽  
S. Kathleen Lyons ◽  
Felisa A. Smith
Keyword(s):  
Community Structure ◽  
Body Size ◽  
Size Range ◽  
Taxonomic Diversity ◽  
The Body ◽  
Niche Shift ◽  
Specific Effects ◽  
Ontogenetic Niche Shift ◽  
Ontogenetic Niche

Despite dominating biodiversity in the Mesozoic, dinosaurs were not speciose. Oviparity constrained even gigantic dinosaurs to less than 15 kg at birth; growth through multiple morphologies led to the consumption of different resources at each stage. Such disparity between neonates and adults could have influenced the structure and diversity of dinosaur communities. Here, we quantified this effect for 43 communities across 136 million years and seven continents. We found that megatheropods (more than 1000 kg) such as tyrannosaurs had specific effects on dinosaur community structure. Although herbivores spanned the body size range, communities with megatheropods lacked carnivores weighing 100 to 1000 kg. We demonstrate that juvenile megatheropods likely filled the mesocarnivore niche, resulting in reduced overall taxonomic diversity. The consistency of this pattern suggests that ontogenetic niche shift was an important factor in generating dinosaur community structure and diversity.

scholarly journals Character Displacement Through an Evolutionary Change in Ontogenetic Niche Shifts

2021 ◽  
Author(s):  
Jaime Anaya-Rojas ◽  
Ronald Bassar ◽  
Blake Matthews ◽  
Joshua Goldberg ◽  
David Reznick ◽  
...  
Keyword(s):  
Body Size ◽  
Poecilia Reticulata ◽  
Character Displacement ◽  
Trophic Niche ◽  
Niche Shift ◽  
Ontogenetic Niche Shifts ◽  
Ontogenetic Niche Shift ◽  
Significant Difference ◽  
Niche Shifts ◽  
Ontogenetic Niche

In communities structured by body size, coexistence can occur through combinations of ontogenetic changes in competitive ability and dietary niche. Using stable isotopes, we examined ontogenetic niche shifts in Trinidadian guppies (Poecilia reticulata) and killifish (Rivulus hartii) in three types of natural communities (both species with predators, KGP; both without predators, KG; killifish only, KO) and four experimental KG communities, initiated with KGP guppies and KO killifish between 13 and 45 years ago. In all communities, killifish occupied higher trophic positions and changed their diet (δ^13 C) with body size. Only KGP guppies displayed an ontogenetic niche shift. The KG guppies displayed a significant difference in trophic niche from KGP guppies, a character displacement that can facilitate coexistence with killifish. In the experimental communities, the guppy trophic niche was intermediate between those in KGP and KG communities, indicating that evolution has driven the niche shift in KG guppies.

scholarly journals Character Displacement Through and Evolutionary Change in Ontogenetic niche shifts

2021 ◽  
Author(s):  
Jaime Anaya-Rojas ◽  
Ronald Bassar ◽  
Blake Matthews ◽  
Joshua Goldberg ◽  
David Reznick ◽  
...  
Keyword(s):  
Body Size ◽  
Poecilia Reticulata ◽  
Character Displacement ◽  
Trophic Niche ◽  
Niche Shift ◽  
Ontogenetic Niche Shifts ◽  
Ontogenetic Niche Shift ◽  
Significant Difference ◽  
Niche Shifts ◽  
Ontogenetic Niche

In communities structured by body size, coexistence can occur through combinations of ontogenetic changes in competitive ability and dietary niche. Using stable isotopes, we examined ontogenetic niche shifts in Trinidadian guppies (Poecilia reticulata) and killifish (Rivulus hartii) in three types of natural communities (both species with predators, KGP; both without predators, KG; killifish only, KO) and four experimental KG communities, initiated with KGP guppies and KO killifish between 13 and 45 years ago. In all communities, killifish occupied higher trophic positions and changed their diet (δ^13 C) with body size. Only KGP guppies displayed an ontogenetic niche shift. The KG guppies displayed a significant difference in trophic niche from KGP guppies, a character displacement that can facilitate coexistence with killifish. In the experimental communities, the guppy trophic niche was intermediate between those in KGP and KG communities, indicating that evolution has driven the niche shift in KG guppies.

scholarly journals A Parent-Offspring Trade-Off Limits the Evolution of an Ontogenetic Niche Shift

2017 ◽  
Vol 190 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Hanna ten Brink ◽  
André M. de Roos
Keyword(s):  
Niche Shift ◽  
Trade Off ◽  
Ontogenetic Niche Shift ◽  
Ontogenetic Niche

scholarly journals Effect of changes in the fractal structure of a littoral zone in the course of lake succession on the abundance, body size sequence and biomass of beetles

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5662
Author(s):  
Joanna Pakulnicka ◽  
Andrzej Zawal
Keyword(s):  
Fractal Dimension ◽  
Body Size ◽  
Fractal Structure ◽  
Lake Management ◽  
Open Water ◽  
Taxonomic Diversity ◽  
The Body ◽  
Water Beetles ◽  
Water Surface Area ◽  
Depth Analysis

Dystrophic lakes undergo natural disharmonic succession, in the course of which an increasingly complex and diverse, mosaic-like pattern of habitats evolves. In the final seral stage, the most important role is played by a spreading Sphagnum mat, which gradually reduces the lake’s open water surface area. Long-term transformations in the primary structure of lakes cause changes in the structure of lake-dwelling fauna assemblages. Knowledge of the succession mechanisms in lake fauna is essential for proper lake management. The use of fractal concepts helps to explain the character of fauna in relation to other aspects of the changing complexity of habitats. Our 12-year-long study into the succession of water beetles has covered habitats of 40 selected lakes which are diverse in terms of the fractal dimension. The taxonomic diversity and density of lake beetles increase parallel to an increase in the fractal dimension. An in-depth analysis of the fractal structure proved to be helpful in explaining the directional changes in fauna induced by the natural succession of lakes. Negative correlations appear between the body size and abundance. An increase in the density of beetles within the higher dimension fractals is counterbalanced by a change in the size of individual organisms. As a result, the biomass is constant, regardless of the fractal dimension.

Evidence that an ontogenetic niche shift by native masu salmon facilitates invasion by nonnative brown trout

2012 ◽  
Vol 14 (10) ◽  
pp. 2049-2056 ◽  
Author(s):  
Koh Hasegawa ◽  
Chitose Yamazaki ◽  
Kazumasa Ohkuma ◽  
Masatoshi Ban
Keyword(s):  
Brown Trout ◽  
Masu Salmon ◽  
Niche Shift ◽  
Ontogenetic Niche Shift ◽  
Ontogenetic Niche

Ontogenetic niche shifts and their implications for recruitment in three clonal Vaccinium shrubs: Vaccinium myrtillus, Vaccinium vitis-idaea, and Vaccinium oxycoccos

2002 ◽  
Vol 80 (6) ◽  
pp. 635-641 ◽  
Author(s):  
Ove Eriksson
Keyword(s):  
Negative Relationship ◽  
Plant Ecology ◽  
Vaccinium Myrtillus ◽  
Niche Shift ◽  
Ontogenetic Niche Shifts ◽  
Ontogenetic Niche Shift ◽  
Niche Shifts ◽  
Recruitment Behavior ◽  
Species Recruitment ◽  
Ontogenetic Niche

Ontogenetic niche shifts, i.e., changes in niche breadth and (or) position during the life of individuals, have received rather limited attention in plant ecology. An experiment was designed to assess ontogenetic niche shifts in three clonal Vaccinium shrubs in order to examine their recruitment behavior. Seeds were sown, and juveniles transplanted, at sites along a gradient of changing occurrence of the three species. Recruitment was seed limited, varied among sites, and was correlated with juvenile survivorship. No niche shift occurred during seed to seedling stages for any of the plants. For Vaccinium myrtillus L., recruitment was not related to adult occurrence, whereas for Vaccinium oxycoccos L., recruitment was highest at the site where adults dominated. However, for both of these species, recruitment also occurred outside the range of adult occurrence. Vaccinium vitis-idaea L. exhibited a negative relationship between adult occurrence and recruitment and between adult occurrence and juvenile survivorship, indicating an ontogenetic niche shift. For V. myrtillus the results suggested an uncoupling of niche requirements of juvenile and adult stages, whereas for V. oxycoccos the results suggested a niche contraction towards the requirements for adults. Thus, the form of ontogenetic niche shifts differs among the species. These differences in niche shifts contribute to understanding dispersal and recruitment behavior of the species.Key words: clonal plants, dispersal, niche shifts, recruitment.

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