Evolutionary Branching and Sympatric Speciation Caused by Different Types of Ecological Interactions

2000 ◽  
Vol 156 (4) ◽  
pp. S77 ◽  
Author(s):  
Doebeli ◽  
Dieckmann
Keyword(s):  
Sympatric Speciation ◽  
Ecological Interactions ◽  
Evolutionary Branching ◽  
Different Types

scholarly journals Forest Ecology beyond the Growing Season: Surveys of Fallen Leaves & Learning about Ecological Interactions

2020 ◽  
Vol 82 (4) ◽  
pp. 241-246
Author(s):  
Evan Lampert
Keyword(s):  
Forest Ecology ◽  
Mechanical Damage ◽  
Growing Season ◽  
Literacy Skills ◽  
Quantitative Literacy ◽  
Ecological Interactions ◽  
Analysis Techniques ◽  
Animal Activity ◽  
Different Types ◽  
Fallen Leaves

Forests are excellent “outdoor classrooms” for active learning in ecology and evolution; however, in many areas trees have no leaves or visible animal activity for much of the year. Fallen leaves may preserve evidence of interactions such as herbivory and infectious diseases, although these can be difficult to differentiate from mechanical damage and decomposition in older fallen leaves. I developed an exercise in which students collect fallen leaves and observe several different types of damage to the leaves. I provide images and descriptions of different types of damage and practices to differentiate them. In addition, I provide a list of questions that can be answered by collecting fallen leaves and observations of damage. My students gained valuable quantitative literacy skills by entering data into an online worksheet and performing various calculations and data analysis techniques. This exercise provides many benefits and can be an engaging addition to a high school's or college's outdoor curriculum outside of the growing season.

Morphological variation in leaf domatia enables coexistence of antagonistic mites in Cinnamomum camphora

2005 ◽  
Vol 83 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Sachiko Nishida ◽  
Akiyo Naiki ◽  
Takayoshi Nishida
Keyword(s):  
Discriminant Analysis ◽  
Morphological Variation ◽  
Canonical Discriminant Analysis ◽  
Cinnamomum Camphora ◽  
Ecological Interactions ◽  
Natural Habitats ◽  
Different Types ◽  
Egg Shells ◽  
Plant Herbivore

We examined variation in Cinnamomum camphora (L.) J. Presl (Lauraceae) leaf domatium morphology with respect to domatium inhabitants in the tree's natural habitats. Canonical discriminant analysis revealed that domatium morphology could be classified into four different types: pouch type, domatia with a narrow (about 0.06 mm) pubescent opening; pubescent pit type, domatia with a wider (about 0.21 mm) pubescent opening; glabrous pit type, domatia similar to the pubescent pit type but with a glabrous opening; and dish type, domatia with a wide (about 0.26 mm) glabrous opening. These four domatium types were found in different positions on a leaf, and domatia with narrower openings tended to occur in or near the position between the midrib and basal secondary veins. The four domatium types were associated, respectively, with herbivorous Eriophyidae mites and herbivorous or fungivorous Tarsonemidae mites; with carnivorous Stigmaeidae mites; with Stigmaeidae mites and egg shells or excuviae of carnivorous Phytoseiidae mites; and with egg shells or excuviae of Phytoseiidae mites. These results suggest that different mites use different domatia, even on the same C. camphora leaf. This conclusion may explain the different results in previous reports about domatium fauna. It suggests that ecological interactions within the plant–herbivore–carnivore system are complicated.Key words: carnivorous mite, Cinnamomum camphora, domatia, herbivorous mite, inhabitant, morphology.

scholarly journals Species competition: coexistence, exclusion and clustering

2009 ◽  
Vol 367 (1901) ◽  
pp. 3183-3195 ◽  
Author(s):  
Emilio Hernández-García ◽  
Cristóbal López ◽  
Simone Pigolotti ◽  
Ken H. Andersen
Keyword(s):  
Analytical Solution ◽  
Carrying Capacity ◽  
Volterra Equations ◽  
Stability Conditions ◽  
Species Competition ◽  
Ecological Interactions ◽  
Niche Space ◽  
Interacting Species ◽  
Species Trait ◽  
Different Types

We present properties of Lotka–Volterra equations describing ecological competition among a large number of interacting species. First we extend previous stability conditions to the case of a non-homogeneous niche space, i.e. that of a carrying capacity depending on the species trait. Second, we discuss mechanisms leading to species clustering and obtain an analytical solution for a state with a lumped species distribution for a specific instance of the system. We also discuss how realistic ecological interactions may result in different types of competition coefficients.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Differentiating between different forms of moral obligations

2020 ◽  
Vol 43 ◽  
Author(s):  
Rajen A. Anderson ◽  
Benjamin C. Ruisch ◽  
David A. Pizarro
Keyword(s):  
Moral Character ◽  
Moral Obligations ◽  
Different Types

Abstract We argue that Tomasello's account overlooks important psychological distinctions between how humans judge different types of moral obligations, such as prescriptive obligations (i.e., what one should do) and proscriptive obligations (i.e., what one should not do). Specifically, evaluating these different types of obligations rests on different psychological inputs and has distinct downstream consequences for judgments of moral character.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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