Divergent melanism strategies in Andean butterfly communities structure diversity patterns and climate responses

2018 ◽  
Vol 45 (11) ◽  
pp. 2471-2482 ◽  
Author(s):  
Pauline C. Dufour ◽  
Keith R. Willmott ◽  
Pablo S. Padrón ◽  
Shuang Xing ◽  
Timothy C. Bonebrake ◽  
...  
Keyword(s):  
Diversity Patterns ◽  
Butterfly Communities ◽  
Climate Responses ◽  
Structure Diversity

How does species richness accumulate over time?

2019 ◽  
pp. 189-212
Author(s):  
Timothy G. Barraclough
Keyword(s):  
Phylogenetic Trees ◽  
Species Turnover ◽  
Neutral Theory ◽  
Diversity Patterns ◽  
Extinction Rates ◽  
Neutral Theory Of Biodiversity ◽  
Per Se ◽  
Long Timescales ◽  
Over Time ◽  
Structure Diversity

Species are units for understanding the evolution of diversity over large geographical scales and long timescales. This chapter investigates the processes causing proliferation and demise of species diversity within lineages and regions. Phylogenetic approaches have focused on documenting speciation and extinction rates, but mechanistic theory explaining variation in rates is scarce. Diversity patterns are better explained by geographical and ecological opportunity than by correlates of speciation and extinction rates per se. The neutral theory of biodiversity provides a framework that can be adapted to predict diversity patterns in terms of limits due to competition for space and resources, and species turnover (which cannot be detected directly from phylogenetic trees). These theories bring macroevolutionary and microevolutionary theories closer together. In particular, diversity patterns are the outcome of individual selection and dispersal playing out over long timescales. Some of the processes influencing species patterns can also structure diversity at higher taxonomic levels.

Stufige Mischwälder im Unter-Thurgau | Stratified Mixed Forests in the Lower Thurgau

1999 ◽  
Vol 150 (7) ◽  
pp. 249-251
Author(s):  
Heinz Kuhn
Keyword(s):  
20Th Century ◽  
Forest Regeneration ◽  
Central Plateau ◽  
Intervention Intensity ◽  
Continuous Forest ◽  
Federal Institute ◽  
As Species ◽  
Landscape Research ◽  
Selection Forest ◽  
Structure Diversity

As in many parts of the Swiss Central Plateau, vast coppices with standards have grown in the region of Diessenhofen for centuries. While in other parts of the first decades of the 20th century the forests were converted to areas of forest regeneration species, the foresters of the Diessenhofen region altered numerous pillaged coppices with standards to a stratified continuous forest. The advantages of this form of management such as species and structure diversity and lower costs in comparison with the forest stratified by age are being presented. Each of the four foresters in the region has formed different stand images through his personal intervention intensity. There are different ways possible for achieving a continuous forest, in order to prove this, differences of managing a selection forest system are carried out by the four regional foresters. After decades of experience in tending stands established out of former coppices with standards, the approach of converting plenter forests from existing forests stratified by age to stratified continuous forests is experienced. The successes also encouraged the foresters of the neighbouring district Steckborn to do the same. This creative task is being accompanied scientifically by the WSL (Federal Institute of Forest, Snow and Landscape Research, Birmensdorf, Switzerland), which has established permanent observation areas. The steps in the previously intuitive procedure can, therefore, now be traced.

DIFFERENCES IN EXTINCTION RATES EXPLAIN CONTRASTING REGIONAL DIVERSITY PATTERNS IN MODERN TROPICAL BRYOZOANS

2017 ◽  
Author(s):  
Jeremy B.C. Jackson ◽  
◽  
Emanuela Di Martino ◽  
Paul D. Taylor ◽  
Kenneth G. Johnson
Keyword(s):  
Diversity Patterns ◽  
Regional Diversity ◽  
Extinction Rates

scholarly journals SARS-CoV-2 within-host diversity and transmission

Science ◽  
2021 ◽  
Vol 372 (6539) ◽  
pp. eabg0821 ◽  
Author(s):  
Katrina A. Lythgoe ◽  
Matthew Hall ◽  
Luca Ferretti ◽  
Mariateresa de Cesare ◽  
George MacIntyre-Cockett ◽  
...  
Keyword(s):  
United Kingdom ◽  
Severe Acute Respiratory Syndrome ◽  
Phylogenetic Tree ◽  
Immune Escape ◽  
Clinical Samples ◽  
Diversity Patterns ◽  
Host Diversity ◽  
Viral Loads ◽  
The United Kingdom ◽  
Low Levels

Extensive global sampling and sequencing of the pandemic virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have enabled researchers to monitor its spread and to identify concerning new variants. Two important determinants of variant spread are how frequently they arise within individuals and how likely they are to be transmitted. To characterize within-host diversity and transmission, we deep-sequenced 1313 clinical samples from the United Kingdom. SARS-CoV-2 infections are characterized by low levels of within-host diversity when viral loads are high and by a narrow bottleneck at transmission. Most variants are either lost or occasionally fixed at the point of transmission, with minimal persistence of shared diversity, patterns that are readily observable on the phylogenetic tree. Our results suggest that transmission-enhancing and/or immune-escape SARS-CoV-2 variants are likely to arise infrequently but could spread rapidly if successfully transmitted.

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