Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New model for studying species distributions and the mid-domain effect developed

11.07.2005


Understanding why some parts of the world sustain more species than others is one of the most enigmatic problems in ecology. One particularly common pattern is a "hump-shaped" biodiversity gradient: for example, biodiversity peaks near the equator and declines going either north or south.



Historically, explanations for such gradients invoked coincident geographical variation in environmental factors hypothesized to reduce extinction rates or promote the evolution of new species.

Recently, however, random re-arrangements ("randomizations") of species’ distributions in geographical space have been shown to reproduce these hump-shaped gradients (termed "mid-domain effects").


Because randomizations do not explicitly include environmental factors, some have argued that such factors may be less important for biodiversity than previously thought. However, randomization analyses are controversial: critics argue that they are devoid of any ecological processes (not just environmental gradients), and thus have no explanatory utility.

Addressing this criticism requires models that make explicit biological assumptions about how species’ distributional limits are determined, consistent with a particular hypothesized cause of biodiversity gradients.

In an article in the July 2005 issue of The American Naturalist, Sean R. Connolly (James Cook University) develops a general framework for such models and analyzes specific models that omit roles for variation in the quality of environmental conditions.

Under a very general set of conditions, these models are shown to produce mid-domain effects. These are qualitatively similar in shape, but of substantially lower magnitude, compared to randomization analyses. These results reveal that the mid-domain effect is likely to be a real phenomenon, and thus cannot be ignored, but that comparing real biodiversity patterns to those produced by randomizations may be misleading. They also identify an alternative way forward: formulating process-oriented models of species distributions and testing them directly against empirical data.

Carrie Olivia Adams | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>