Where is the world's greatest concentration of unique species of mammals? A team of American and Filipino authors have concluded that it is Luzon Island, in the Philippines. Their 15-year project, summarized in a paper published ...
Plants & Animals
Jul 14, 2016
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8579
Temple University researchers have assembled the largest and most accurate tree of life calibrated to time, and surprisingly, it reveals that life has been expanding at a constant rate.
Evolution
Mar 3, 2015
37
4785
Researchers from Zhejiang University, Kunming Institute of Zoology, Northwest University, and Yunnan University, Aarhus University, and BGI-Research have jointly led a series of significant new studies are published in a ...
Plants & Animals
Jun 1, 2023
0
1217
Brown bears foraging for food in the Shiretoko Peninsula of Hokkaido, Japan, have been disrupting tree growth in artificial conifer forests, according to a new study published in Ecology. Researchers compared soil and tree ...
Plants & Animals
Mar 1, 2024
1
155
The evolution of birds on the Galápagos Islands, the cradle of Darwin's theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin's finches have already reached an equilibrium, ...
Evolution
Jun 23, 2015
1
27
Researchers report important new insights into evolution following a study of mitochondrial DNA from about 5 million specimens covering about 100,000 animal species.
Evolution
May 21, 2018
8
87
Birds that are related, such as Darwin's finches, but that vary in beak size and behavior specially evolved to their habitat are examples of a process called speciation. It has long been thought that dramatic changes in a ...
Evolution
Nov 20, 2014
643
0
The Tasmanian tiger was doomed long before humans began hunting the enigmatic marsupial, scientists said Tuesday, with DNA sequencing showing it was in poor genetic health for thousands of years before its extinction.
Plants & Animals
Dec 12, 2017
0
293
(PhysOrg.com) -- Scientists from the UK, US and elsewhere have been carrying out a comprehensive assessment of flowering plants and adjusting the estimate of their total number. The new estimate is that there are about 400,000 ...
Starting with normal skin cells, scientists from The Scripps Research Institute have produced the first stem cells from endangered species. Such cells could eventually make it possible to improve reproduction and genetic ...
Cell & Microbiology
Sep 4, 2011
4
0
Species diversity is an index that incorporates the number of species in an area and also their relative abundance. It is generally a much more useful value than species richness.
The most common index of species diversity is a family of equations called Simpson's Diversity Index[1].
Here is one such example
D = (n / N)2
Where n is the total number of organisms of a particular species and N is the total number of organisms of all species.D is the value of diversity. It can range between 0 and 1, whre 1 is the richest an Ecosystem can possibly be.
Humans have a huge effect on species diversity; the main reasons are: - Destruction, Modification, and/or Fragmentation of Habitat - Introduction of Exotic Species - Overharvest - Global Climate Change
This text uses material from Wikipedia, licensed under CC BY-SA
