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Shelford's law of tolerance is a principle developed by American zoologist Victor Ernest Shelford in 1911. It states that an organism 's success is based on a complex set of conditions and that each organism has a certain minimum, maximum, and optimum environmental factor or combination of factors that determine success. [ 1 ]
Placental mammals (infraclass Placentalia / p l æ s ə n ˈ t eɪ l i ə /) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the ...
A May 2018 study published in PNAS found that 83% of wild mammals, 80% of marine mammals, 50% of plants and 15% of fish have been lost since the dawn of human civilization. Currently, livestock make up 60% of the biomass of all mammals on earth, followed by humans (36%) and wild mammals (4%). [ 29 ]
The Life of Mammals is a nature documentary series written and presented by David Attenborough, first transmitted in the United Kingdom from 20 November 2002. It is a documentary on the study of the evolution and habits of the various mammal species.
Synapsida [a] is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and birds).
Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment. [15] It is the study of how the population sizes of species living together in groups change over time and space, and was one of the first aspects of ecology to be studied and modelled mathematically.
The changing distribution of the world's land mammals in tonnes of carbon. The biomass of wild land mammals has declined by 85% since the emergence of humans. [147] The world's population numbered nearly 7.6 billion as of mid-2017 and is forecast to peak toward the end of the 21st century at 10–12 billion people. [148]
When the species abundances of an ecological system are treated with a set of differential equations, it is possible to test for stability by linearizing the system at the equilibrium point. [7] Robert May used this stability analysis in the 1970s which uses the Jacobian matrix or community matrix to investigate the relation between the ...