Collapse of the world`s largest herbivores
... Hunting large herbivores for body parts is also driving down populations of some species, especially the iconic ones. Organized crime is facilitating a dramatic decline of elephants and rhinoceros in parts of Africa and southern Asia, reversing decades of conservation accomplishments. Poaching and i ...
... Hunting large herbivores for body parts is also driving down populations of some species, especially the iconic ones. Organized crime is facilitating a dramatic decline of elephants and rhinoceros in parts of Africa and southern Asia, reversing decades of conservation accomplishments. Poaching and i ...
Whatever happened to the Floreana Mockingbird?
... mockingbird but not others. N. trifasciatus. though, was common on FIoreana when Porter visited the island in 1813 while patrolling the archipelago in the U.S. Frigate Essex. (Porter, 1815). It seems eertain that even if Darwin did not calleet mockingbirds on Floreana, he did see mockingbirds there ...
... mockingbird but not others. N. trifasciatus. though, was common on FIoreana when Porter visited the island in 1813 while patrolling the archipelago in the U.S. Frigate Essex. (Porter, 1815). It seems eertain that even if Darwin did not calleet mockingbirds on Floreana, he did see mockingbirds there ...
Extinctions in Ecological Communities – Alva Curtsdotter
... has become only too relevant. The number of known extinctions (~850) during the last centuries translates to extinction rates elevated above the background rate, matching those of previous mass extinction events. The main drivers of these extinctions have been human land use, introduction of exotic ...
... has become only too relevant. The number of known extinctions (~850) during the last centuries translates to extinction rates elevated above the background rate, matching those of previous mass extinction events. The main drivers of these extinctions have been human land use, introduction of exotic ...
Biodiversity What is Biodiversity? `The total variability of life on earth
... productivity by 10% by making better use of space: polycultures • Genetic diversity in crop plants and plants increases the stability of both global and local food sources by protecting populations from diseases. ...
... productivity by 10% by making better use of space: polycultures • Genetic diversity in crop plants and plants increases the stability of both global and local food sources by protecting populations from diseases. ...
Chapter 55
... • So far, 11.5 percent of Earth’s terrestrial surface has been set aside as protected areas. • Researchers are using a geographic approach called the Gap Analysis Program (GAP) to assess the effectiveness of the current system of protected areas. ...
... • So far, 11.5 percent of Earth’s terrestrial surface has been set aside as protected areas. • Researchers are using a geographic approach called the Gap Analysis Program (GAP) to assess the effectiveness of the current system of protected areas. ...
10 Most Endangered Animals
... Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings ...
... Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings ...
Opposing intraspecific vs. interspecific diversity effects on
... Tree species richness promoted growth but had no effect on herbivory. In contrast, SF diversity reduced growth and increased herbivory but only so in species mixtures. Most of the observed effects were time dependent, with the largest effect found in 2013. Our results suggest that biodiversity can a ...
... Tree species richness promoted growth but had no effect on herbivory. In contrast, SF diversity reduced growth and increased herbivory but only so in species mixtures. Most of the observed effects were time dependent, with the largest effect found in 2013. Our results suggest that biodiversity can a ...
Neanderthal-modern human competition?
... hypothesis that there was competition between Neanderthals and modern humans during the time that they coexisted, i.e. during Oxygen Isotope Stage Three (OIS 3) (ca. 60–20 ka BP) and that this competition led to the extinction of the Neanderthals. To this end, this paper will analyse European mammal ...
... hypothesis that there was competition between Neanderthals and modern humans during the time that they coexisted, i.e. during Oxygen Isotope Stage Three (OIS 3) (ca. 60–20 ka BP) and that this competition led to the extinction of the Neanderthals. To this end, this paper will analyse European mammal ...
Slide 1
... diverse a species is, the greater its chances of surviving disturbances. So as human activity reduces genetic diversity, species are put at a greater risk for extinction. Species diversity is also linked to ecosystem diversity. As ecosystems are damaged, the organisms that inhabit them become more v ...
... diverse a species is, the greater its chances of surviving disturbances. So as human activity reduces genetic diversity, species are put at a greater risk for extinction. Species diversity is also linked to ecosystem diversity. As ecosystems are damaged, the organisms that inhabit them become more v ...
6.3 Biodiversity - Mater Academy of International Studies
... diverse a species is, the greater its chances of surviving disturbances. So as human activity reduces genetic diversity, species are put at a greater risk for extinction. Species diversity is also linked to ecosystem diversity. As ecosystems are damaged, the organisms that inhabit them become more v ...
... diverse a species is, the greater its chances of surviving disturbances. So as human activity reduces genetic diversity, species are put at a greater risk for extinction. Species diversity is also linked to ecosystem diversity. As ecosystems are damaged, the organisms that inhabit them become more v ...
Section 4: Population Samplings
... they can drive the prey to extinction. There are three major reasons why predators rarely kill and eat all the prey: 1. Prey species often evolve protective mechanisms such as camouflage, poisons, spines, or large size to deter predation. 2. Prey species often have refuges where the predators cannot ...
... they can drive the prey to extinction. There are three major reasons why predators rarely kill and eat all the prey: 1. Prey species often evolve protective mechanisms such as camouflage, poisons, spines, or large size to deter predation. 2. Prey species often have refuges where the predators cannot ...
Changes in the flora of Thoreau`s Concord
... Hosmer, so we have not analyzed his plant list separately. Later in the paper, however, we discuss his practice of introducing new plants into Concord. Richard Eaton recorded the most comprehensive flora of Concord (Eaton, 1974). His flora was based on decades of fieldwork extending from the 1920s t ...
... Hosmer, so we have not analyzed his plant list separately. Later in the paper, however, we discuss his practice of introducing new plants into Concord. Richard Eaton recorded the most comprehensive flora of Concord (Eaton, 1974). His flora was based on decades of fieldwork extending from the 1920s t ...
Genetic diversity
... extinction with ecology and environmental systems - Design, test, and implement ways to mitigate human impacts • Conservation geneticists = study genetic attributes of organisms to infer the status of their population • Minimum viable population = how small a population can become before it runs int ...
... extinction with ecology and environmental systems - Design, test, and implement ways to mitigate human impacts • Conservation geneticists = study genetic attributes of organisms to infer the status of their population • Minimum viable population = how small a population can become before it runs int ...
10 The Conservation of Ecological Interactions
... increasing recognition that species and species lists are not the best units for study by conservation biologists, and that species interactions may be much more important. Although this issue was raised more than 30 years ago by Daniel Janzen (1974) stating that ‘what escapes the eye, however, is a ...
... increasing recognition that species and species lists are not the best units for study by conservation biologists, and that species interactions may be much more important. Although this issue was raised more than 30 years ago by Daniel Janzen (1974) stating that ‘what escapes the eye, however, is a ...
Pleistocene fauna (Zoogeography and Plaeontology).
... replaced by the cervid mesic-adapted species which eat leaves of dycotyledons, twig tips, and lichens. ...
... replaced by the cervid mesic-adapted species which eat leaves of dycotyledons, twig tips, and lichens. ...
The Global Decline of Reptiles, Deja Vu Amphibians
... importance. If they should all disappe ar, it would not make much difference one way or the other ”( Zim and Smith 1953, p. 9). Fortunately, this opinion from the Golden Guide Series does not persist tod ay; most people have come to recognize the va lue of both reptiles and amphibians as an in tegra ...
... importance. If they should all disappe ar, it would not make much difference one way or the other ”( Zim and Smith 1953, p. 9). Fortunately, this opinion from the Golden Guide Series does not persist tod ay; most people have come to recognize the va lue of both reptiles and amphibians as an in tegra ...
Niche conservatism as an emerging principle in ecology and
... as a single ancestral species that utilizes a given environment or resource (e.g. diet, host, habitat, climatic regime). Early in the history of the group, there is a niche shift to utilize an alternate resource or environment. At the present time, there are four species utilizing resource 1 and two ...
... as a single ancestral species that utilizes a given environment or resource (e.g. diet, host, habitat, climatic regime). Early in the history of the group, there is a niche shift to utilize an alternate resource or environment. At the present time, there are four species utilizing resource 1 and two ...
Conserving Biodiversity Notes (5.3)
... individuals in one area to reproduce with individuals from another area. Carving the large ecosystem into small parcels increases the number of ____________—creating edge effects. ...
... individuals in one area to reproduce with individuals from another area. Carving the large ecosystem into small parcels increases the number of ____________—creating edge effects. ...
Immigration and the Maintenance of Local Species Diversity
... influence of immigration from a regional pool (regional process) on a plant community governed by competition for space (local process). This model may be viewed as providing a formal and mechanistic theoretical foundation for the “mass-effect hypothesis” proposed by Shmida and Wilson (1985). We exa ...
... influence of immigration from a regional pool (regional process) on a plant community governed by competition for space (local process). This model may be viewed as providing a formal and mechanistic theoretical foundation for the “mass-effect hypothesis” proposed by Shmida and Wilson (1985). We exa ...
"Species Richness: Small Scale". In: Encyclopedia of Life Sciences
... richness peaking at intermediate levels of productivity (Grace and Jutila, 1999). Where productivity is very low few species can persist, and where productivity is very high a small number seem to win at competition, but at intermediate levels many coexist. Peet and Christensen (1988) suggested that ...
... richness peaking at intermediate levels of productivity (Grace and Jutila, 1999). Where productivity is very low few species can persist, and where productivity is very high a small number seem to win at competition, but at intermediate levels many coexist. Peet and Christensen (1988) suggested that ...
Endangered Species
... in immediate danger of becoming extinct and needs protection to survive. Threatened A species is likely to become endangered if it is not protected ...
... in immediate danger of becoming extinct and needs protection to survive. Threatened A species is likely to become endangered if it is not protected ...
The Influence of Predator-Prey Population Dynamics on the Long
... can be compared with the evidence from the fossil record. There has been considerable interest in macro-evolutionary models recently, generated by the claim that extinction dynamics are related to the concept of self-organised criticality (Bak & Sneppen, 1993; Solé et al. 1996; ...
... can be compared with the evidence from the fossil record. There has been considerable interest in macro-evolutionary models recently, generated by the claim that extinction dynamics are related to the concept of self-organised criticality (Bak & Sneppen, 1993; Solé et al. 1996; ...
Estimating the tolerance of species to the effects
... change and mutualistic trade-offs can have a different impact on species’ tolerance. Contrary to the scenario of constant environmental conditions, where degree is the gold standard measure for estimating species’ tolerance, here we have demonstrated that in a changing environment this is not alway ...
... change and mutualistic trade-offs can have a different impact on species’ tolerance. Contrary to the scenario of constant environmental conditions, where degree is the gold standard measure for estimating species’ tolerance, here we have demonstrated that in a changing environment this is not alway ...
conservation of biodiversity
... Low breeding rate Natural disasters Anthropogenic causes: Habitat modification Overexploitation of selected species Innovation by exotic species ...
... Low breeding rate Natural disasters Anthropogenic causes: Habitat modification Overexploitation of selected species Innovation by exotic species ...
Evolutionary diversification, coevolution between populations and
... persist in the absence of competitors, predators, and pathogens. Those other species can exclude a population from parts of the local environment or from regions which have marginally supportive conditions; the remaining distribution is the realized niche. Species in nature rarely, if ever, fill out ...
... persist in the absence of competitors, predators, and pathogens. Those other species can exclude a population from parts of the local environment or from regions which have marginally supportive conditions; the remaining distribution is the realized niche. Species in nature rarely, if ever, fill out ...
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly ""reappears"" (typically in the fossil record) after a period of apparent absence.The age of the Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive with virtually no morphological change for hundreds of millions of years. Mass extinctions are relatively rare events; however, isolated extinctions are quite common. Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions. Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100.