PPT File
... Phenotypes that gain the most from a positive interaction or suffer least from a negative interaction will increase in frequency in the population, and the population will evolve. Natural selection will favor the trait and its frequency will increase in the population ...
... Phenotypes that gain the most from a positive interaction or suffer least from a negative interaction will increase in frequency in the population, and the population will evolve. Natural selection will favor the trait and its frequency will increase in the population ...
Loss of Diversity as a Consequence of Habitat Destruction in
... existing worldwide trend of decreasing biodiversity (Ehrlich, 1988). As human populations grow at ever-accelerating rates, an increasing proportion of the land which supports ecological communities is converted for agriculture, urban development, or other human activities. The degree to which habita ...
... existing worldwide trend of decreasing biodiversity (Ehrlich, 1988). As human populations grow at ever-accelerating rates, an increasing proportion of the land which supports ecological communities is converted for agriculture, urban development, or other human activities. The degree to which habita ...
What Is Conservation Biology? Michael E. Soulé BioScience
... disappear simultaneously. Species hundred individuals) will cause a prowill disappear if their habitats gressive loss of genetic variation; in disappear. turn, such genetic erosion will reduce Second, outbursts reduce diversity. immediate fitness because multilocus If population densities of ecologi ...
... disappear simultaneously. Species hundred individuals) will cause a prowill disappear if their habitats gressive loss of genetic variation; in disappear. turn, such genetic erosion will reduce Second, outbursts reduce diversity. immediate fitness because multilocus If population densities of ecologi ...
the paleoecological significance of opportunistic
... temperature, salinity, etc. (e.g. subtidal tropics). This is because resources are rarely underexploited enough to allow rapid infiltration of opportunists, and also due to the fact that sudden changes in the environment, which allow explosions, are rare. I n practice, the distinction of such opport ...
... temperature, salinity, etc. (e.g. subtidal tropics). This is because resources are rarely underexploited enough to allow rapid infiltration of opportunists, and also due to the fact that sudden changes in the environment, which allow explosions, are rare. I n practice, the distinction of such opport ...
RESEARCHING INVASIVE SPECIES 50 YEARS AFTER ELTON: A
... that 57% of imperilled US plants were threatened by predation or competition from alien species. Because predation is unlikely to be a common threat to plants, one must assume the authors meant to imply that most of the threat to native plants came from non-native plant species. However, it is widel ...
... that 57% of imperilled US plants were threatened by predation or competition from alien species. Because predation is unlikely to be a common threat to plants, one must assume the authors meant to imply that most of the threat to native plants came from non-native plant species. However, it is widel ...
chapter 12 - Geoclassroom Home
... fossil record. The lack of hard parts before the Cambrian explosion means that there are fewer soft-bodied specimens preserved in the fossil record, not that the life forms didn’t exist. It is possible that the Cambrian is a recording of the diversity of life that was already present—but that didn’t ...
... fossil record. The lack of hard parts before the Cambrian explosion means that there are fewer soft-bodied specimens preserved in the fossil record, not that the life forms didn’t exist. It is possible that the Cambrian is a recording of the diversity of life that was already present—but that didn’t ...
State of the World 1998: Chapter 1, The Future of Growth
... concentrated in just a handful of populations, if one such group is wiped out by a temporary catastrophe such as a drought, the birds often have few population sources from which they can recolonize the formerly occupied habitat. Equally important is that many island birds have evolved in isolation ...
... concentrated in just a handful of populations, if one such group is wiped out by a temporary catastrophe such as a drought, the birds often have few population sources from which they can recolonize the formerly occupied habitat. Equally important is that many island birds have evolved in isolation ...
Biodiversity Conservation
... beef cattle. Besides total loss, the degradation of many habitats by pollution also threatens the survival of many species. When large habitats are broken up into small fragments due to various human activities, mammals and birds requiring large territories and certain animals with migratory habits ...
... beef cattle. Besides total loss, the degradation of many habitats by pollution also threatens the survival of many species. When large habitats are broken up into small fragments due to various human activities, mammals and birds requiring large territories and certain animals with migratory habits ...
biodiversity
... Most went extinct before humans arrived. - End of Cretaceous period - Dinosaurs and 50% of existing genera disappeared. - Permian period - Two-thirds of all marine species and nearly half of all plant and animal families died out. ...
... Most went extinct before humans arrived. - End of Cretaceous period - Dinosaurs and 50% of existing genera disappeared. - Permian period - Two-thirds of all marine species and nearly half of all plant and animal families died out. ...
Principles of Conservation Biology, Third Edition
... are a part (Convention on Biological Diversity Rio Summit) • variety of species and ecosystems on Earth and the ecological processes of which they are a part (Canadian Biodiversity Strategy) ...
... are a part (Convention on Biological Diversity Rio Summit) • variety of species and ecosystems on Earth and the ecological processes of which they are a part (Canadian Biodiversity Strategy) ...
Habitats PPT
... • Increased risk of extinctions: all of these factors together contribute to an increased likelihood that species will be lost. ...
... • Increased risk of extinctions: all of these factors together contribute to an increased likelihood that species will be lost. ...
Has the debate over genetics and extinction of island endemics truly
... modest levels of inbreeding depression accelerated times to extinction by 25–31% even when other demographic, environmental and catastrophic factors are operating. The major variable explaining variation among species with regard to the impact of inbreeding was the initial population growth rate. Fo ...
... modest levels of inbreeding depression accelerated times to extinction by 25–31% even when other demographic, environmental and catastrophic factors are operating. The major variable explaining variation among species with regard to the impact of inbreeding was the initial population growth rate. Fo ...
Habitats PPT
... The shape, height, density, location, and diversity of a habitat’s plant life. The combination of these factors create… ...
... The shape, height, density, location, and diversity of a habitat’s plant life. The combination of these factors create… ...
Speech HRH Princess Irene Wild Wonders of Europe
... “Over the last few decades species are dying out faster than ever before. Due to the reduction in the number of plant species, animals are losing their source of food. Man is also dependent on a wide variety of species. Commercial interests threaten biodiversity. For example, it is a fact that large ...
... “Over the last few decades species are dying out faster than ever before. Due to the reduction in the number of plant species, animals are losing their source of food. Man is also dependent on a wide variety of species. Commercial interests threaten biodiversity. For example, it is a fact that large ...
Biodiversity - Jean-Francois Le Galliard
... by laws of ecology & evolution (and geology) There have been statis and crisis in the history of life with time periods of fast speciation and time periods of fast extinction leading to evolutionary shifts in community composition and life forms Our understanding of this history is still very superf ...
... by laws of ecology & evolution (and geology) There have been statis and crisis in the history of life with time periods of fast speciation and time periods of fast extinction leading to evolutionary shifts in community composition and life forms Our understanding of this history is still very superf ...
Chapter 15 Biodiversity and Conservation Biology
... several more species, like the whooping crane, California condor, and Kirtland's warbler, teeter on the brink of extinction. Human-caused extinction is nothing new: Thousands of years ago, waves of extinctions occurred wherever people colonized new areas, from Hawaii to Australia. Current extinction ...
... several more species, like the whooping crane, California condor, and Kirtland's warbler, teeter on the brink of extinction. Human-caused extinction is nothing new: Thousands of years ago, waves of extinctions occurred wherever people colonized new areas, from Hawaii to Australia. Current extinction ...
Population and Community Ecology
... o A bee performs the waggle dance when she wants to inform other bees of a nectar source she has found. The waggle occurs on a special dance floor, which is conveniently located near the entrance to facilitate quick entry and exit of foragers, and only bees with news of highly profitable sources of ...
... o A bee performs the waggle dance when she wants to inform other bees of a nectar source she has found. The waggle occurs on a special dance floor, which is conveniently located near the entrance to facilitate quick entry and exit of foragers, and only bees with news of highly profitable sources of ...
Modern lessons from ancient food webs
... and Jonathan Mitchell of University that robustness was lower in the post- millions of years ago of Chicago, respectively, have shown perturbation Triassic versus the pre- that both post-perturbation communi- perturbation Permian. Similarly, the ties (the Triassic following the Perm- restructurin ...
... and Jonathan Mitchell of University that robustness was lower in the post- millions of years ago of Chicago, respectively, have shown perturbation Triassic versus the pre- that both post-perturbation communi- perturbation Permian. Similarly, the ties (the Triassic following the Perm- restructurin ...
Food webs and networks: the architecture of biodiversity
... • Cohen suggested that often yes, overlaps among predators in the prey that they consume can be represented by a series of line segments arranged in a single dimension. Argued that this means that a single niche dimension is sufficient to describe feeding ...
... • Cohen suggested that often yes, overlaps among predators in the prey that they consume can be represented by a series of line segments arranged in a single dimension. Argued that this means that a single niche dimension is sufficient to describe feeding ...
Document
... Genetic diversity is variation of individual genes, which provides an opportunity for populations of organisms to adapt to their ever-changing environment. The more variation, the better the chance that at least some of the individuals will have a variation that is suited for the new environment, an ...
... Genetic diversity is variation of individual genes, which provides an opportunity for populations of organisms to adapt to their ever-changing environment. The more variation, the better the chance that at least some of the individuals will have a variation that is suited for the new environment, an ...
Biodiversity conservation and its opponents
... crops and livestock. This is partly because these are less photogenic and because as human constructs they are somehow less ‘natural’. At the same time, all across the planet, people who will never read any articles in professional journals are voting against biodiversity conservation with their fee ...
... crops and livestock. This is partly because these are less photogenic and because as human constructs they are somehow less ‘natural’. At the same time, all across the planet, people who will never read any articles in professional journals are voting against biodiversity conservation with their fee ...
Endangered Species
... environment) threatens the survival of any species that cannot adapt to it. Already many species have vanished forever. Many others are poised on the brink of extinction. This is because any species that is unable to survive or reproduce in its environment, and unable to move to a new environment wh ...
... environment) threatens the survival of any species that cannot adapt to it. Already many species have vanished forever. Many others are poised on the brink of extinction. This is because any species that is unable to survive or reproduce in its environment, and unable to move to a new environment wh ...
Ecosystem Services - Philosophy Department
... • Amazon: 2.7 million square miles (about 90% size of continental U.S.). The Amazon River is 4000 miles long and puts 170 billion gallons of water into the Atlantic per hour. In a small area of the forest one might find: 750 tree species, 125 mammal species, 400 bird species, 60 amphibian species, ...
... • Amazon: 2.7 million square miles (about 90% size of continental U.S.). The Amazon River is 4000 miles long and puts 170 billion gallons of water into the Atlantic per hour. In a small area of the forest one might find: 750 tree species, 125 mammal species, 400 bird species, 60 amphibian species, ...
Effects of Physical Dimensions on Tide Pool Diversity
... Many studies have shown that the number of species ...
... Many studies have shown that the number of species ...
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.