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| | Overview of Extinction - Endangered Species In The Wild Spotlight - Bagheera |
 | | Local extinctions mean the loss of the genetic diversity represented by that population and the removal of that species' contribution to the local ecosystem. | | | Another important type of extinction is extinction in the wild. | | | No matter how small that area is, their disappearance from it is a global extinction if the species is not found anywhere else.A local extinction is the extirpation of a species from a portion of its geographic range. |
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http://www.bagheera.com/inthewild/ext_background.htm
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| | Sixth Extinction |
| | The result: species of animals and plants are vulnerable to extinction for as much as a half a mile into the forest. | | | If the observed levels of extinction known in these cases is typical for similar species worldwide, then current extinction is running at a rate some thousand to ten-thousand higher than background extinction. | | | Other species may be vulnerable to extinction in small islands, because of the small population sizes that can be sustained there. |
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http://www.well.com/user/davidu/sixthextinction.html
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| | Late Pleistocene Extinctions |
| | Before this extinction the diversity of large mammals in North America was similar to that of modern Africa. | | | The environmental changes might have caused extinction by eliminating food sources, disrupting birth schedules, or exposing animals to climatic conditions to which they were not adapted. | | | However, on all of these continents the extinction was less severe (fewer species involved). |
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http://www.museum.state.il.us/exhibits/larson/LP_extinction.html
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| | Extinction |
| | The Cretaceous Extinction (65 Ma) in which 20% of the families of plants and animals on land (50% in the sea) and 85% of all species became extinct. | | | The present extinction rate may be so high because humans have been: 1) destroying habitats (genetic drift and demographic stochasticity important in the small populations left), 2) introducing competing and predatory species and parasites, and 3) overexploiting resources. | | | So, in reference to extinction, survival and reproduction of a species depends upon the population size, the sex ratio, the birth and death rates for each age class, etc. If we have a small population, the sex ratio could get become extreme, just due to chance, and reproduction would suffer. |
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http://www.bio.miami.edu/tom/bil160/bil160goods/10_extinct.html
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| | Soil Water Relations |
| | Ecologists are increasingly realizing that extinction has shaped the communities and ecosystems we see today, and that it operates on a range of timescales and spatial scales. | | | The megafaunal extinctions may be a foretaste of how in our modern world, with the 'squeeze' on each species provided by humans overhunting, overfishing and harvesting wild populations, can make them more likely to go extinct when climate change occurs. | | | The 'local extinction' mechanism (and also the counterbalancing mechanism of how often new populations colonize or recolonize) can thus help us to understand some of the more local-scale species richness differences we see in nature, between (say) different patches of forest, or between different nearby islands. |
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http://www.providence.edu/bio/faculty/adams/LECTUREProvCollegeExtinction.htm
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| | Extinction! |
| | Extinction is one of the most common observations in palaeontology, but it remains very difficult to understand precisely why a particular ancient plant or animal species went extinct. | | | A third possibility is that natural selection changed the appearance of the species to such an extent that palaeontologists mistakenly assign younger members to a different species. | | | But there may be other explanations for the absence of the species in younger deposits. |
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http://www.firstscience.com/site/articles/macleod.asp
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| | Evolution: Extinction: A Modern Mass Extinction? |
| | He has conducted extensive research on the rates and causes of species extinction, on the nature of ecological communities, and on the impacts and management of introduced species (those who migrate to a new area). | | | Information on the rate of species introduction and the nature of the impacts of introduced species on native species and ecosystems allows inferences about extinction rates. | | | Of about 6 to 10 million currently existing species, we have still only identified 1 million; we know more about vertebrate species than we do about plants and insects. |
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http://www.pbs.org/wgbh/evolution/extinction/massext/statement_03.html
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| | Endangered Animals - Extinction is Forever |
| | Extinction is the disappearance, brought about by natural or unnatural means, of an entire species. | | | Some species of plants and animals die out naturally because newer species are more successful at competing for food and living space. | | | In today's world, however, species mostly become extinct or are threatened with extinction because of humans. |
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http://www.uen.org/utahlink/activities/view_activity.cgi?activity_id=3820
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| | [No title] |
| | Human-mediated extinction: Extinction of species associated with human immigration and colonizations. | | | Humans have also indirectly caused extinction of species by introducing competitively strong pests or by the elimination of habitat. | | | Local extinction: The disappearance of a species from part of its geographic range. |
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http://www.nau.edu/~biology/gloss4.html
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| | INTRODUCTION, HISTORY OF LIFE |
| | Cenozoic (the "Age of Mammals"): The diversification of flowering plants, insects, birds and mammals, and the appearance of humans. | | | About 10 percent of the world's tree species are in danger of extinction. | | | Subspecies are distinct groups within a species, and they are important because they would probably evolve into sparate species in the future. |
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http://darwin.bio.uci.edu/~sustain/bio65/lec01/b65lec01.htm#Rise_of_biological_diversity
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| | On Bjorn Lomborg and extinction By E. O. Wilson Grist Magazine Arts and Minds 12 Dec 2001 |
| | Finally, consider that species extinction is increasingly enhanced by pollution, climate change, and the growing flood of invasive species -- hence the foregoing estimates of extinctions based on habitat reduction are, sadly, minimal and modest. | | | Consider that at an area-species exponent of 0.27 (a typical middle level), half the species are extinguished or committed to extinction by a 90 percent reduction in habitat area. | | | Estimates for current species extinction rates range from 100 to 10,000 times that, but most hover close to 1,000 times prehuman levels (0.1 percent per year), with the rate projected to rise, and very likely sharply. |
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http://www.grist.org/advice/books/2001/12/12/point
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| | Study: Mass extinctions via warming - Environment - MSNBC.com |
| | Depending on the temperature increase, the researchers found that 15 to 37 percent of the studied species will either go extinct or be on the road to extinction by 2050. | | | Earth is home to an estimated 4 million to 6 million plant and animal species, a tiny fraction of which — about 12,000 — conservationists estimate are threatened with extinction, although thousands of others are likely on the brink as well. | | | The sweeping new analysis, enlisting scientists from 14 laboratories around the globe, found that more than one-third of 1,103 native species they studied in six regions around the world could vanish or plunge to near extinction by 2050 as climate change turns plains into deserts or alters forests. |
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http://www.msnbc.msn.com/id/3897120
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| | Causes of the Permian Extinction |
| | A third possible mechanism for the Permian extinction is rapid warming and severe climatic fluctuations produced by concurrent glaciation events on the north and south poles. | | | A similar glaciation event in the Permian would likely produce mass extinction in the same manner as previous, that is, by a global widespread cooling and/or worldwide lowering of sea level. | | | This caused severe climatic fluctuations around the globe, and is found by sediment record to be representative of when the Permian mass extinction occurred. |
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http://park.org/Canada/Museum/extinction/permcause.html
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| | Articles / Impact / Extinction - Institute for Creation Research |
| | The money and effort put into protecting, restoring, and sustaining a few minor species of plants and animals becomes a questionable national effort. | | | Nearly one-half of the then known animal species became extinct at the close of the Permian Period! | | | There is a failure to mate for social reasons below a certain population density. |
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http://www.icr.org/index.php?module=articles&action=view&ID=167
(1839 words)
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| | Atmospheric Extinction |
| | However, soot (carbon) particles are quite strong absorbers, and a considerable part of their reddening is due to the increase in their absorption at short wavelengths. | | | Most of the aerosol particles are so weakly absorbing that their extinction is almost entirely due to scattering, rather than absorption. | | | Because the extinction is generally larger at short (blue) wavelengths, the setting Sun is usually so dim at short wavelengths as to be lost in the scattered light of the foreground sky, and the remaining transmitted light appears red. |
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http://mintaka.sdsu.edu/GF/explain/extinction/extintro.html
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| | Extinction |
| | At the present time there are about 5,000 species of animals and more than 25,000 species of plants facing extinction. | | | Extinction generally occurs under one of three headings: | | | Suddenly, the word EXTINCTION has not one, but several possible definitions depending upon the species being studied or discussed and the reason for its decline or extermination. |
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http://www.yptenc.org.uk/docs/factsheets/env_facts/extinction.html
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| | Glossary - Endangered Species Classroom In The Wild - Bagheera |
| | Estimates of the background rate of extinction range from one to ten species per year, which is 100 to 1,000 times lower than the current rate. | | | Biodiversity encompasses variation at all levels, from the genetic diversity within a species to the variation between higher level evolutionary groupings such as families and classes. | | | The complete removal of a particular type of organism from an area, usually a specified geographic area. |
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http://www.bagheera.com/inthewild/class_glossary.htm
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| | Environment News Service (ENS) |
| | At the time of the mass extinction event, higher latitude temperatures were warmer than today by 18 to 54 degrees Fahrenheit (10 to 30 degrees Celsius). | | | The modeling presented unique challenges because of limited data and geographic differences between present day Earth and the planet during the Permian era when all the continents were consolidated into the giant land mass known as Pangaea. | | | Previous studies of the Permian extinction used more limited computer models that focused on only a single component of Earth's climate system, such as the ocean. |
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http://www.ens-newswire.com/ens/aug2005/2005-08-29-01.asp
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| | Technorati Tag: extinction |
| | Reuters: Global warming will become a top cause of extinction from the tropical Andes to South Africa with thousands of species of plants and animals... | | | Independent: Tens of thousands of animals and plants could become extinct within the coming decades as a direct result of global warming. | | | Posts tagged Extinction per day for the last 30 days. |
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http://www.technorati.com/tag/extinction
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| | National Museum of Natural History - Dinosaur Extinction |
| | Three copies of the boundary interval at one site were collected in a section that includes a 10-17 cm thick graded bed of green spherules capped by a fine-grained, rusty brown limonitic layer that is overlain by dark gray clay of the earliest Danian. | | | In addition, the chemistry of the well-preserved calcareous microfossils will be used to document climate variability when the Earth's climate switched from a greenhouse to an icehouse state. | | | The K-T boundary was recovered at three sites, each with a biostratigraphically and magnetostratigraphically complete sequence that includes the earliest part of the aftermath of the Late Cretaceous extinctions. |
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http://www.nmnh.si.edu/paleo/blast/joides_article.htm
(1487 words)
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| | Extinction |
| | In Hawaii, many species of the Lobelia tree are endangered, due to the declining populations (extinction) of native nectar feeding birds | | | Causes of extinction: Introduction of Pests, Predators and competitors | | | probability of extinction depends on both the population size and fine details of the population demography |
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http://nitro.biosci.arizona.edu/courses/EEB105/lectures/extinction/extinction.html
(232 words)
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| | Chapter 6 Changing Life in a Changing World |
| | The evidence suggests that land plants were "clear-cut", leaving nothing to hold the soil in place. | | | Peter Ward and colleagues describe evidence for major erosion right at the P-T boundary in South Africa, at the same time as a major plant extinction. | | | The great extinction at the end of the Permian took place shortly after the continents finally merged into a giant supercontinent, Pangea, composed of a large northern land mass, Laurasia, and a southern land mass, Gondwanaland. |
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http://www.geology.ucdavis.edu/~cowen/HistoryofLife/CH06.html
(2052 words)
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| | Catastrophism and Mass Extinctions |
| | Carriers of Extinction by Carl Zimmer suggests that the megafaunal extinctions at the end of the last ice age were caused by pathogens carried by migrating humans. | | | Disaster from space discusses evidence in favor of a large impact event causing the extinction at the end of the Cretaceous. | | | McLean is the originator of the volcano theory, which couples the K-T extinctions to a major perturbation of earth's carbon cycle caused by the Deccan Traps mantle plume vulcanism. |
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http://www.pibburns.com/catastro/extinct.htm
(1469 words)
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| | mass extinction - Columbia Encyclopedia article about mass extinction |
| | The most devastating was that at the end of the Permian period, when an estimated 95% of marine species and 8 of 27 insect orders were lost. | | | The dinosaurs, which were egg-laying animals, ranged in length from 2 1-2 ft (91 cm) to about 127 ft (39 m). | | | The extinctions, however, did not conform to the usual evolutionary rules regarding who survives; the only factor that appears to have improved a family of organisms' chance of survival was widespread geographic colonization at the time of the event. |
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http://columbia.thefreedictionary.com/mass+extinction
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| | ClickerSolutions Training Articles -- Extinction |
| | However, this is most likely to happen if the overall rate of reinforcement has also fallen, such as when the trainer lumps criteria or increases too quickly. | | | Extinction can also be helpful in solving some problem behaviors. | | | However, for this to be true, the trainer must control the reinforcement. |
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http://www.clickersolutions.com/articles/2003/extinction.htm
(859 words)
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| | SPACE.com -- The Five Worst Extinctions in Earth's History |
| | The Permian-Triassic catastrophe was Earths worst mass extinction, killing 95 percent of all species, 53 percent of marine families, 84 percent of marine genera and an estimated 70 percent of land species such as plants, insects and vertebrate animals. | | | Still others believe the impact triggered the volcanism and also may have done so during the Cretaceous-Tertiary extinction. | | | Some argue for other causes, including gradual climate change or flood-like volcanic eruptions of basalt lava from Indias Deccan Traps. |
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http://www.space.com/scienceastronomy/planetearth/extinction_sidebar_000907.html
(479 words)
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| | Species Experts Are Nearing Extinction |
| | Even as public concern grows over the accelerating extinction of species, the scientists who traverse the globe to collect, identify, and enumerate the world's plants and animals also have been disappearing at an alarming rate. | | | Summary As public concern grows over the accelerating extinction of species, taxonomists—the scientists who traverse the globe to collect, identify, and enumerate the world's plants and animals—have also been disappearing at an alarming rate. | | | They are called taxonomists, and in the last 20 years their field has been crushed like a hapless bug wandering into the path of speeding technology. |
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http://news.nationalgeographic.com/news/2002/01/0116_020116wiretaxonomist.html
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| | Dinosaur Extinction - Enchanted Learning Software |
| | As flowering plants came to dominate the landscape, Edmontosaurus died out, unable to find enough conifers to sustain itself. | | | Extinction is the process in which groups of organisms (species) die out. | | | These extinctions are not caused by major catastrophes or horrendous climactic changes, but by small changes in climate or habitat, depleted resources, competition, and other changes that require adaptation and flexibility. |
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http://www.enchantedlearning.com/subjects/dinosaurs/extinction
(602 words)
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| | Extinction chess |
| | c7 - c5 // Extinction very often features a blocked center, with the attacks developing on the wings. | | | When a Pawn promotes to some type of piece, this piece is also counted among the pieces of the type; e.g., when a Pawn promotes to a Queen, and the other Queen is taken from the player, then the Queens are not considered to be extinct, i.e., the game continues. | | | N d4 - e6 // Checkmate // Extinction mate. |
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http://www.chessvariants.com/winning.dir/extinction.html
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| | Australia's Biodiversity - Extinction |
| | Did megafauna, such as Procoptodon (the giant short-faced kangaroo) or Diprotodon (the giant wombat-like marsupial), that used to roam Australia, become extinct because of climate change or because of hunting? | | | Extinctions of species have been occurring since the first life forms evolved. | | | Their hunting practices may have affected population levels of some animals, and the building of fish traps in coastal and inland rivers may also have had environmental effects. |
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http://www.amonline.net.au/biodiversity/happening/extinction.htm
(368 words)
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| | Extinction: What is it ? |
| | It is widely accepted that all geological time periods have a continous level of extinction, known as background extinction. | | | This means that a certain number of species are expected to die out, the average species life expectancy is approximately 4 million years or 20 Ma at the generic level (Sepkoski). | | | (how long were high levels of extinction's in progress ?), the |
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http://palaeo.gly.bris.ac.uk/communication/Belton/Extn.html
(243 words)
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| | The Unnatural Museum - Dinosaur Extinction |
| | A sudden change in climate might affect the growth of plants and the dinosaur's food supply. | | | Part of the mystery of extinction is why certain species died while others survive. | | | Scientists believe that climatic changes might be responsible for most of these extinctions. |
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http://www.unmuseum.org/deaddino.htm
(603 words)
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| | E X T I N C T I O N : the novel : footnotes |
| | The smoke shut out all light and heat from the Sun for months, causing a world-wide life-destroying Extinction Winter. | | | Harry and Friedrich, marooned in the past, battling Nature and each other, must desperately reinvent every method the human race has used to survive. | | | Around them rages a parallel battle for the planet, as the mammals wrest control of the Earth from the dinosaurs in the Extinction Year. |
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http://www.dinosaurextinction.com
(943 words)
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| | Mail & Guardian Online: |
| | "I don't expect all endangered species to have short telomeres, since there are clearly other extinction mechanisms resulting from human threats to ecosystems, but I would expect some correlation between extinction risk and telomere length." | | | Charles Darwin proposed that evolution is controlled by "survival of the fittest". | | | For over 100 years, scientists have grappled with the cause of "background" extinction. |
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http://www.mg.co.za/Content/l3.asp?o=46456
(1169 words)
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| | Cambridge Dictionaries Online - Cambridge University Press |
| | Many species of plants and animals are in danger of/threatened with extinction (= being destroyed so that they no longer exist). | | | The extinction of the dinosaurs occurred (= they stopped existing) millions of years ago. | | | Some people predict the extinction of family life as we know it today. |
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http://dictionary.cambridge.org/define.asp?key=27244&dict=CALD
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| | Did a meteor wipe out the dinosaurs? What about the iridium layer? |
| | But the spread in the geological record makes sense if much of the sedimentary deposits were formed in Noah’s Flood. | | | The causes were probably no more dramatic than those that cause extinctions of other species, e.g. | | | This caused the extinction of the dinosaurs and many other species. |
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http://www.answersingenesis.org/home/area/faq/docs/dino_meteor.asp
(1013 words)
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| | Extinction - Michael Boulter - Mobipocket eBook |
| | The world will adapt and survive -humanity will not. | | | EXTINCTION is an immaculately researched introduction into the new developments in the science of life as well as a chilling account of the effects that humans have had on the planet. | | | One method of this system is extinction - if the system is disrupted it will do what it has to correct itself. |
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http://www.ebookmall.com/ebook/87580-ebook.htm
(812 words)
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| | Extinction event - Wikipedia, the free encyclopedia |
| | The extinction of many megafauna near the end of the most recent ice age is also sometimes considered a part of the Holocene extinction event. | | | This catastrophe was Earth's worst mass extinction, killing 53% of marine families, 84% of marine genera, and an estimated 70% of land species (including plants, insects, and vertebrate animals.) | | | Climate change - Rapid transitions in climate may be capable of stressing the environment to the point of extinction. |
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http://en.wikipedia.org/wiki/Extinction_event
(1510 words)
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| | Dinosaur Extinction Page |
| | After a short period of time some of the plants that had been burnt down would have regrown from buried seeds or rootstock. | | | Whatever caused the death of the dinosaurs also caused the death of around 70% of all of the species on the Earth. | | | As is common with all mass extinctions there would have a sudden evolutionary burst as new species developed. |
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http://web.ukonline.co.uk/a.buckley/dino.htm
(2059 words)
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| | The Kill-Off |
| | Islands are, in the nature of things, hot-spots of extinction. | | | One in four mammal species and one in eight bird species face a high risk of extinction in the near future: the population of each species is expected to fall by at least a fifth in the next 10 years. | | | As it turns out, Manson has been hard at work lately. |
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http://www.motherjones.com/news/dailymojo/2003/12/12_508.html
(4412 words)
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| | Dinosaur Extinction - Enchanted Learning Software |
| | Background extinctions and many minor extinctions accounted for the disappearance of most of the dinosaur species. | | | About 65 million years ago, at the end of the Cretaceous, a large fraction of plant and animal families suddenly went extinct. | | | In this Cretaceous-Tertiary or K-T mass extinction (K is for Kreide, meaning chalk in German, which describes the chalky sediment layer from that time; T is for Tertiary, the next geologic period), all land animals over about 55 pounds went extinct, as did many smaller organisms. |
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http://www.enchantedlearning.com/subjects/dinosaurs/extinction/Asteroid.html
(1063 words)
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| | Morehead Planetarium and Science Center :: Extinction! |
| | The âKT eventâ spanned nearly 10,000 years, triggering the extinctions of thousands of species, (including dinosaurs and plant life). | | | And sea levels rose, inundating vast areas of land with water. | | | âEXTINCTION!â uses their findings as a strong foundation for its message. |
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http://www.moreheadplanetarium.org/index.cfm?fuseaction=page&filename=extinct.html
(406 words)
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| | The Raw Story Survival, extinction and global warming |
| | Scientists have postulated theories of the extinction of most species, from Pacific salmon to freshwater turtles to rainforest plants. | | | The International Union for the Conservation of Nature held its third World Conservation Congress in November of last year, warning that there were now nearly 16,000 species at risk of extinction. | | | Hundreds of species of apes, monkeys, lemurs and other close relatives of mankind risk being among the first primate extinctions for more than a century.” |
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http://www.rawstory.com/exclusives/selinger/survival_extinctionl_051705.htm
(776 words)
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| | SPACE.com -- Theory: Mass Extinction by Our Own Sun |
| | Melott said there is no known evidence of such a nearby supernova, but that in 440 million years the Milky Way would have rotated almost twice and traces of the explosion could have been moved during that time. | | | ATLANTA (AP) - The second-largest extinction in the Earth's history, the killing of two-thirds of all species, may have been caused by ultraviolet radiation from the Sun after gamma rays destroyed the Earth's ozone layer. | | | All this happened some 440 million years ago and led to what is known as the Ordovician extinction, the second most severe of the planet's five great periods of extinction. |
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http://space.com/scienceastronomy/solar_extinction_040108.html
(873 words)
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| | Extinction |
| | Identify evidence which is relevant to your hypotheses | | | Discuss opportunities for the evolution and expansion of surviving species | | | In fact, most of the mass extinctions occurred over a period of tens, if not hundreds, of thousands of years. |
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http://www2.nau.edu/~gaud/bio372/class/extinction/extinct.htm
(308 words)
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| | Raising the MammothHow did the mammoths die? |
| | The extinction of the mammoth began in North America right around the time humans first crossed the Bering Land Bridge. | | | We've taken a close look at the three main theories of extinction in the stories below. | | | According to Paul Martin, professor at the University of Arizona's Geosciences department, the Clovis were methodical human predators who pursued their quarry relentlessly - ultimately to the point of extinction. |
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http://www.exn.ca/mammoth/Extinction.cfm
(699 words)
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| | The Permian Mass Extinction |
| | The Permian mass extinction occurred about 248 million years ago and was the greatest mass extinction ever recorded in earth history; even larger than the previously discussed Ordovician and Devonian crises and the better known End Cretaceous extinction that felled the dinosaurs. |
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http://hannover.park.org/Canada/Museum/extinction/permass.html
(248 words)
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| | Extinction |
| | This BBC site covers all the known major mass extinctions as well as the K-T and shows a refreshing lack of certainty about their causes. | | | The Hooper Virtual Paleontological Museum hosts this extensive survey of extinction events from the Proterozoic to the Holocene, without the most recent developments. | | | A paper from a Santa Fe Institute researcher shoots down the theory that mass extinctions just happen due to "coevolutionary avalanches." |
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http://geology.about.com/od/extinction
(496 words)
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