 |
|
Current mass extinction spurs major study of which plants to save
October 21, 2008(Santa Barbara, Calif.) -- The Earth is in the midst of the sixth mass extinction of both plants and animals, with nearly 50 percent of all species disappearing, scientists say.
Because of the current crisis, biologists at UC Santa Barbara are working day and night to determine which species must be saved. Their international study of grassland ecosystems, with flowering plants, is published this week in the Proceedings of the National Academy of Sciences.
"The current extinction event is due to human activity, paving the planet, creating pollution, many of the things that we are doing today," said co-author Bradley J. Cardinale, assistant professor of ecology, evolution and marine biology (EEMB) at UC Santa Barbara. "The Earth might well lose half of its species in our lifetime. We want to know which ones deserve the highest priority for conservation."
He explained that the last mass extinction near the current level was 65 million years ago, called the Cretaceous Tertiary extinction event, and was probably the result of a meteor hitting the Earth. It is best known for the extinction of non-avian dinosaurs, but massive amounts of plant species became extinct at that time as well.
According to the current study, the most genetically unique species are the ones that have the greatest importance in an ecosystem. These are the ones that the scientists recommend be listed as top priority for conservation.
"Given that we are losing species from ecosystems around the world, we need to know which species matter the most -- and which we should pour our resources into protecting," said first author Marc W. Cadotte, postdoctoral fellow at UCSB's National Center for Ecological Analysis and Synthesis (NCEAS).
Cadotte, Cardinale, and co-author Todd Oakley, an EEMB associate professor, put together a "meta-analysis" of approximately 40 important studies of grassland ecosystems around the world. They reconstructed the evolutionary history among 177 flowering plants used in these studies by comparing the genetic makeup of the plants.
The scientists found that some species are more critical than others in preserving the functions of ecosystems and that these species tend to be those that are genetically unique. Therefore, they are looking to evolutionary history for guidance in conservation efforts and in understanding the potential impacts of species loss.
Recent studies show that ecological systems with fewer species generally produce less biomass than those with more species. Less plant biomass means that less carbon dioxide is absorbed from the atmosphere and less oxygen is produced. So, as the biomass of plants plummets around the globe, the composition of gasses in the atmosphere that support life could be profoundly affected. Additionally, there are fewer plants for herbivorous animals to eat. Entire food chains can be disrupted, which can impact the production of crops and fisheries.
The loss of species that are not closely related to other species in the ecosystem reduces productivity more than the loss of species with close relatives. And the more genetically distinct a species is, the more impact it has on the amount of biomass in an ecosystem.
"Losing a very unique species may be worse than losing one with a close relative in the community," said Oakley. "The more evolutionary history that is represented in a plant community, the more productive it is."
Cadotte explained that the buttercup is a very unique species, evolutionarily. Losing the buttercup, where it occurs in grasslands, would have a much bigger impact on the system than losing a daisy or a sunflower, for example. The latter species are closely related. Each could therefore help fill the niche of the other, if one were to be lost. The daisy and sunflower also have a more similar genetic make-up.
"These 40 studies are showing the same thing for all plants around the world," said Cardinale. "It is not a willy-nilly conclusion. This study is very robust. It includes studies of plants that are found throughout the U.S., Europe, and Asia. We can have a high degree of confidence in the results. And the results show that genetic diversity predicts whether or not species matter."
University of California - Santa Barbara
He explained that the last mass extinction near the current level was 65 million years ago, called the Cretaceous Tertiary extinction event, and was probably the result of a meteor hitting the Earth. It is best known for the extinction of non-avian dinosaurs, but massive amounts of plant species became extinct at that time as well.
According to the current study, the most genetically unique species are the ones that have the greatest importance in an ecosystem. These are the ones that the scientists recommend be listed as top priority for conservation.
"Given that we are losing species from ecosystems around the world, we need to know which species matter the most -- and which we should pour our resources into protecting," said first author Marc W. Cadotte, postdoctoral fellow at UCSB's National Center for Ecological Analysis and Synthesis (NCEAS).
Cadotte, Cardinale, and co-author Todd Oakley, an EEMB associate professor, put together a "meta-analysis" of approximately 40 important studies of grassland ecosystems around the world. They reconstructed the evolutionary history among 177 flowering plants used in these studies by comparing the genetic makeup of the plants.
The scientists found that some species are more critical than others in preserving the functions of ecosystems and that these species tend to be those that are genetically unique. Therefore, they are looking to evolutionary history for guidance in conservation efforts and in understanding the potential impacts of species loss.
Recent studies show that ecological systems with fewer species generally produce less biomass than those with more species. Less plant biomass means that less carbon dioxide is absorbed from the atmosphere and less oxygen is produced. So, as the biomass of plants plummets around the globe, the composition of gasses in the atmosphere that support life could be profoundly affected. Additionally, there are fewer plants for herbivorous animals to eat. Entire food chains can be disrupted, which can impact the production of crops and fisheries.
The loss of species that are not closely related to other species in the ecosystem reduces productivity more than the loss of species with close relatives. And the more genetically distinct a species is, the more impact it has on the amount of biomass in an ecosystem.
"Losing a very unique species may be worse than losing one with a close relative in the community," said Oakley. "The more evolutionary history that is represented in a plant community, the more productive it is."
Cadotte explained that the buttercup is a very unique species, evolutionarily. Losing the buttercup, where it occurs in grasslands, would have a much bigger impact on the system than losing a daisy or a sunflower, for example. The latter species are closely related. Each could therefore help fill the niche of the other, if one were to be lost. The daisy and sunflower also have a more similar genetic make-up.
"These 40 studies are showing the same thing for all plants around the world," said Cardinale. "It is not a willy-nilly conclusion. This study is very robust. It includes studies of plants that are found throughout the U.S., Europe, and Asia. We can have a high degree of confidence in the results. And the results show that genetic diversity predicts whether or not species matter."
University of California - Santa Barbara
Mass Extinction Current Events and Mass Extinction News RSSConservation targets too small to stop extinction
Conservation biologists are setting their minimum population size targets too low to prevent extinction.
The first neotropical rainforest was home of the Titanoboa
Smithsonian researchers working in Colombia's Cerrejón coal mine have unearthed the first megafossil evidence of a neotropical rainforest.
A new day dawned fast
In 1980, Luis Alvarez and his collaborators stunned the world with their discovery that an asteroid impact 65 million years ago probably killed off the dinosaurs and much of the the world's living organisms. But ever since, there has been an ongoing debate about how long it took for life to return to the devastated planet and for ecosystems to bounce back.
Surviving mass extinction by leading a double life
Drifting across the world's oceans are a group of unicellular marine microorganisms that are not only a crucial source of food for other marine life - but their fossils, which are found in abundance, provide scientists with an extraordinary record of climatic change and other major events in the history of the earth.
Ancient volcanic eruptions caused global mass extinction
A previously unknown giant volcanic eruption that led to global mass extinction 260million years ago has been uncovered by scientists at the University of Leeds.
Princeton geoscientist offers new evidence that meteorite did not wipe out dinosaurs
A Princeton University geoscientist who has stirred controversy with her studies challenging a popular theory that an asteroid wiped out the dinosaurs has compiled powerful new evidence asserting her position.
New blow for dinosaur-killing asteroid theory
The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper to be published in the Journal of the Geological Society on April 27, 2009.
New theory on largest known mass extinction in the history of the earth
Did volatile halogenated gases from giant salt lakes at the end of the Permian Age lead to a mass extinction of species?
Study unravels why certain fishes went extinct 65 million years ago
Large size and a fast bite spelled doom for bony fishes during the last mass extinction 65 million years ago, according to a new study to be published March 31, 2009, in the Proceedings of the National Academy of Sciences.
No joy in discoveries of new mammal species -- only a warning for humanity, Paul Ehrlich says
In the era of global warming, when many scientists say we are experiencing a human-caused mass extinction to rival the one that killed off the dinosaurs, one might think that the discovery of a host of new species would be cause for joy.
More Mass Extinction Current Events and Mass Extinction News Articles
 |
THE GRAVITY THEORY OF MASS EXTINCTION: A New Unified Theory of Mass Extinction Explains The Rise and Fall of The Dinosaurs by John Stojanowski (Author) A new unified theory of mass extinction that identifies the primary cause for the 'Big Five' mass extinctions as a gravitational one. The theory proposed in this book posits a lowered surface gravity as a result of the coalescing of the continents that formed the supercontinent Pangea. The linkage of continental tectonic plate movement and the shifting of the Earth's inner iron core is described and is the underlying basis for changes in surface gravity. The gigantism of the sauropod dinosaurs and other Mesozoic life forms are attributed to reduced surface gravity as well as their gradual extinction as Pangea broke apart, resulting in increased gravitation. The rapid fall and rise of global sea levels during periods of mass extinction, unexplained by current mass extinction theories,... |
 |
Creations Undoing Do you like thrash? Do you like Bay Area Thrash? A fan of Exodus, Forbidden, Testament et al? Well now's the time to get yourself some Dublin Bay Area Thrash! Another Lesson In Violence, if you will! |
![Mass Extinctions [VHS]](http://ecx.images-amazon.com/images/I/518XGEHCH3L._SL160_.jpg) |
Mass Extinctions [VHS] Starring: Mass Extinctions Evolution has been interrupted five times by major catastrophes, and 99.9 percent of all species of plants and animals that have ever lived on earth are now extinct. But large-scale destruction clears the way for new species to thrive--in fact, if the dinosaurs hadn't died out, humans may never have evolved. With such dramatic subject matter, you'd think it would be easy to produce a fascinating, thought-provoking documentary. Unfortunately, this is not the case with Mass Extinctions. Poor production quality consistently distracts from the program's attempted message. The sound is often not synchronized with the footage of scholars being interviewed. Although the program was filmed in 1993, the animation and graphics are on a par with high school filmstrips from the 1970s. To indicate the... |
 |
Mass Extinctions Starring: Mass Extinctions Evolution has been interrupted five times by major catastrophes, and 99.9 percent of all species of plants and animals that have ever lived on earth are now extinct. But large-scale destruction clears the way for new species to thrive--in fact, if the dinosaurs hadn't died out, humans may never have evolved. With such dramatic subject matter, you'd think it would be easy to produce a fascinating, thought-provoking documentary. Unfortunately, this is not the case with Mass Extinctions. Poor production quality consistently distracts from the program's attempted message. The sound is often not synchronized with the footage of scholars being interviewed. Although the program was filmed in 1993, the animation and graphics are on a par with high school filmstrips from the 1970s. To indicate the... |
 |
When Life Nearly Died: The Greatest Mass Extinction of All Time by Michael Benton (Author) "The focus is the most severe mass extinction known in earth's history….The science on which the book is based is up-to-date, thorough, and balanced. Highly recommended."—Choice Today it is common knowledge that the dinosaurs were wiped out by a meteorite impact 65 million years ago that killed half of all species then living. Far less known is a much greater catastrophe that took place at the end of the Permian period 251 million years ago: ninety percent of life was destroyed, including saber-toothed reptiles and their rhinoceros-sized prey on land, as well as vast numbers of fish and other species in the sea. This book documents not only what happened during this gigantic mass extinction but also the recent rekindling of the idea of catastrophism. Was the end-Permian... |
 |
The Sixth Mass Extinction Minushuman (Primary Contributor) |
 |
Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future by Peter D. Ward (Author) More than 200 million years ago, a cataclysmic event known as the Permian extinction destroyed more than 90% of all species and nearly 97% of all living things. Its origins have long been a puzzle for paleontologists, and during the 1990s and the early part of this century a great battle was fought between those who thought that death had come from above and those who thought something more complicated was at work. Paleontologist Peter D. Ward, fresh from helping prove that an asteroid had killed the dinosaurs, turned to the Permian problem, and he has come to a stunning conclusion. In his investigations of the fates of several groups of mollusks during those extinctions and others, he discovered that the near-total devastation at the end of the Permian was caused by rising... |
 |
Extinction - Exploring the Causes of the Mass Extinctions That Have Occurred Over the Life of the Planet (Evolution Series - A Journey Into Where We're From and Where We're Going) Also With: Liam Neeson (Narrator) Some 99.9 percent of all species that have ever lived on earth are now extinct. While cataclysmic events have pruned the tree of life, extinction also opens the door for new species to emerge and thrive. Extinction explores the causes of the mass extinctions that have occurred over the lift of the planet - and takes us to the sources of extinctions happening today. In doing so, it confronts a frightening notion: are humans causing the next mass extinction - the sixth in the history of life on earth? If so, what does evolutionary theory predict for the world that is left to our descendants? The Evolution series' goals are to heighten public understanding of evolution and how it works, to dispel common misunderstandings about the process, and to illuminate why it is relevant to all of us. |
 |
Mass Extinction: Examining the Current Crisis (Discovery!) by Tricia Andryszewski (Author) Some scientists believe that Earth is heading toward a crisis--its sixth great mass extinction, where possibly two-thirds of its existing species could disappear. But what do scientists know for sure? Is there a way to avoid such a crisis? |
 |
Living In The Age of Mass Extinction Purification (Primary Contributor) |
| © 2009 BrightSurf.com |