|
|
KNOW-THIS
Joined: 14 Jul 2003
Posts: 3694
|
 Sat Apr 10, 2004 8:25 pm
|
 |
|
Amazon shrinkage alarms activists
Much Amazon destruction occurs due to logging to create farms
Environmental groups are calling for urgent action to slow deforestation in Brazil's Amazon jungle.
About 9,170 square miles (23,750 sq km) of forest were lost in 2003, just up from 8,983 square miles (23,266 sq km) in 2002, the Brazilian government says.
The scale is not as high as in the mid-1990s, but it confirms the world's largest forest is disappearing rapidly.
Rising exports of beef and soya in Brazil are said to encourage farmers to clear the forest for farms.
Scientists fear the clearances could affect the global climate as well as threatening thousands of unique plant and animal species.
"I am worried - the figures are too high," said Rosa Lemos de Sa of conservation group WWF Brazil.
"The tendency is for it to stay high unless drastic measures are taken, and I don't see the government doing anything drastic."
Brazil's environment minister said the growth rate of deforestation had been halted.
"The big challenge is that 23,000 (sq km) is still a very worrying number," said Marina da Silva.
Criticism
Last month, Brazilian President Luiz Inacio Lula da Silva unveiled plans to halt the destruction amid criticism his government failed to act.
He promised satellite monitoring and joint action by ministries after a 28 % jump in deforestation between 2001 and 2002 pushed the level toward the record rate seen in 1995.
On Wednesday, the government announced it had overestimated its 2001-2 figure of 10,190 square miles (25,500 sq km) and revised it to 8,983 square miles (23,260 sq km).
|
| |
|
|
KNOW-THIS
Joined: 14 Jul 2003
Posts: 3694
|
|
Sat Apr 10, 2004 8:28 pm
|
|
|
People need to wake the fu&* up!
Md. Scientists Say Algae Blooms Increasing in Bay
Thursday April 08, 2004 12:09pm
Annapolis, Md. (AP) - Scientists with Maryland's Department of Natural Resources have found unusually large algae blooms in portions of the Chesapeake Bay.
That's worrisome news to members of the Chesapeake Bay Foundation, who say the blooms have the potential of creating the largest "dead-zone" ever measured in the bay. The Foundation says last year's "dead-zone" spanned 40 percent of the bay.
The algae blooms deprive fish and marine animals of live-giving oxygen.
The Foundation is lobbying Maryland lawmakers to approve the so-called "flush tax" - $30.00 annual surcharge on sewer bills to upgrade sewage treatment plants in the bay watershed. Pollution from existing treatment plants has been blamed for algae growth.
DNR scientists are waiting for more test results to be certain of the cause of the large blooms. Some speculate that the past year's heavy rains caused an unusual amount of nutrient runoff.
|
| |
|
|
KNOW-THIS
Joined: 14 Jul 2003
Posts: 3694
|
|
Sat Apr 10, 2004 8:30 pm
|
|
|
http://www.guardian.co.uk/life/feature/story/0,13026,1187579,00.html
The final countdown
All Earthly species will eventually die out, we're being told. Kate Ravilious asks if humans can possibly endure
Thursday April 8, 2004
The Guardian
Every species seems to come and go. Some last longer than others, but nothing lasts forever. Humans are a relatively recent phenomenon, jumping out of trees and striding across the land around 200,000 years ago. Will we persist for many millions of years to come, or are we headed for an evolutionary makeover, or even extinction?
According to Reinhard Stindl, of the Institute of Medical Biology in Vienna, the answer to this question could lie at the tips of our chromosomes. In a controversial new theory he suggests that all eukaryotic species (everything except bacteria and algae) have an evolutionary "clock" that ticks through generations, counting down to an eventual extinction date. This clock might help to explain some of the more puzzling aspects of evolution, but it also overturns current thinking and even questions the orthodoxy of Darwin's natural selection.
For over 100 years, scientists have grappled with the cause of "background" extinction. Mass extinction events, like the wiping out of dinosaurs 65m years ago, are impressive and dramatic, but account for only around 4% of now extinct species. The majority slip away quietly and without any fanfare. Over 99% of all the species that ever lived on Earth have already passed on, so what happened to the species that weren't annihilated during mass extinction events?
Charles Darwin proposed that evolution is controlled by "survival of the fittest". Current natural selection models imply that evolution is a slow and steady process, with continuous genetic mutations leading to new species that find a niche to live in, or die. But digging through the layers of rock, palaeontologists have found that evolution seems to go in fits and starts. Most species seem to have long stable periods followed by a burst of change: not the slow, steady process predicted by natural selection. Originally scientists attributed this jagged pattern to the imperfections of the fossil record. But in recent years more detailed studies have backed up the idea that evolution proceeds in fits and starts.
The quiet periods in the fossil record where evolution seems to stagnate are a big problem for natural selection: evolution can't just switch on and off. Over 20 years ago the late Stephen Jay Gould suggested internal genetic mechanisms could regulate these quiet evolutionary periods but until now no-one could explain how it would work.
Stindl argues that the protective caps on the end of chromosomes, called telomeres, provide the answer. Like plastic tips on the end of shoelaces, all eukaryotic species have telomeres on the end of their chromosomes to prevent instability. However, cells seem to struggle to copy telomeres properly when they divide, and very gradually the telomeres become shorter. Stindl's idea is that there is also a tiny loss of telomere length between each generation, mirroring the individual ageing process.
Once a telomere becomes critically short it causes diseases related to chromosomal instability, or limited tissue regeneration, such as cancer and immunodeficiency. "The shortening of telomeres between generations means that eventually the telomeres become critically short for a particular species, causing outbreaks of disease and finally a population crash," says Stindl. "It could explain the disappearance of a seemingly successful species, like Neanderthal man, with no need for external factors such as climate change."
After a population crash there are likely to be isolated groups remaining. Stindl postulates that inbreeding within these groups could "reset" the species clock, elongating telomeres and potentially starting a new species. Studies on mice provide strong evidence to support this. "Established strains of lab mice have exceptionally long telomeres compared to those in wild mice, their ancestors," says Stindl. "Those strains of lab mice were inbred intensively from a small population."
Current estimates suggest telomeres shorten only a tiny amount between each generation, taking thousands of generations to erode to a critical level. Many species can remain stable for tens to hundreds of thousands of years, creating long flat periods in evolution, when nothing much seems to happen.
Telomere erosion is a compelling theory, helping to explain some of the more mysterious patterns in evolution and extinction. There are few data - partly because telomeres are tiny and difficult to measure - but new DNA sequencing techniques could soon change that. Studies have already shown a huge variation in telomere length between different species.
Other scientists are going to take some convincing. David Jablonski, a palaeontologist from the University of Chicago, says: "The telomere hypothesis is interesting, but must be tested against factors like geographic extent, or population size and variability, that have already been proven effective in predicting extinction risk."
Stindl accepts that more experiments need to be done to test his ideas. "We need to compare average telomere lengths between endangered species and current successful species," he says. "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."
If Stindl is correct it will have interesting implications for mankind. Although inbreeding seems to have been the traditional way of lengthening telomeres, there could be a less drastic alternative. Stindl believes that it may be possible to elongate telomeres by increasing the activity of the enzyme telomerase in the embryo. So humans could perhaps boost biodiversity and save endangered species simply by elongating their telomeres. We may even be able to save ourselves when our own telomeres become critically short, making humans the first species to take hold of destiny and prevent their own extinction.
Indicators for human extinction
Human telomeres are already relatively short. Are we likely to become extinct soon?
1: Cancer
Cancer incidence does seem to have increased, but it is hard to say whether this is due to longer lifespans, more pollution, or telomere erosion. The shortest telomere in humans occurs on the short arm of chromosome 17; most human cancers are affected by the loss of a tumour suppressor gene on this chromosome.
2: Immunodeficiency
Symptoms of an impaired immune system (like those seen in the Aids patients or the elderly) are related to telomere erosion through immune cells being unable to regenerate. Young people starting to suffer more from diseases caused by an impaired immune system might be a result of telomere shortening between generations.
3: Heart attacks and strokes
Vascular disease could be caused by cells lining blood vessels being unable to replace themselves - a potential symptom of telomere erosion.
4: Sperm counts
Reduction in male sperm count (the jury is still out on whether this is the case) may indicate severe telomere erosion, but other causes are possible.
|
| |
|
|
KNOW-THIS
Joined: 14 Jul 2003
Posts: 3694
|
|
Sat Apr 10, 2004 8:35 pm
|
|
|
"Man did not weave the web of life, he is merely a strand in it. Whatever he does to the web, he does to himself. All things are bound together. All things connect." |
| |
|
|
adam
Joined: 02 Apr 2004
Posts: 25
Location: tamaqua, pa. U.S.A. |
|
Sun Apr 11, 2004 2:31 am
|
|
|
WOW,
Know This, rain forrests, ice shelves, water supplies, global warming, hamburgers, the year 2350? Who is Kate Ravilious?, I think she is delirious! There is nothing NATURAL about Darwin! You need more faith to believe his theory, than you do to believe the entire Bible, word for word, without any other research!!! Have you ever noticed that scientists use words like, might, could, suggest, could be caused by, hard to say, maybe etc., etc. The more they know, the less they understand! You say here, somewhere in this series of post replies,that you don't care what people think. I was at the lib. and I think I was looking under the foreboding visions of a luciferian, where you're view was completely opposite with which you seemed to care very much what people seemed to think. Matter of fact, I even left you a short little reply over there NOT to care. My friend, how could you possibly worry about 2350 when tomorrow hasn't come yet? You did manage to strangle a coupl of simple questions that I asked. I am very slow here at home with my '95 lap.Ijust hope somebody will pick up on those Matt.-Ex. questions. I'm not trying to disrespect you KT, serious,I just think you got a little bit carried away, that's all. I really wanted to stay in the spirit here but, Stratospheric Welsbach seeding for reduction of global warming(US503186). You guys all know about this patent, right? This is really a different topic. This is about the metal oxides the're spraying in the trails to try and fix the holes they've been blasting with all their rockets! Enough...Know This did say..."Man did not weave the web of life, he is merely a strand in it. Whatever he does to the web, he does to himself. All things are bound together. All things connect." One thing I do know. If Yahweh found it necessary for my eternal salvation, and Loved me enough to send His only begotten Son,I must be a pretty important strand. To top it all off, Yahshua lay down his life of his own free will, for me, and you, and it doesn't matter who you are. Truth is in Him. All you have to do is ask, and you will receive.
------------------
|
| |
|
|
 
|
|
 Goto page Previous
1, 2
All times are GMT. The time now is Sat May 26, 2012 1:19 pm
|
|
|
|
|
Login
