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Post by Pem on Oct 22, 2008 8:05:45 GMT -7
The International Union for Conservation of Nature has just released data regarding the 5487 known species of mammals on earth and the outlook is grim. 1 in 4 species are now considered endangered with at least 29 including the Chinese river dolphin on the verge at at extinction now. This data has been pulled together in an attempt to be a guideline for policy makers and conservationist. This data was reported in the 10 October edition of Science, 2008.
Source: E. Pennisci. 2008. Comprehensive Conservation Database Details Threats to Mammals. Science 322, 178-179.
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Light
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Post by Light on Oct 22, 2008 13:43:41 GMT -7
I've been thinking about this recently, and I'd like to say in advance that I don't mean to offend anyone. Why does it matter? Species have gone extinct in the past, it's a fundamental part of natural selection. Why do we care now?
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Post by Pem on Oct 23, 2008 8:06:14 GMT -7
The reason we care now is that we are currently going through a mass extinction, diversity is taking a huge dip world wide. Now mass extinctions have occurred before in the past, and were caused by natural events (Oxygen production, meteors, etc....). The reason we care this time is the mankind is the cause for the current mass extinction. We are conscious of this and are attempting to undo what we have done. In a sense our actions haven't caused a natural selection so much as an artificial selection, selecting for animals that can live with the actions of our lives. Pigeons and Rats are examples of animals who have evolved to deal with us.
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Light
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Post by Light on Oct 23, 2008 16:06:21 GMT -7
It wouldn't be the first time we've messed with natural selection on a wide scale. As a botanist you might already know this, but during the neolithic age, when our long-past ancestors switched from purely nomadic/hunting tribes to agricultural towns that many call the first form of civilization, they changed the evolutionary process of plants. Instead of those that would be best suitable to growing in the wild, we chose those with tastier fruit or more ease in harvesting and replanted their seeds. We changed the plants to suit us, why are the animals so different?
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Post by Pem on Nov 14, 2008 8:59:23 GMT -7
The difference is that we changed changed the plants to suit us and we are killing off the mammals. Mind you we only manipulated plants that were genetically easy enough to manipulate. Basically we are having issues with killing off of mammal diversity because evolution cannot replace them. Their niche's may be filled again but it's unlikely to happen in our lifetimes... destabilizing an ecosystem just so we can enjoy driving the 5 minutes it takes to walk to work. Humans have the greatest potential to harm, and the help, of all the species on the planet. Sure we can make life better to us but if there is only us left, with livestock, and crops, what kind of existence is that. I guess it comes down to opinion in situations like this. But remember once something is extinct it can never re-evolve.
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Post by electroshock on Nov 15, 2008 8:02:38 GMT -7
in my opinion, we should just kill all the people on the earth. problem solved. no more pollution, no more "westward expansion", no more "for the good of mankind( but at the expense of everything else on this planet), buildings deteriorate, roads become grown over, and soon, the world would be close to what is was before people.
Pem, your last sentence disturbs me. as a scientist you should already know this: nothing is impossible, just highly improbable.
a species can re-evolve, sure it won't be EXACTLY the same, but close enough to fill the same niche. it's just that human existence has been so short, we have seen/documented none of it.
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Light
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Posts: 59
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Post by Light on Nov 16, 2008 18:02:36 GMT -7
Wonderfully explained, Pem, thank you. Now, I'm curious as to what would happen if humans were killed off. Surely we've done enough damage to make a lasting impression that the planet could not naturally recover from it. Electroshock, consider the near impossibility that a species would form in the first place. For another to form and be even remotely close, there would need to be that improbability, plus a repetition of the conditioning that made the species in the first place. Surely even a scientist must admit when something is so improbable that it may as well be deemed impossible.
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Post by electroshock on Nov 16, 2008 18:50:08 GMT -7
well, if the probability of life on earth is so small, then isn't the probability of life elsewhere in the universe equally as small, and therefore also so small "that it may as well be deemed impossible"?
the conditions do not necessarily need to be the same. It's just a matter of a series of random mutations, and having conditions that allow for that mutation's survival. eventually, the mammalian class would re-diversify, just like it did all those millions of years ago. of course, it would take an extremely long time, as all things naturally do. And who knows, maybe all the radiation we put into the world would increase the number of mutations and accelerate the re-diversification process.
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Post by Pem on Nov 17, 2008 9:13:31 GMT -7
Just a quick correction on your equation electroshock: Probability of life on any given planet is very small. The probability of life developing on any other planet in the universe is equally small. However because there are billions and billions of planets the probability of life occurring anywhere in the universe is therefore higher due to the amount of replications. Plus we know that life has indeed arisen on a planet at least once, we wouldn't be here discussing it otherwise. Unfortunately, in terms of evolution, we don't have that kind of replications to work with, and the ancestors that led to a current creature are long extinct. Although you are right, mammals could re-diversify however you will not be getting the same mammals they are going to replace.
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Post by millis on Mar 1, 2009 4:22:06 GMT -7
At least people are taking responsibility for the fact humans have caused this kind of problem, its better than trying to sweep it under the carpet or blame something else entirely. Its sad to see a species made extinct, if its a natural process it should be allowed to continue, theres no point keeping a doomed species alive in a zoo or whatever 'just so people can see it'. As cute as they are I never understood why they were so intent of breeding up the numbers of white bengals, look at its surroundings, its a completely doomed species, right from the start, yet are included in endangered breeding programs... Mini rant aside, i think the dolphin mentioned is actually classed as extinct now, none have been sighted for a while. Hopefully that kicked someone into gear.
Side note, if humans disappeared off the earth, i think the earth would recover eventually, yes the remnants of our civilization would still be there but animals can be very adaptable, to an extent. I doubt all of it would remain uninhabited for too long.
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Post by Pem on Mar 4, 2009 11:29:25 GMT -7
There is a famous book called World Without Us by Alan Weisman in which he examines what would happen should we suddenly disappear. Unfortunately, there is a mentality in the US that it does not matter what would happen to our Earth as the rapture is soon due and God will clear the earth. This mentality is dangerous to life as we know it.
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Post by millis on Mar 4, 2009 11:59:53 GMT -7
Wow...what a depressing outlook on life...
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Post by electroshock on Mar 4, 2009 13:05:54 GMT -7
yes. yes it is.
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Light
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Posts: 59
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Post by Light on Mar 4, 2009 15:42:12 GMT -7
Um...but isn't the purpose of the rapture Jesus coming back for the big party where all the believers fly naked into heaven? Seems like if we weren't here, it wouldn't happen...
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Post by millis on Mar 4, 2009 15:46:42 GMT -7
Flying naked could be worth staying here and being destroyed for just to watch that... *shot* Would be a funny sight XD But, anyway, you has a point, without people, earth wold still, in theory, be fine, or at least in better shape than it is now. So God probably wouldnt destroy it yet... Unless we're all really a huge mouse science experiment, then we're all screwed...
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