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Why Alien Species Thrive
planux writes "The Sacramento Bee has an interesting article about why invasive animal species thrive, pushing out native species -- sometimes to the point of extinction. Kevin Lafferty, a U.S. Geological Survey marine ecologist at the Western Ecological Research Center in Santa Barbara says "Invasive species end up with about half the parasites, or diseases, they had at home." Animals with an average of 16 parasites on their home turf typically bring about three of the parasites with them to new locations. And only about four new parasites will typically adapt to attack the invading species. Net gain: 9 fewer parasites!"
Makes sense. That's why the colonists came to America. Damned European parasites.
Sunlit World Scheme. Weird and different.
The logical conclusion is that species that change location more often thrive more often and are therefore "more fit". So when some new weed comes in and starts killing all the grass, let it do so. It's the darwin way.
The GeekNights podcast is going strong. Listen!
A species new to an area has no known predators in that area. Hence, they may thrive and continue to do so until they have wiped out the population of the prey in that area. By that time overpopulation fixes itself because of a shortage in food supply. (or, think long term the development of resistence - if the given species feeds on plants, eventually they will start to taste bad to the species.
Basically, this is a built-in function of nature. It's just like life. When things are new and great you're happy, but you will adapt to your enviroment and will be bitchin about something soon - I promise.
Don't mess with nature, I suppose.Any info on why they adapt so well to the new cuisine?
This is exactly why we shouldn't be cloning things like mammoths! Jurassic Park 4! Oops, we cloned it again!
Ripley: How do we kill it? Ash: You can't. Parker: Bullshit! Ash: You still don't know what you're dealing with do you? Perfect organism. Its structural perfection is matched only by its hostility. Lambert: You admire it. Ash: I admire its purity, its sense of survival; unclouded by conscience, remorse, or delusions of morality. Parker: I've heard enough and I'm asking you to pull the plug. Ash: One more word. I can't speak for your chances, but... you have my sympathies.
this sig limit is too small to put anything good h
this reminded me of an older paper that tried to rationalize why optimal growing conditions does not seem to favor rapid evolution of a species. That is what scant evidence there is, it appears that evolutionary diversity and advancement occurs under not the optimal growing conditions but rather in the harshest. e.g. at the highest altitude, hottest temperaures or any place life struggles to survive.
While its obvious that harsh conditions by themselves impose evolutionary pressure this does NOT promote diversity--after all that pressure only is placed on genes that govern adaptation to the environment, and even there there is generally a narrowing of the gene pool not an expansion.
No instead the diversity arises because you have left your old balanced environment and predators, and thus have LOST the finely honed evolutionary pressure on those genes. thus you can evolve semi randomly with little selective pressure, leading to diversity. Another factor leading not to diversity but to rapid differentiation is that when these new traits that have nothing to do with survival get chromosomally linked to the features that enhance a species survival in the harsh environment, they get amplified.
some people call this the poker hand effect. You dont need a royal straight flush to win. all you have to do is beat your opponents. Or to put it another way if you are trying to live in a chemical wasteplant out flow, you dont have to generate a a very good enzyme for digesting plastics, anything that is better than your competitors is good enough for now. You can evolve it more later.
this explanation is perhaps the simplest and best answer to creationists who want to insist that life is too complex a process to spring into existance fully developed (.e.g. behe's mouse trap argument). The answer is that being adaptive can beat being the best.
anyhow its interesting that a species poised to exploit an opportunity will evolve faster than one that dominates its native environment.
Some drink at the fountain of knowledge. Others just gargle.
On my native network where the domiant boxen is Windows, I have found that non-indiginous boxen such as Solaris, Linux, and Mac are slowly taking over one part of my network. They often don't fall victum to the numerous virus and dipshit users. Either by design or just from complexity built into thier mutated form. I have also noticed a cross pollonation that has caused a raise in stability in our fringe windows boxes that are protected by the Alien unix and linux boxen.
It is all just nature at work, I one day hope to see all my boxeb being some kind of freakish hybrid of windows and unix/linux....or maybe the dominate boxen will take over the whole network.
Neck_of_the_Woods
#/usr/local/surf/glassy/overhead
Most species are going to have predators pleased to greet them, as most plants and animals are edible. What's important is the edge, a relative rather than absolute advantage over native species.
A couple of examples are kudzu and zebra mussels -- they don't complain about much. Our local favorite is the Asian "tiger" mosquito. But there are serious bad effects from monoculture -- one disease can destroy everything in its path. Think Windows desktops and a nasty virus.
Nature will tend to reach an equilibrium, or oscillate wildly, or the newcomers either exterminate the old, or vice versa. There are equatios for estimating equilibrium. Only in a really catastrophic situation does shortage of food supply rein in the invader. But evolution, as opposed to natural selection, is slow, so an alien species can easily exterminate native species before they have a chance to develop defenses, even to the point of suicide. Hawaii is suffering significant losses of species diversity because of newcomers. It takes thousands or millions of years for a new species to develop, yet perhaps the blink of an eye to perish.
I hate seeing natural selection described as some sort of moral quest for the "best," when it's just a way of explaining natural phenomena (I'm not saying you're doing that, but lots of people do). Darwin didn't judge was was "best," just tried to predict which species would do better under given circumstances. Nature doesn't care about the outcome, or become improved as a result. Species diversity is often the preferable situation.
Maybe I'm being clueless, but I'm hazy on your relevance to "devil's weed," slang for pot (which does grow quite nicely in the wild).
Or to put it another way, people with a family history of being prone to genetic mutation, or behavioural disorders, may in the long long long term have a greater influence on the genetics and sociology of future humanity, than those beautiful, well behaved people. What I cant decide is if this slash dot community represents a breeding place for diversification under harsh conditions or is a swarm fuzzy well balanced world for a particularly obnoxious phenotype and is thus not promoting its own evolution.
Some drink at the fountain of knowledge. Others just gargle.
At the same time, said new individual may be emerging into an environment it is totally unprepared for. Think of a plant going into an environment with lots of herbivores. While all of the native plants may have evolved nasty chemicals and physical defenses which have co-evolved with the local herbivores, the non-native plant has bupkis, and gets hammered as soon as it establishes itself.
Of course, there are a huge number of other wrinkles to this - higher dispersive ability and more efficient resource usage due to a the new plant not devoting any energy to costly defenses, etc., but this hypothesis was by no means a sure thing - that it has borne out is really quite extraordinary, and may yield some interesting insite into top-down versus bottom-up control of species invasions.
Well, common sense would dictate that in order for an organism to survive and reproduce in the first place, and hence invade, it has to be able to get its food from somewhere - there's an immense literature out there about attempts by man to introduce a variety of organisms for aquaculture, farming, etc, and failing due to those organisms not being able to eat, reproduce, or what have you. It follows then that if we see a succesful non-native organisms, its pappy was able to eat something when he first landed, and so can it!
The problems caused by invasive species are not due to the natural migration or spreading of species. They are caused when humans start shipping stuff all over the world. For example, there was that Chinese lung-fish that some dope in Delaware threw in to a pond roughly a year ago because he didn't want it as a pet anymore.
If you consider all of this to still be part of Darwinism, then you can look at it from another perspective. People want to protect the environment for their own sakes. For example, they like the varied swamp plants that they have in the Northeast US and hate seeing them all wiped out and replaced with a single invasive plant, a la purple loosestrife.
If you're somewhere that has access to Nature's archives, you can read the two original articles this one was based off of:
Release of invasive plants from fungal and viral pathogens and
Introduced species and their missing parasites
I am only half joking when I say that. With all the debate nowadays about the value of manned space flight, this is actually a very good argument for putting people out there. Space is harsh and there are many perils that we have to learn to deal with out there. But, those are the equivalent to the new parasites in any new environment.
For a little idea of how many paraites we would bring with us just look at the Earth similar ailments that astronauts get. They rarely get sick and never get into car accidents.
It just goes to show that getting into space and staying there might not be as daangerous for the log stay as just visiting is.
Is this the end yet?...How 'bout now...how 'bout now...how 'bout now?
It takes thousands or millions of years for a new species to develop, yet perhaps the blink of an eye to perish.
Makes you wonder what could happen to humans, with just the right set of environmental/climate changes.
cpeterso
There is a really good book that addressing this, along with lots of other geek interesting things. I read it a few years ago, but it is equally interesting today as it was then.
If you have a favorite book search engine, then you might only want the details:
ISBN number: 0679425632
Title: Why things bite back: Technology and the Revenge of Unintended Consequences
Author: Edward Tenner
Publisher: Random House Canada
Published: May 1996
If you want, you can see it at Amazon, Barnes and Noble and Indigo.
Go read it. It's interesting.
I agree.
Take sickle cell anemia for example. It is a deadly disease, but being heterozygous (that is, having the trait, but only partially or not exhibiting it) for it makes you unsusceptible to malaria. Hence, sickle cell is common in tropical cultures. Is sickle cell a good thing, has it made nature a better place? No, and no, but it has simply continued until evolution produced immunity towards a disease. Was this because cells and our genome have minds. No it's because people that are not heterozygous sickle cell lived, and those that weren't died because of malaria.
Ah yes, that would be kudzu. I apologize in the South that is what I have often heard it called, and I could not remember the real name. On a sidenote, are you saying pot came from China?
Whynot transplant the speices thats being wiped out back to the invaders home territory? Would the opposite apply? Cane toads are wiping out the austrailian frogs, would transplanting the austraialn frogs to the cane toads native habitat work the same way? I konw it would be bad enviornmentally, but it would be a fun experiment.
All Troll + "offtopic" mods are meta moderated as "Unfair", because you abused the system.
I just checked, and marijuana (from the hemp plant) apparently was cultivated thousands of years ago in central asia (yes, China), then made its way west to Europe. It was imported (alien species!) to the New World very around 1600, as the hemp provided valuable fiber. I saw the stuff growing wild many feet tall in Asia, which was kind of startling. The varieties grown for drug use has been refined to have many times the THC of the wild variety. The US prohibits growing low-THC hemp for the idiotic reason that it makes law enforcement look bad. Soem argue it does have economic value.
Don't ask me to connect pot and natural selection....
Sickle cell is oh-so-nasty, and even the heterozygotes show some mild symptoms. Yes, I learned the same thing sickle cell and malaria. Only a fraction (8-45% by region) of Africans have the trait, so probably people with it simply survive somewhat more often. I guess it was a glitch at some point that helped, but was not do-or-die essential to survival.
Rats, cockroaches, and humans. (Some of, not sure if list is exclusive) the only species that exist on all 7 continents. If and when humans spread out far enough to interact with extraterrestrial species, chances are they'll not only have to cope with us, but those other two as well.
No, you're wrong. Modern evolutionary theory avoids talking about 'best'; Darwin certainly had no such compunctions. Here's a quote from On The Origin of Species:
Now, in the context of 'perfecting' mental endowments, read the following excerpt from The Descent of Man:
Darwin was a good scientist, but he never entirely shook off the prejudices of his day.
- undoware.ca
Only a fraction (8-45% by region) of Africans have the trait, so probably people with it simply survive somewhat more often.
The key to understanding the genetics of sickle cell is to realize that the benefit is in having one normal gene and one sickle gene. In that case you get most of the protection against malaria and little of the harm of sickle cell.
Anyone with 2 sickle cell genes tends to dies of sickle cell anemia and anyone with no sickle genes tends to die of malaria. Most survivors will have one of each gene. The problem is that a population entirely of people with one of each gene is not "stable". When they reproduce their children will be 25% double sickle cell anemic, 25% sickle-cell-free and malaria vulnerable, and 50% healthy and protected.
The greater the malaria threat the closer the population will get to 50% sickle cell genes. As the threat diminishes the percentage will shift towards zero.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Only a few famous cases get the attention for surviving in alien environments.
An extreme example would be why don't we have dolphins here in Oklahoma? Afterall, we are surrounded on all sides by their natural environment, why haven't they invaded? They've even been actively transported into the area by humans. Why haven't they taken over? The answer is simple, they just can't live in/on the dirt. They gotta have seawater and there's just not very much available in OK.
Like I said, most don't. If you doubt the "most", just look around and count the number of species living in any particular ecosystem, then count the number of species living elsewhere and compare the numbers.
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
They come here in droves, stick together, and in 4 years they're your boss.
Chinese, Lebanese, you name it.
The canadian government is more anxious to pay for your university if you're an immigrant. They live packed 18 to a two bedroom apartement above a convenience store. They get their kids to work for free while they send the oldest to university. In two years, they own the store and the apartment above it. In two more years they buy the whole building.
Meanwhile the kid in university graduates with honors because he doesn't have to worry about eating or living expenses.
Then he's your boss, underpaying you, so you can't even afford to eat the over-priced food his parents sell at the convenience store.
The varieties grown for drug use has been refined to have many times the THC of the wild variety. The US prohibits growing low-THC hemp for the idiotic reason that it makes law enforcement look bad.
:))
THC is only the primary psychoactive cannabinoid present in marijuana; it's _much_ more complicated than that. (I realize the correction isn't exactly relevant to this discussion, but as a huge fan of cannabinoids--and hemp in general--I'm inclined to try and prevent this massively widespread misconception from getting any worse.
Do they need any insecteside?