[tony6789 (OP)]

Well...dam it we screwed up big this time its official we are in another "mass extinction" and this 1 is worse than the dinasaurs. Guess who is to blame? Yup us...jeezz.

[Biology Guy]

How exactly are we to blame? Is it due to global warming that we caused or is it a different reason?

[tony6789 (OP)]

we have caused most of the extinctions...yes global warming contributes to some like the polar bear..but we also cause most of it by #1 HABITAT DESTRUCTION....like for instance the florida panther...there are only 50-70 left in the wild and captivity...there exteme endagerment is all due to blame for habitat destruction.
   Also hunting is another casue...along with another example...the whooping crane and the passenger pigeon...now the whooping crane is slowly recovering thru intense efforts...when the crane migrate from canada to america in the winter they had to land now and then in fields to eat and sleep..now when a farmer sees a huge bird like this in his field wat do u think his first reaction is? shoot em. and so the # of the crane went down to extremly low numbers reaching as far as 15-20 left...
the passenger pigeon used to b more numberous than ants...but now after a crazed hunting spree they are all gone...not a single 1 left....


There are many other examples which our teacher has explained to us a few...
and i dont know if iv'e ever met u b4 but welcome to the chat...and just get this straight im 14..so yea...i like braging to pplz about that...lol

[Biology Guy]

Nice to meet you and the fact that you are 14 is pretty impressive.

What you did leave out, which is important, is the extinction of fish and other marine animals which are mainly being extinct by over fishing, cod would be an example for this. Aquaculture is also the main reason why wild salmon are endangered in certain parts of the earth.

[another_someone]

There are many extinctions, but there are many species that are thriving (just look at the rat populations).

Ofcourse, when there are only a few of an animal left, we all cry over its demise, yet when there are a lot of them around, we complain that they are dangerous and should be eliminated.

Extinctions have always happened (if the old never died, the new could never be born).  Are we contributing - yes, but only insofar as we are another natural process, no different in that respect to a new strain of bacteria.

[Biology Guy]

This is true, but our specie is pushing more species to the brink of extinction then other species are. The current extinction rate is more then a thousand times larger then the background extinction rate which can largely be contributed by humans. This is due because humans have the innate ability to directly or indirectly kill those animals that are at the bottom of certain food chains thus causing the complete food chain to collapse.

If the humans, as a species, had the will (which they don't) to conserve those species then the extinction rates will go down. The fact that this is not happening shows that humans do not care about natural processes. If they did. these extinction rates would never have been allowed to happen.

The fact that many species, such as rats and jellyfish, are thriving is that they have no natural predator anymore due to the fact that those predators are extinct by us and we are thus dislocating the whole natural ecosystem of those species.

I am not sure if a new strain of bacteria have ever pushed a species into extinction but to the best of my knowledge, they haven't. (I'd be more then welcome to be corrected on this) This means that they are not the same as humans who have pushed certain species to the brink of extinction.

[another_someone]

This is true, but our specie is pushing more species to the brink of extinction then other species are. The current extinction rate is more then a thousand times larger then the background extinction rate which can largely be contributed by humans. This is due because humans have the innate ability to directly or indirectly kill those animals that are at the bottom of certain food chains thus causing the complete food chain to collapse.

I actually believe (although this is different from saying I can prove) this is to be false in a number ways (not saying it is totally false in every way, but in certain key aspects).

Firstly, the notion of a background extinction implies that there is a steady turnover of species, with a constant rate of birth and death of species.  I am not sure that this is at all true.  We know there have been mass extinction events in the past, and thus clearly indicating there is substantial variability in the extinction rates, and there is no reason to assume that the variability only exists in those short periods of mass extinctions (even within those times, there is still much controversy as to the exact duration it took for those mass extinctions to take place).  I suspect that species extinction is, like the weather, constantly subject to change, having irregular short, medium, and long term cycles.

Secondly, I disagree with you that we preferentially target the bottom of the food chain.  On the contrary, it is the larger animals that have become extinct the fastest.  The reasons for this are:

• The biggest make the biggest targets.  If you want to go out and hunt an animal, the bigger the animal, the bigger the benefit you will obtain for the same effort.
• Bigger animals tend to have longer lifespans, which means they are less capable of rapidly adapting to a rapidly changing environment.  This is the case whether the change in the environment is anthropogenic or not.
• Bigger animals need more space (as well as other resources), and so any change of land usage (or other resource availability) will tend to hit the biggest animals first.

The fact that many species, such as rats and jellyfish, are thriving is that they have no natural predator anymore due to the fact that those predators are extinct by us and we are thus dislocating the whole natural ecosystem of those species.

But does this not contradict what you earlier said about humans preferentially removing the bottom of the food chain.  If we were dismantling the food chain from the bottom, then how is it that these animals can thrive while their predators do not.  I agree, at least with regard to the jellyfish, that we have removed the predator, and started to dismantle to food chain from the top, not from the bottom.

I specified that the above was with regard to jellyfish, because I think the issue with rats and mice and foxes are different.  On land, at least in many parts of the world, human kind has become such a dominant part of the environment that the species that thrive are those that make use of this dominant force in the environment.

Domesticated animals have a symbiotic relationship with humankind, and have thrived wherever humans have thrived.  They have adapted from their wild form, but in the form they exist, they thrive nonetheless (and in fact substantially help carve the environment humans inhabit).
The second group of animals that have thrived in the human dominated environment are animals we regard as vermin.  They have adapted superbly to the human environment, often living off human waste, and often the primary way humans have to control their numbers is to better manage our waste.  Rats and mice certainly fall into this category.  They thrive not because we have removed their predators, but because we actively (if unintentionally) create an environment that they might thrive in.

Is it possible that those species that currently thrive in the human dominated environment might some day also risk extinction?  It is certainly possible (if we stop eating meat, it will certainly endanger many of the domestic species; and better waste management might remove the resources available for vermin), but I don't see it happening in the very near future.

If the humans, as a species, had the will (which they don't) to conserve those species then the extinction rates will go down. The fact that this is not happening shows that humans do not care about natural processes. If they did. these extinction rates would never have been allowed to happen.

Yes, we could do something to reduce extinctions rates – commit collective suicide.  Actually, even this would risk causing extinctions, the extinction of species that have become dependent upon humankind.

As I see it, the underlying reason why humans have caused so many extinctions is down to our inquisitive nature.

Species develop to utilise a particular niche in the environment.  Humans developed to exploit a small niche somewhere in Africa, but since that time, we have constantly been expanding out of that niche, and learning to thrive in an ever wider range of niches.  As we explore and thrive in ever more niches, not only across 7 continents, but on sea, in the air, beneath the soil, on mountains, in marshland, in every conceivable domain; so we inevitably displace those species that previously utilised those niches.  That is unavoidable except by refraining from exploring new niches, to refrain from developing technologies to utilise previously unusable (to us) resources.

As I said, in the past, the greatest impact we have had on competing with other species is with regard to large species, but increasingly we are venturing into ever smaller world, into the world of nanotechnology – so I wonder what competition this will bring to life forms that already occupy that world?

I am not sure if a new strain of bacteria have ever pushed a species into extinction but to the best of my knowledge, they haven't. (I'd be more then welcome to be corrected on this) This means that they are not the same as humans who have pushed certain species to the brink of extinction.

The easiest answer to this is to refer to cyanobacteria, which were responsible for large scale damage to the early anaerobic environment of the Earth.

Maybe not bacteria, but the fungus that causes Dutch Elm Disease all but wiped out that particular species of tree (apparently trees that were part of hedgerows survived, but free-standing trees all succumbed).

In general, it is much more difficult to asses extinction events that are separate from the human environment, since we only become aware of an extinction event when it impacts upon us (e.g. they loss of a species we prey upon will impact us, but equally is more likely that we would have had an influence upon the extinction).  So, for instance, there may regularly be extinction events at the bottom of the ocean that we cannot influence, but equally are unaware of.  We are primarily aware of those things we interact with, and so have some influence over; and the species we have influence over either flourish in our environment (such as vermin and domestic animals) or perish under its influence.

[tony6789 (OP)]

THis was said by u Another someone "In general, it is much more difficult to asses extinction events that are separate from the human environment, since we only become aware of an extinction event when it impacts upon us" ur point of view is off. Everything that extincts will affect us in some way. Like for instance if u woud say that the mosquito would go extinct and many beleive it wud not effect us but think about all the things that eat the mossquitos like bats...if mosquito populations cease then the bats wud lower but probably not go extinct but since the populations are low that means less flowers get pollenated by the bats..(bats pollenate flowers in case u didnt know) also if bats #s lower that means and over population of other bugs and that wud lead to more chaos...so everything in the earth is there for a reason...and everything affects EVERYTHING else.

             Also i have learned something else from our bio-teacher....should we let other animals die of extinction? becasue we all argue that we need there to be a "natural" amount..but arent we something a natural? We are just another animal...we always think that just becasue we are smart taht we rule and control everything. That is just a dumb human view...in the wild if a specie went exticnt and we didnt have any thing to do with it then wed prolly call it natuaral..but if we casue something to b extinct its not...we are just another animal...we arent the rulers...

[that mad man]

quote by tony6789

"we arent the rulers"

Unfortunately I think we are and benefit from the Dinosaurs and Neanderthals extinctions.

Man is in now control to a certain extent of his (and the earth's) own evolution and it is within our means to dictate what lives or dies and becomes extinct.

Natural or unnatural, right or wrong its evolution doing its work.



TMM

[Biology Guy]

Man is in now control to a certain extent of his (and the earth's) own evolution and it is within our means to dictate what lives or dies and becomes extinct.

This is true but that does not mean that we are morally allowed to decide what lives or dies.

[tony6789 (OP)]

we arent the rulers dude...we arent even close!!! we are just another liveing thing that happens to have more memory capability ok so we are smarter does that mean that the unsmart ones dont deserve to live? What if something was smarter than us...how would u feel if they thought the same thing? that they are the rulers and we shouldnt give a flying hoot about them cause we are smarter so we rule

[Ben6789]

We aren't the rulers. We are just a species conscius that we are destroying other creatures and perfectly capable of stopping it. This is what angers me the most. We are doing things..and we've had sucesses like the bald eagle and the sea otter..but a lot are still endangered or threatened becuase of us..i just with we could do more. Like my friend Tony said, #1 it's habitat loss. And not just construction, but also us bringing in invasive species that we think are nice, or pretty, or conveinent and then they reproduce out of control and we are like "crap, we screwed up and it's too late. Like the tree used in Florida used to drain swamps..and now it's draining too much.

That's all i have to say for now.

[tony6789 (OP)]

actuallly its not all because of us...some things will go extinct or threatened natuarally...and we think its our job to help them

[Biology Guy]

actually its not all because of us...some things will go extinct or threatened naturally...and we think its our job to help them

As far as I know, this is called the background extinction rate which is now several hundred times smaller then the actual extinction rate that is happening now. This means that the rate at which extinction happens is not natural and the number of extinctions that do happen naturally are almost insignificant compared to present extinction rates.

The human species isn't the most abundant species on earth but it is the most globally spread (not taking into account certain microorganisms) we therefore have the most impact on the environment and the extinction rates.

[another_someone]

THis was said by u Another someone "In general, it is much more difficult to asses extinction events that are separate from the human environment, since we only become aware of an extinction event when it impacts upon us" ur point of view is off. Everything that extincts will affect us in some way. Like for instance if u woud say that the mosquito would go extinct and many beleive it wud not effect us but think about all the things that eat the mossquitos like bats...if mosquito populations cease then the bats wud lower but probably not go extinct but since the populations are low that means less flowers get pollenated by the bats..(bats pollenate flowers in case u didnt know) also if bats #s lower that means and over population of other bugs and that wud lead to more chaos...so everything in the earth is there for a reason...and everything affects EVERYTHING else.

Firstly, as a matter of detail, there are bats, and there are bats.  The bats that pollinate flowers will generally feed of nectar and not on mosquitoes.

But even ignoring that minor detail - it does not address the issue I raised.

If we only observe an extinction event through a secondary, tertiary, or even more indirect, byproduct - it is very difficult for us to detect unambiguously that the extinction event took place.  If we find that there is a lower yield in some plant because some fungus has become extinct, that caused an increase in the number of some particular animal that used to be plagued by the fungus, and that animal is feeding off our plants - yes, there will be a knock on event from that extinction, but being able to identify that the extinction took place (particularly if we had not even previously been aware that the fungus ever existed) would be technically difficult, so we would not be aware of the extinction event.  On the other hand, if we hunt a particular species (e.g. a species of fish), and our hunting pushes the species of fish to extinction, we will immediately become aware that the species we are trying to hunt is no longer there to be hunted, so the extinction event is highly visible and obvious.

That is the point I was trying to make - that extinction events may be happening that we are not aware of, whether or not they have a knock on effect that indirectly might effect us.

Also i have learned something else from our bio-teacher....should we let other animals die of extinction? becasue we all argue that we need there to be a "natural" amount..but arent we something a natural? We are just another animal...we always think that just becasue we are smart taht we rule and control everything. That is just a dumb human view...in the wild if a specie went exticnt and we didnt have any thing to do with it then wed prolly call it natuaral..but if we casue something to b extinct its not...we are just another animal...we arent the rulers...

I would not disagree with this, although I am not exactly sure of the point you are trying to make with it (I am not saying there is no point that can be made, just I am not certain in this case what point it is that you are trying to make).

[another_someone]

actually its not all because of us...some things will go extinct or threatened naturally...and we think its our job to help them

As far as I know, this is called the background extinction rate which is now several hundred times smaller then the actual extinction rate that is happening now. This means that the rate at which extinction happens is not natural and the number of extinctions that do happen naturally are almost insignificant compared to present extinction rates.

The human species isn't the most abundant species on earth but it is the most globally spread (not taking into account certain microorganisms) we therefore have the most impact on the environment and the extinction rates.

You are firstly assuming that there is a steady state rate of extinction that has always, and will always, remain constant, and against which we can compare the current extinction rate.  How do you know this?

Secondly, how do you know what the extinction rate is even today (you may be able to provide a minimum value for the number of species we are actually aware of becoming extinct - but can you be sure you have today, or at any time in the past, a complete total of the number of extinctions - even at some approximate level?).

[Ben6789]

"actually its not all because of us...some things will go extinct or threatened naturally...and we think its our job to help them."--Tony6789

Yes we think we can help..but we really can't. My science teacher told me about when they were building a highway near San Diego, but a wetland was right in the way. "No problem." We said. We copied the wetlands to a nearby spot, everybodies happy.

Unfortunatly, we the endangered birds in that wetland which was almost the entire point for moving it were not breeding. We wondered why and then we found out we forgot a bug we thought was insignificant. That bug ate another bug which ate the grass. The birds wouldn't breed because the grass was too short. They felt too exposed.

Yes, we humans try to help, but oft times we end up screwing up..

[tony6789 (OP)]

good point...i love that i know u lol...everyone give ben6789 a warm welcome he is in my class and aslo right next to me typing to the site as i type...i introduced him to the site and i think hes hooked now hes also a godd and umm crazy friend(lol) of mine so yea...we have them same classes and everything so yea...he sitting next to me laughing rite now...lol

[tony6789 (OP)]

no1 has anymroe relies

[Ben6789]

What? No welcome for the n00b? Heh heh  []

Maybe everyone's run out of things to say...