After humans?

[Gilded]

Let's take this scenario (which I think is disturbingly likely to happen):

 

Nuclear war has ended. Just about every continent is a wasteland, mostly with radiation and toxic levels nearly unbearable to homo sapiens species. All mammals including humans become extinct within about 10 years or so.

 

The interesting part comes first: Now that the sections in the food chain and ecosystem where humans and mammals used to be is empty, a new species will most likely take it over within a couple of hundred million years. But which species will natural selection choose to be the next "dominant" species? Highly radioactivity withstanding insects? Bacteria will start to evolve to something more? Just something to think about.

[5614]

a scenario such as that which wipes out the human race would also wipe out most if not all living species on the entire earth.

 

chosing the 'next human' is do-able, but knowing which specy will react best to high radiation levels is almost anyones guess, as that kinda thing is not generally experimented with [bombarding animals with radiation]

in theory, the specie which evolves quickest will have a very big head start.

 

but if all the humans die, i think a better question would be, whats left?

[mikeasdfasdf]

cockroaches

[Gilded]

Yeah, in the nuclear war scenario, the nuclear winter wouldn't be nice for even the most radiation resistant species.

[deltanova]

yeah, it was nothing, then it was the fish, then the reptillians, then the mammals(incl. humans) then it will be the time of the insects, wouldnt it be cool if they get realyrealyrealy big

[coquina]

Nuclear war has ended. Just about every continent is a wasteland, mostly with radiation and toxic levels nearly unbearable to homo sapiens species. All mammals including humans become extinct within about 10 years or so.

 

The interesting part comes first: Now that the sections in the food chain and ecosystem where humans and mammals used to be is empty, a new species will most likely take it over within a couple of hundred million years. But which species will natural selection choose to be the next "dominant" species? Highly radioactivity withstanding insects? Bacteria will start to evolve to something more? Just something to think about.

 

It is becoming increasingly more evident that impact events have caused most, in not all of the previous mass extinctions on earth.

 

I don't believe nuclear war is anywhere near as probable as it once was. I am a child of the 60's. I remember atomic bomb shelters, and "duck and cover" drills, where we were told to crouch beneath our desks. (Later, we became aware of just how futile that was and joked about "putting our heads beneath our knees and kissing our butts goodbye")

 

I do not believe that any of the larger nations would start a nuclear war. All that are capable of mass annhilation know that the favor would be returned before the missiles even reach their targets. There are a couple of rogue nations who might try it, if they become capable of intercontinental delivery. They would have to accept the fact that by starting a war they were committing suicide. I think the retaliation against them would be measured.

 

So - if you're talking mass extinction from an impact event, you wouldn't be dealing with radiation, but you would be dealing with an "impact winter". A lot would depend on how much warning we had, but large objects go by relatively closely on a regular basis, and we don't know how close they came til after they've gone.

 

Here are my thoughts on a "post-impact world"

 

1. In all the previous extinctions up til the next one, the creatures that were alive at the time had no means of altering their environment. We do and more importantly, we have.

 

2. The biggest factor would be at what angle the impactor arrived and where it hit. For example, evidence suggests that the Chixulub Impactor hit on an angle that set fire to most of North America.

 

When North America burned

Discover, Feb, 1997 by Carl Zimmer

 

Sixty-five million years ago, at the end of the Cretaceous Period, a 10-mile-wide comet or asteroid dropped out of the sky and plowed out a 120-mile-wide crater in the Caribbean near Mexico's Yucatin Peninsula. The impact, many researchers believe, was at least partly responsible for the fifth biggest extinction of all time, with numerous species of plants, marine animals, and, most famously, dinosaurs vanishing. But finding the links between the crater, known as Chicxulub, and the pattern of extinctions has been tricky. Recently, however, two Rhode Island researchers have found a clue - the angle of the impact - that could explain a lot about the extinctions, particularly why North America suffered more than the rest of the world. The Chicxulub fist of fury, say the researchers, came streaking toward the northwest over the Atlantic at an angle of 20 to 30 degrees, creating an enormous, searing vapor cloud that within minutes incinerated large parts of the western United States.

 

Peter Schultz, a planetary geoscientist at Brown, applied to Chicxulub his years of experience studying craters on other worlds. Analyzing the surfaces of our moon and the planets Mercury and Venus, he figured out ways to determine the angles at which impacts occurred from the craters they left behind. If an asteroid falls straight down on its target, he found, it leaves a symmetrical ring. If it comes in more obliquely, however, the bottom of the asteroid rams into the ground while the top, its tremendous momentum unchecked, shears off, spraying debris forward. An egg-shaped crater forms, with the long, narrow end down-range. "It was one of these deals where you hit yourself on the head," says Schultz. "I started noticing that repeatedly there was a nice relationship between the asymmetry of the crater and the angle of impact. I saw it on the moon, I saw it on Mercury, and I saw it on Venus."

 

Since researchers first realized in 1991 that a crater lay hidden a mile underground in the Yucatan, they have studied the patterns of magnetism and gravity of the area to map Chicxulub. Schultz's own recent study of the crater revealed that it had the telltale egg shape and a number of other signs of an oblique collision pointing toward the northwest.

 

If the Chicxulub impact had been perpendicular to the ground, much of its energy would have been absorbed by Earth, with most of the debris launched straight up into space. But the oblique trajectory of the impactor must have produced a very different aftermath, says Schultz. The impact shaved off a vast acreage of surface rock and launched a huge low cloud of hot vapor that hugged the ground as it continued along the impactor's path. Within three minutes the cloud overran much of the western United States. Only after this local cataclysm did the impacts debris begin to spread more evenly around the world.

 

Schultz's scenario makes sense to paleobiologist Steven D'Hondt of the University of Rhode Island. Such a regional apocalypse, says D'Hondt, explains some puzzles of the fossil record. The extinction rate of plants in North America, for example, was at least triple that found in the rest of the world. The fossil record in North America also shows an odd abundance of ferns after the extinction event. D'Hondt and Schultz point out that even 2,000 miles northwest of the Yucatan, the heat of the cloud would have ignited plants. After the conflagration, opportunistic ferns would have invaded and dominated for a time.

 

The theory may also explain another anomaly: studies of late Cretaceous fossils in Montana suggest that a species that lived on land was nine times more likely to go extinct than a freshwater resident. That seems logical if a scorching vapor cloud raced across North America at six miles a second: a turtle submerged in a pond might survive, while a Tyrannosaurus rex stalking in a glade would fry.

 

If Schultz and D'Hondt are right, further study should continue to show that extinction patterns in North America were unique, providing mute testimony to a time when the continent burned.

 

COPYRIGHT 1997 Discover

COPYRIGHT 2004 Gale Group

 

 

I have read logs from cores in this area - the K/T impact strata is referred to as a "barren zone", and it often mentions large quantities of carbonized (not as in "Carboniferous" or from that period) material, so that supports the theory put forth by this article.

 

If the impactor was closer to a 90 degree angle, and dropped in the ocean (most likely, since 3/4 of the earth is ocean), certainly all marine life within hundreds, if not thousands of miles, would immediately perish.

 

The resulting tsunami would wipe out all life on the coast of both bordering continents.

 

3. I don't think humans would go extinct as a direct result of the impact. We have a big advantage over all the creatures that existed before us - we can think and have the manual dexterity to apply our knowledge. They might eventually go extinct if the impact decimated the population to the extent there wasn't a viable number left to survive plagues of "new" diseases.

 

4. Certainly, the organisms occupying some niches would go extinct and leave them vacant. There would be a lateral spreading to occupy the vacant niches.

 

One other survivor would almost certainly be the 17 year locust:

http://insects.ummz.lsa.umich.edu/fauna/michigan_cicadas/Periodical/Index.html

 

By the time the larva that were underground were ready to metamorphize, the dust would have settled - literally.

[Martin]

thats a good point about the locusts

what a thought

McDonalds would reopen selling McLocustburgers

 

your post's title said Gammaray Bursts too, and they would do. A nearby supernova or whatever causes GRB. Do you have a link about GRB doomsday?

 

I dont think any nearby stars are candidates and I think humans would be able to

divert any aspiring Chicxulub so eventually if we insist on going extinct it will probably have to be by our own doing

[coquina]

I got so carried away with the impact bit, I forgot to throw in what I had read about gamma ray bursts.

 

http://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=246

 

http://arxiv.org/abs/astro-ph/0309415

 

http://www.planetsave.com/ViewStory.asp?ID=4647

 

A google search page:

http://www.google.com/search?hl=en&ie=UTF-8&q=gamma+ray+bursts+mass+extinction

[Martin]

...

 

http://arxiv.org/abs/astro-ph/0309415

 

...

 

I looked at that one. It's pretty interesting.

 

the loss of ozone layer is catalyzed by NOX and the global cooling comes from formation of a lot of NO2 (nitrogen dioxide is opaque or absorbs visible light quite a bit anyway)

 

they talk about loss of ozone protection from solar UV

and acid rain

and cooling and glaciation

 

their figures on the power in gamma and Xray are for a couple of different cases: the star itself puts out equiv to 5 x 10⁴⁴ watts (if it were in all directions instead of beamed) for 10 seconds. the two cases are the star could be say 6000 lightyears away or it could be 2100 lightyears away.

just rough distance conversions. they use parsecs.

 

"GRB1 and GRB2 both have equivalent power of 5 x 10^44 W for 10s. GRB1 is at 2 kpc and GRB2 is at 700 pc. GRB1 uses the low end of the rate estimates; GRB2 uses the high end and includes as a correction the contribution of the more luminous, distant events. In both cases we assume a burst of 10s. From GRB1 the upper atmosphere of the Earth is irradiated by about 10 kW/m^2, and in GRB2 it is about 80 kW/m^2 in X-rays and ?-rays."

 

it is this ionizing radiation that ionizes the nitrogen and oxygen and promotes all these weird chemical reactions producing the bad oxides of nitrogen. so basically we all get smogged, or our upper atmosphere layers do.

 

that was a good article. thanks

[eighth man]

A solid state civilization in the long run.

Humans will evolve again, then after

a few thousand years will learn to modify

their own minds, their mental circuits, their

emotional circuits, the way information is

organized. Then minds will be hooked up

to computers and then trillions of solid state

neurons , minds, computers will keep on

evoliving continuosly until it is completely

uncomprehensible. A Solid state civilization.

[Irken_Link]

yeah, it was nothing, then it was the fish, then the reptillians, then the mammals(incl. humans) then it will be the time of the insects, wouldnt it be cool if they get realyrealyrealy big

Insects being enormous is an impossibilty. They would collapse under their own weight because of their exoskeleton system.

Let's take this scenario (which I think is disturbingly likely to happen):

 

Nuclear war has ended. Just about every continent is a wasteland' date=' mostly with radiation and toxic levels nearly unbearable to homo sapiens species. All mammals including humans become extinct within about 10 years or so.

 

The interesting part comes first: Now that the sections in the food chain and ecosystem where humans and mammals used to be is empty, a new species will most likely take it over within a couple of hundred million years. But which species will natural selection choose to be the next "dominant" species? Highly radioactivity withstanding insects? Bacteria will start to evolve to something more? Just something to think about. [/quote'] I don't think it would take hundreds of millions of years for a new dominent species. Example:After the extinction of the dinosaurs and other major reptiles, mammels and birds took the jump for evolution.

[Sorcerer]

Actually there have been some massive insects in the past, like the giant dragonflies of the Carboniferous for example, higher oxgen concentration in the air is one hypothesis as to how they evolved.

 

http://studentwebs.coloradocollege.edu/~m_ulbrick/

[philbo1965uk]

Unfortunately i agree with a poster further up cockroaches are the prime candidate as this species eats anything........even each other alive or dead..

If you consider an impact event would blot out the sun and all plant life was dead after only a short period of time.Cockroaches would evolve into the next super species...as for growing larger or looking more human with its own developed intelligence,this wont happen its an insect with millions of years of evolution behind it,if was going to become as intelligent as us it would have already done it.

just a thought though,if an ant colony survived boy would they rule.Poor cockroaches would be the cows in the fields getting milked..

[Sayonara]

Actually there have been some massive insects in the past' date=' like the giant dragonflies of the Carboniferous for example, higher oxgen concentration in the air is one hypothesis as to how they evolved.

 

http://studentwebs.coloradocollege.edu/~m_ulbrick/[/quote']

Which is handy, because it's actually the oxygen requirement that limits insect growth.

 

Few insect species are able to actively pump air into their respiratory system as we do - it's all diffusion for the most part, so a giant insect would need to high oxygen environment in order to survive.

[philbo1965uk]

you forgot to mention the weight of the insect,which is also a factor.in order to counter the effects of gravity a large bodied insect is improbable

[Mokele]

Why is large size or inteligence even a factor in which taxon would become the next dominant one? Not only could one argue that post-apocalyptic insects would be the dominant taxa on account of them spreading to fill in vacant ecological niches, but one could use the same arguement, based on the sheer number, diversity and ecological importance of insects to claim that they're also the *current* dominant taxon.

 

Does something really have to be big or smart to be "dominant"? Those make them noticable, sure, but is what we notice really the case when you objectively analyze the data?

 

Mokele

[Skye]

I think they mean the location within the food chain by dominance.

[Sayonara]

you forgot to mention the weight of the insect,which is also a factor.in order to counter the effects of gravity a large bodied insect is improbable

Not really so improbable, seeing as they have existed.

 

I don't think there are many animals that can counter the effects of gravity.

[[Tycho?]]

Why is large size or inteligence even a factor in which taxon would become the next dominant one? Not only could one argue that post-apocalyptic insects would be the dominant taxa on account of them spreading to fill in vacant ecological niches' date=' but one could use the same arguement, based on the sheer number, diversity and ecological importance of insects to claim that they're also the *current* dominant taxon.

 

Does something really have to be big or smart to be "dominant"? Those make them noticable, sure, but is what we notice really the case when you objectively analyze the data?

 

Mokele[/quote']

 

Yeah pretty much. Is dominant by population? Imagine how many rats there are in the world. Its a bit of a fluke that we became dominant, an ape that moves on two feet really has little in the way of a physical advantage over other ground animals. We survived long enough to start using tools, and then we were pretty much set because we had such a good structure for that. But there is certainly no guaruntee that an intelligent species will evolve, over hundreds of millions of years we are the only one that we know of.

[Kedas]

I think there will always be a small group of people that manage to survive.

here a quote from A. Einstein that fits this thread

 

I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.

[Gilded]

"But there is certainly no guaruntee that an intelligent species will evolve, over hundreds of millions of years we are the only one that we know of."

 

That's because humans "fill" the "locker" where the most intelligent species belong. That's also the reason why we won't be seeing apes developing into humans right now, or in the future.

[[Tycho?]]

"But there is certainly no guaruntee that an intelligent species will evolve' date=' over hundreds of millions of years we are the only one that we know of."

 

That's because humans "fill" the "locker" where the most intelligent species belong. That's also the reason why we won't be seeing apes developing into humans right now, or in the future.[/quote']

 

Why is this? If by "locker" you mean ecological niche, then you are kinda right I guess. But nothing says that another animal cannot occupy the same niche. For humans, being intelligent proved to be advantagous. Apes have the same basic body structure, so it would be advantagous to them as well. It would take them such a long time to evolve that we probably wouldn't be around to see most of it, plus we are taking away their natural habitat pretty damn quickly. But there is nothing stopping them from doing it. Humans existing doesn't somehow prevent another intelligent species from emerging, its not like there is some magic law that says there can be only one at a time.

[Sorcerer]

Ummm are you forgetting the competition exclusion principle??

 

"Two species cannot coexist in a community if their niches are are identical."

 

Since the Human community is global, I think that rules that niche out. Hmmm except perhaps for aquatic animals... maybe intelligent plants too, the nich would be significantly different.

[LucidDreamer]

Ummm are you forgetting the competition exclusion principle??

 

"Two species cannot coexist in a community if their niches are are identical."

I believe this principle to be false. You will find many examples of two species that compete over the same niche and each survives for millions of years. What is to stop humans and evolved apes from cohabiting in cities? What's to prevent apes from evolving human-level intelligence if we allow them to have the resources and let natural selection to do its magic?

 

What makes that principle have a particle of truth is the word identical. Of course two individuals of the same species or of two different species cannot occupy the same spot nor can they eat the exact same crumb of food.

[Sayonara]

Ummm are you forgetting the competition exclusion principle??

 

"Two species cannot coexist in a community if their niches are are identical."

 

Since the Human community is global' date=' I think that rules that niche out. Hmmm except perhaps for aquatic animals... maybe intelligent plants too, the nich would be significantly different.[/quote']

You're confusing community and range.