Welcome Guest [Log In] [Register]
Speculative biology is simultaneously a science and form of art in which one speculates on the possibilities of life and evolution. What could the world look like if dinosaurs had never gone extinct? What could alien lifeforms look like? What kinds of plants and animals might exist in the far future? These questions and more are tackled by speculative biologists, and the Speculative Evolution welcomes all relevant ideas, inquiries, and world-building projects alike. With a member base comprising users from across the world, our community is the largest and longest-running place of gathering for speculative biologists on the web.

While unregistered users are able to browse the forum on a basic level, registering an account provides additional forum access not visible to guests as well as the ability to join in discussions and contribute yourself! Registration is free and instantaneous.

Join our community today!

Username:   Password:
Add Reply
Life Without Vertebrates; *OP updated*
Topic Started: Dec 24 2009, 04:12 PM (2,291 Views)
KayKay
Adult
 *  *  *  *  *  *
This will be an open project, anyone can join in to give their input and ideas.

This is a time line where a major extinction event early in Earth's history wipes out all vertebrate life on the planet, and many invertebrates along with them. Life Without Vertebrates is actually going to see the loss of all chordates. This will happen at the transition between the Devonian and the Carboniferous (if anyone thinks another point in history would be better, feel free to speak out).

The remaining invertebrates take the place of vertebrates and dominate the sea and land.

The mass extinction that causes this will have to be tailored to give vertebrates the hardest time. It must also be very severe, to be able to wipe out every single last chordate, so there would be a loss of many invertebrates too. Which invertebrates die out will depend upon the extinction event.

1. Decide what the extinction event will be, and how it will affect the climate. It must allow a significant number of invertebrates to survive, but wipe out all chordates.

2. Find out all of the known invertebrates that existed during the Late Devonian and Early Carboniferous, preferably as close to just before the extinction event as possible, and preferably species where there is adequate information available.

3. Decide which invertebrate species will survive, and mark out basic food webs for all of the major climate zones of the surviving invertebrates after the aftermath.

This will provide a starting point for the project.

So... first an extinction event suited for wiping out vertebrates and allowing enough invertebrates to live... Any ideas? If anyone wants to move on to the other steps that's fine, they were just a guideline anyway.

EDIT:

what we have so far....

A disease spreads that attacks chordates. Chordate species numbers plummet, but some chordates and a minimal number of vertebrates survive. Soon after, a meteorite impact on the main equilateral continent wipes out a large portion of both invertebrates and vertebrates. Many invertebrates make it through, but vertebrates are already dying out so the impact brings them down to critical numbers. After this point, vertebrate species are too low to ever recover, and they are gradually phased out by invertebrates.

Extinct

All vertebrates

Survivors

Arachnids
Trilobites
Centipede relatives (looking for names to be more specific)

Onychophora

Nautiloids *
Ammonoids *
Orthocerids *

*Could one of them become squid analogues?

Archaeopteris (spore-bearing)

Considering

Marine arachnids (to replace eurypterids) *
Marine scorpions (to replace eurypterids) *
Eurypterids (should they live or die off?) *

*Did eurypterids survive to the carboniferous? Would they survive the impact?

Squid, possibly land squid (maybe leave this idea for later on when cephalopods are more evolved)
Edited by KayKay, Dec 28 2009, 02:24 PM.
Offline Profile Quote Post Goto Top
 
Replies:
ATEK Azul
Member Avatar
Transhuman
 *  *  *  *  *  *  *  *
Many people have but others want to make their own versions or old projects transform into something else while a new one is made for the original idea.
I am dyslexic, please ignore the typo's!
Offline Profile Quote Post Goto Top
 
Canis Lupis
Member Avatar
Dinosaurs eat man, woman inherits the Earth.

If you are thinking "Rewriting Earth": yes, this was the original idea. But due to a want of more varied creatures, we decided to scrap that and change it into its current state.

Which, BTW, you are free to submit individual creature ideas to "Rewriting Earth" now.


Anyway, back on topic. Water could be a potential vector for notovoria ("notochord eater" (this is assuming we go with a notochord digesting bacterium)). Plus, it would help to wipe out the marine chordates. I'm a bit hazy as to how an asteroid impact can cause extinctions in the oceans, so a disease that spreads via water would work wonders.
Offline Profile Quote Post Goto Top
 
ATEK Azul
Member Avatar
Transhuman
 *  *  *  *  *  *  *  *
I had actually thought we were waiting for sub-forums on Rewrighting Earth?

Also I am glad you like the Idea of a water desease I thought it fit the best in this sitchuation.
I am dyslexic, please ignore the typo's!
Offline Profile Quote Post Goto Top
 
Canis Lupis
Member Avatar
Dinosaurs eat man, woman inherits the Earth.

Well, yes. I forgot abothe subforum thing. I'll have to PM Parasky and ask him to set up those subforums and to give someone who is active a lot the ability to move topics just in the "Rewriting Earth" section. Just to help Parasky and the mods along, to get it to run more smoothly.



The reason I like your water as a vector thing is that it is so dang plausible. If you look at most epidemics throughout history (in fact, you don't have to look at epidemics. Just look at a dish of pond water), you'll notice that the disease started in the water out of terrible water conditions. Poor sewage creates a breeding ground for all kinds of bacteria. This is why you are told to wash your hands (though I'm sure you all knew that).

So it's not too farfetched for a bacterial disease to begin in the water. In fact, it's almost a given.
Offline Profile Quote Post Goto Top
 
ATEK Azul
Member Avatar
Transhuman
 *  *  *  *  *  *  *  *
See while I didn't go into our history with my reasoning that is the sort of thoughts I was having.

Anyway we now have a roughly defined extinction event for this world. Now we need to figuer out what else will die and then start speculating on the after events. Cephalopods have already been suggested along with Echinoderms but what others?

Also with the Oxygen levels and Wood in the enviroment a celestial impact will cause a large amount of fires. So my question is how will these fires effect Plant evolution and the Swamp Enviroments of the Carboniferous?

Also I'm glad I reminded you about the Sub-Forums then.
Edited by ATEK Azul, Dec 25 2009, 10:52 PM.
I am dyslexic, please ignore the typo's!
Offline Profile Quote Post Goto Top
 
KayKay
Adult
 *  *  *  *  *  *
So, just for clarification... a water-borne disease wipes out majority of chordate life, particularly sea-fairing life. Some continental species survive, and those are wiped out by a meteorite impact? Then, anything left over is out-competed by invertebrates? Yeah that sounds reasonable. :)

I'm still having a hard time imagining no chordates would be left over, particularly in freshwater habitats on unaffected continents for some reason (honestly can't think of a reason why it's nagging away at the back of my mind). But I may be wrong.

I was thinking the meteorite could hit the continent I've often seen named "Euramerica". I think it should be pretty severe, what about you guys?

I've often heard a meteorite impact would be more devastating if it hit a coastal area.

I think oxygen levels are suspected to be, while still falling, reasonably high By the Late Devonian/Early Carboniferous.

In deciding which invertebrates would go extinct, I think we should consider the effects of the extinction. What sort of damage does a meteorite impact cause? What sort of damage would the loss of vertebrates do, perhaps something invertebrate relied on them for prey to eat?

I may come back and edit this post if I think of anything.
Edited by KayKay, Dec 26 2009, 12:58 PM.
Offline Profile Quote Post Goto Top
 
Canis Lupis
Member Avatar
Dinosaurs eat man, woman inherits the Earth.

I think you are referring to Laurasia with that Euramerica thing. Though I could be wrong.

The only thing about this chordate extinction I'm having a massive problem with is the extinction of the tunicates. Those are some really diverse chordates (well, diverse in body form, but all doing similar things). I wouldn't be surprised if they survive and if they survive, it probably would not cause the chordates to regain dominance.

Yes, an asteroid impact would be more devastating if it hit a coastal area. That is one of the reasons K-T was so devastating.

And Atek, you are right about massive forest fires ensuing from this asteroid impact. There were no flying chordates at the time, so the forest fires could be one of the deciding factors in the extinction of the chordates. Slow moving arthropods (like Arthropleura) would be doomed. Burrowing arhtropods (like Mesothelae) would survive as the fire would just rush over them.

Amphibians would be one of the first chordates to go. Acid rain is a byproduct of large asteroid impacts and amphibians absorb oxygen and other atmospheric elements directly through their skin. So they would be the first to be effected by acid rain and thus the first to become extinct.

In the oceans, plankton would begin to die when the sun becomes blocked out. Thus, most filter feeders experience a massive die off. This kills most sponges, most (if not all) tunicates, most (if not all) cephalochordates, and most fish. The creatures that feed upon the filter feeding fish would go extinct when their food source dies off. Only the creatures that eat other things besides the fish would survive.

From what I can tell, the amphibian numbers would have dropped off well before the asteroid impact. Their reproduction is so dependent upon the water that the eggs would be destroyed by notovoria before they had a chance to hatch.

If the disease begins early in the Carboniferous, reptiles would fall victim to extinction much more easily. Their shells would still be rather thin and would still need to be kept relatively moist. Perfect victims of notovoria.
Offline Profile Quote Post Goto Top
 
KayKay
Adult
 *  *  *  *  *  *
I like what you're suggesting so far. :)

Hm... maybe we should make it that not all chordates go? We could be lenient in letting a few chordates slip through the extinction, but just not with vertebrates (after all, it is life without vertebrates and not life without chordates)? That would give tunicates the chance to survive.
Edited by KayKay, Dec 26 2009, 02:23 PM.
Offline Profile Quote Post Goto Top
 
Canis Lupis
Member Avatar
Dinosaurs eat man, woman inherits the Earth.

Yes, this would be way more plausible as a vertebrate-less world than a chordate-less world.
Offline Profile Quote Post Goto Top
 
Venatosaurus
Member Avatar
HAUS OF SPEC
 *  *  *  *  *  *  *  *  *
Wonderful compromise. This would also give cephalopods a chance to persist, and nothing would be more satisfying than seeing amphibious or fully terrestrial cephalopods in this planets future :D Now since we have an agreement as to how the extinction occurs, does the fun part begin ?!



Offline Profile Quote Post Goto Top
 
Holben
Member Avatar
Rumbo a la Victoria

Terrestrial cephalopods? Not again...

I hope cephalopods do survive though, because they could become the giants of the seas. I'm imagining a 20-metre furry octopus with trailing tentacles. It traps mini things on the fur, which it scrapes off with the tentacles and sucks off its tentacles with its beak.
Time flows like a river. Which is to say, downhill. We can tell this because everything is going downhill rapidly. It would seem prudent to be somewhere else when we reach the sea.

"It is the old wound my king. It has never healed."
Offline Profile Quote Post Goto Top
 
KayKay
Adult
 *  *  *  *  *  *
Keep that idea in mind and we might just be able to use it in the future. :D

We should be able to decide now what species will survive and what will die out, maybe even speculate their evolution. I will keep a record of all of the species going to survive and go extinct on this post. Remember post #27 to check back on to see what's been agreed to survive. Oh, I thought as a sort of starting point we could use Wikipedia's categories, they're not entirely accurate I've found on occasion but if you're really lost for ideas or don't know what species lived during the Late Devonian, this page might help: Category: Devonian Life.

Extinct

All vertebrates

Survivors

Arthropods:
Arachnids
Trilobites

Trees:
Archaeopteris (spore-bearing)

Considering

Marine arachnids (to replace eurypterids)
Marine scorpions (to replace eurypterids)
Eurypterids (should they live or die off?)

Velvet worms

Centipede relatives (looking for names to be more specific)

Squid, possibly land squid (maybe leave this idea for later on when cephalopods are more evolved)
Edited by KayKay, Dec 27 2009, 03:26 AM.
Offline Profile Quote Post Goto Top
 
Canis Lupis
Member Avatar
Dinosaurs eat man, woman inherits the Earth.

Arachnids would be a survivor, as would the highly diverse trilobites.

That's all I know for right now. I'll get back to you when I find out more information.
Offline Profile Quote Post Goto Top
 
ATEK Azul
Member Avatar
Transhuman
 *  *  *  *  *  *  *  *
This all sounds good except I'm not sure how a Salt water desease could survive a fresh water enviroment, and if it can't be in both how does that effect the extinction list?

Also while I dislike land Squid Like the Megasquid and Squibbon, I don't mind Swampus and flying veriaties.
I am dyslexic, please ignore the typo's!
Offline Profile Quote Post Goto Top
 
KayKay
Adult
 *  *  *  *  *  *
I agree with arachnids and trilobites, anyone else agree or disagree?

I think any disease that is so successful it can wipe out an entire phylum of animals would be able to gain enough numbers to eventually find that lucky mutation that allows it to jump between salt water and fresh water.
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
Go to Next Page
« Previous Topic · Alternative Evolution · Next Topic »
Add Reply