Evolution to water instead of from water

[MadScientist]

Is there any reason why life on land couldn't have evolved to the oceans??

 

I don't mean life started evolving on the land.

Something like a bird that lives off fish evolving into a "fish bird" thing.

 

Like the penguins, evolve from life in the sea, evolve on land for a while and become air breathers but since their prey is in the sea and they have to spend so much time underwater. Wouldn't evolution mutate them into water breathers again??

Or would the predators already in the oceans force them to stay on land??

 

Considering these facts..

I recently watched a documentary David Attenborough IIRC saying we've only explored around 5 percent of the Earths oceans.

The fact that our ocean exploration methods aren't too fast or manoeverable.

 

I consider the octopusses (octopi??) to be the primates of the seas, pretty clever creatures. And life's been evolving in the oceans for longer than on land.

Is there some reason why a far more advanced species couldn't have evolved down there a long time ago??

They'd be fast enough and clever enough to evade detection by us.

 

And I'm not talking about mermaids/men here either or an advanced civilisation that can build cities, they'd never have discovered fire for a start.

But couldn't a species evolve that had more intelligence than octupuses or doplins??

[Sayonara]

Fatal exception error: Too many queries

 

++ redo from start ++

 

 

ps - yes, it's 'octopi'.

[Ophiolite]

ps - yes' date=' it's 'octopi'.[/quote']Exactly what I've always thought, but I got curious and found this.

 

Although it is often supposed that octopi is the 'correct' plural of octopus, and it has been in use for longer than the usual Anglicized plural octopuses, it in fact originates as an error. Octopus is not a simple Latin word of the second declension, but a Latinized form of the Greek word oktopous, and its 'correct' plural would logically be octopodes.

 

Source:http://www.askoxford.com/asktheexperts/faq/aboutgrammar/plurals

 

I shall continue to say octopi, except in the presence of classics shcolars.

[YT2095]

I wouldn`t consider the discovery of "fire" a prerequisite for inteligence to address one point of many. perhaps the need for "Fire" isn`t necesary to them, perhaps they use something different? Thermals for instance

 

I like the film Abyss, although it`s a work of fiction, I wouldn`t consider it Impossible either

[Sorcerer]

octopiss

 

we knew what he meant

 

cotopuses

octopi

octopods

octopoda

octopodata

whateva

[Ophiolite]

Is there any reason why life on land couldn't have evolved to the oceans??

None.

I Like the penguins, evolve from life in the sea, evolve on land for a while and become air breathers but since their prey is in the sea and they have to spend so much time underwater. Wouldn't evolution mutate them into water breathers again??

If there were an evolutionary advantage in getting your oxygen from the water they might evolve that way, but to my recollection it never has. Seals and dolphins and whales all started out as land animals. The seals aren't quite so far along the route of adaptation as the cetaceans, so they still spend time on land. In the Mezozoic pleisiosaurs, the long necked sea creatues, also evolved, I believe, from land animals.

Or would the predators already in the oceans force them to stay on land??

Clearly not. Difficult to argue with a blue whale, unless you're a giant squid. And evolution is clever: dolphins sleep with one half of their brain at a time to keep watch for predators.

I consider the octopusses (octopi??) to be the primates of the seas' date=' pretty clever creatures. And life's been evolving in the oceans for longer than on land.

Is there some reason why a far more advanced species couldn't have evolved down there a long time ago??a species that had more intelligence than octupuses or doplins??[/quote']Well I wouldn't say impossible, but the absence of any evidence - even though we have explored only a smidgeon of the deep - makes it unlikely.

[Sayonara]

Exactly what I've always thought, but I got curious and found this.

Interesting source if you want to know the etymology, but it's the common usage so I don't see how it can be "incorrect". I guess that's why they put correct in inverted commas.

[Sorcerer]

ya no ef aye tolk lyke dis den yo kan stull undistarnd mi roit?

[Ophiolite]

ya no ef aye tolk lyke dis den yo kan stull undistarnd mi roit?

nthr pprch s smply rmv ll th vwls frm th wrds. thgh ths my lk strng y cn stll gnrlly ndrstnd

[MadScientist]

None.

If there were an evolutionary advantage in getting your oxygen from the water they might evolve that way' date=' but to my recollection it never has. Seals and dolphins and whales all started out as land animals. The seals aren't quite so far along the route of adaptation as the cetaceans, so they still spend time on land. In the Mezozoic pleisiosaurs, the long necked sea creatues, also evolved, I believe, from land animals.

Clearly not. Difficult to argue with a blue whale, unless you're a giant squid. And evolution is clever: dolphins sleep with one half of their brain at a time to keep watch for predators.

Well I wouldn't say impossible, but the absence of [b']any[/b] evidence - even though we have explored only a smidgeon of the deep - makes it unlikely.

 

I didn't know whales and dolphins evolved on land and migrated to water.

 

The only whale that can really be classed as a predator is the killer whale, isn't it?? The rest just collect plancton don't they??

 

 

And YT2095 I wasn't thinking of life as advanced as the Abyss type life, they were aliens visiting Earth anyway weren't they??

 

All I mean is some kind of advanced octopi type species that doesn't use any tools but it's so timid and lives so deep.. If it saw the lights of a submarine from far away it would scarper straight away.

 

A species as "sentient" (??) as ours or just far more advanced than any other sea life.

Maybe they can communicate with each other though, giving them a large advantage over other sea life.

If they could outsmart all their prey so much and evade predators well enough they wouldn't need to evolve much more, would they??

 

 

I was just wondering if there were any reason why it couldn't happen or have happened..

 

There is one thing I just realised. Large areas of land used to be under the sea and we haven't found any fossils, maybe they never lived in those areas though.

[Ophiolite]

I didn't know whales and dolphins evolved on land and migrated to water.

 

The only whale that can really be classed as a predator is the killer whale' date=' isn't it?? The rest just collect plancton don't they??[/quote']Wrong. The cetaceans fall into two major sub-divisions: Odontoceti (toothed whales) and Mysticeti (baleen whales). The baleen whales are the ones that eat plankton. There are plenty of the other kinds too: killer whales, belugas, sperm whales, narwhals, and all dolphins and porpoises.

 

 

There is some detailed information on their origin here:

 

http://darla.neoucom.edu/DEPTS/ANAT/Thewissen/whale_origins/index.html

 

[Skye]

Some tortoises here draw water in and out of their cloaca (arse) and absorb oxygen from it. It's not super efficient, but I think it can sustain them while their hibernate. I had one for a while as a kid that never seemed to come out of the water. Lazy bastard. Other species were barrels of fun though.

[MadScientist]

Wrong. The cetaceans fall into two major sub-divisions: Odontoceti (toothed whales) and Mysticeti (baleen whales). The baleen whales are the ones that eat plankton. There are plenty of the other kinds too: killer whales' date=' belugas, sperm whales, narwhals, and all dolphins and porpoises.

 

 

There is some detailed information on their origin here:

 

http://darla.neoucom.edu/DEPTS/ANAT/Thewissen/whale_origins/index.html

 

 

I was forgetting about dolphins, I didn't do it on porpoi.. Nahhh I won't do that joke..

Thanks for the info though, I'll do some reading up on my whales.

[Bernstein]

I didn't know whales and dolphins evolved on land and migrated to water.

 

They share the same common ancestor with the sheep and sheep-related species. The ones that returned to the ocean entered their niche as predators. Their great intelligence evolved as a result of their enforced change in feeding habits. In a similar way this is how human intelligence is also thought to have evolved.

 

All I mean is some kind of advanced octopi type species that doesn't use any tools but it's so timid and lives so deep.. If it saw the lights of a submarine from far away it would scarper straight away.

A species as "sentient" (??) as ours or just far more advanced than any other sea life.

Maybe they can communicate with each other though, giving them a large advantage over other sea life.

If they could outsmart all their prey so much and evade predators well enough they wouldn't need to evolve much more, would they??

I was just wondering if there were any reason why it couldn't happen or have happened..

There is one thing I just realised. Large areas of land used to be under the sea and we haven't found any fossils, maybe they never lived in those areas though.

 

A species that can alter the structure of its matter in such a way that it enables it to pass through normal solid matter, such as rock or mantel, might have evolved and remained out of sight. Such a creature could move through rock as easily as a fish swimming through water, or a bird flying through the air. In this way their molecular structure would be so different our paleontologists would not recognise their remains as fossilised fragments of a once living creature. It is doubtful if they would ever be seen at all.

[Mokele]

If there were an evolutionary advantage in getting your oxygen from the water they might evolve that way, but to my recollection it never has.

 

It's actually the reverse: Oxygen does not disolve in water to anywhere near the concentration it does in air. Thus, if you ventilate your respiratory surfaces with 1L of water and 1L of air, you'll get much more O2 from the air.

 

To my knowledge, the only vertebrates that have returned to gills from lungs are some amphibians like sirens and Necturus (mudpuppies) which are neotenic (basically remaining in larval form, but becoming sexually mature).

 

In the Mezozoic pleisiosaurs, the long necked sea creatues, also evolved, I believe, from land animals.

 

yep, from lizards/diapsids, though which group is a contentious issue.

 

The only whale that can really be classed as a predator is the killer whale, isn't it?

 

Others have actually already answered this, but I feel I should add one more note: Killer Whales are not actually whales; they're the largest species of dolphin, iirc.

 

 

On a slightly related note, I've actually considered basing of my occaisional sci-fi stories on a species that evolved mostly independently of both land and light, around the deep-sea thermal vents. But, well, that's fiction...

 

Mokele

[iglak]

Is there any reason why life on land couldn't have evolved to the oceans??

A major factor in this is the rescource of available space. Oceans are fairly empty, because animals in oceans require lots of open space to grow and live normally. Whereas on land much less space is required, and thus more space is available, especially at the time of the evolution onto land in a species.

 

And as was already said, predators would pose a large threat to any species evolving into the ocean.

[coquina]

Is there any reason why life on land couldn't have evolved to the oceans??

 

I don't believe anyone has mentioned that anything that evolved on land and moved to the oceans would have to evolve an adaptation to maintain osmotic balance in an environment where the fluid on the outside is more salty than the fluids on the inside. As I recall, marine fish have salt glands (that look like nostrils). They drink lots of water and excrete the excess salt. Sea turtles have salt glands too - if you have seen documentaries of the female coming on the beach to lay her eggs, you may have noticed that she appears to be crying - not - that is excess salt being excreted.

 

I think the whales and dolphins have evolved super-efficient kidneys. Sharks and rays put urea in their bloodstreams. I don't know what the mollusks do.

 

At any rate, a "new" marine creature would have to cope with this problem somehow.

[Mokele]

I don't know what the mollusks do.

 

IIRC, they use free amino acids in the cells and body fluids to maintain osmotic balance.

 

However, I'm not sure salt is that much of a disadvantage, if you compare it to terrestrial organism's problems with water. Unless the organism in question doesn't regulate it's osmolarity, then it's got problems in any environment: Marine critters have to stop water loss and salt accumulation, freshwater critters have to stop water influx and salt loss, and terrestrial critters have to try to hang on to their precious water.

 

So, which salt poses a different problem, I'm not really sure it's a bigger problem than, say, water for a terrestrial organism.

 

Mokele

[MadScientist]

I think we can forget about life on the land evolving back to the water, since Opiolite pointed out that it's already happened with the whales...

 

So that just leaves the species that stayed in the water evolving into something more advanced than the octopus.

I assume I am right to assume that the octopi are the cleverest of the marine based life forms, disregarding dolphins since they're mammals...

So if the octopi are the primates of the aquatic world, a more advanced species would be based on their form. It's logical, to me anyway, that a more advanced species would evolve from those.

 

I've still not convinced myself they'd turn into something as technologically advanced as we have, if they used any tools at all.

So what would it take for a species of octopus to develop an even more advanced brain?? Would that even be biologically possible??

 

If one species evolved a more advanced camofauging system, one that changed very quickly so it didn't need to rest on a rock bed and slowly change its appearance. It could just glide over the rocks and change as it did so. Giving it an even better chance of evading predators.

 

Then if they evolved primate type behavior of living in groups, so they hunted in packs giving them even more of an evolutionary advantage.

 

Are there any comparisons we can make between the primate evolutionary path to the octopi's evolutionary path to predict the existence of a more advanced species??

 

I look at a chimpanzee or something similar using a stick to "fish" out ants from the inside of a nest and think "They might evolve into something more advanced like we did."

I think the same think when I see an octopus showing off its skills.

[Blackfin]

I didn't know whales and dolphins evolved on land and migrated to water.

 

The only whale that can really be classed as a predator is the killer whale, isn't it?? The rest just collect plancton don't they??

 

The theory goes that there was too much competition on land and plenty of food in water, so the ancestors of whales eventually evolved back into marine organisms. Cetacea has actually been proposed as a suborder of Artiodactyla (even-toed herbioves) because of molecular and physiological similarities (both have a compartmented stomach, for example). That, and fossil evidence supports the evolution of Cetaceans from Artiodactylans.

 

Anyways, the only true cetacean carnivores at Odontocetes, as said above. You'd have to classify Mysticetes as omnivores because they do not differentiate between eating zooplankton and phytoplankton.

 

Are there any comparisons we can make between the primate evolutionary path to the octopi's evolutionary path to predict the existence of a more advanced species??

 

Not to be nit-picky, but aren't we ignoring an extremely important mollusk? What about the squid? If you take a look at the evolution of mollusks, it starts out with the very simplest, the bivalves - stuff like clams, scallops, and oysters. Their organ system are extremely simple and they're really just benthic organisms. Also, the biggest trait marking them as the "primitive" mollusks are their shells - they completely enclose the organism. Despite its effectiveness, in evolutionary terms, this was the very earliest body plan for mollusks. Next, you get into Gastropods - snails and slugs - that generally have only one shell used for protection. They're still mostly benthic (bottom dwellers), but they're more capable of active motion that bivalves are. Also, there are some shelless gastropods that make magnificent marine predators (nudibranchs & sea hares being good examples). There organ systems are also somewhat more complex than bivalves' are.

 

You see a general evolution away from the body plan of a mantle producing a shell. This is even more apparent in an octopus, which is made up entirely of muscle and has only remnants of a vestigial internal 'shell'. The cephalopods are far more advanced because of their physiology - they have closed vascular systems, more complex organ systems, a concentration of nerves that passes for a brain - and they are adapted for active motion. They are also all predators. Now, you could argue a squid is more advanced than an octopus because it's a better swimmer and dwells actively in the water column, but I think it's more of a case of divergent evolution where octopuses occupy a niche preying on benthic species and squid prey on nekton.

 

While squid and octopi are both quite aware and intelligent for invertebrates, I find it highly unlikely they will ever develop intelligence comparable to our own. They might very well be intelligent, but as they aren't social, I don't see how we'll ever understand or quantify it from the point of view of a species whose entire evolution has depended on social interaction for survival.

[Skye]

I don't believe anyone has mentioned that anything that evolved on land and moved to the oceans would have to evolve an adaptation to maintain osmotic balance in an environment where the fluid on the outside is more salty than the fluids on the inside. As I recall, marine fish have salt glands (that look like nostrils). They drink lots of water and excrete the excess salt. Sea turtles have salt glands too - if you have seen documentaries of the female coming on the beach to lay her eggs, you may have noticed that she appears to be crying - not - that is excess salt being excreted.

Alot of sea birds have similar glands on their head.

[Skye]

While squid and octopi are both quite aware and intelligent for invertebrates, I find it highly unlikely they will ever develop intelligence comparable to our own. They might very well be intelligent, but as they aren't social, I don't see how we'll ever understand or quantify it from the point of view of a species whose entire evolution has depended on social interaction for survival.

They are somewhat social, with all the colour flashing and that. Not building societies that threaten the existence of life on the planet, granted. But pretty nifty in their own way.

 

One of the problems for invertebrates developing intelligence, such as learned behaviour, seems to be that they don't have the same level of centralisation of the nervous system as vertebrates. IIRC about two thirds the mass of an octopuses nervous system is in its arms. These ganglia do alot of processing of information before it gets sent to the brain, and also probably control precise movements. I think the striking action an octopus arm makes when it goes to grab something is controlled by the arm itself, upon instruction of the brain. This limits the way the brain can respond to problems, as it only has a finite array of behaviours it can use.

[Mokele]

These ganglia do alot of processing of information before it gets sent to the brain, and also probably control precise movements. I think the striking action an octopus arm makes when it goes to grab something is controlled by the arm itself, upon instruction of the brain.

 

Actually, many vertebrates, including mammals, have similar reliance on spinal ganglia to coordinate movements. It was actually verified in some Russian experiments on cats a *long* time ago, before animal welfare laws. The connection between the brain and posterior spinal cord was cut, and stimulated with a simple, repeating electrical pulse. The result was perfectly identical to walking movement, in all ways. Increasing the frequency resulted in walking faster and eventually running. The only information being given to the legs was the frequency of the nerve impulses, everything else about how the leg moved, responded to local sense stimuli, etc, was governed by the spinal cord and ganglia.

 

In fact, at a lecture I recently attended, I learned of experiments which showed that, at least in some circumstances, classical (Pavlovian) conditioning requires only a spinal cord, as demonstrated with spinalized rats (where the brain was disconnected from everything but vital functions).

 

We tend to think of the spinal cord as just a cable, but it's actually far more complex.

 

Mokele

[Hellbender]

Is there any reason why life on land couldn't have evolved to the oceans??

 

I don't mean life started evolving on the land.

 

mesonychids--->cetaceans.

[KholdStunner]

dont all carbon-based creatures (such as humans, and basically everything on this planet) need water to survive? so how could carbon-based life forms have formed without water?? i think we evolved from water, because we cannot survive without it.