Sendraks wrote:

DavidMcC wrote:
... Which would include ancient vertebrate fish. The only known fish group with three eyes is the lampreys, which were certainly around at 200mYa, according to most versions of evolution.

The order Rhynchocephalia, of which the Tuatara is the last surviving member, existed 200million years ago. There were certainly lampreys around then and indeed the oldest lamprey fossils date back to 360million years ago, although I'm sure you already know that.

The existence of three eyes in basal reptile forms like Rhynchocephalia (the remains of which are found in many specialised extant forms) could be the product of convergent evolution. However, as Rhynchocephalia is a basal form, it is reasonable to conclude that all members of that order share common unspecialised features which in turn they inherited from a common ancestor, who would have been more basal still.

Yes, like the lampreys, maybe, retained by expressing the relevant genes in other ways than an imaging eye.

Sendraks wrote:
I'm not sure where this sudden fixation on lampreys has come from.

Still relevant.

DavidMcC wrote:

Sendraks wrote:

DavidMcC wrote:
... Which would include ancient vertebrate fish. The only known fish group with three eyes is the lampreys, which were certainly around at 200mYa, according to most versions of evolution.

The order Rhynchocephalia, of which the Tuatara is the last surviving member, existed 200million years ago. There were certainly lampreys around then and indeed the oldest lamprey fossils date back to 360million years ago, although I'm sure you already know that.

The existence of three eyes in basal reptile forms like Rhynchocephalia (the remains of which are found in many specialised extant forms) could be the product of convergent evolution. However, as Rhynchocephalia is a basal form, it is reasonable to conclude that all members of that order share common unspecialised features which in turn they inherited from a common ancestor, who would have been more basal still.

Yes, like the lampreys, maybe, retained by expressing the relevant genes in other ways than an imaging eye.

There is nothing to suggest that basal reptile forms evolved from Lampreys, which is referred to convergent evolution. Indeed the evolutionary relationship between lampreys and jawed vertebrates is sketchy at best.

Sendraks wrote:

DavidMcC wrote:

Sendraks wrote:

DavidMcC wrote:
... Which would include ancient vertebrate fish. The only known fish group with three eyes is the lampreys, which were certainly around at 200mYa, according to most versions of evolution.

The order Rhynchocephalia, of which the Tuatara is the last surviving member, existed 200million years ago. There were certainly lampreys around then and indeed the oldest lamprey fossils date back to 360million years ago, although I'm sure you already know that.

The existence of three eyes in basal reptile forms like Rhynchocephalia (the remains of which are found in many specialised extant forms) could be the product of convergent evolution. However, as Rhynchocephalia is a basal form, it is reasonable to conclude that all members of that order share common unspecialised features which in turn they inherited from a common ancestor, who would have been more basal still.

Yes, like the lampreys, maybe, retained by expressing the relevant genes in other ways than an imaging eye.

There is nothing to suggest that basal reptile forms evolved from Lampreys, which is referred to convergent evolution. Indeed the evolutionary relationship between lampreys and jawed vertebrates is sketchy at best.

Nothing is straightforward at hundreds of MYa. The lampreys certainly seem to be more related to sharks than other fish, I admit.
However, I am arguing that the lamprey (which pre-dates any reptile in most versions of the evolutionary time-line), effectively "invented" the three eyes, so the tuatara could have inherited the genetic structure for it indirectly from lampreys, via Rhynchocephalia, and maybe other intermediate species, because, no doubt the lamprey was not a direct ancestor of any reptile, though it would have been the closest you get in known or extant species to being the "inventor" of the three eyes. It certainly predated Rhynchocephalia, in most versions of the evolutionary time-line (they change from time to time,sometimes drastically).

I see what you're saying David and it is one possible route, dependant on there being a relationship between lampreys and reptiles that can be determined through phylogenetics.

However, just because something predated another organism, doesn't necessarily mean there is any sort of genetic relationship between them.

Sendraks wrote:I see what you're saying David and it is one possible route, dependant on there being a relationship between lampreys and reptiles that can be determined through phylogenetics.

However, just because something predated another organism, doesn't necessarily mean there is any sort of genetic relationship between them.

I wasn't thinking of predation. You said that. I was thinking of the lamprey being relatively close to the basal vertebrate, as far as extant species are concerned.

Typo on my part, that should read "pre-dated."

Ostracoderms are, I think, the oldest fish in the fossil record. They were jawless and, importantly to this diversion from the overall discussion of possible phenotypes of extraterrestrial sapient flyers (???), had three eyes. It appears that jawed fish and eventually terrestrial tetrapods did evolve from jawless fish, but those early ostracoderms weren't all that much like lampreys. I don't think it's terribly helpful to keep going back to lampreys, and I don't think lampreys can be considered a basal species. They diverged from the lineages which eventually became tetrapods back in the early Ordovician. There's a lot of water under that bridge.

I feel it worth noting, again, that none of this is informative when attempting to consider possible phenotypes of extraterrestrial sapient flyers with any number of eyes. I would ask how much longer you intend to keep up this very much irrelevant thread derail, DavidMcC.

ScholasticSpastic wrote:Ostracoderms are, I think, the oldest fish in the fossil record. They were jawless and, importantly to this diversion from the overall discussion of possible phenotypes of extraterrestrial sapient flyers (???), had three eyes. ...

Not everyone agrees that the ostracoderms left any descendants before going extinct as a group, SS.
Of course, there are different opinions about that, which may never be resolved.

DavidMcC wrote:

ScholasticSpastic wrote:Ostracoderms are, I think, the oldest fish in the fossil record. They were jawless and, importantly to this diversion from the overall discussion of possible phenotypes of extraterrestrial sapient flyers (???), had three eyes. ...

Not everyone agrees that the ostracoderms left any descendants before going extinct as a group, SS.
Of course, there are different opinions about that, which may never be resolved.

Cool. You are more than welcome to support this with a reference which shows someone disagreeing with the idea that ostracoderms left any descendants. You are also more than welcome to explain why this is relevant in any way to anything we've been talking about. What is your proposed alternative jawless ancestor for lampreys and what resource(s) can you offer which support your proposed alternative? Or is this to be yet another massive derail where we await with baited breath the declarations of our lord and seer DavidMcC, who is too special for us to ask for him to support his assertions?

Finally, what in the name of a godless universe does ANY of this have with the subject of the thread?

ScholasticSpastic wrote:

DavidMcC wrote:

ScholasticSpastic wrote:Ostracoderms are, I think, the oldest fish in the fossil record. They were jawless and, importantly to this diversion from the overall discussion of possible phenotypes of extraterrestrial sapient flyers (???), had three eyes. ...

Not everyone agrees that the ostracoderms left any descendants before going extinct as a group, SS.
Of course, there are different opinions about that, which may never be resolved.

Cool. You are more than welcome to support this with a reference which shows someone disagreeing with the idea that ostracoderms left any descendants. ...

Sorry, I didn't realise that you were unaware of the history of this subject.

DavidMcC wrote:
Sorry, I didn't realise that you were unaware of the history of this subject.

Ah, so it's to be another thread where you make a shit-tonne of unsupported assertions and then try to deflect responsibility for rational discourse onto others. This shit is why I wish we would stop winding up in so many threads together. Our disagreements COULD be educational, except you go out of your way to make certain they're not.

I'm reporting this useless derail and suggesting we get back to discussing the actual subject of the thread rather than your irrelevant lamprey fixation.

ScholasticSpastic wrote:

DavidMcC wrote:
Sorry, I didn't realise that you were unaware of the history of this subject.

Ah, so it's to be another thread where you make a shit-tonne of unsupported assertions and then try to deflect responsibility for rational discourse onto others. ....

No, it's one where you show your ignorance of the history of the subject.

EDIT: You probably never saw the evolutionary charts on the WWW, showing the ostracoderms as a "dead end" group, leaving no decendants. However, it is possible that such information has been removed from the web. Therefore, you will, no doubt, claim that such charts never existed, right?

Oh look:

The Subclass Ostracodermi has been placed in the division Agnatha along with the extant Subclass Cyclostomata, which includes lampreys and hagfishes.

https://en.wikipedia.org/wiki/Ostracoderm

DavidMcC wrote:

ScholasticSpastic wrote:

DavidMcC wrote:
Sorry, I didn't realise that you were unaware of the history of this subject.

Ah, so it's to be another thread where you make a shit-tonne of unsupported assertions and then try to deflect responsibility for rational discourse onto others. ....

No, it's one where you show your ignorance of the history of the subject.

EDIT: You probably never saw the evolutionary charts on the WWW, showing the ostracoderms as a "dead end" group, leaving no decendants. However, it is possible that such information has been removed from the web. Therefore, you will, no doubt, claim that such charts never existed, right?

The internet doesn't work that way. I suppose if you were to learn to make more facile use of it, you might know that. If information concerning ostracoderms has been removed from the web, including from academic websites, what would this tell us about how likely that information is to be consistent with a current understanding of ostracoderms? It seems to me that if academic websites stop making a claim, it has probably been shown to be incorrect. If so, that would demonstrate that it is you who is ignorant of the subject, if not the history of the subject, because rather than desiring to continue learning, like a scientist does, you have decided instead to rest upon your out-dated laurels.

I have no idea whether this is the case. It is your claim to support and I have thus not made the effort. Do your own fucking homework.

ScholasticSpastic wrote:

DavidMcC wrote:

ScholasticSpastic wrote:

DavidMcC wrote:
Sorry, I didn't realise that you were unaware of the history of this subject.

Ah, so it's to be another thread where you make a shit-tonne of unsupported assertions and then try to deflect responsibility for rational discourse onto others. ....

No, it's one where you show your ignorance of the history of the subject.

EDIT: You probably never saw the evolutionary charts on the WWW, showing the ostracoderms as a "dead end" group, leaving no decendants. However, it is possible that such information has been removed from the web. Therefore, you will, no doubt, claim that such charts never existed, right?

The internet doesn't work that way.
,.,.

So, you think that articles on the internet last forever? I've got news for you - they don't always, especially not during a financial crisis.

DavidMcC wrote:

ScholasticSpastic wrote:
The internet doesn't work that way.
,.,.

So, you think that articles on the internet last forever? I've got news for you - they don't always, especially not during a financial crisis.

This is what I said:

The internet doesn't work that way. I suppose if you were to learn to make more facile use of it, you might know that. If information concerning ostracoderms has been removed from the web, including from academic websites, what would this tell us about how likely that information is to be consistent with a current understanding of ostracoderms? It seems to me that if academic websites stop making a claim, it has probably been shown to be incorrect. If so, that would demonstrate that it is you who is ignorant of the subject, if not the history of the subject, because rather than desiring to continue learning, like a scientist does, you have decided instead to rest upon your out-dated laurels.

I have no idea whether this is the case. It is your claim to support and I have thus not made the effort. Do your own fucking homework.

If the sense of the entire paragraph differs from the sense of the very tiny fragment you've picked out and responded to, that is called quote-mining. Along with refusing to support your claims, it is another tactic used by people who eschew rational discourse. It is also a violation of the FUA. I'm not reporting it because it's simple to just scroll upward and see what an asshat you've been by just responding to that little bit of what I had to say. You're only hurting yourself by behaving like an asshat, David.

I am just going to come right out and say it: three-eyed flying sapient lampreys are impossible.

scott1328 wrote:I am just going to come right out and say it: three-eyed flying sapient lampreys are impossible.

Yet delicious.

ScholasticSpastic wrote:

DavidMcC wrote:

ScholasticSpastic wrote:
The internet doesn't work that way.
,.,.

So, you think that articles on the internet last forever? I've got news for you - they don't always, especially not during a financial crisis.

This is what I said:

The internet doesn't work that way. I suppose if you were to learn to make more facile use of it, you might know that. If information concerning ostracoderms has been removed from the web, including from academic websites, what would this tell us about how likely that information is to be consistent with a current understanding of ostracoderms? It seems to me that if academic websites stop making a claim, it has probably been shown to be incorrect. If so, that would demonstrate that it is you who is ignorant of the subject, if not the history of the subject, because rather than desiring to continue learning, like a scientist does, you have decided instead to rest upon your out-dated laurels.

I have no idea whether this is the case. It is your claim to support and I have thus not made the effort. Do your own fucking homework.

If the sense of the entire paragraph differs from the sense of the very tiny fragment you've picked out and responded to, that is called quote-mining. Along with refusing to support your claims, it is another tactic used by people who eschew rational discourse. It is also a violation of the FUA. I'm not reporting it because it's simple to just scroll upward and see what an asshat you've been by just responding to that little bit of what I had to say. You're only hurting yourself by behaving like an asshat, David.

This is all nonsense. Tbh, I don't know how you have the nerve to post such junk. The items were on the internet for years, but have obviously been dropped recently, no doubt because of doubts about their validity. Still, that wouldn't be anything new in evolutionary biology, which is, after all, one of the murkier areas of science.