I once read an article maybe about 30 years ago that
said that monotremes do not have electroencephalic patterns
similar to REM sleep in humans but marsupials and placental
mammals do.

The article speculated that monotremes may have brains
slightly bigger than some marsupials and placentals due
to less efficient memory processing because of lack of
dreaming.

If birds could do more with smaller brains, that might
enable them to do more with less weight at least slightly.

I was wondering, is there anything in the EEG patterns of
sleeping birds that might mimic REM sleep patterns in
in some mammals, that could indicate that they might
potentially dream in a speculative similar manner to humans
perhaps as potentially caused by convergent evolution?

On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> I once read an article maybe about 30 years ago that
> said that monotremes do not have electroencephalic patterns
> similar to REM sleep in humans but marsupials and placental
> mammals do.
>
> The article speculated that monotremes may have brains
> slightly bigger than some marsupials and placentals due
> to less efficient memory processing because of lack of
> dreaming.
>
> If birds could do more with smaller brains, that might
> enable them to do more with less weight at least slightly.
>
> I was wondering, is there anything in the EEG patterns of
> sleeping birds that might mimic REM sleep patterns in
> in some mammals, that could indicate that they might
> potentially dream in a speculative similar manner to humans
> perhaps as potentially caused by convergent evolution?

I don't know, but I once claimed that vertebrate bone construction appeared connected to sleep & dreaming. Didn't find support for it elsewhere, but I suspect it is true.

In my pursuit of backlog in s.b.p., I found this thread to be of special interest.

On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:

> I once read an article maybe about 30 years ago that
> said that monotremes do not have electroencephalic patterns
> similar to REM sleep in humans but marsupials and placental
> mammals do.

It may depend on how broadly or narrowly "similar" is meant.
The following passage argues for a broad interpretation.

"Mammals and birds engage in two distinct states of sleep, slow wave sleep (SWS) and rapid eye movement (REM) sleep. SWS is characterized by slow, high amplitude brain waves, while REM sleep is characterized by fast, low amplitude waves, known as activation, occurring with rapid eye movements and reduced muscle tone. However, monotremes (platypuses and echidnas), the most basal (or ‘ancient’) group of living mammals, show only a single sleep state that combines elements of SWS and REM sleep, suggesting that these states became temporally segregated in the common ancestor to marsupial and eutherian mammals."

On the other hand, in the same abstract, there is something that seems
to argue for a somewhat narrow interpretation:

"...during REM sleep in ostriches, forebrain activity would flip between REM sleep-like activation and SWS-like slow waves, the latter reminiscent of sleep in the platypus. Moreover, the amount of REM sleep in ostriches is greater than in any other bird, just as in platypuses, which have more REM sleep than other mammals."

Title: Ostriches Sleep like Platypuses
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/

> The article speculated that monotremes may have brains
> slightly bigger than some marsupials and placentals due
> to less efficient memory processing because of lack of
> dreaming.

I could not find anything about brain sizes in the article. Instead,
I found a difference between forebrain, cortex and brain stem.

"Unlike SWS, which is initiated and maintained by the forebrain, REM sleep-related cortical activation, rapid eye movements, and reduced muscle tone are generated by the brainstem [2], [3]. Interestingly, the cortex of monotremes (platypuses and echidnas), the most basal (or ‘ancient’) group of living mammals, shows only SWS-like slow waves during sleep [4]–[6], [ but see 7].

This segregation of cortical and brainstem functions is clarified next:

"Furthermore, during sleep in the platypus (Ornithorhynchus anatinus), cortical slow waves occur with REM sleep-like rapid eye movements and reduced muscle tone [8]. This suggests that REM sleep at the level of the brainstem and SWS in the cortex were present in the most recent common ancestor to all mammals, and that REM sleep with cortical activation evolved only after the appearance of the marsupial/eutherian lineage [5], [9]. Alternatively, the unusual brain activity of sleeping monotremes may reflect an evolutionary loss of REM sleep with cortical activation [10]."

> If birds could do more with smaller brains, that might
> enable them to do more with less weight at least slightly.
>
> I was wondering, is there anything in the EEG patterns of
> sleeping birds that might mimic REM sleep patterns in
> in some mammals,

In the ostrich, yes, with monotremes the most similar mammals.
Presumably also in other ratites. This is true of the rhea:

"These REM sleep-related head movements have also been described in a close relative of the ostrich, the greater rhea (Rhea americana) [42] "

> that could indicate that they might
> potentially dream in a speculative similar manner to humans
> perhaps as potentially caused by convergent evolution?

Convergent it would have to be, because living reptiles, which
are closer to birds than they are to us, lack REM sleep,
and presumably their common ancestral amniote also lacked REM sleep:

"However, reptiles do not exhibit the neuronal activity observed in the brainstem during REM sleep in mammals [11], including monotremes [12], nor do they show cortical signs of REM sleep and SWS [11], [13], [14]."

CONTINUED in next reply to this post, slated for later today.

Peter Nyikos
Professor, Department of Mathematics
University of South Carolina -- standard disclaimer --
https://people.math.sc.edu/nyikos/

On Saturday, May 14, 2022 at 8:16:41 PM UTC-4, daud....@gmail.com wrote:
> On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:

> > I was wondering, is there anything in the EEG patterns of
> > sleeping birds that might mimic REM sleep patterns in
> > in some mammals, that could indicate that they might
> > potentially dream in a speculative similar manner to humans
> > perhaps as potentially caused by convergent evolution?

> I don't know, but I once claimed that vertebrate bone construction appeared connected to sleep & dreaming. Didn't find support for it elsewhere, but I suspect it is true.

Probably only in a very indirect way. Vertebrates alone are able to achieve great size on land, and it takes a certain
brain size to make room for such "wasteful" activity. Have you thought much about octopi and squids? They are
also big enough, with some researchers studying the intelligence of octopi in various ways.

Richness of environment, and keen senses to take it in, are also needed for dreaming, I would think.
This seems greatest on land and in coral reefs.

Peter Nyikos

This second reply to the same post was slated for yesterday,
but I got sidetracked by a thread in talk.origins about mathematics,
and I decided some fine points about spherical geometry needed to be clarified.

On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:

> I was wondering, is there anything in the EEG patterns of
> sleeping birds that might mimic REM sleep patterns in
> in some mammals, that could indicate that they might
> potentially dream in a speculative similar manner to humans
> perhaps as potentially caused by convergent evolution?

The following excerpt from the same article from which I quoted yesterday
suggests that is likely only in a few kinds of living birds.

"Episodes of REM sleep, typically less than 10 s in duration in other birds [36], [37], [50], [54], lasted 27±7 s on average in ostriches, and could last up to 5 min (2.3±0.9 min, mean maximum ± s.e.m.), the longest reported for any bird."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/

It seems reasonable that any episode of REM sleep that lasts for
over two minutes is a good candidate for a dream of the sort
that we humans have. On the other hand, the "less than 10 seconds"
typical of other birds seem hardly conducive to anything like dreaming.

A difference between ostriches and humans is that ostriches have
much more frequent episodes of REM sleep, typically totaling
25%, on average, on five hours of each night. See Figure 4 of the linked article.

The total is greater than for humans, but it is much more chopped up.

It's conceivable, though, that there is some degree of continuity between
successive episodes. I often have the experience of waking up in the
middle of the night for a short time, and then of having the dreams
when I go back to sleep be similar to the ones before I woke.

What is the experience of other readers?

Peter Nyikos

PS before the weekend, I will post the final reply to this post,
on a strongly evolutionary aspect of sleep that is more in
the mainstream of sci.bio.paleontology.

On Wednesday, June 22, 2022 at 4:25:57 PM UTC-7, peter2...@gmail.com wrote:
> This second reply to the same post was slated for yesterday,
> but I got sidetracked by a thread in talk.origins about mathematics,
> and I decided some fine points about spherical geometry needed to be clarified.
> On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > I was wondering, is there anything in the EEG patterns of
> > sleeping birds that might mimic REM sleep patterns in
> > in some mammals, that could indicate that they might
> > potentially dream in a speculative similar manner to humans
> > perhaps as potentially caused by convergent evolution?
> The following excerpt from the same article from which I quoted yesterday
> suggests that is likely only in a few kinds of living birds.
>
> "Episodes of REM sleep, typically less than 10 s in duration in other birds [36], [37], [50], [54], lasted 27±7 s on average in ostriches, and could last up to 5 min (2.3±0.9 min, mean maximum ± s.e.m.), the longest reported for any bird."
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/
>
> It seems reasonable that any episode of REM sleep that lasts for
> over two minutes is a good candidate for a dream of the sort
> that we humans have. On the other hand, the "less than 10 seconds"
> typical of other birds seem hardly conducive to anything like dreaming.
>
>
> A difference between ostriches and humans is that ostriches have
> much more frequent episodes of REM sleep, typically totaling
> 25%, on average, on five hours of each night. See Figure 4 of the linked article.
>
> The total is greater than for humans, but it is much more chopped up.
>
> It's conceivable, though, that there is some degree of continuity between
> successive episodes. I often have the experience of waking up in the
> middle of the night for a short time, and then of having the dreams
> when I go back to sleep be similar to the ones before I woke.
>
> What is the experience of other readers?
>
>
> Peter Nyikos
>
> PS before the weekend, I will post the final reply to this post,
> on a strongly evolutionary aspect of sleep that is more in
> the mainstream of sci.bio.paleontology.

I dream as probably everyone does, but my dreams seem to "evaporate" very quickly once I
wake. Sometimes they disappear even as I try to relate them to my wife. I have (I think) recurring
dreams, or at least the same situation, but I've no recollection of "picking up the thread" where I
previously waked up.

On Saturday, May 14, 2022 at 8:16:41 PM UTC-4, Daud Deden wrote:
> On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > I once read an article maybe about 30 years ago that
> > said that monotremes do not have electroencephalic patterns
> > similar to REM sleep in humans but marsupials and placental
> > mammals do.
> >
> > The article speculated that monotremes may have brains
> > slightly bigger than some marsupials and placentals due
> > to less efficient memory processing because of lack of
> > dreaming.
> >
> > If birds could do more with smaller brains, that might
> > enable them to do more with less weight at least slightly.
> >
> > I was wondering, is there anything in the EEG patterns of
> > sleeping birds that might mimic REM sleep patterns in
> > in some mammals, that could indicate that they might
> > potentially dream in a speculative similar manner to humans
> > perhaps as potentially caused by convergent evolution?
> I don't know, but I once claimed that vertebrate bone construction appeared connected to sleep & dreaming. Didn't find support for it elsewhere, but I suspect it is true.

Non-avian ungulates: sleep standing up, dream laying down

https://infoorb.quora.com/Why-do-cows-and-horses-actually-sleep-standing-up?ch=10&oid=119606248&share=7393030a&srid=RPhZF&target_type=question

On Thursday, June 23, 2022 at 5:11:58 AM UTC-4, daud....@gmail.com wrote:
> On Saturday, May 14, 2022 at 8:16:41 PM UTC-4, Daud Deden wrote:
> > On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > > I once read an article maybe about 30 years ago that
> > > said that monotremes do not have electroencephalic patterns
> > > similar to REM sleep in humans but marsupials and placental
> > > mammals do.
> > >
> > > The article speculated that monotremes may have brains
> > > slightly bigger than some marsupials and placentals due
> > > to less efficient memory processing because of lack of
> > > dreaming.
> > >
> > > If birds could do more with smaller brains, that might
> > > enable them to do more with less weight at least slightly.
> > >
> > > I was wondering, is there anything in the EEG patterns of
> > > sleeping birds that might mimic REM sleep patterns in
> > > in some mammals, that could indicate that they might
> > > potentially dream in a speculative similar manner to humans
> > > perhaps as potentially caused by convergent evolution?
> > I don't know, but I once claimed that vertebrate bone construction appeared connected to sleep & dreaming. Didn't find support for it elsewhere, but I suspect it is true.

There's a very remotely connected way you've found so far, even if it is correct.

> Non-avian ungulates: sleep standing up, dream laying down

I've known about the "sleep standing up" since I was a young child.

In contrast, the rest of your sentence is a simplification of
the claim, "Cows...can only dream if they're lying down" which the linked article
makes no attempt to explain or support:

> https://infoorb.quora.com/Why-do-cows-and-horses-actually-sleep-standing-up?ch=10&oid=119606248&share=7393030a&srid=RPhZF&target_type=question

The article goes to a great length to show how horses are
able to sleep standing up, but it doesn't try to explain why
they (or, rather cows) can't also dream standing up.

Typical popular science writing. Somewhat atypical is the concluding remark:
"There. That's a thing you know now." You can even click on the picture and it will
give the cow spiel in isolation.

Peter Nyikos

On Thursday, June 23, 2022 at 2:11:58 AM UTC-7, daud....@gmail.com wrote:
> Non-avian ungulates: sleep standing up, dream laying down

Wait a sec… does that mean there are AVIAN ungulates? Do ornithischians count as avian?

On Thursday, June 23, 2022 at 8:46:47 AM UTC-4, peter2...@gmail.com wrote:
> On Thursday, June 23, 2022 at 5:11:58 AM UTC-4, daud....@gmail.com wrote:
> > On Saturday, May 14, 2022 at 8:16:41 PM UTC-4, Daud Deden wrote:
> > > On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > > > I once read an article maybe about 30 years ago that
> > > > said that monotremes do not have electroencephalic patterns
> > > > similar to REM sleep in humans but marsupials and placental
> > > > mammals do.
> > > >
> > > > The article speculated that monotremes may have brains
> > > > slightly bigger than some marsupials and placentals due
> > > > to less efficient memory processing because of lack of
> > > > dreaming.
> > > >
> > > > If birds could do more with smaller brains, that might
> > > > enable them to do more with less weight at least slightly.
> > > >
> > > > I was wondering, is there anything in the EEG patterns of
> > > > sleeping birds that might mimic REM sleep patterns in
> > > > in some mammals, that could indicate that they might
> > > > potentially dream in a speculative similar manner to humans
> > > > perhaps as potentially caused by convergent evolution?
> > > I don't know, but I once claimed that vertebrate bone construction appeared connected to sleep & dreaming. Didn't find support for it elsewhere, but I suspect it is true.
> There's a very remotely connected way you've found so far, even if it is correct.
> > Non-avian ungulates: sleep standing up, dream laying down
> I've known about the "sleep standing up" since I was a young child.
>
> In contrast, the rest of your sentence is a simplification of
> the claim, "Cows...can only dream if they're lying down" which the linked article
> makes no attempt to explain or support:
>
> > https://infoorb.quora.com/Why-do-cows-and-horses-actually-sleep-standing-up?ch=10&oid=119606248&share=7393030a&srid=RPhZF&target_type=question
>
> The article goes to a great length to show how horses are
> able to sleep standing up, but it doesn't try to explain why
> they (or, rather cows) can't also dream standing up.
>
> Typical popular science writing. Somewhat atypical is the concluding remark:
> "There. That's a thing you know now." You can even click on the picture and it will
> give the cow spiel in isolation.
>
>
> Peter Nyikos

Actually I have no idea. There is a sort of sleep paralysis during dreaming, but there is also the example of cats and dogs dreaming while chasing or being chased, legs in full gear while eyes closed. And arboreal birds and apes must have gripping tendons locked while asleep.
It does seem likely that dreaming could occur only during safe sleep, when predators are least likely to attack, waking from a dream tends to be disorienting.

On Thursday, June 23, 2022 at 1:45:14 PM UTC-4, thesigh...@gmail.com wrote:
> On Thursday, June 23, 2022 at 2:11:58 AM UTC-7, daud....@gmail.com wrote:
> > Non-avian ungulates: sleep standing up, dream laying down
> Wait a sec… does that mean there are AVIAN ungulates? Do ornithischians count as avian?
Nope, ungulates are mammals with hooves.

On Wednesday, June 22, 2022 at 4:25:57 PM UTC-7, peter2...@gmail.com wrote:
> This second reply to the same post was slated for yesterday,
> but I got sidetracked by a thread in talk.origins about mathematics,
> and I decided some fine points about spherical geometry needed to be clarified.
> On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > I was wondering, is there anything in the EEG patterns of
> > sleeping birds that might mimic REM sleep patterns in
> > in some mammals, that could indicate that they might
> > potentially dream in a speculative similar manner to humans
> > perhaps as potentially caused by convergent evolution?
> The following excerpt from the same article from which I quoted yesterday
> suggests that is likely only in a few kinds of living birds.
>
> "Episodes of REM sleep, typically less than 10 s in duration in other birds [36], [37], [50], [54], lasted 27±7 s on average in ostriches, and could last up to 5 min (2.3±0.9 min, mean maximum ± s.e.m.), the longest reported for any bird."
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/
>
> It seems reasonable that any episode of REM sleep that lasts for
> over two minutes is a good candidate for a dream of the sort
> that we humans have. On the other hand, the "less than 10 seconds"
> typical of other birds seem hardly conducive to anything like dreaming.
>
>
> A difference between ostriches and humans is that ostriches have
> much more frequent episodes of REM sleep, typically totaling
> 25%, on average, on five hours of each night. See Figure 4 of the linked article.
>
> The total is greater than for humans, but it is much more chopped up.
>
> It's conceivable, though, that there is some degree of continuity between
> successive episodes. I often have the experience of waking up in the
> middle of the night for a short time, and then of having the dreams
> when I go back to sleep be similar to the ones before I woke.
>
> What is the experience of other readers?
>
Well for one that REM sleep in humans may not correlate to bird experiences, and even in humans, it is not yet possible to determine what is really happening in REM sleep.
You don't know whether you were in REM sleep when you wake in the middle of the night, nor in REM sleep when continuing the dream that you apparently remember in the morning. You don't even know whether you were dreaming the same thing before waking in the middle of the night, although you say you have a memory of it. But the experience you describe is not unusual, and is claimed to happen occasionally.

Dreaming is fascinating for me. I have had lucid dreams as well as recurrent dreams. I even recall being conscious of my mind 'playing a movie" so to speak, and wondering why it was chosen, even waking up and attempting to convince "myself" to change the movie when falling asleep again. The NDE I experienced was nothing like any dream, lucid or otherwise, though. So that is why I am interested in consciousness. I couldn't speculate
about other critters, except that I suspect that all life has some degree of consciousness, and intelligence.

On Saturday, June 25, 2022 at 8:38:25 PM UTC-4, Glenn wrote:
> On Wednesday, June 22, 2022 at 4:25:57 PM UTC-7, peter2...@gmail.com wrote:
> > This second reply to the same post was slated for yesterday,
> > but I got sidetracked by a thread in talk.origins about mathematics,
> > and I decided some fine points about spherical geometry needed to be clarified.
> > On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > > I was wondering, is there anything in the EEG patterns of
> > > sleeping birds that might mimic REM sleep patterns in
> > > in some mammals, that could indicate that they might
> > > potentially dream in a speculative similar manner to humans
> > > perhaps as potentially caused by convergent evolution?

> > The following excerpt from the same article from which I quoted yesterday
> > suggests that is likely only in a few kinds of living birds.
> >
> > "Episodes of REM sleep, typically less than 10 s in duration in other birds [36], [37], [50], [54], lasted 27±7 s on average in ostriches, and could last up to 5 min (2.3±0.9 min, mean maximum ± s.e.m.), the longest reported for any bird."
> > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/
> >
> > It seems reasonable that any episode of REM sleep that lasts for
> > over two minutes is a good candidate for a dream of the sort
> > that we humans have. On the other hand, the "less than 10 seconds"
> > typical of other birds seem hardly conducive to anything like dreaming.
> >
> >
> > A difference between ostriches and humans is that ostriches have
> > much more frequent episodes of REM sleep, typically totaling
> > 25%, on average, on five hours of each night. See Figure 4 of the linked article.
> >
> > The total is greater than for humans, but it is much more chopped up.
> >
> > It's conceivable, though, that there is some degree of continuity between
> > successive episodes. I often have the experience of waking up in the
> > middle of the night for a short time, and then of having the dreams
> > when I go back to sleep be similar to the ones before I woke.
> >
> > What is the experience of other readers?
> >
> Well for one that REM sleep in humans may not correlate to bird experiences, and even in humans, it is not yet possible to determine what is really happening in REM sleep.

True.

> You don't know whether you were in REM sleep when you wake in the middle of the night, nor in REM sleep when continuing the dream that you apparently remember in the morning.

Unless someone monitors my eye movements and wakes me up before the latest REM episode is over.
That has never happened to me, but plenty of others have been subjects of experiments where this was done.

>You don't even know whether you were dreaming the same thing before waking in the middle of the night, although you say you have a memory of it.

I only remember a small fraction of my dreams, but some from long ago were so vivid, I still remember them.

One kind of dream that was fairly common some decades ago was where I would find, to my embarrassment,
that I was naked in public. But when they were most common, I was able to employ something I had read in
a science fiction book: I generated an "I'm not here" aura that caused those around me to ignore me.
And so I was able to exit gracefully from their company.

> But the experience you describe is not unusual, and is claimed to happen occasionally.
>
> Dreaming is fascinating for me. I have had lucid dreams as well as recurrent dreams. I even recall being conscious of my mind 'playing a movie" so to speak, and wondering why it was chosen, even waking up and attempting to convince "myself" to change the movie when falling asleep again. The NDE I experienced was nothing like any dream, lucid or otherwise, though.

What does NDE stand for?

> So that is why I am interested in consciousness. I couldn't speculate
> about other critters, except that I suspect that all life has some degree of consciousness, and intelligence.

I'm fairly confident that mammals and birds are conscious. Hence I'm very supportive of
our laws against cruelty to animals.

I also think that all normal human fetuses are conscious at 8 weeks past fertilization, at least in
the rudimentary sense of being past the stage of complete oblivion. That's why I favor restricting
abortion strongly beyond that point. Portugal and Turkey are two countries where that kind of law is in force.

However, invertebrates are a different matter. Already when I was 7 years old, I thought, "How lucky I am!
there are so many more ants in the world than human beings, and *I* am a human being!"

I had never heard of Hinduism by that point, yet the possibility of me experiencing the world through the body
of an ant seemed to be a real one for me, and so it was a great mystery how I could be so lucky.

But if ants aren't conscious, that removes a lot of the mystery.

We've moved rather far from paleontology, but it is hovering in the background and giving
rise to such questions as: were all the dinosaurs and pterosaurs conscious? And how
rich were their conscious lives?

Which brings us back in a roundabout way to dreaming and such observable phenomena as REM sleep.
It's getting late [1], so the post about paleognaths that I promised Harshman will get at least one
more day of delay.

Also, since Trolidan7 hasn't shown up since I revived his thread, I'm thinking of
starting a new thread for it.

[1] I'm an early riser in the summer, because early morning is the best part of the day to be outside
here in South Carolina.

Peter Nyikos

On Monday, June 27, 2022 at 6:26:47 PM UTC-7, peter2...@gmail.com wrote:
> On Saturday, June 25, 2022 at 8:38:25 PM UTC-4, Glenn wrote:
> > On Wednesday, June 22, 2022 at 4:25:57 PM UTC-7, peter2...@gmail.com wrote:
> > > This second reply to the same post was slated for yesterday,
> > > but I got sidetracked by a thread in talk.origins about mathematics,
> > > and I decided some fine points about spherical geometry needed to be clarified.
> > > On Sunday, May 8, 2022 at 6:28:46 PM UTC-4, Trolidan7 wrote:
> > > > I was wondering, is there anything in the EEG patterns of
> > > > sleeping birds that might mimic REM sleep patterns in
> > > > in some mammals, that could indicate that they might
> > > > potentially dream in a speculative similar manner to humans
> > > > perhaps as potentially caused by convergent evolution?
>
> > > The following excerpt from the same article from which I quoted yesterday
> > > suggests that is likely only in a few kinds of living birds.
> > >
> > > "Episodes of REM sleep, typically less than 10 s in duration in other birds [36], [37], [50], [54], lasted 27±7 s on average in ostriches, and could last up to 5 min (2.3±0.9 min, mean maximum ± s.e.m.), the longest reported for any bird."
> > > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160860/
> > >
> > > It seems reasonable that any episode of REM sleep that lasts for
> > > over two minutes is a good candidate for a dream of the sort
> > > that we humans have. On the other hand, the "less than 10 seconds"
> > > typical of other birds seem hardly conducive to anything like dreaming.
> > >
> > >
> > > A difference between ostriches and humans is that ostriches have
> > > much more frequent episodes of REM sleep, typically totaling
> > > 25%, on average, on five hours of each night. See Figure 4 of the linked article.
> > >
> > > The total is greater than for humans, but it is much more chopped up.
> > >
> > > It's conceivable, though, that there is some degree of continuity between
> > > successive episodes. I often have the experience of waking up in the
> > > middle of the night for a short time, and then of having the dreams
> > > when I go back to sleep be similar to the ones before I woke.
> > >
> > > What is the experience of other readers?
> > >
> > Well for one that REM sleep in humans may not correlate to bird experiences, and even in humans, it is not yet possible to determine what is really happening in REM sleep.
> True.
> > You don't know whether you were in REM sleep when you wake in the middle of the night, nor in REM sleep when continuing the dream that you apparently remember in the morning.
> Unless someone monitors my eye movements and wakes me up before the latest REM episode is over.
> That has never happened to me, but plenty of others have been subjects of experiments where this was done.

Not sure what you meant, but

"Dreaming also occurs during non rapid eye movement sleep"

https://www.sciencedaily.com/releases/2016/08/160809121817.htm

> >You don't even know whether you were dreaming the same thing before waking in the middle of the night, although you say you have a memory of it.
> I only remember a small fraction of my dreams, but some from long ago were so vivid, I still remember them.
>
> One kind of dream that was fairly common some decades ago was where I would find, to my embarrassment,
> that I was naked in public. But when they were most common, I was able to employ something I had read in
> a science fiction book: I generated an "I'm not here" aura that caused those around me to ignore me.
> And so I was able to exit gracefully from their company.
> > But the experience you describe is not unusual, and is claimed to happen occasionally.
> >
> > Dreaming is fascinating for me. I have had lucid dreams as well as recurrent dreams. I even recall being conscious of my mind 'playing a movie" so to speak, and wondering why it was chosen, even waking up and attempting to convince "myself" to change the movie when falling asleep again. The NDE I experienced was nothing like any dream, lucid or otherwise, though.
> What does NDE stand for?

Near Death Experience

> > So that is why I am interested in consciousness. I couldn't speculate
> > about other critters, except that I suspect that all life has some degree of consciousness, and intelligence.
> I'm fairly confident that mammals and birds are conscious. Hence I'm very supportive of
> our laws against cruelty to animals.
>
> I also think that all normal human fetuses are conscious at 8 weeks past fertilization, at least in
> the rudimentary sense of being past the stage of complete oblivion. That's why I favor restricting
> abortion strongly beyond that point. Portugal and Turkey are two countries where that kind of law is in force.
>
> However, invertebrates are a different matter. Already when I was 7 years old, I thought, "How lucky I am!
> there are so many more ants in the world than human beings, and *I* am a human being!"
>
> I had never heard of Hinduism by that point, yet the possibility of me experiencing the world through the body
> of an ant seemed to be a real one for me, and so it was a great mystery how I could be so lucky.
>
> But if ants aren't conscious, that removes a lot of the mystery.
>
>
> We've moved rather far from paleontology, but it is hovering in the background and giving
> rise to such questions as: were all the dinosaurs and pterosaurs conscious? And how
> rich were their conscious lives?
>
> Which brings us back in a roundabout way to dreaming and such observable phenomena as REM sleep.
> It's getting late [1], so the post about paleognaths that I promised Harshman will get at least one
> more day of delay.
>
> Also, since Trolidan7 hasn't shown up since I revived his thread, I'm thinking of
> starting a new thread for it.
>
>
> [1] I'm an early riser in the summer, because early morning is the best part of the day to be outside
> here in South Carolina.
>
>
> Peter Nyikos