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Author Topic:   Is evolution of mammals finished?
RAZD
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Posts: 19811
From: the other end of the sidewalk
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Member Rating: 10.0


Message 46 of 213 (385932)
02-18-2007 9:53 AM
Reply to: Message 45 by MartinV
02-18-2007 8:18 AM


Re: Marine K-T extinctions and opportunity
Warm-blooded predators were superseded by other warm-blooded mammalian predators and cold-blooded reptilian predators.

You are lumping two things together: survival of the K/T extinction event and radiation after that event. Fitness to survive the extinction event does not translate into fitness for the niches evacuated by that event.

If you have warm-blooded predators filling the niche before, having taken the opportunity to evolve to fill that niche, then it is logical that the same niche would be filled by warm-blooded predators after the niche again becomes available.

What was the disatvatage of this warm-blooded predators to be replaced by another ones ...

They couldn't survive the K/T extinction event.

(it is claimed by darwinists that warm-blooded feature was one of the reason of succesfull mammalian radiation during Eocene)?

That is radiation to fill available niches AFTER the K/T event. There were no animals in those niches then, so they were up for grabs by whatever came along that could take advantage of the opportunity.

Warm blooded just means that they have higher levels of energy available, whether they were reptiles, birds or mammals. That higher energy translates to increased fitness.

Evolution does not say that it HAD to be mammals that filled the niches, just that the animals that did so were better fit to take advantage of the opportunities. Mammals just happened to be the ones in the right place at the right time with the right equipment at that moment.

Just like dinosaurs happened to be the ones in the right place at the right time with the right equipment after the previous mass extinction event.

Enjoy.


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Chiroptera
Member
Posts: 6531
From: Oklahoma
Joined: 09-28-2003


Message 47 of 213 (385956)
02-18-2007 1:37 PM
Reply to: Message 44 by MartinV
02-18-2007 8:02 AM


Weird.
quote:
Pachinko ball doesn't have predators hunting it like crocs and sharks. Try game again using pachinko ball made of meat in the pool overcrowded with crocks or sharks.

You seem to have an unhealthy obsession with crocodiles and sharks. Is this a national trait because Slovakia is landlocked? I suggest you try to make it to the Mediterranean on your next vacation. Even if you are too scared to go into the water yourself, go to the beach anyway just to watch the people. You will see lots of people playing in the water without being eaten by crocodiles and sharks.

Even today, we have lots of aquatic and semi-aquatic mammals -- whales, manatees, seals, nutrias, and otters -- all living in the water. Some of these avoid being eaten by crocodiles and sharks, and others manage to survive despite occassionally being eaten by crocodiles and sharks. So what is the problem with paleocene and eocene mammals living in or near water?

And what prevents some sort of direct evolutioned mammals from facing the same crocodile and shark problem? I don't think a crocodile will care much whether amulocetus evolved due to natural selection or through some sort of directed evolutionary process. A meal is a meal. Whatever prevents an directed evolutioned ambulocetus from being eaten by a shark will also prevent a naturally selected ambulocetus from being eaten by a shark.

-

quote:
According some popular medieval conceptions (Giordano Bruno was it's follower) matter possesed spirit once. Might be that spirit is going upwards and is now fully presented in humans. The spirit presented himself and his creativity in mammals during "adaptive radiation" during Eocene and before during "Cambrian evolution" in lowest phyla. That's why evolution of mammals is finished. Species do not possess as much spirit as once.

Heh.

Heh heh heh.

Hee hee hee hee hee hee hee hee hee.

BWAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!

-

Okay, so we're taking about some sort of New Age woo woo. That's fine, I just want to make sure we aren't talking about science any more.

-

But let's make sure I got this straight. You want to believe in some sort of directed evolution, so you have to come up with a "problem" for natural selection. The "problem" that you came up with is that the world is filled is demonic ravenous crocodiles and sharks that will gobble up anything that so much as touches water. But there is that magical spirit that not only forced mammals to evolve, but it also protected them from crocodiles and sharks. But this magical spirit has run out, so not only do mammals not evolve anymore, but they are now all being eaten by crocodiles and sharks and that is why they are endangered.

Uh-huh. Thanks for sharing.


Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
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RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 48 of 213 (385962)
02-18-2007 2:06 PM
Reply to: Message 42 by Lithodid-Man
02-18-2007 12:35 AM


Crocodiles and Dinosaurs?
We have seen where dinosaurs were once thought to be cold-blooded and now are considered to be warm-blooded. Where birds are now thought to be descended from dinosaurs (or are dinosaurs).

Now we have evidence of a remnant of warm-blooded adaptation in the hearts of crocodiles:

http://www.adelaide.edu.au/adelaidean/issues/5501/news5550.html
(also nature article and others)

Do you know of any thoughts on the line of crocodiles being another surviving branch of dinosaurs, even though they reverted to cold-blooded behavior, due to this heart issue?

It seems to me that the hearts of dinosaurs being soft tissue and not preserved in fossils would make this a possibility, but I am not sure of the rest of the lineage\cladistics issues.

Comment?

(perhaps this should be a new thread, although this would make it about a "new" order of dinosaurs?)


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This message is a reply to:
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Chiroptera
Member
Posts: 6531
From: Oklahoma
Joined: 09-28-2003


Message 49 of 213 (385963)
02-18-2007 2:18 PM
Reply to: Message 48 by RAZD
02-18-2007 2:06 PM


Re: Crocodiles and Dinosaurs?
quote:
Do you know of any thoughts on the line of crocodiles being another surviving branch of dinosaurs, even though they reverted to cold-blooded behavior, due to this heart issue?

Birds and crocodiles are the surviving branches of the archosaurs (which also may have included the pterosaurs.

During the Permian, the therapsids were the most dominant land form. Then the PT extinction event (the worst that is known) allowed the archosaurs to become dominant; the extinction event that marked the end of the Triassic allowed one particular branch of the archosaurs, the dinosaurs, the opportunity to become dominant, and the the KT extinction then allowed one particular branch of the therapsis, the placental mammals, to once again reclaim their ancestor's place as the dominant land form.

Added by edit:
As far as the warm-blooded croc thing, I found this abstarct:

We present other evidence for endothermy in stem archosaurs and suggest that some dinosaurs may have inherited the trait.

I also found an old Pharygula article that I remembered spoke of this.

Edited by Chiroptera, : No reason given.


Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
This message is a reply to:
 Message 48 by RAZD, posted 02-18-2007 2:06 PM RAZD has responded

Replies to this message:
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RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 50 of 213 (385968)
02-18-2007 3:33 PM
Reply to: Message 49 by Chiroptera
02-18-2007 2:18 PM


Re: Crocodiles and Dinosaurs?
So both are surviving dinos. Thanks. That means that crocs are not (strictly speaking) cold-blooded reptiles eh?

I found this abstarct:
I also found an old Pharygula article

Saw both of those when googling the warm-hearted crocs.

During the Permian, the therapsids were the most dominant land form. Then the PT extinction event (the worst that is known) allowed the archosaurs to become dominant; the extinction event that marked the end of the Triassic allowed one particular branch of the archosaurs, the dinosaurs, the opportunity to become dominant, and the the KT extinction then allowed one particular branch of the therapsis, the placental mammals, to once again reclaim their ancestor's place as the dominant land form.

Several changes in the pecking order eh? So much for directed evolution.

Or did the therapsids somehow recover their lost "spirit"?

LOL.

Thanks.


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we are limited in our ability to understand
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This message is a reply to:
 Message 49 by Chiroptera, posted 02-18-2007 2:18 PM Chiroptera has responded

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 Message 51 by Chiroptera, posted 02-18-2007 3:38 PM RAZD has responded

Chiroptera
Member
Posts: 6531
From: Oklahoma
Joined: 09-28-2003


Message 51 of 213 (385969)
02-18-2007 3:38 PM
Reply to: Message 50 by RAZD
02-18-2007 3:33 PM


Re: Crocodiles and Dinosaurs?
quote:
So both are surviving dinos.

Oops. Not quite. Crocs are close cousins to dinosaurs, sharing a common ancestor that they do not share with any other living taxon.

But I am mostly responding because I found something cool on the Wikipedia article:

  • A few crocodilians were herbivores, e.g. Simosuchus.
  • The large crocodilian Stromatosuchus was a filter feeder.

Wow! How cool is that!


Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
This message is a reply to:
 Message 50 by RAZD, posted 02-18-2007 3:33 PM RAZD has responded

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RAZD
Member
Posts: 19811
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 10.0


Message 52 of 213 (385976)
02-18-2007 5:08 PM
Reply to: Message 51 by Chiroptera
02-18-2007 3:38 PM


Re: Crocodiles and Dinosaurs?
okay, common ancestor older than croc\dino ...

... so how old is the warm-blooded heart? We have this feature in therapsid\mammals, crocs\archosaurs and bird\dinos ... is it the same heart or were there several evolutions of a 4-chambered heart?

http://en.wikipedia.org/wiki/Archosaurs

quote:
The metabolism of archosaurs is still a controversial topic.
  • 4-chambered hearts. Mammals and birds have 4-chambered hearts. Non-crocodilian reptiles have 3-chambered hearts,
  • How does that archosaur phylogeny match up with the synapsids?
    http://en.wikipedia.org/wiki/Synapsid

    Do we go back to amniotes to get to the heart of this?
    http://en.wikipedia.org/wiki/Amniote

    quote:
    Amniota
  • Class Synapsida - Mammal-like "reptiles"
  • Class Sauropsida - Reptiles
  • But some reptiles are 3-chambered.


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    we are limited in our ability to understand
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    RebelAAmericanOZen[Deist
    ... to learn ... to think ... to live ... to laugh ...
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    This message is a reply to:
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    MartinV 
    Suspended Member (Idle past 3934 days)
    Posts: 502
    From: Slovakia, Bratislava
    Joined: 08-28-2006


    Message 53 of 213 (386026)
    02-19-2007 2:19 AM
    Reply to: Message 47 by Chiroptera
    02-18-2007 1:37 PM


    Re: Weird.

    I suggest you try to make it to the Mediterranean on your next vacation. Even if you are too scared to go into the water yourself, go to the beach anyway just to watch the people. You will see lots of people playing in the water without being eaten by crocodiles and sharks.

    And perhaps you should try your next vacation somewhere at forgotten India's tidal estuaries or marine swamps. Don't bother yourself nobody except you is entering the water to swim and relax there.

    It was Thewissen not me who claimed that Pakicetus evolved in such an environment (and ambulocetus possessed even crocodile-like head!). As you know during Eocene the climate was much more warmer than today - ideal condition for crocodiles I would say. And it were you darwinists and not me who claimed that there were emptied niches after K/T that mammals filled. Might be crocodiles were gentlemen at that time and did not filled their own niches in order to enable enough time for hoofed Artiodactyla Pakicetus to became crocodile-like Ambulocetus in shallow water.


    But there is that magical spirit that not only forced mammals to evolve, but it also protected them from crocodiles and sharks.

    I have given you only some idea. Might be that macroevolution represented by Davison's Manifesto is the better explanation. Species aroused via saltationism - then they are adapted to the environment fully and can compete with those that have been already there. And we don't need anymore darwinistic fairy-tales about emptied niches.


    This message is a reply to:
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    MartinV 
    Suspended Member (Idle past 3934 days)
    Posts: 502
    From: Slovakia, Bratislava
    Joined: 08-28-2006


    Message 54 of 213 (386027)
    02-19-2007 2:49 AM
    Reply to: Message 46 by RAZD
    02-18-2007 9:53 AM


    Re: Marine K-T extinctions and opportunity

    They couldn't survive the K/T extinction event.

    Yet cold-blooded reptiles could survive quite well.
    It seems like warm-bloodeness was disatvantage during K/T boundary - but only for dinos. For mammals it was somehow advantageous.


    That is radiation to fill available niches AFTER the K/T event. There were no animals in those niches then, so they were up for grabs by whatever came along that could take advantage of the opportunity.

    We don't know if niches were really so empty.


    Warm blooded just means that they have higher levels of energy available, whether they were reptiles, birds or mammals. That higher energy translates to increased fitness.

    In the warm climate of Eocene I do not see the advantage. Cold-blooded reptiles thrive in the warm areas quite well even today.


    This message is a reply to:
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    Lithodid-Man
    Member (Idle past 1037 days)
    Posts: 504
    From: Juneau, Alaska, USA
    Joined: 03-22-2004


    Message 55 of 213 (386036)
    02-19-2007 6:59 AM
    Reply to: Message 54 by MartinV
    02-19-2007 2:49 AM


    Re: Marine K-T extinctions and opportunity
    Yet cold-blooded reptiles could survive quite well.
    It seems like warm-bloodeness was disatvantage during K/T boundary - but only for dinos. For mammals it was somehow advantageous.

    It wasn't cold or warm bloodedness that made the decision ultimately. It was a giant freakin rock that killed everything on the planet (except maybe deep sea oganisms) over 50 kg in size. Trees, dinosaurs, mammals, reptiles, birds, sharks, the like. The clock was reset at the K-T boundry. Very few species survived, but those species quickly evolved to fill the empty niches. Birds made it, mammals made it. Some evidence from Alaska suggests that even some dinos made it for a short time.

    I think size was the ultimate factor. Little things or those who could hibernate did better than those who were swift and powerful. In the terresrial realm it was the mammals who were excluded from dino niches. They undoubtedly suffered massive extinctions. But only two main lineages exist today (Protheria and Theria).


    Doctor Bashir: "Of all the stories you told me, which were true and which weren't?"
    Elim Garak: "My dear Doctor, they're all true"
    Doctor Bashir: "Even the lies?"
    Elim Garak: "Especially the lies"
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    AZPaul3
    Member
    Posts: 3853
    From: Phoenix
    Joined: 11-06-2006
    Member Rating: 6.3


    Message 56 of 213 (386058)
    02-19-2007 11:28 AM


    Be careful of "niches."
    Keep in mind that a “niche” is a human construct to describe the environment and life/reproductive style of an organism. There are no “empty” niches. There are no empty boxes in an environment sitting around waiting for some organism to evolve “into” them.

    Over time populations adapt to an environment and develop a reproductive vector conducive to that environment. Either that or they go extinct. As a human descriptive convenience we say this population “inhabits this niche.”

    The “niche” adapted by some trypanosomes requires warm blood of mammals and the Tsetse fly. Without either these organisms do not survive. This was not some “empty” niche waiting for some bug to take advantage. The bugs evolved a reproductive life style that was adequate for their continued survival as a species and we have named this a “niche.”

    Often multiple species develop life-style dependencies on the same resources in an environment. Some species of birds and some species of bats depend upon the same populations of insects as food in their environment. If the resource is plentiful then both species (birds and bats) can survive (inhabit the same niche). If competition becomes intense then populations rise and fall with the resource or extinction may occur or adaptations are developed by one (sometimes both) to broaden or change the dependencies. When the latter occurs we say the population has inhabited a new niche. In the case of some bats, developing an ability to feed on mammalian blood in addition to/in place of insects, new niches were exploited. Birds did not evolve in this direction.

    When an environment changes and mass extinctions occur the remaining species are better able to express/develop phenotypes that are adequate to new modes of reproductive success. We describe this as “radiating into the empty niches.” The mass extinctions do not create pre-determined holes with specified requirements into which some sub-species radiate. Instead, a blank sheet of paper is created onto which radiating species write their own survival plans.

    Edited by AZPaul3, : No reason given.


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    MartinV 
    Suspended Member (Idle past 3934 days)
    Posts: 502
    From: Slovakia, Bratislava
    Joined: 08-28-2006


    Message 57 of 213 (386077)
    02-19-2007 1:18 PM
    Reply to: Message 56 by AZPaul3
    02-19-2007 11:28 AM


    Re: Be careful of "niches."
    Problem is the fact that let say last 30.000.000 years no mammalian Order aroused - and families declined. No doubt there were great extinctions also after K/T boundary which concerns mammals - even if not so spectacular. Wheter we believe Raup or not. Also major Europe-wide mammalian faunal turnover termed the Grande Coupure occurs during Eocene-Oligocene boundary. There were glacial periods too. None of these events created enough "niches" for any interesting development of mammals. I also discussed above that there were probably no "emptied" niches for mammals to enter the sea while crocodiles survived K/T boundaries and probably occupied niches that mammal Ambulocetus (looked like crokodile too btw) had to enter into as "unoccupied".

    It all seems like play with magic formula "empty niche".
    Stasis? - there were no "empty niches".
    Radiation? - there were lot of "empty niches".
    That stasis and fast evolution occurs together hand in hand on the same area at the same time concerns nobody.


    This message is a reply to:
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    AZPaul3
    Member
    Posts: 3853
    From: Phoenix
    Joined: 11-06-2006
    Member Rating: 6.3


    Message 58 of 213 (386092)
    02-19-2007 3:00 PM
    Reply to: Message 57 by MartinV
    02-19-2007 1:18 PM


    Re: Be careful of "niches."
    Let’s take one of your observations from post #34:

    And it seems also that there was in the air enough space and niches for mammalian bats to enter it - yet it is hard to believee that birds could not find these niches or accomodate to them before bats evolved.

    You are assuming that having a few species of bird flying around “occupies” the “air niches” to the exclusion of all other species. And that, since birds were already able to fly they should have “occupied” all these airborne “niches.”

    Birds developed a reproductive life-style that was adequate for their continued survival. Some small little mammal develops useful un-feathered leathery wings and takes to the air to eat insects and develops a reproductive life-style adequate to its survival (even in competition in some areas with birds). So what?

    It appears that the evolution of bats had no discernable negative impact on the life-style of birds and the presence of birds appears to not have hampered the evolution of bats.

    The bats did not “enter” an unused airspace-flying insect-eating unoccupied niche that just happened to be laying around. Bats developed a reproductive scheme that involved flying, eating insects and hiding in caves during the day that did not involve insurmountable competition from any other species and was adequate for their survival. They “created” the niche. They exploited the scheme. They survived.

    Birds, on the other hand, had no need to develop the same life-style as bats since the scheme(s) they grew into were adequate for their survival.


    It all seems like play with magic formula "empty niche".
    Stasis? - there were no "empty niches".
    Radiation? - there were lot of "empty niches".

    If you are tripping over the vernacular of a human conceived definition then don’t think in those terms.

    Stasis: Well adapted to present environment, selective pressures against major phenotype changes, building genetic diversity within the population.

    Radiation: Adaptation to changing environment, lower constraints on phenotype changes, expression/usage of prior developed genetic diversity.

    That stasis and fast evolution occurs together hand in hand on the same area at the same time concerns nobody.

    Well, it concerns you and I don’t think you’re nobody.

    The issue is that, from all available evidence, the two do not occur at the same time in the same population.


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    Chiroptera
    Member
    Posts: 6531
    From: Oklahoma
    Joined: 09-28-2003


    Message 59 of 213 (386095)
    02-19-2007 3:26 PM
    Reply to: Message 56 by AZPaul3
    02-19-2007 11:28 AM


    Re: Be careful of "niches."
    quote:
    Keep in mind that a “niche” is a human construct to describe the environment and life/reproductive style of an organism. There are no “empty” niches. There are no empty boxes in an environment sitting around waiting for some organism to evolve “into” them.

    I was wondering when someone was going to bring this up. The fact is, a niche does not exist until there is a species that is actually occupying it. I realized that potential confusion that could arise using these terms carelessly, but I did so anyway. Sorry about that, folks.


    Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
    This message is a reply to:
     Message 56 by AZPaul3, posted 02-19-2007 11:28 AM AZPaul3 has not yet responded

    Chiroptera
    Member
    Posts: 6531
    From: Oklahoma
    Joined: 09-28-2003


    Message 60 of 213 (386097)
    02-19-2007 3:38 PM
    Reply to: Message 53 by MartinV
    02-19-2007 2:19 AM


    Re: Weird.
    quote:
    And perhaps you should try your next vacation somewhere at forgotten India's tidal estuaries or marine swamps.

    Would three years in Africa on the equator count? There were crocodiles in some of the rivers. Sometime people got eaten. Sometimes they didn't. People, and animals, can use the rivers and only be eaten on occassion. Same with the oceans. Seals manage to survive as a species even though a few get eaten by sharks. The fact that completely non-aquatic deer can drink out of a river without being eaten to extinction, the fact that manatees can live in swamps without being eaten to extinction, and so forth shows that prey animals can coexist in the same environment as predators. In fact, if they couldn't the predators themselves would become extinct. So I see no reason why the transitional forms between, say, pakicetus and modern whales couldn't coexist with crocodiles and sharks; other animals manage to do it.

    -

    quote:
    Might be crocodiles were gentlemen at that time and did not filled their own niches in order to enable enough time for hoofed Artiodactyla Pakicetus to became crocodile-like Ambulocetus in shallow water.

    I'm not sure why you think that crocodiles should have grabbed up all the good niches (uh-oh, there's that word again) before ambulocetus had a chance to evolve into them.

    -

    quote:
    Species aroused via saltationism - then they are adapted to the environment fully and can compete with those that have been already there.

    Is there any, like, evidence that this can happen? You know, assuming we're going to pretend we are still talking about science?

    -

    quote:
    And we don't need anymore darwinistic fairy-tales about emptied niches.

    Heh. Except the Darwinist fairy-tale of "natural selection" has been verified to be a real phenomenon in the real world. Unlike your "magical spirit force", the motivations for which I am still trying to understand.


    Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
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