The Cave Lion (Panthera spelaea and Panthera fossilis)

[tigerluver]

Bergmann's rule is simply not that accurate as more data rolled in historically and the assumptions made by the rule are much too volatile and to a degree paradoxical. Cold regions are hostile to high biomass and diversity as compared to warmer regions usually, thus the assumptions of the Bergmann's rule are very difficult to meet. For instance, P. atrox and P. spelaea from Alaska were rather small compared to the counterparts in California and Germany, respectively. 

Copious fossil data shows that P. atrox was definitely larger than the late Pleistocene P. spelaea. This as of yet cannot be argued as there are relatively plenty of fossils for these species. P. fossilis, on the other hand, seems to have matched and surpassed P. atrox. Do note that P. fossilis is a very likely candidate to be the progenitor group of P. atrox.

Lastly, the idea of being further northern would be less accurate than saying the further one goes from the equator. Remember, temperature, the factor behind Bergmann's rule, drops as one moves toward both poles. Reply

[GrizzlyClaws]

(11-19-2017, 09:50 AM)tigerluver Wrote: Bergmann's rule is simply not that accurate as more data rolled in historically and the assumptions made by the rule are much too volatile and to a degree paradoxical. Cold regions are hostile to high biomass and diversity as compared to warmer regions usually, thus the assumptions of the Bergmann's rule are very difficult to meet. For instance, P. atrox and P. spelaea from Alaska were rather small compared to the counterparts in California and Germany, respectively. 

Copious fossil data shows that P. atrox was definitely larger than the late Pleistocene P. spelaea. This as of yet cannot be argued as there are relatively plenty of fossils for these species. P. fossilis, on the other hand, seems to have matched and surpassed P. atrox. Do note that P. fossilis is a very likely candidate to be the progenitor group of P. atrox.

Lastly, the idea of being further northern would be less accurate than saying the further one goes from the equator. Remember, temperature, the factor behind Bergmann's rule, drops as one moves toward both poles.

Now it has been widely theorized that Panthera atrox could have spawned from the Panthera fossilis population in East Asia, namely Panthera (fossilis) youngi.

Since now they are already a lot of confirmed fossil records of Panthera fossilis in Asia, and the timeline of Panthera youngi also seems to fill the void perfectly to precede Panthera atrox.

If this hypothesis is correct, then Panthera youngi could be served as a right bridge to connect the missing link between Panthera fossilis and Panthera atrox. Reply

[Polar]

@GrizzlyClaws,


Ah, sorry, forgot to account for the relatively higher levels of genetic mixing in Amurs. Genes are important as well. Reply

[GrizzlyClaws]

(11-19-2017, 10:00 AM)Polar Wrote: @GrizzlyClaws,


Ah, sorry, forgot to account for the relatively higher levels of genetic mixing in Amurs. Genes are important as well.

The Amur tiger has also showed quite diversity, from the mildly sized Korean tiger to the gargantuan Manchurian tiger.

Some group must have showed higher level of genetic throwback to the prehistoric population than others. Reply

[Polar]

(11-19-2017, 09:20 AM)Wolverine Wrote: When we make size comparisons between Cave lions (P.fossilis and Pspelaea) and American lion, probably there are too scenarios:

1. IF two carnivores  from same clade enjoy SIMILAR abundance of food, SIMILAR prey base, the carnivore inhabiting Northern and colder latitudes will grow larger,more massive.

2 IF the carnivore inhabiting more Southern and warmer latitudes enjoys MORE abundant food resources, MORE prey base than the carnivore from same clade inhabiting to the North due to scarcity of prey in that northern region than the case is getting a bit more complicated, but probably too animals would be similar in size, as now we can see from Bengal and Siberian tigers, which are roughy equal in size. Bengal has in his side great abundance of food, Amur - Bergman's rule.

In other words Cave lions (fossilis and spelaea) who had inhabited subarctic regions of the Earth - Siberia, Alaska, Beringia could be or larger or same in size to P.atrox, who inhabited continental United States but they cant be smaller then him. No way. To rich compromise we probably could state that Cave lions and American lion are roughly equal in size.

1. Genetic lineage also plays an important part in determining size, even if temperature changes. Amur tigers, as described by @GrizzlyClaws description in post #107, is an example of this. Amur tigers are pretty genetically varied within their own domain as well: large Manchurian giants vs smaller inner-Korean counterparts. Genetic variance is either a positive or negative depending on how one looks at it.


2. This is much more true, although genes still play an important role. It isn't a matter of if, it is a matter of how much of a difference more abundant food resources affects potential size, which is, in turn, tied into genetics. Extinct Sunda tigers had more robustness due to the need to hunt larger prey and from their internal genetics. Amur tigers (and Wanhsien tiger in Siberia) were/are smaller than the extinct Sunda tigers mostly because of genes and the difference of environment. Note that back then, Siberia was rich with prey before human expansion. Reply

[GrizzlyClaws]

(11-19-2017, 10:10 AM)Polar Wrote:

(11-19-2017, 09:20 AM)Wolverine Wrote: When we make size comparisons between Cave lions (P.fossilis and Pspelaea) and American lion, probably there are too scenarios:

1. IF two carnivores  from same clade enjoy SIMILAR abundance of food, SIMILAR prey base, the carnivore inhabiting Northern and colder latitudes will grow larger,more massive.

2 IF the carnivore inhabiting more Southern and warmer latitudes enjoys MORE abundant food resources, MORE prey base than the carnivore from same clade inhabiting to the North due to scarcity of prey in that northern region than the case is getting a bit more complicated, but probably too animals would be similar in size, as now we can see from Bengal and Siberian tigers, which are roughy equal in size. Bengal has in his side great abundance of food, Amur - Bergman's rule.

In other words Cave lions (fossilis and spelaea) who had inhabited subarctic regions of the Earth - Siberia, Alaska, Beringia could be or larger or same in size to P.atrox, who inhabited continental United States but they cant be smaller then him. No way. To rich compromise we probably could state that Cave lions and American lion are roughly equal in size.

1. Genetic lineage also plays an important part in determining size, even if temperature changes. Amur tigers, as described by @GrizzlyClaws description in post #107, is an example of this. Amur tigers are pretty genetically varied within their own domain as well: large Manchurian giants vs smaller inner-Korean counterparts. Genetic variance is either a positive or negative depending on how one looks at it.


2. This is much more true, although genes still play an important role. It isn't a matter of if, it is a matter of how much of a difference more abundant food resources affects potential size, which is, in turn, tied into genetics. Extinct Sunda tigers had more robustness due to the need to hunt larger prey and from their internal genetics. Amur tigers (and Wanhsien tiger in Siberia) were/are smaller than the extinct Sunda tigers mostly because of genes and the difference of environment. Note that back then, Siberia was rich with prey before human expansion.

The hybridization could also trigger the potential gigantism.

For example, the Amur tiger is genetically confirmed to be the offspring population of the Caspian tiger, but there were possibly few Amur tiger populations being genetically affected by the autosome of the northern population of the Wanhsien tiger. The Bengal tiger in Northeast India is just a also prime example of hybridization with Indochinese tiger that becomes larger.

Some Amur tigers could have been genetically affected by the autosome of the Wanhsien tiger, even though their Y-DNA and mtDNA are both descended from the Caspian tiger. Reply

[Polar]

(11-19-2017, 10:19 AM)GrizzlyClaws Wrote:

(11-19-2017, 10:10 AM)Polar Wrote:

(11-19-2017, 09:20 AM)Wolverine Wrote: When we make size comparisons between Cave lions (P.fossilis and Pspelaea) and American lion, probably there are too scenarios:

1. IF two carnivores  from same clade enjoy SIMILAR abundance of food, SIMILAR prey base, the carnivore inhabiting Northern and colder latitudes will grow larger,more massive.

2 IF the carnivore inhabiting more Southern and warmer latitudes enjoys MORE abundant food resources, MORE prey base than the carnivore from same clade inhabiting to the North due to scarcity of prey in that northern region than the case is getting a bit more complicated, but probably too animals would be similar in size, as now we can see from Bengal and Siberian tigers, which are roughy equal in size. Bengal has in his side great abundance of food, Amur - Bergman's rule.

In other words Cave lions (fossilis and spelaea) who had inhabited subarctic regions of the Earth - Siberia, Alaska, Beringia could be or larger or same in size to P.atrox, who inhabited continental United States but they cant be smaller then him. No way. To rich compromise we probably could state that Cave lions and American lion are roughly equal in size.

1. Genetic lineage also plays an important part in determining size, even if temperature changes. Amur tigers, as described by @GrizzlyClaws description in post #107, is an example of this. Amur tigers are pretty genetically varied within their own domain as well: large Manchurian giants vs smaller inner-Korean counterparts. Genetic variance is either a positive or negative depending on how one looks at it.


2. This is much more true, although genes still play an important role. It isn't a matter of if, it is a matter of how much of a difference more abundant food resources affects potential size, which is, in turn, tied into genetics. Extinct Sunda tigers had more robustness due to the need to hunt larger prey and from their internal genetics. Amur tigers (and Wanhsien tiger in Siberia) were/are smaller than the extinct Sunda tigers mostly because of genes and the difference of environment. Note that back then, Siberia was rich with prey before human expansion.

The hybridization could also trigger the potential gigantism.

For example, the Amur tiger is genetically confirmed to be the offspring population of the Caspian tiger, but there were possibly few Amur tiger populations being genetically affected by the autosome of the northern population of the Wanhsien tiger. The Bengal tiger in Northeast India is just a also prime example of hybridization with Indochinese tiger that becomes larger.

Some Amur tigers could have been genetically affected by the autosome of the Wanhsien tiger, even though their Y-DNA and mtDNA are both descended from the Caspian tiger.

From what I've researched, there have been many tiger subspecies that have at least reached Siberia a couple times: Caspian, Wanhsien, maybe a bit of mainland Bengal through the Altai Mountains. Maybe the Cave lions in Siberia could have inter-mixed with the tigers there, or no evidence for that? Reply

[GrizzlyClaws]

Caspian tiger: The genetically confirmed progenitor of the Amur tiger.

Wanhsien tiger: Could have a played a significant role in the gene pool of the Amur tiger. It is the possible that the leftover population of the Wanhsien tiger could have been absorbed by the late arrival Caspian tiger. Even it is possible that we won't find any trace of the Wanhsien tiger in the Y-DNA and mtDNA of the modern Amur tiger, but it is still possible that their autosome is still there and played a significant role for Amur tiger's appearance alteration from its Caspian ancestor.

Bengal tiger: Its expansion was quite late, most likely some northern population of the Bengal tigers being genetically affected by the Caspian tiger from Central Asia, not the other way around.

Cave lion: It is nearly impossible for a lion and tiger to interbreed in the wild. So I doubt some morphological resemblance to tiger was the result of interspecies hybridization.

BTW, Panthera spelaea looked morphologically quite different from Panthera fossilis, so it was possible that they were not necessarily the pure descendant of Panthera fossilis, could have been hybridization with other unknown ancient lion population. And Panthera atrox on the other hand did look like a pure descendant of Panthera fossilis. Reply

[GrizzlyClaws]

@Polar

The interbreeding is only possible between two closely related species within the same genus. Lion and tiger although belong to the same genus, but they are genetically the most far away between each other. Therefore, the interbreeding is less likely in the wild.

For instance, the Y-DNA of the Polar bear has been discovered with some unknown ancient lineage, and this ancient lineage could have possibly belonged to the Cave bear.

If this turns out to be true, then the formation of the Polar bear was created via the hybridization between the male Cave bear and female Brown bear. Not just for the environmental adaption, but the hybridization could be the main factor that triggered the radical appearance shift of the Polar bear from the Brown bear.

So if they use the genome of the modern lion to clone the Cave lion, although the clone would be hybridized, but it should still be a functionally viable species that is capable to reproduce just like the naturally hybridized Polar bear, unlike sterile the liger. Reply

[tigerluver]

The classification of the Mokhnevskaya skull came to be an unclear as there the three studies that have mentioned it did not come to the same conclusion. I ran a few ratios with a small sample size as I don't have much time right now.

*This image is copyright of its original author

The ratio numbers correlate to the measurements of Marciszak et al. (2014). The most significant indicator of grouping was alveolar width to GSL (ratio 9---1) despite such a small sample size. Therefore, this is probably the best ratio to use for species differentiation. By that, the Mokhnevskaya skull is P. spelaea and not P. fossilis.

*This image is copyright of its original author

Reply

[GrizzlyClaws]

@tigerluver

Thanks a lot for the specification, and could you also specify the names of the measurement variables? Reply

[tigerluver]

Just edited the definitions into the post. Reply

[GrizzlyClaws]

@tigerluver

I am trying to compare the correlation of the variables between the Mokhnevskaya specimen and the later Panthera spelaea specimens via linear regression.


I just figure out that the Mokhnevskaya specimen was quite unique and rather primitive in comparison, and with some variables more correlated with Panthera fossilis.


Now I can finally understand why Marciszak et al. (2014) has emphasized so much about the transitional phase. And from this aspect, it is also plausible to say that Panthera spelaea as the biological successor of Panthera fossilis. However, compared to the Panthera atrox group, they may have adapted with different morphological evolution. Reply

[tigerluver]

Right, the Mokhnevskaya skull does have some odd ratios that also don't seem to belong in any group. Unfortunately we only have 3 earlier form P. fossilis skulls (both Chateau skulls and the Mauer) and 5 later form P. fossilis skulls to group (I only showed 4 in the chart above because one of the skulls in Marciszak et al. (2014) doesn't have enough measurements). It's hard to then see if the oddities in the Mokhnevskaya skull are truly odd or we just haven't seen the full variety yet. Nonetheless, I think we all have noticed how exceptional skulls can carry weird proportions in modern animals as well as these are probably abnormal growth patterns. Reply

[tigerluver]

Panthera atrox in South America?

A new paper was just published stating that a fossil pantherine of South America, known as P. onca mesembrina, has been misidentified at least a few times. The true identity of this cat they assert is Panthera atrox. Their assertion is based on morphological similarities of the specimen to P. atrox rather than the jaguar. The skull they reference is the best example of their point. The paper.

*This image is copyright of its original author

*This image is copyright of its original author

Take a look at the above photos. Which species does the skull in the top photo looks most similar too? Based on visibility of the incisive foramina and the nasal shape, the authors conclude that the skull is actually of P. atrox.

At first take, the logic looks good. However, Dr. Ross Barnett disagrees, mentioning on twitter that cats of these areas have been DNA tested and shown to be jaguar. He cited this paper. 

The authors in a way already had a response built into the paper to such a rebuttal, stating that the ancient jaguar and American lion would have shared the domain. So what does everyone think? Is this skull of a jaguar or an American lion? Reply