The Cave Lion (Panthera spelaea and Panthera fossilis)

[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