STL Science Center

STL Science Center

04 April 2017

Genetics and Lions

Ice Age animals have a long, in the somewhat short time that it has been available, history of genetic and isotope research. The reason for this is that the thawed cubs mentioned yesterday have generated not only a lot of sensation but have provided scientists with intact remains that preserved the majority of the soft tissues and organs of the animals. This of course has led to chemical, microbiological, and genetic work being carried out using the preserved tissues of the animals. Some of these studies include molecular phylogeny (Burger, et al. 2004), diet inquiries using isotopes (Bocherens, et al. 2011), and studies of genetic diversity (Ersmark, et al. 2015). Some might be asking "How does one study diversity from a single litter of cubs?" and this is not without its caveats and misgivings; however, it is important to note that we have not discussed all of the populations of known cave lion with some tissue preservation. Many American Cave Lions have been recovered from the tar pits of Rancho La Brea in Southern California and these could add to the genetic diversity of known populations. However, the destructive nature of tar pits has hampered DNA recovery but that is not to say that there have been no efforts to recover DNA. These efforts have been largely unsuccessful unfortunately. This leaves us hoping there are other soft tissue deposits to back up these studies on genetic diversity that have not been mentioned here this week. There are, in fact, soft tissue preserved specimens from across Eurasia and many known from Alaska and Northwest Canada that are mentioned in the paper linked above. These are not entire cubs as we saw yesterday, and are therefore less famous, but are nonetheless quite important in terms of genetic studies of cave lion populations and diversity.

Non-genetic, chemical, or microbiological study is also important in the history of cave lions. These have included phylogenetic studies based on skeletal tissue, specifically cranial and dental characters (Sotnikova and Nikolskiy, 2006), as well as a detailed timeline of the extinction processes that affected and eliminated the Eurasian and American (Stuart and Lister, 2011) Cave Lions from their respective habitats. Though we have been discussing the American Cave Lion in conjunction with its Eurasian relatives seamlessly, there is mitochondrial evidence (see the linked molecular phylogeny paper above by Burger, et. al.) that this population split early enough in their evolution that it has been argued that these represent merely a "lion-like cat" with a very popular misnomer. This phrase was first prominently used in 1969 by C. R. Harington as far as I can tell, but his paper suggests that the North American and Eurasian animals were likely conspecific (Harington, 1969).

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