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| Asian golden cat, Catopuma temminckii |
The frustrating thing about trying to teach creationists about evolution is the way they look for reasons to dismiss the evidence rather than to accept it and deal with with the conclusions to which it is pointing them.
For example, they will argue on the one hand that what they call 'macro-evolution', i.e., the evolution of a new species, is impossible but 'micro-evolution' is not only possible but happened at inexplicably high rates after their supposed global flood to give us all the variation we see today within species. It was just that non-one noticed it happening so made no historical record of it. Then when you show them the evidence that a single species diverged into two different species, the definition of 'macro-evolution' changes so that now 'micro-evolution' includes new species evolving so long as they are the same 'kind' of species.
But then, of course, the definition of 'kind' also changes to be whatever they need, from closely related species to entire orders, phyla or even kingdoms and even the entire Earthly biota.
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| Bay cat, Catopuma badia |
So, we can be sure a creationist will dismiss this paper as 'not evolution' because the two species were still 'cat kind'. To someone genuinely interested in learning how the real world actually works however, this is a fascinating study into how environmental changes in part of the range of a species caused it to diverge into two quite different, yet still closely-related species. Creationists must be left to flounder in their self-satisfying ignorance, happy in the knowledge that no facts are going to be allowed to intrude on their delusional self-adulation.
Attempting to work out the relationship between the different closely-related species and subspecies within the Catopuma genus, an international team of geneticists found evidence of two major environmental changes that were responsible firstly for splitting the population into two genetically isolated groups and then bringing one group close to extinction forcing it to go through an evolutionary bottleneck.
Abstract
Background. The bay cat Catopuma badia is endemic to Borneo, whereas its sister species the Asian golden cat Catopuma temminckii is distributed from the Himalayas and southern China through Indochina, Peninsular Malaysia and Sumatra. Based on morphological data, up to five subspecies of the Asian golden cat have been recognized, but a taxonomic assessment, including molecular data and morphological characters, is still lacking. Results. We combined molecular data (whole mitochondrial genomes), morphological data (pelage) and species distribution projections (up to the Late Pleistocene) to infer how environmental changes may have influenced the distribution of these sister species over the past 120 000 years. The molecular analysis was based on sequenced mitogenomes of 3 bay cats and 40 Asian golden cats derived mainly from archival samples. Our molecular data suggested a time of split between the two species approximately 3.16 Ma and revealed very low nucleotide diversity within the Asian golden cat population, which supports recent expansion of the population.
Discussion. The low nucleotide diversity suggested a population bottleneck in the Asian golden cat, possibly caused by the eruption of the Toba volcano in Northern Sumatra (approx. 74 kya), followed by a continuous population expansion in the Late Pleistocene/Early Holocene. Species distribution projections, the reconstruction of the demographic history, a genetic isolation-by-distance pattern and a gradual variation of pelage pattern support the hypothesis of a post-Toba population expansion of the Asian golden cat from south China/Indochina to Peninsular Malaysia and Sumatra. Our findings reject the current classification of five subspecies for the Asian golden cat, but instead support either a monotypic species or one comprising two subspecies: (i) the Sunda golden cat, distributed south of the Isthmus of Kra: C. t. temminckii and (ii) Indochinese, Indian, Himalayan and Chinese golden cats, occurring north of the Isthmus: C. t. moormensis.
Riddhi P. Patel, Daniel W. Förster, Andrew C. Kitchener, Mark D. Rayan, Shariff W. Mohamed, Laura Werner, Dorina Lenz, Hans Pfestorf, Stephanie Kramer-Schadt, Viktoriia Radchuk, Jörns Fickel, Andreas Wilting
Two species of Southeast Asian cats in the genus Catopuma with diverging histories: an island endemic forest specialist and a widespread habitat generalist
R. Soc. open sci. 2016 3 160350; DOI: 10.1098/rsos.160350. Published 19 October 2016
Copyright © 2016 The Royal Society
Reprinted under terms of a Creative Commons Attribution 4.0 International license (CC-BY 4.0)
Surprisingly, given the wide variation in size and colouration, with several colour morphs being recognised in the Asian golden cat, the team found a very narrow range of genetic variation, suggesting a major near-extinction event and a genetic bottleneck.
We think that the Toba super-volcanic eruption on Sumatra, about 73, 000 years ago, destroyed so much forest habitat that it caused a massive population decline in most of the range of the Asian golden cat, with populations surviving only in Indochina. Only a long time after suitable climatic conditions returned during the last Ice Age were Asian golden cats able to move out from their Indochinese refuge and return to former habitats, spreading north to southern China, east to India and, in particular, south to Sumatra.
The first major change was the flooding of the the Isthmus of Kra in the Pliocene 3.16 million years ago, followed by climate and vegetation variations between Sundaland and Indochina. This caused the ancestor of the modern bay cat to become restricted to Northern Borneo especially during the last glacial maximum when evergreen forests were restricted to that area. This forced it to become an environmental specialist. Meanwhile the other group which gave rise to the Asian golden cat lineage was free to spread across a wide range of habitats and to become much more of a generalist in its environmental preferences.The second major environmental change was the Toba super-volcanic eruption on Sumatra, about 73,000 years ago, destroyed so much forest habitat that it brought the Asian golden cat close to extinction, surviving only in Indochina, from where it was able to expand its range considerably when the forests recovered.
This is of course a classic example of how speciation occurs due to genetic isolation and how living species evolve in response to climate, geological and environmental change. There never is an underlying purpose or direction; all the happens is that the variations which do better in the prevailing conditions, by definition, leave more descendants and those descendants inevitably inherit the characteristics that enabled their parent to do better.
If, as seems to be the case with the ancestor of the bay cat and the Asian golden cat, this leads to speciation than that is a consequence of the process, not the purpose of it. It's such a shame that creationists can't allow themselves to appreciate the inevitability yet simple, elegant beauty in this process which has given us over time all the diversity we see wherever we look. And all because they are too afraid to even consider that they could be wrong for fear of what might happen to them after they have died.
Not that I believe this, but imagine, for a moment, being a god which created this process watching creationists do everything humanly possible not to recognise its exquisite beauty. I wonder if creationists who can't lose their superstition ever give a thought to that.
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