Hello Tan,

Of course paleo-climate can greatly affect genetic divergence of populations, in the conditions that existed in the past disfavored gene flow/connectivity. However, if populations have remained isolated since then, then the divergence can as well be as a result of current barriers to gene flow, and any genetic markers could be used to asses this, like microsatellite markers. Neverthelelss, since palaeo-climatic conditions are effects of the past, microsatellite markers with a quick mutation rate are not suitable for such analysis.... therefore you may want to consider using  Chloroplast DNA (CpDNA) sequences or mitochondrial (MtDNA), depending on what species you are working with. These latter markers have much slower mutation rates and can reveal the effects of historical vicariance events that led to divergence of Populations.

Of course as far as divergence is concerned, it will she light in gene flow patterns, which are very crucial for the management of the populations in question.

I hope this helps? I think you question is very broad, for better help, try to be a bit more specific.

Good luck

Thank you very much for your helpful reply, Magdalene. 

I was wondering why some (ancient) plant taxa have disjunctive distribution and some restricted to highlands in Malaysia (South-east Asia) and thinking if it could be related to paleoclimate and climate change.

I should read more about gene flow and barrier you pointed out.

Regards.

Even if population gentics is far from my domain, I know there are a few works looking at the last glaciation. You could do a search related to the Last Glacial Maximum (LGM) and perhaps you will find papers that deal with your subject + palaeoclimatology.

Thank you for your suggestion, Gustavo.

A recent read on phylogeography of southeast asian stone oak (Cannon and Manos, 2003) suggested that rain forests in southeast Asia persist through climate changes in Quaternary.

I suppose I should look sometime further as I want to deal with more ancient plant.

Regards.

Climatic change is closely related to the development of new species.  During the last glaciation, 12 new species of alpine plants were evolved on the nunataks in southwest Alberta, only four on Haida Gwai which had a more maritime climate, and over 40 in the North American areas of Beringia.  The latter presumably had the most extreme climate change of the three areas.

On deglaciation, these new species spread rapidly along the available mountain ranges with a suitable climate and substrate until the warming trend confined alpine conditions to the tops of the mountains.  The species from Haida Gwai could not leave the island, while those from southwest Alberta were calciphiles that could only colonize the adjacemt limestone mountain ranges such as the Selkirks.  However, the new Beringian specis spread south in a remarkably short time and are now isolated on the mountaintops along much of the formerly glaciated Canadian Cordillera.

In the case of the Qinghai-Tibet Plateau, it has a distinct endemic flora characterized by the evolution of large numbers of families including Oxytropis of the Leguminosae, the Gentianacae (over 100 species),  Papaveracae (particularly Mecanopsis), Saussurea (Compostae), etc..  The flora that is found across the boreal forest realm of the Northern Hemisphere disappears almost completely south of the Hexi Corridor between Inner Mongolia and the Plateau.  However, on the Plateau, tectonic history appears to be important in the species distribution in many cases, since the individual species are often limited in elevational range to 200 m out of the 6000+ m possible. 

In your case, the development and demise of Sundaland is involved, together with the tectonics resulting from the northward movement of the Indian Plate though it would appear that the area was a refugium for many tropical ans subtropical species during the last glaciation.  Sea level had dropped over 120m, so that the China Sea was largely dry land with lakes until about 18 ka when the climate started to change and sea level started to rise, inundating the China Sea, and causing the East China monsoon to begin again.  Before that, bitterly cold and dry conditions affected the northeastern part of the Plateau and it is thought that permafrost conditions evtended south almost to the Himalayas.  The Indian monsoon would have affected the south coast of Sundaland.

I can give you references if you need them, but more work on the development and demise of Sundaland will be necessary to answer your questions.  Good Luck!

Dear Prof Stuart,

I am delighted to have your comment. Very interesting reconstruction. Thank you very much.

Please provide me some references.

Regards.

For North America:

Harris, S.  A., 2012.  The role that diastrophism and climate change have played in  determining the biodiversity in continental North America.  In: Lameed, G. A., Ed..  Biodiversity, conservation and uitilization in a diverse world.  Intech (interchopen.com).   Chapter 10: 233-260.  doi.org/10.5772/50286.

For China and Sundaland:

Harris, S. A. and Jin, H. J., 2012.  Tessellons and "sand wedges" on the Qinghai-Tibet Plateau and their palaeoenvironmental implications.  In: Proceedings of the 10th International Conference on Permafrost, Salekhard. 1: 147-153.

Voris, H. K., 2000.  Maps of Pleistocene sea levels on Southeast Asia, shorelines, river systems and time durations.  Journal of Biogeography 27(5): 1153-1167.

Flora of Siberia

Flora of Tibet.

Stuart.

Here you are a nice paper dealing with the speciation pattern of blind mole-rats (Spalacidae). Here the authors proved, that far before the Quaternary climatic fluctuations the dry/wet climatic cycles caused significant speciation in the investigated group (of course also tectonic changes resulted in speciation).