Clinal variation in quantitative traits is often attributed to the effects of spatially varying selection. However, identical patterns can be produced by the interplay between purely stochastic processes (i.e. drift in combination with spatially restricted gene flow). One means of distinguishing between adaptive and nonadaptive causes of geographical variation is to compare relative levels of between-population divergence in quantitative traits and neutral DNA markers. Such comparisons can be used to test whether levels of trait divergence attributable to additive genetic effects (as measured by QST) exceed null expectations based on the level of divergence at neutral marker loci (as measured by FST). The purpose of this study was to use an approach based on 'QST vs. FST' contrasts to test for evidence of diversifying selection on body size of an Indian fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae). Specifically, relative levels of between-population divergence in body size and microsatellite DNA markers were compared to assess whether the observed pattern of clinal size variation could be explained by a neutral model of isolation by distance. QST for body size was calculated using unbiased estimators of within- and between-population variance of principal component scores. The association between body size variation and geographical/environmental distance was tested using pairwise and partial matrix correspondence tests (MCTs). Independent variables (representing causal hypotheses) were constructed as between-locality distance matrices. The effects of neutral genetic divergence were assessed by including a matrix of pairwise FST as an independent variable. Partial MCTs revealed highly significant associations between phenotypic divergence (QST) and both geographical and environmental distance, even when the effects of neutral genetic divergence (FST) were partialled out. Results of the tests confirmed that migration-drift equilibrium is not a sufficient explanation for the latitudinal pattern of clinal size variation in C. sphinx. The geographical patterning of pairwise QST is most likely attributable to spatially varying selection and/or the direct influence of latitudinally ordered environmental effects.

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Contrasting patterns of divergence in quantitative traits and neutral DNA markers: analysis of clinal variation.

There are many vanishing cultures that possess a wealth of knowledge on the medicinal utility of plants. The Malasars of Dravidian Tamils are an indigenous society occupying the forests of the Western Ghats, South India. They are known to be exceptional healers and keepers of traditional aboriginal knowledge (TAK) of the flora in the Velliangiri holy hills. In fact, their expertise is well known throughout India as evidenced by the thousands of pilgrims that go to the Velliangiri holy hills for healing every year. Our research is the first detailed study of medicinal plants in India that considers variation in TAK among informants using a quantitative consensus analysis. A total of 95 species belonging to 50 families were identified for medicinal and general health purposes. For each species the botanical name, family, local name, parts used, summary of mode of preparation, administration and curing are provided. The consensus analysis revealed a high level of agreement among the informants usage of a particular plant at a local scale. The average consensus index value of an informant was FIC > 0.71, and over 0.80 for some ailments such as respiratory and jaundice. Some of the more common problems faced by the Malasars were gastrointestinal disorders, respiratory illness, dermatological problems and simple illness such as fever, cough, cold, wounds and bites from poisonous animals. We also discovered several new ethnotaxa that have considerable medicinal utility. This study supports claims that the Malasars possess a rich TAK of medicinal plants and that many aboriginals and mainstream people (pilgrims) utilize medicinal plants of the Velliangiri holy hills. Unfortunately, the younger generation of Malasars are not embracing TAK as they tend to migrate towards lucrative jobs in more developed urban areas. Our research sheds some light on a traditional culture that believes that a healthy lifestyle is founded on a healthy environment and we suggest that TAK such as that of the Malasars may serve toward a global lifestyle of health and environmental sustainability.

/pdf/consensus-of-the-malasars-traditional-aboriginal-knowledge-4g5ocfjmvr.pdf

Consensus of the 'Malasars' traditional aboriginal knowledge of medicinal plants in the Velliangiri holy hills, India

A reappraisal of the zoogeography and systematics of Asian colobines demonstrates marked discontinuities in their distribution. The Borean proboscis monkey is separated by Sumatra from its sole congener on the Mentawai Islands.Pygathrixspecies have a discontinuous distribution at the range limit of the Asian Colobinae. The existence in the Himalayas of some disjunct relatives of the south Indian fauna, has obscured a wider disjunction in which for example, the hooded black leaf monkey,Semnopithecus johnii, has one subspecies in southern India and another in north Vietnam. A closely related Vietnamese leaf monkey is a subspecies of the otherwise IndonesianS. auratus. Presbytis comatais disjunct between west Java, northern Sumatra and northern Borneo. The Mentawai IslandsP. potenzianiis closely related. Biogeographic parallels imply a common cause and previous continuity across the intervening areas. The only wholly compatible explanation is that the disjunct areas alone retained adequate moisture and temperature to support their endemic biota during a cool drought. That not only genera, but species are disjunct, indicates such conditions prevailed recently, and are probably attributable to the Pleistocene glaciations. The supposition that its maritime climate shielded Asian rainforest from the glacial drought known to have partially deforested Africa and South America, is inapplicable to the Indian subcontinent, and ignores the climatic effects of the emergence of the Sunda and the Sahul shelves. Such known influences, the distribution of drought indicator plants, fossil plants and fossil mammals, grassland birds and freshwater fish, and the anatomical specializations ofNasalisconfirm the instability of the Asian environment. The absence of endemic representatives of certain primates in north Sumatra implies the occurrence of two cold droughts. Available evidence appears to correlate the deforestations with the abrupt curtailment of glacial Stages 7 and 5, at about 190 000 years BP and about 80 000 years BP. The greater significance of climatic than topographical barriers in delineating the Oriental zoogeographic region, and a rapid speciation rate, is implied. Morphological change is evidently generated by geographic dispersal, rather than geographic isolation.

The Asian Colobinae (Mammalia: Cercopithecidae) as indicators of Quaternary climatic change

Geographic variation in body size and sexual dimorphism of the short-nosed fruit bat (Cynopterus sphinx) was investigated in peninsular India. Bats were sampled at 12 localities along a 1200 km latitudinal transect that paralleled the eastern flanks of the Western Ghats. The geographic pattern of variation in external morphology of C. sphinx conforms to the predictions of Bergmann's Rule, as indicated by a steep, monotonic cline of increasing body size from south to north. This study represents one of the first conclusively documented examples of Bergmann's Rule in a tropical mammal and confirms that latitudinal clines in body size are not exclusively restricted to temperate zone homeotherms. Body size was indexed by a multivariate axis derived from principal components analysis of linear measurements that summarize body and wing dimensions. Additionally, length of forearm was used as a univariate index of structural size to examine geographic variation in a more inclusive sample of bats across the latitudinal transect. Multivariate and univariate size metrics were strongly and positively correlated with body mass, and exhibited highly concordant patterns of clinal variation. Stepwise multiple regression on climatological variables revealed that increasing size of male and female C. sphinx was associated with decreasing minimum temperature, increasing relative humidity, and increasing seasonality. Although patterns of geographic size variation were highly concordant between the sexes, C. sphinx also exhibited a latitudinal cline in the magnitude and direction of sexual size dimorphism. The size differential reversed direction across the latitudinal gradient, as males averaged larger in the north, and females averaged larger in the south. The degree of female-biased size dimorphism across the transect was negatively correlated with body size of both sexes. Canonical discriminant analysis revealed that male- and female-biased size dimorphism were based on contrasting sets of external characters. Available data on geographic variation in the degree of polygyny in C. sphinx suggests that sexual selection on male size may play a role in determining the geographic pattern of sexual size dimorphism.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1022&context=bioscistorz

Clinal variation in body size and sexual dimorphism in an Indian fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae)

The acceleration of processes such as forest fragmentation and forest fires in landscapes under intense human pressures makes it imperative to quantify and understand the effects of these processes oil the conservation of biodiversity in these landscapes. We combined information from remote-sensing, imagery and ground maps of all fires in the Mudumalai Wildlife Sanctuary (MWLS) in the Western Ghats of India over 14 years (1989-2002). These spatial data on fire occurrence were integrated with maps of vegetation types found in the MWLS to examine fire conditions in each. We calculated the average fire-return interval for. each of the vegetation types individually, and for the MWLS as a whole. Using vegetation data from the larger Nilgiri Biosphere Reserve and the entire Western Ghats region, we conservatively estimated fire frequency information for these larger regions. Because the MWLS does not contain tropical evergreen or montane forests, we were unable to estimate fire conditions in these fire conditions in these forest types, which represent 31% of all Western Ghats vegetation cover. For the MWLS, all vegetation types had average fire-return intervals of < 7 years, and the sanctuary as a whole had a fire-return interval of 3.3 years. Compared with a 13-year MWLS fire data set from 1909-1921, this represents a threefold increase in fire frequency over the last 80 years. We estimated average fire-return intervals of roughly 5 years for both the larger Nilgiri Biosphere Reserve and the entire Western Ghats region. Given other recent reports, the estimated fire frequencies for the Western Ghats forests outside protected reserves are conservative. We conclude that the current fire regime of the Western Ghats poses a severe and persistent conservation threat to forests both within and outside protected reserves.

Conservation Threat of Increasing Fire Frequencies in the Western Ghats, India

This chapter attempts to present on outline of the characteristic vegetation and phytogeographical peculiarities of the Western Ghats. The general features of the Western Ghats, the geological structure and tectonic history and the climatic characters of the region are discussed in sufficient detail by specialists in earlier chapters of this book. From the stand point of the present chapter, we may appropriately describe the Western Ghats as an important part of the monsoonland, where the vegetation is influenced more by the abundance and distribution of the seasonal rainfall than the atmospheric temperature. The western side of the Western Ghats is on the threshold of southwest monsoon and receives a rainfall of 203–254 cm, and the eastern side lies in the rain-shadow area of the Peninsula. The main types of soils met with in the Western Ghats are red soils, laterites, black soils and humid soils. The red soils are developed on the Archean crystallines and are brown, grey or black, is deficient in organic matter, phosphoric acid and nitrogen. Evergreen forest of Calophyllum, Dipterocarpus, Hopea, Myristica and Xylia are characteristic of red-soil areas. The laterites consist of 90–95% of iron, aluminium, titanium and manganese oxides and are deficient in lime and organic material, an extend up to 1600 m in the Western Ghats. Shorea and Xylia are the dominant species in lateritic soils of Western Ghats. Black soils, formed out of the basaltic Deccan lava, are deficient in organic matter, nitrogen and phosphoric acid, but generally have enough lime and potash.

K. Subramanyam

Papers

Vegetation and Phytogeography of the Western Ghats