Previous studies have argued that movement of organisms typically does not favour animals helping or cooperating each other. Therefore, in species that exhibit collective movement and fission-fusion among groups, cooperation is considered unlikely to occur. In a recent paper published in PLoS Computational Biology, Jaideep Joshi (PhD student), Vishwesha Guttal and collaborators from Germany and USA challenge this common perception.
Image credit: Deepak Veerappan
Deepak. V (a postdoc) and Praveen Karanth show that fan-throated lizards consist of at least 15 species, with much of the diversification dating back to 8–5 million years and possibly caused by climatic shifts in India in that period. This is one of the few studies that establishes a link between climate change and adaptation in the Indian subcontinent. The study also highlights the importance of the dry zone as centers of biodiversity.
Dynamic evolution of olfactory receptor genes in mammals: Possible link to anatomy and ecology
Olfaction, the sense of smell, is essential for the survival of most animals. It is used for foraging, communicating with conspecifics, and recognizing predators. Diverse odor molecules in the environment are detected by olfactory receptors (ORs) expressed in the olfactory epithelium of the nasal cavity. There are ~400 and ~1,100 OR genes in the human and mouse genomes, respectively, constituting the largest multigene family in mammals. Bioinformatic analyses using various genome sequences revealed that the numbers of OR genes vary greatly among species: African elephants have the largest number of functional OR genes ever examined, with ~2,000, while bottlenose dolphins, which have completely lost the olfactory apparatus, retain only ~10.
In my talk, I would like to introduce our recent study on the degeneration of OR genes in primate evolution, since it provides an excellent example of how anatomical/ecological factors affect the OR gene repertoire in each species. I will also briefly mention preliminary results on the OR genes in Asian elephants.
Population history of whales (and elephants) based on individual whole-genome sequences
Speciation in the open ocean has long been studied, but it remains largely elusive how populations of highly mobile animals, such as whales, in such an open environment become reproductively isolated. Baleen whales of the genus Balaenoptera undertake extensive migrations, and there are few obvious barriers that potentially isolate their populations in the open ocean. In this talk, population history of common minke whales B. acutorostrata and Antarctic minke whales B. bonaerensis was inferred based on the whole genome sequence data of an individual, and discuss about speciation of these two species using such recently-developed genomics tools. I will also talk about very preliminary data on the demographic history of Indian elephants and presence of a bottleneck during the last glacial period.
Worker castes of fungus-growing termite depositing “agar boluses” on the fungal plug of weedy
Pseudoxylaria (from the October issue of Journal of Chemical Ecology). Photo Credit: Nikhil More
Lakshya Katariya and colleagues (Renee M Borges’ lab) discover that fungus-farming termites
selectively bury the weedy fungi that smell different from crop fungi
Recent research findings by a CES Ph.D. student Sanjeeta Sharma Pokharel, Prof. Polani B Seshagiri (MRDG, IISc) and Prof. Raman Sukumar (CES, IISc) show that the stress levels and body condition of elephants varied between seasons. Wild Asian elephants were showed ‘poor’ body condition and were found to be ‘more’ stressed during resource-deficient periods. This pattern was more conspicuous in female Asian elephants.
The terrestrial biogeochemical processes are perhaps the most dynamic and complex
component of the Earth’s Climate system. In order to better understand this complex system, the
integrated use of process-based modeling, remote sensing (RS) and measurements at multiple scales
(with an ecohydrological spirit) is proposed.
At the outset, a process-based ecohydrological model (BEPS-TerrainLab V2.0) that has tight
coupling of water (W), energy (E), carbon (C) and nitrogen (N) cycles is discussed as applied to a
forested ecosystem in boreal Canada. The potential errors in the simulated C fluxes under abstracted
hydrology are presented using a numerical experiment. Further, an improved and generic model
(STEPS) is presented as applied to a patchy-landscape in southern France. Improvements made
towards the modeling of canopy radiative transfer mechanism, in addition to some issues that are
pertinent to agro-ecosystems (C4 photosynthesis, irrigation, fertilizer N etc.) are presented. In the
second part of the presentation, long-term modeling of C in the soil and vegetation is discussed from
the lessons learnt from various projects in the Canadian C Program and the AmeriFlux programs.
Some studies on the long term ecohydrological responses under climate change in the lower
Himalayas are also discussed.
Finally, large-scale ecohydrological interactions are discussed. An analysis of the recent trends
in the global vegetation is explored using long-term RS data (AVHRR). Because of the importance of
soil water in governing the global vegetation, I hypothesize a major limitation in the widely used
global estimate of terrestrial photosynthesis (MOD17A2). A modeling strategy that is being developed
to improve the MOD17A2 by incorporating soil moisture data is briefly explained. In this regard, I
also present an analysis of some global soil moisture products obtained from microwave RS (SMOSL3
and AMSRE-LPRM) with respect to a reanalysis product (ECMWF).