Evolution

Topic: 
Dispersal vs. Vicariance: The origin of India’s extant tetrapod fauna
Speaker: 
Dr. Praveen Karanth, IISc
Date & Time: 
3 Mar 2021 - 3:00pm
Event Type: 
CES Buzz
Venue: 
https://teams.microsoft.com/l/channel/19%3ae0eb69cd574c47bd8a645eee9bfd53fd%40thread.tacv2/General?groupId=73d8cbc5-a9cb-4d2f-b6b5-30c43d8980b9&tenantId=6f15cd97-f6a7-41e3-b2c5-ad4193976476
Abstract:

Given India’s ancient association with Gondwana and subsequent separation from Africa and Madagascar, vicariance has often been invoked to explain the current distribution of some of its so-called Gondwanan biota. In this talk, I review phylogenetic studies and fossil data of Indian tetrapods to ascertain the relative contribution of dispersal and vicariance in shaping their distributions. Results indicate that Paleogene dispersal into India better explains the current distribution of most of the tetrapods in India. Vicariance is invoked for three fossorial groups, namely caecilians, frog family Nasikabatrachidae and blindsnake family Gerrhopilidae. It is plausible that much of India’s Late Cretaceous tetrapod fauna of Gondwanan origin went extinct due to Cretaceous-Paleogene mass extinction and Deccan volcanism. Subsequently, it was replaced by intrusive elements as India proceeded to dock with Asia in the Paleogene. In this regard, soil invertebrates might be a promising study system to understand the Gondwanan component of Indian biota.  

Multiple Sensory Modalities in Diurnal Geckos Is Associated with the Signaling Environment and Evolutionary Constraints

Gecko

Being conspicuous in the environment allows males to attract mates and warn other males of their presence. Males of a species often use signal traits in different sensory modalities to achieve this. However, as elaboration of several signal-traits is demanding, trade-offs in investment in signal-traits in different modalities is expected, especially since not all traits are equally conspicuous in all environments. In Kabir et al. 2020, we show that signal traits in the chemical and visual modalities in the diurnal gecko, Cnemaspis are well associated with the local environment.

Topic: 
CES In-House Symposium
Speaker: 
Students and Faculties of CES
Date & Time: 
20 Jan 2020 - 9:00am to 22 Jan 2020 - 12:45pm
Event Type: 
Symposium
Venue: 
CES Seminar Hall, 3rd Floor, Biological Sciences Building
Abstract:

CES IHS 2020
Talks, Posters, Short documentaries, Panel discussion, Science and Creativity stalls

Unravelling the venomous bite of an endangered mammal

Solenodon

Highly similar venom toxins found in shrews and endangered Caribbean mammals, despite common ancestor over 70 million years ago

Researchers from Liverpool School of Tropical Medicine (LSTM) and ZSL (Zoological Society of London) have worked with scientists from institutions across the globe, including the Evolutionary Venomics Lab at IISc, to uncover the truth behind the origin of venom in some very unusual mammals.

New publication: Past climate change and the diversification of geckos from Peninsular India.

geckos

Around 33.5 million years ago, during the Eocene–Oligocene period, there was an abrupt shift towards a cooler drier climate. This resulted in a corresponding shift in biological diversity globally. In Peninsular India, the study of fossil pollens suggests a shift from wet rainforest vegetation to dry and seasonal species during this period. However, the grassland and open habitats that dominate the region today expanded relatively recently as a result of the Late Miocene aridification ~ 11 million years ago.

New publication: Morphological diversification of geckos from Peninsular India

Morphology

Studying adaptive radiations, such as Darwin's finches from the Galápagos Islands, can give us key insights into generalities of ecomorphological diversification. This paper from the Karanth lab examines morphological diversification in Hemidactylus geckos from Peninsular India that occur in a wide range of microhabitats. 

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