Sensory System Evolution

- Evolutionary process of five senses in wildlives -

   The first vertebrates are thought to be born in Cambrian (541mya-485mya). The origin of the vertebrates is still the controversial problem, but the clue for solving that enigma is supposed to be hidden in 'amphioxus'. To date, the vertebrates have diversified from much simpler organisms like them, adapting to various habitats. Following their 'glorious' evolutionary trend, the sensory system has also evolved variously. For instance, toothed whales and most of bats have acquired the specific auditory system for perceiving the ultrasonic sound signals we humanbeings cannot catch. The ultrasonic sound, they emit and receive, is utilized for grasping habitats (to avoid obstacles) and tracing their preys. However, it is not still revealed, 'How have their auditory systems evolved?'. This is just thing I have investigated, and henceforth intend to approach. I'm happy if you will know about my research interest via this homepage, and then you will also become interested in the evolution of animals.

Evolution of  Bat Auditory System

 As the first step for the future comprehensive research of the sensory system evolution in animals, I focused on the bat auditory system. Bat (Order: Chiroptera) is the second largest mammalian group following rodents and there are about 1000 species on earth. They are divided into two suborders: Yinpterochiroptera and Yangochiroptera, and each species acquire each distinctive bio-sonar system. Surprisingly, in order to trace on the flying insects and grasp the surrounding environment, they utilize the ultrasonic sound, we mankind cannot receive. I have somehow approached to the bat mystery: ''Why did they have to acquire the complicated biosonar?'' since I was amazed at their specific bio-sonar: echolocation. 

Embryology as a Clue of Evolution

 Embryology is the subject to study the developmental process of each trait in various organisms. Since the period when 'the Haeckel's recapitulation theory' was advocated at first, various works have engaged in the integration between the organogenesis and evolutionary process. This subject is called 'Evo-Devo'. My research plan is to approach to the evolutonary origin of the sensory system in the wildlives. In addition, it has been thought that the ecology is also essential for resolving the evolutionary enigma to take the fact that the organogenesis proceeds involving with the environment into consideration in recent years. This subject integrated among ecology, evolution, and development is called 'Eco-Evo-Devo'. I focused on the relationship among the ecology, evolution, and development and considered to apply to my research interest, the origin of the bat echolocation.