Shell Shape of Snails
34 mins 42 secs,
132.69 MB,
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480x270,
29.97 fps,
44100 Hz,
522.08 kbits/sec
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About this item
Description: |
Larsson, J
Friday 17th November 2017 - 11:00 to 11:30 |
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Created: | 2017-11-17 16:29 |
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Collection: | Growth form and self-organisation |
Publisher: | Isaac Newton Institute |
Copyright: | Larsson, J |
Language: | eng (English) |
Distribution: | World (downloadable) |
Explicit content: | No |
Aspect Ratio: | 16:9 |
Screencast: | No |
Bumper: | UCS Default |
Trailer: | UCS Default |
Abstract: | The beautiful, intricate, and widely diverse shapes of snail shells have fascinated people for centuries. In particular, shells have been analysed by mathematicians wanting to understand their geometric properties. One of the greatest contributors to the field is D'Arcy Thompson with his book On Growth and Form. This book celebrates one hundred years this year, and has played a major role in the field of morphometric analysis.
One well established and simple way of visualising snail shells is built on Raup's growth model, using logarithmic equations with three growth parameters. However, analysing a shell to find the correct values for the growth parameters is not always a straightforward task. The goal of my research is to develop a method for obtaining the growth parameters from 2D images of shells. I will test my methods with a set of images of the species Littorina saxatilis. This species is biologically interesting because strong natural selection maintains different shell shapes in distinct environments. It would therefore be an advantage to have a way of describing this natural shape variation, and the shapes of laboratory hybrids, in terms of meaningful growth parameters. This is expected to give a better understanding of the operation of selection and of the underlying genetic basis of shape variation, compared to more classical PCA analysis of landmarks. |
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Format | Quality | Bitrate | Size | |||
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MPEG-4 Video | 640x360 | 1.94 Mbits/sec | 504.99 MB | View | Download | |
WebM | 640x360 | 513.99 kbits/sec | 130.63 MB | View | Download | |
iPod Video * | 480x270 | 522.08 kbits/sec | 132.69 MB | View | Download | |
MP3 | 44100 Hz | 249.73 kbits/sec | 63.53 MB | Listen | Download | |
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