Man in the mirror - Charles Stirling 1992 Christmas Lectures 1/5

Video Description

In his first lecture Charles Stirling explains how humans’ chiral properties are important and how this is acquired. Watch all the lectures in this series here: https://www.youtube.com/playlist?list=PLbnrZHfNEDZwZ-av1yzKu5_6pKUSVxHEm Watch our newest Christmas lectures here: https://www.youtube.com/playlist?list=PLbnrZHfNEDZyQJZLPMjwEoOLdkFBLU2m1 This was recorded on 1 Dec 1992. -- This year marks 200 years of the Royal Institution Christmas Lectures — a world famous series showcasing science, curiosity, and mind-blowing demos, and started by the legendary Michael Faraday himself. To celebrate, we're unlocking the archive. Every Saturday, we’ll upload a classic lecture to our YouTube channel — some not seen since they aired on TV. Sign up as a Science Supporter and get early access here: https://www.youtube.com/channel/UCYeF244yNGuFefuFKqxIAXw/join -- From the 1992 programme notes: Humans are distinct from all other animals in two important respects. First, we are chiral, i.e. handed and prefer to use one hand for skilled tasks. Second, we communicate with structured language as opposed to the small range of specific sounds used by whales or apes. These capabilities are controlled by the brain which is itself chiral, speech being controlled by the left hemisphere in a way that is more specific for right-handers than for left-handers. Overall, we are much less symmetrical than we appear. The mirror image of one side of our bodies is often quite different from the other. Fingerprints from the left hand are different from the right, and our hearts lie on one side of the centre line and our livers on the other. One of our eyes and one of our ears is dominant and we fold our arms and hands in an asymmetric fashion. We ask whether handedness is innate or acquired. Evidence suggests that handedness is inherited in a complex way and there is no evidence to suggest an adaptive advantage. The mechanisms of inheritance depend upon handed molecules, and we return to this theme in Lecture 5. Meanwhile, our perceptions of left versus right are crucial. -- About the 1992 CHRISTMAS LECTURES We are set apart from other animals both by language and by the fact that unlike most other animals, which have mixed handedness, we are predominantly right-handed. Recent speculations have focused on the possibility that these two attributes are interconnected genetically, a link that could lead to an understanding of the neurobiology of language and its molecular biological basis. In these lectures, we shall look at first our own symmetry, in terms of handedness and our appearance, and also below the surface at our brains and other organs. Then we shall look at ourselves in the world at large, focusing on the symmetry of our fellow creatures and the artefacts that we have created. The connection of both of these to left-right relationships will be explored. The most significant handed (chiral) objects we encounter, are the molecules that we and all our surroundings are made of. We will look at the nature of these molecules and trace the understanding of the significance of handedness at the molecular level in the 19th century, for which it was the most far-reaching chemical realisation. Our contact with handed molecules has profound significance in terms of sensory perceptions such as taste and smell. We can distinguish between handed molecules and this tells us that our sensory apparatus is itself handed. Our existence depends upon the handedness of molecules both large and small and without such molecules, we would not be able to digest our food, build our bodies, or transmit our characteristics to the next generation. We return to the opening speculation. The genes - themselves composed of handed molecules - control the development of handedness and cerebral dominance, a link that has the potential to give us an understanding of the biology of language. We leave our consideration of chirality - handedness -with an unsolved mystery. Where do chiral molecules come from? Find out more about the CHRISTMAS LECTURES here: https://www.rigb.org/christmas-lectures --- Join this channel to get access to perks: https://www.youtube.com/channel/UCYeF244yNGuFefuFKqxIAXw/join Subscribe for regular science videos: http://bit.ly/RiSubscRibe The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and TikTok: https://www.tiktok.com/@ri_science Listen to the Ri podcast: https://podcasters.spotify.com/pod/show/ri-science-podcast Donate to the RI and help us bring you more lectures: https://www.rigb.org/support-us/donate-ri Our editorial policy: https://www.rigb.org/editing-ri-talks-and-moderating-comments Subscribe for the latest science videos: http://bit.ly/RiNewsletter Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link.