Seashells
Summary
Melvyn Bragg discusses the biology, evolution, and cultural significance of seashells with experts Suzanne Williams, Liz Harper, and Helen Scales. They explore how mollusks construct their calcium carbonate shells, the mathematical logic behind spiral shapes, and the functions of color and pattern. The conversation also covers the historical use of shells as currency, including their role in the slave trade, and modern threats like ocean acidification.
Topics discussed
Sponsors and intro
Introduction to seashells and guests
What are mollusks and where do they live?
Human history and symbolism of shells
Evolutionary origins of shells
Physical composition and structure of shells
Classification of mollusk groups
Color in shells: pigments vs structural color
Spiral shapes and chirality in snails
Sponsors
Mother of Pearl and shell toughness
Functions of color and mollusk vision
Shell patterns and growth lines
Chitons and their unique shells
Hermit crabs and shell competition
Collecting shells and museum specimens
Using museum collections for research
Cowrie shells as currency and trade
Threats to mollusks and habitat restoration
Bonus: Giant clams and conch eyes
Scalyfoot snails at hydrothermal vents
Tyrian purple dye from snails
Ocean acidity and the age of clams
Outro and other BBC shows
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