In this episode we explore the diversity of the animal kingdom. I first discuss the history of taxonomy and give an overview of some key concepts such as morphological similarity, phylogenetic analysis, systematics, cladistics, binomial classification, and the taxonomic hierarchy. Then follows an explanation of the diversity of and relationships between the major animal phyla, including arthropods, echinoderms, molluscs, and many others, with special emphasis is given to the classes and orders in the phylum of chordata (vertebrates).

An overview of the structure and function of proteins. Beginning with a discussion of some key research methods for studying proteins, including column chromatography, electrophoresis, and x-ray crystallography, we then discuss the structure of proteins, with a focus on secondary structure, motifs, structural domains, and quaternary structure. The episode concludes with a look at protein function, including protein folding, denaturation, enzymatic function, and allosteric regulation. Recommended pre-requisites are Episode 18: Biochemistry Basics, and Episode 10: The Cell. Episode 32: Light and Optics may also be helpful for the crystallography portion.

Concluding the brief exploration of language begun last time, this episode examines semantics, including the distinction between sense and reference and different types of utterances, pragmatics, including conversational maxims and implicatures, and sociolinguistics, including prestige dialects and speech acts. Recommended pre-listening is Episode 66: An Overview of Language Part 1.

In this first of a two-part episode, I discuss the phenomenon of language. Here we consider phonetics, how sounds are produced and articulated, phonology, how different sounds are distinguished from one another and treated across different languages, morphology, how sounds are combined into units of meaning called morphemes, and in turn how these are combined into words, and syntax, how words are put together in accordance with particular rules to form sentences.

An introduction to the concept of money, including its uses, purpose, and a brief account of its history. I discuss the notion of money as a medium of exchange, a unit of account, and a store of value, and some of the properties that make particular goods useful as money. I also discuss various measures of the money supply, and briefly outline the difference between the monetary base and money created through the fractional reserve system. I discuss inflation, including its definition, causes, and effects on the economy, before concluding with a brief look at interest rates and exchange rates.

A look at how we understand and think about semantic knowledge. I discuss semantic and propositional networks, the spreading activation model, present some evidence in favour of these models, and discuss the promising new approach of connectionism. I also examine how we classify objects into categories, looking at prototype and exemplar theories, family resemblance, graded membership, and the theory-theory of concepts.

An overview of the structure and function of the nervous system, including a discussion of the autonomic and somatic divisions of the peripheral nervous system, the spinal cord, and the brain. I discuss the major regions and structures of the brain, including the brainstem, the cerebellum, the cerebral cortex, and various subcortical structures. I conclude with some brief remarks about lateralization and the relationship between brain size and IQ.

An overview of organic chemistry, beginning with a discussion of the nature of organic compounds, the history of vitalism and its influence on the development of organic chemistry, and what makes carbon so special. I then discuss some important concepts in organic chemistry, including IUPAC nomenclature, functional groups, aromaticity, fullerenes, polymers, and organic synthesis. Recommended prelistening is Episode 15: Chemical Bonding, and Episode 23: Chemical Reactions.

A discussion of the basic concepts of magnetism, including magnetic fields, magnetic poles, and electromagnets. I also discuss the ultimate subatomic source of magnetic force in the phenomenon of electric spin, and explain how this leads to the different types of magnetic materials: ferromagnets, paramagnets, and diamagnets. I conclude with some applications of electromagnetism, including electric generators and motors, transformers, and a brief discussion of Maxwell's equations. Recommended prelistening is Episode 43: Electric Forces and Fields.