Paul Andersen explains the importance of biodiversity. He starts by describing how biodiversity can be species, genetic or ecosystem diversity. He explains the importance of keystone species in an environment and gives two examples; the jaguar and the sea otter. He finishes with a quote from the father of biodiversity, E.O. Wilson.
Paul Andersen explains the importance of genetic variation within a population. He begins with a discussion of the devil facial tumor that is a form of cancer transferred between Tasmanian devils. He then explains how a decrease in genetic variability nearly led to the extinction of the black-footed ferret. He finally discussed the importance of genetic variability in disease resistance. He explains how mutations in humans allow some of them to be resistant to HIV and how the allele frequency can be calculated in a population using the Hardy-Weinberg equation.
Paul Andersen explains how genotypes can be expressed or not based on changes in the environment. He starts with a brief description of the Himalayan rabbit and how melanin production can be disrupted by high temperature. He explains how this could be advantageous in both the arctic fox and hare. He explains how flowers can vary temperature based on the pH of the soil. He finally describes gene expression in Lac+ bacteria.
Paul Andersen explains how variation is created within a cell. He starts by showing how molecular variation can increase fitness at the local level. He explains how an additional chlorophyll molecule allows plants to absorb more light from the sun. He also explains how cells can vary the composition of phospholipids in their cell membrane. He explains the significance of heterozygote advantage and how gene duplication can create novel genes. The antifreeze protein evolved from a simple digestive protein.
Paul Andersen explains how ecosystems change over time. He starts by explaining how global climate change will impacts ecosystems around the planet. He then discusses how continental drift created climatic changes that impacted mammal species. He finishes with a brief discussion of how local meteorological changes can impact local ecosystems.
Paul Andersen explains how populations interact in an ecosystem. The symbiosis of several populations is based on effects that may be neutral, positive, or negative. Interactions like mutualism, commensalism and parasitism are included. Human impacts to ecosystems are also considered using the invasive species kudzu.
Paul Andersen emphasizes the importance of cooperation in living systems. He starts with a brief description of game theory and why countries at peace do better over the long term. He then explains how microscopic cells cooperate in the rumen of a cow, how organelles cooperate in a cell, and how organs cooperate in the digestive system.
Paul Andersen explains how ecosystems interact with biotic and abiotic factors. He explains and gives examples of food chains and food webs. He shows how limiting factors eventually leads to logistic growth. Real data from Yellowstone Park is used to show how populations interact. He ends the podcast by showing how human impacts can eventually lead to changes within an ecosystem.
Paul Andersen starts by explaining the major classification terms in ecology. He then explains how a community can be measured by species composition and species diversity. The symbiosis of leaf cutter ants is included. The podcast ends with a discussion of population growth.
Paul Andersen explains how organs work together to form organ systems and how organ systems work together to form organisms. The kidney and bladder work together to filter blood in the excretory system. The circulatory and respiratory system work together to bring oxygen and nutrients to the cells. A quick survey of the major organ systems is also included.
In this podcast Paul Andersen explains how cells differentiate to become tissue specific. He also explains the role of transcription factors in gene regulation. The location of a cell within the blastula ultimately determines its fate. The SrY gene is an important external stimuli in human development. The heat shock factor is also discussed as an example of an environmental simuli.
Paul Andersen describes the structure and function of the major organelles in a eukaryotic cell. The endoplasmic reticulum, ribosomes, and golgi complex produce and store proteins in the cell. Lysosomes dissolve broken and invasive material. Vacuole store material in plant cells. Mitochondria produce ATP through cellular respiration and chloroplasts use the energy of the sun to produce sugars.
Paul Andersen describes the four major biological molecules found in living things. He begins with a brief discussion of polymerization. Dehydration synthesis is used to connect monomers into polymers and hydrolysis breaks them down again. The major characteristics of nucleic acids are described as well as there directionality from 3' to 5' end. Protein structure is describes as well as the structure of its monomers; amino acids. The carboxyl and amino ends of a protein are described. The major groups of lipids are included with a brief discussion of saturated, unsaturated and trans fats. Finally carbohydrates and their sugar monomers are discussed.
Paul Andersen begins this podcast with a discussion of brain lateralization and gives a brief demonstration of tests that were performed on split-brain individuals. He then discusses the major parts of a neuron and explains how action potentials are generated using voltage-gated ion channels. He explains how neurotransmitters transmit messages across a synapse and how these messages can be either inhibitory or excitatory.
Paul Andersen explains how organisms use information to communicate with each other. Signals are used by bees doing the waggle dance to communicate the location of flowers. Territorial markings are used by wolves to establish territory. Complex courtship rituals are used by sage grouse to ensure mating success. Cooperation is used by organisms that flock to ensure their individual survival.
Paul Andersen explains how changes in the signal transduction pathway can affect organisms. He begins with a brief discussion of the tetrodotoxin produced by the California Newt. He then explains how anthrax affects adenylate cyclase and thereby shuts down the signal transduction pathway. He also explains how diabetes mellitus is caused by the blood glucose pathway. A brief discussion of zombie powder is also included.
Paul Andersen explains how signal transduction pathways are used by cells to convert chemical messages to cellular action. Epinephrine is used as a sample messenger to trigger the release of glucose from cells in the liver. The G-Protein, adenylyl cyclase, cAMP, and protein kinases are all used as illustrative examples of signal transduction. A review of the concepts is also included.
Paul Andersen discusses cell communication. He begins by explaining how he communicates with other individuals using various forms of electronic communication. He them explains how cells communicate when the distance between them is big, small, and zero. He explains how antigen presenting cells pass information on antigen structure by touching in the immune response. He explains how neurotransmitters are used to transfer and manipulate nerve signals. And he finally explains how the endocrine system sends messages throughout the body.
Paul Andersen describes how cell communication is used in both single-celled and multicellular organisms. He starts by describing the symbiotic relationship between the bobtail squid and the bacteria Vibrio fisheri. He explains how bacteria use quorum sensing to communicate between each other and respond to changes in their environment. He also explains how multicellular organisms (like humans) can coordinate activities. He explains how epinephrine release from the adrenal gland can trigger a series of signal transduction pathways that can eventually lead to the release of glucose from the liver.
Paul Andersen explains how viruses reproduce using the lytic cycle. He also shows how viruses can pick up new genetic material and how retroviruses (like HIV) can enter into the lytic cycle. He also describes the lysogenic cycle and how it increases the virulence of bacteria.
