Paul Andersen shows you how to construct a cladogram from a group of organisms using shared characteristics. He also discusses the process of parsimony in cladogram construction. He then explains how modern cladograms are constructed and walks through a cladogram of primates.
Paul Andersen defines microevolution as any change in the frequency of the allele pool. He then explains the five mechanisms of evolution; small sample size, non-random mating, mutations, gene flow and natural selection.
Paul Andersen describes pieces of evidence that Charles Darwin used to support the idea of evolution and his process of natural selection. He begins with the following evidence use in the Origin of Species; artificial selection, biogeography, fossils and homologies. He finishes with a discussion of DNA and how it can be used to unravel the evolution of life on our planet.
Paul Andersen explains the concept of coevolution. He begins with an analogy comparing the relationship of humans to technology with those of coevolving species. He then discriminates between coevolution and convergent evolution. He finishes by describing many symbiotic relationships that formed through coevolution. The rough skinned newt and the garter snake, the acacia tree and the acacia ant, and finally all the symbiotic relationships utilized by leaf cutter ants.
Paul Andersen reviews the major concepts within the second unit of the new AP Biology framework. He starts by describing how life is organized into three domains. He explains how the history of life on the planet is characterized by mass extinctions followed by adaptive radiation. He explains how geographic, behavioral, temporal and mechanical isolation can create new species. He also explains how microevolution within a population can explain. He ends the podcast by describing abiogenesis and mentioning the major milestones in the evolution of life on the planet.
Paul Andersen reviews the major within the first unit on natural selection. He starts by defining evolution and explaining how evolution can occur in a population. He reviews the population genetics and camouflage lab. He reviews genetic drift and finishes with a brief discussion of characteristics that are conserved in living organisms.
Paul Andersen explains how the behavior of various organisms is shaped by natural selection. The action of phototropism and the timing of photoperiodism have both been shaped by the relative availability of light. Courtship in the bower bird determines the success of offspring. And finally pollination represents the combined success of the coevolution between insects and flowers.
Paul Andersen discusses scientific evidence of the origin of life on our planet. He begins with a brief discussion of the age of the earth and ends with the future of humanity. He includes geologic, chemical and molecular data.
Paul Andersen describes how life could have formed on our planet through natural processes. The progression from monomers, to polymers, to protocells and finally to cells is described. The Miller-Urey experiment is described in detail as well as characteristics of the latest universal ancestor.
Paul Andersen explains how life has evolved and continues to evolve today. A brief discussion of artificial, natural and sexual selection is included. The beak of the finch is used to explain how directional selection is achieved.
Paul Andersen explains how reproductive isolation can eventually lead to speciation. Three main barriers to gene flow are included: geographic, pre-zygotic and post-zygotic. Both allopatric and sympatric speciation are discussed. A brief discussing of polyploidy and punctuated equilibrium are also included.
Paul Andersen details the evolutionary processes of speciation and extinction. Stickleback evolution in Lake Loberg is used as example of rapid speciation. Adaptive radiation is illustrated using the Hawaiian honeycreeper. A brief discussion of extinctions and mass extinctions is also included.
Paul Andersen discusses the specifics of phylogenetics. The evolutionary relationships of organisms are discovered through both morphological and molecular data. A specific type of phylogenetic tree, the cladogram, is also covered.
Paul Andersen describes three main characteristics of life that are conserved in all organisms on the planet. The universal genetic code, the central dogma of biology, and shared metabolic pathways give us details of the original universal ancestor. He also explains how eukaryotic cells gained complexity through infolding of the cell membrane and endosymbiosis.
Paul Andersen lists major evidence for the existence of evolution. He begins with a discussion of Charles Darwin and the evidence that he presented in the Origin of Species, including biogeography, fossils, and homologies. He also explains how DNA evidence can be used to trace evolutionary history.
Paul Andersen describes genetic drift as a mechanism for evolutionary change. A population genetics simulator is used to show the importance of large population size in neutralizing random change. The near extinction of the northern elephant is used as an example of the bottleneck effect. The high incidence of total colorblindness due to a typhoon that hit the small island of Pingelap is also included.
Paul Andersen details examples of natural selection in the world. He starts by explaining how changes in global temperatures are causing plants to adapt. He explains how mutations cause changes in phenotype which give organisms varying levels of fitness. Two specific examples of natural selection; sickle cell disease and muti-drug resistant tuberculosis are also included.
Paul Andersen explains how natural selection is a major mechanism in evolution. The video begins with a discussion of Charles Darwin and the details of natural selection. The data of the peppered moth during the industrial revolution is used to show the process of adaptation. Allele frequencies are calculated before and after the selection. The adaptation of cichlids in African lakes is also included.
Mr. Andersen explains how carbon-14 dating can be used to date ancient material. The half-life of radioactive carbon into nitrogen is also discusse
