In this video lesson, 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.--Publisher.

In this video lesson, 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.--Publisher.

In this video lesson, 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.--Publisher.

In this video lesson, 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 discussed. Human impacts to ecosystems are also considered using the invasive species kudzu.--Publisher.

In this video lesson, 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.--Publisher.

The Oedogoniales are remarkable filamentous green algae. Their method of cell elongation is unique, utilizing a donut-shaped ring of soft wall material which is stretched to form the new daughter cell. While Oedogonium is a simple filament, the related Bulbochaete and Oedocladium are branched and Bulbochaete differentiates long hair cells. The zoospore is large and multiflagellated. Sexual reproduction is oogamous and either “macrandrous” or “nannandrous.”...

Diatoms are an extraordinarily successful group of organisms and their many thousands of species have diversified and specialized so as to occupy every environmental niche. Part of their success derives from their unique protective cell walls, beautifully elaborate structures made of pure silica. However, living inside walls made of this rigid, refractory material creates many problems. Just how diatoms circumvent these problems provides the major...

Combining images of living plant stages with computer simulations allows you to easily bridge the gap between the familiar plant and the micro-environment contained within it. Three dimensional animations take you inside the flower to witness dynamic events such as pollination, gametophyte formation, fertilization, embryo formation and fruit formation are seen as spectacular computer simulations..

The Volvocales and Chlorococcales share a common ancestry from a cell type exemplified by Chlamydomonas. Using live cells, this video shows how simple evolutionary trends working on Chlamydomonad ancestors have generated diversity and complexity.. In Volvocalean evolution, unicellular ancestors became multicellular (e.g., Volvox) by daughter cells adhering after division. Concurrently, they evolved various advanced characters (e.g., differentiation...

Combining images of living plant stages with computer simulations allows you to easily bridge the gap between the familiar plant and the micro-environment contained within it. Three dimensional animations take you in and around reproductive structures such as the sorus, sporangium, and antheridium and archegonium. You see dynamic events such as spore formation, spore release, prothallus formation, sperm release, fertilization and embryo growth..