In this talk, I will first define the approaches used to study ontogeny, the advantages and disadvantages of the various organisms used as research models, and the three fundamental cellular processes of ontogeny. This will be followed by a discussion of eight principles that function in the formation of a new multicellular organism. These principles are:
• Differentiation is the result of differential activity of equivalent genomes.
• Localized maternal factors specify the axes of the body plan during fertilization.
• The structure of the basic body plan is set up during cleavage by interactions between cells receiving different maternal factors.
• Organ fields within the basic body plan are established by cascades of regional cell interactions.
• Boundaries of organ fields specify the organization of pattern within them.
• Developmental mechanisms operate throughout life for growth and maintenance of tissue integrity.
• Species continuity is assured by reproductive stem cells.
Developmental mechanisms constrain the types of possible evolutionary change
Audio (MP3 File, Podcast Ready)
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