BILD 3 Lecture Notes - Lecture 3: Tiktaalik, Irish Elk, Ovipositor
17 Mar 2018
School
Department
Course
Professor
Document Summary
Fossil record - any trace of an organism that lived in the past. Irish elk - found fossil, and realized it was an extinct species. People say a useless wing would not be preserved by natural selection in evolution: they serve other purposes. Wing assisted incline running: homology, analogous structures are structures that are similar but do not have a common ancestor and arise independently, homology, structural homology: structure is homologous: shares some common ancestor, definition. Stinger in bees and wasps is homologous to the ovipositor of other insects; parasitoid wasps have a functioning ovipositor: male bees (drones) can"t sting. Similar at a molecular level: bacteria bacillus thuringinesis produces toxin that is lethal to caterpillars, bacterial genes that encode toxin can be inserted into crop plants, all because bacteria and plants share common ancestor and use the same.
