Biology 3229F/G Lecture Notes - Lecture 5: Coral Reef, Burgess Shale, Basal Lamina
24 Feb 2019
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Lecture 5 base of the animal tree. 500-600 million years ago animals appeared and we have fossils at the burgess. 542 million years ago: cambrian explosion: bauplan, the designs are unique to each one of those phylum. 5 mass extinctions, getting into our sixth: no change in phyletic diversity. Increases and decreases in species diversity but no changes observed in phyletic diversity. Knowing relationship from one to another, there"s genetic evidence that supports notion that all things come from a common ancestor in life. Monophyletic: it is a true clade, has a common ancestor and the tree that you create has all the descendants from that common ancestor. Paraphyletic: a non-true clade that does not include all the descendants. Invertebrate biology is paraphyletic; clade for annelids is paraphyletic. Atoll: created by cnidarians, by the corals (class anthozoans) Soft corals: don"t produce calcium carbonate system. Sponges: unsung hero of coral reefs (phylum porifera)
