outline19 - trilobites - dominate Cambrian record

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
  Outline 19 4/4/03   Origins and Precambrian Record of Life   3 features of living organisms cells, cell wall, metabolism Oparin - Haldane model for spontaneous generation of 1st living     organism prokaryotic cells eukaryotic cells endosymbiotic origin - Lynn Margulis organelles, nucleus Bacteria, Archaea, Eukaryota vs. Monera, Protista, Plants, Fungi, Animals Precambrian cells in cherts stromatolites - appear middle Archean (~3.5 bill. yrs.), peak in      Proterozoic, big drop in early Phanerozoic, barely survive to Recent metazoans - eukaryotic, multicellular animals "Small shelly fossils" Ediacara Fauna - 1st metazoans in latest Proterozoic
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: trilobites - dominate Cambrian record "Patterns" in metazoan groups - radiation, persistence through time, decline in diversity to "living fossil" status or final extinction correspondence to evolutionary faunas (times of maximum diversity) background extinction (normal times) mass extinctions (unusual events) - 5 medium-to-large events during Phanerozoic in marine environment; physical perturbation (several causes) + collapse of ecosystems; most at period or era boundaries (why?) Back to Outline Main page...
View Full Document

Page1 / 2

outline19 - trilobites - dominate Cambrian record

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online