Unit 4: Mechanisms of Evolution Extras  Study Guide

Chapter 25 The History of Life on Earth Review
  1. A major tool biologists use to study early life on earth is the fossil record buried in layers of rock.
  2. The 4.6 billion years of earth's history is divided into three geologic , which are further divided into and .
  3. Early photosynthetic released oxygen, allowing the evolution of .
  4. The first eukaryotes probably evolved from of prokaryotes within larger host cells and developing into organelles.
  5. Most of the major animal phyla appeared during the early period in what is known as the Explosion.
  6. Mammals are synapsids that belong to the group of chordates called .
  7. The movement of the Earth's due to continental has shaped the diversity of life on Earth.
  8. There have been several episodes of mass , though the trend has been an in diversity over time.
  9. The extinction of the dinosaurs may have led to the radiation of other species, such as mammals, which diversified to adapt to new now made available.
    A Scrolling Geologic Record:
bio1151 Home +space -space Dec 16, 2011 Print Print