Homology and Evolution
Universal common descent- is the hypothesis that all living, terrestrial organisms are
genealogically related. All existing species.
How does the evolution occur?
o DNA Mutation + Natural Selection
Correlation and Dating of the Rock Record
The Rate of Geological events.
o Magnetic polarity
o Normal vs. reversed intervals
o Underlying principle
The Earths magnetic field is thought to be generated by
Major Chemical Cycles
*3.8 billion years ago, the Earth cooled down. There is now water in the oceans.
Rock cycle, Water cycle, Elemental cycle
Once in the Earth System, a particular element may exist in many different forms (or compounds
Measuring the rate of speciation
a. Molecular Clock:
a.i. The accumulation of mutation is usually at a fixed rate for a given DNA
segment of a certain taxonomic group (unaffected by natural selection)
a.ii. But in order to use
Environments and Life
Climate is the environmental factor that exerts the greatest control over the
distribution of species throughout the world.
Ecological Niche- the way a species interacts with its environment defines this.
The Diversity of Life
1. The capacity for self replication
2. The capacity for self-regulation (viruses do not meet this)
Divided into three (3) domains:
Archaea, Bacteria, and
Paleography- The geography of the past.
The identification of ancient sedimentary structures provides geologists with a
framework within which to interpret life of the past.
o Geologists rely heavily on actualism (the idea that th
Rock-Forming Minerals and Rocks
The Structure of Minerals
o What constitutes something as a mineral?
Definite (but not fixed) chemical composition
Made from inorganic processes
Highly ordered atomic arrangement
Mesozoic and Cretaceous Worlds
The Mesozoic World
*Permian- huge mass extinction
*No Polar Ice in the entire Phanerozoic Era.
*Look up 24 hour clock in textbook.
At the transition (Paleo-Mesozoic Era): The supercontinent Pangea took its
Modern Paleozoic world
- Renewed diversification of life after the O3 mass extinction
o Brachiopods attained the highest diversity than ever before;j
o Bivalves invaded non-marine habitats
o Graptolites re-radiated after near-total-death experience in O3
Paleo-temperature: Oxygen isotope compositions
When the number (ratio) becomes bigger, the temperature decreases
o In the last 50 million years, the ocean temperature has gradually been increasing.
o _?_ indicates the formation o