Mechanisms of Organic Change: Evolution (January 23 & 25)

Remember that Monday is Dr. Martin Luther King, Jr., Day. There will be no classes. Instead, how about attending a Justice Dialogue session or three? See you there.

Lots of material this week. Note that you do not need to read every word of every source. These are supplementary resources for your understanding of the topics. Start with a good definition of evolution, for you will soon see that dorm room conversations on the topic often have significant errors and misconceptions. The University of California Museum of Paleontology at Berkeley has an excellent website on the history of evolutionary theory, including good sections on pre-Darwinian thinkers. The Berkeley pages on “Understanding Evolution” are the best on the web. Charles Darwin is well represented web-wise, and Alfred Russel Wallace is the subject of this excellent site by Charles Smith of Western Kentucky University. The full text of Darwin’s most famous work, The Origin of Species (which appeared over 150 years ago), is available on-line. It is not scintillating reading, at least not on a computer, but you may want to peruse the preface and the conclusions. For a simple and effective presentation on evolutionary theory, try this YouTube video by “Stated Clearly”.

This excellent computer graphics animation of DNA replication is helpful, as is this animation of DNA and the construction of proteins. They hit all the major points of the process we will discuss in lecture (and a few more). The “Stated Clearly” channel has a useful tutorial on DNA and its functions. The Crash Course on DNA replication is also very good. Here is yet another animation of protein synthesis. I’m obviously repeating this important material several times!

Here’s a good article on the problems inherent in defining biological species. Evolution is at the species level, but we have difficulty grasping a concept of species.

Anomalocaridid “arm” from the Burgess Shale, Walcott Quarry, British Columbia, Canada. (Click to enlarge.)

Geology in the News –

The Universe Is Disappearing, And There’s Nothing We Can Do To Stop It.” A dramatic headline that is certainly true. This is a good article in Forbes discussing modern ideas of cosmology. The future looks very cold and dark, but at least it is a long time from now!

Interesting idea about extending the Anthropocene concept to Mars (and I would think the Moon as well). This would be the first time an interval of Earth’s geologic time scale (although Anthropocene is not yet approved) to another planet. The Anthropocene is essentially dated as the interval from the time humans first leave a geological record.

Poaching of African elephants for their ivory is apparently producing genetic changes in their populations that favor offspring without tusks. This is a brutal but effective demonstration of selection leading to evolutionary change.

For a lighter touch, puzzle out the origins of giant spinning ice disks!

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