Developing Marine Ecosystems (September 18-22)

Our topic this week  is the rise of animal life and the early development of marine communities. A good place to start on the Web is at Queen’s University’s Ediacaran fauna page. (Canadians are big on the earliest rocks and fossils for good reason — they have a lot of them!) The Wikipedia pages on all these topics are very good and authoritative. An example is the Cambrian article.

We will spend time on the rise of skeleton-bearing invertebrates in the Cambrian. I hope you enjoy the Burgess Shale (this is the Smithsonian’s main page on it), found in the Middle Cambrian. Here is the Smithsonian’s Burgess Shale reconstructed images page. (I was fortunate to visit the Burgess Shale quarries in British Columbia.) This virtual submarine website from the Royal Ontario Museum has great animated images of the Burgess Shale fauna. A new site of Burgess Shale-type fossils in Kootenay National Park in Canada was announced last year. It may soon rival the original for number and diversity of soft-bodied fossils.

You may enjoy this blog post from the superlative science writer Carl Zimmer on the Cambrian animals. (The illustrations by Quade Paul are stunning.) Zimmer also has a New York Times article on new ideas about “Evolution’s Big Bang” in the Cambrian.

Here’s a nerdy but fun music video on the Cambrian Explosion, complete with your favorite Burgess Shale creatures. (It also includes a photo I took of the Burgess Shale in the field.)

Here are the Monday class notes for those of you who could not attend class. It is always useful to also look at a classmate’s notes for any items I may have added during class.

Your first lecture examination is on Friday, September 22. For preparation, I’m giving you a copy of the Spring 2017 first HOL test with student answers as a pdf. I highly recommend reading it through. (See if you can find the errors in the time scale that sharp-eyed Paige discovered!) The student answers are not necessarily the best, but they were good enough to receive full credit. Also note that there are always topics we covered in the past that we may not have done this semester, and vice versa. You will be tested over only what we have completed in lecture through Wednesday, September 20. Test seating: Students with last names starting with A through H in Room 205 (our regular room); I-Z in Room 216 (across the lobby). Test doors open at 7:50 a.m.; all tests due at 8:50 a.m. Review session on Wednesday, September 20, 3:30 – 4:30 p.m. in Room 205.

Anomalocaridid “arm” from the Burgess Shale, Walcott Quarry, British Columbia, Canada.

Geology in the News –

The remarkable Cassini spacecraft will have ended its existence with a planned crash into Saturn by the time you read this. What a spectacular project … and dramatic conclusion.

Portuguese Man-of-Wars in the news! Nothing exceptional — I just like these complex and dangerous hydrozoan colonies.

Here’s a good article about the hunt for soft tissue preserved in Cretaceous dinosaur bones. It is a complex story, and the initial findings have not been replicated in other labs. We may see developments here before the end of the year.

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The First Record: The Oldest Fossils (September 11-15)

Hard to believe we’re already in the fourth week. We will begin with continued discussions of origins, especially hypotheses about the origin of life. Please be sure to look at the links listed for last week on this topic. We will also examine the earliest fossil record, which goes back at least 3.7 billion years. Rhode Island College has a nice page on the six kingdoms of life, which makes a good start. Queen’s University in Ontario also has a good early life online museum website. For an updated summary (and way more than we can cover) the Wikipedia page on the evolutionary history of life is very good. Our whole course in one page! Just read the first parts relevant to this topic for now.

Your first lecture examination is on Friday, September 22. For preparation, I’m giving you a copy of the Spring 2017 first HOL test with student answers as a pdf. I highly recommend reading it through. (See if you can find the errors in the time scale that sharp-eyed Paige discovered!) The student answers are not necessarily the best, but they were good enough to receive full credit. Also note that there are always topics we covered in the past that we may not have done this semester, and vice versa. You will be tested over only what we have completed in lecture through Wednesday, September 20. Test seating: Students with last names starting with A through H in Room 205 (our regular room); I-Z in Room 216 (across the lobby). Test doors open at 7:50 a.m.; all tests due at 8:50 a.m. Review session on Wednesday, September 20, 3:30 – 4:30 p.m. in Room 205.

Trace fossils from the Gog Formation (Middle Cambrian), Lake Louise, Alberta, Canada.

Geology in the News –

Interesting article about how some scientists (to use the term broadly) are exploiting the centuries-old system of taxonomy. Essentially they are spamming the system with poorly-supported new names.

In case you’re running out of apocalyptic visions of the future: Box jellyfish are destroying the oceans ecosystems. It starts with us, of course, warming and acidifying the water, and then these cnidarians take over wiping out basic nutrient stocks.

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The Very Beginning: Origin of the Universe, the Early Earth & Life (September 4-8)

We’ll start the week finishing the biological basis of evolution, and then work into physical origins. Please review the links from last week, especially on DNA.

Here’s a cool YouTube video of the “known universe” produced by the American Museum of Natural History. This puts us in our place (cosmically!) and demonstrates the awesome dimensions of this week’s topic. I also enjoy this digital atlas of the Universe from the Hayden Planetarium. It is a significant download, but very nice. Here is a great interactive website on the Scale of the Universe. These sites give us perspective.

NASA has an excellent website on cosmology. For those of you looking for a simple red shift explanation, click away on this colorless but useful PBS webpage. It even has exercises you can try. There is a nice Big Bang animation on this French website; I may use it in class (despite the French).

This star formation site is easy to follow and understand (more or less). The JPL-NASA Solar System site has the latest news and fantastic images. The NASA Mars Mission webpages are, of course, incredible. This webpage from NOVA has superb animations of the “Big Whack” hypothesis for the origin of the Moon. This Moon-formation video on YouTube is also excellent, although the music could be improved.

Here is the homepage of NASA’s “Stardust” project, which brought to Earth the “dust” of a comet. Now you know the importance of this study to our ideas about the origin of the solar system because comets are samples of the original solar nebula.

Now for the complex and contentious ideas about the origin of life. The elaborate and elegant Exploring Life’s Origins website from the Museum of Science in Boston is the best on the topic. Here’s a good animated Miller-Urey experiment webpage I may use in class.

If you are interested in being on the e-mailing list for the Department of Geology, please send me a note (mwilson). You will receive departmental announcements about upcoming lectures, picnics, field trips, and internship opportunities.

Bivalves and brachiopods in the Logan Formation (Lower Carboniferous) of Wooster, Ohio.

Ancient marine bivalves and brachiopods in the Logan Formation (Lower Carboniferous) of Wooster, Ohio.

Geology in the News –

The largest specimen of Ichthyosaurus has been found in a German museum. It is three meters from snout to tip of tail. It is a pregnant female and a cool specimen. No paleontologist calls them “sea dragons” by the way.

A new Devonian fish found in northern China is challenging the current model for the origin of amphibians (so essentially us as well). I don’t yet fully understand how it fits in, so I’m reserving judgement until I know more.

Good review of a new book on extinctions: The Ends of the Earth. Sounds like it is well-written, up-to-date, and topical seeing how climate change is the root of most of our catastrophes.

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Mechanisms of Organic Change: Evolution (August 28 – September 1)

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 –

A nice little baby bird was found encased in Cretaceous amber in Burma. The detail of preservation is amazing, even including indications of original colors.

Dodos aren’t quite fossils, since they lived into historical times, but they are extinct and can only be studied indirectly though their bones and remains of eggs and nests. New ideas are emerging from investigations of these funny birds.

Warmer conditions are encouraging algae to grow on the surfaces of Greenland’s ice sheets. This darkens the ice, which causes it to absorb more radiation from sunlight, and thus melts even more ice. More evidence, if you need it, of global climate change.

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Antiquity of the Earth and Life (August 23 & 25)

Geologic time is a fascinating topic. It is so unimaginably long it has been called “deep time”. Please learn the Geologic Time Scale as soon as possible because it is the chronological language of this course. Because you certainly don’t want to memorize all those terms, I’ve posted a pdf version of our required-time-scale. You will see that I recognize the Ediacaran before the Cambrian, and the Paleogene and Neogene instead of the old Tertiary. You need to know only the eras, periods, and Cenozoic epochs. William Smith was an Englishman responsible in many ways for the principles behind geologic time. James Hutton was a Scot who first effectively described and applied the concept of “uniformitarianism” in geology, which requires vast amounts of time.

Geologists distinguish between relative and absolute time, with the first being the ordering of events, and the second using measurements of time. We will most often use relative time (such as the “Cretaceous Period”) in this course, but also occasionally cite absolute time (“65 million years ago”).

The concepts of radioactive decay and its use in the dating of Earth materials take some time to master. Wikipedia has an excellent explanatory website on radiometric dating. (I’m a Wikipedia fan and editor, by the way.) On this site called “popcorn” you will see an Applet display of decay demonstrating its spontaneity and constant rate. (It requires a plug-in and loads slowly but is worth it.) A more detailed explanation of how half-lives are really calculated is shown here. See what I have spared you?

As a preview of what’s coming, I give you the evolution of Homer Simpson!

You may not be surprised to learn that the scientific framework of this course is considered a lie or delusion by just over a third of Americans (which is, in fact, a new low point). “Young Earth Creationists” believe that the Earth and the Universe are a few thousand years old, and that evolution did not occur. This is radically different from the cosmological and evolutionary models supported by scientists. Creationist arguments sometimes appear scientific, but you will quickly see that they are based on misconceptions, misrepresentations, mysteries, and zealotry. For example, take a look at this page citing “evidence for a young Earth” from Answers in Genesis. These are the people who produced the multimillion-dollar Creation Museum in Kentucky (“Prepare to Believe”). Check out this visit I had with First-Year Seminar students. Don’t miss the comments by Answers in Genesis officers). These are the same people who spent millions building a full-scale version of the Ark. We will not be covering creationist arguments directly in this course (we have real science to do), but I will always answer any questions you have about them. I am an evolutionary paleontologist and geologist, but please be assured that you will not be judged or graded on your personal beliefs. What you believe is always your business; what you understand about evolution and the history of life is mine.

The new Time Scavengers blog is an excellent resource for geology students, especially those interested in paleontology. University of Tennessee graduate students Jen Bauer and Adriane Lam have put together a fantastic collection of articles, teaching aids, and links just for students like you!

Finally, have a look at this website: From the Big Bang to the World Wide Web. You will have fun exploring this site. Great theme song.

A trilobite from the Middle Cambrian of Utah.

Geology in the News —

If you want some early preparation for the first part of this course, try the wonderful Crash Course in Astronomy, starting with this episode about Big Bang Cosmology. Note that it starts with Darwin!

A top-ten list of the best fossil finds of 2016. Sadly, my work did not make the cut!

There are wildfires in Greenland this month. That alone says much about climate change. Be very afraid.

The new record holder for the largest dinosaur is Patagotitan mayorum from the Cretaceous of Argentina. This magnificent creature probably weighed over 70 tons and had a length of more than 120 feet.

 

 

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