Fluent Essays

In this assignment, students will analyze the current literature regarding the role of biochemistry in the creation of life on earth and explore the views of various scientists, experts on creation, theologians, and their own beliefs on how the earth was created while comparing them from the perspective of the Christian worldview. In the book, A World from Dust: How the Periodic Table Shaped Life, biochemist Ben McFarland states, Life is carried by a river made of chemistry that is pulled along, not by gravity, but by the predictable rules of chemical stability. After reading Chapter 1: Arsenic Life, explain in at least 250 words why McFarland believes that phosphorus is needed to make nucleic acids and why arsenic could not be a substitute for phosphorus in nucleic acids. In Chapter 9: Cracked Open and Knit Together by Oxygen, McFarland details his thoughts on why there was an explosion in the number of fossil species found during the Cambrian period. In at least 250 words, explain what changes may have led to the explosion of species in the Cambrian period. Include your opinion as to whether these changes may have led to a dramatic increase in life during this time. The Cambrian period in time is believed to have begun approximately 542 million years ago based on the abundance of the carbon-13 isotope. This period is characterized by a dramatic explosion in the number of different body plans that were found in the fossil record. The article The Fossil Record of the Cambrian Explosion: Resolving the Tree of Life, by Miller, discusses some of the controversies surrounding the Cambrian period. Read this article, and in at least 250 words, compare your viewpoints and beliefs on the creation of the earth with the viewpoints expressed by both Miller and McFarland about the Cambrian explosion events. Use supporting evidence from at least two other scientists, experts on creation, and/or theologians as you discuss why you agree or disagree with the viewpoints of the authors and compare these various viewpoints with biblical teachings from the perspective of the Christian worldview. Attachments are attached for reading.  Prepare this assignment according to the guidelines found in the APA Style Guide, located in the Student Success Center. An abstract is not required.  This assignment uses a rubric. Review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.1 1 Arsenic Life? a puzzling biochemical press conference // the natural laboratory at Mono Lake // a global scientific test // phosphorus builds, arsenic kills // how to mop up arsenic // magnesium’s fitting relationship // a less wonderful life is more predictable GE OL OGY SH A PE S CH E M IST RY AT MONO L A K E In December 2, 2010, at 11:16 a.m., I received the first of three emails from students in my biochemistry class, all asking if I  had heard the news. A  press conference at 11 a.m. had announced that scientists had discovered a bacterium that uses arsenic instead of phosphorus in its DNA. Soon there was a hashtag for this:  #arseniclife. We were excited and a little puzzled. I had just lectured about how phosphorus was uniquely useful to DNA. I shrugged and mumbled something about how textbooks can be rewritten. Today, the dust has settled— and the textbook reads the same as ever. DNA is made of phosphorus, never arsenic. That December press conference was followed by two full years of multiple experiments in labs around the world. It confirmed what the textbook said all along, yet the story was well worth it. The “arsenic life” story was never just about microbiology. It’s about science itself, how we know things, and the nature of natural history. Everyone should know this story. It will temper expectations when the next press- conference- induced hashtag makes its way halfway around the world while science is still lacing up its boots. More than that, it shows something deep about what kind of world we live in, something underreported because it is so intricate and comes from so many different places. There is a hidden order that makes some sense of biology and even sociology, and that hidden order is chemistry. All life, from a lakewater bacterium to the neurons firing in your brain as you read this, is hemmed in. It is free to randomly adapt to its surroundings with nearly infi- nite creativity, but its overall path is as constrained as if it were walking on the deck of a ship crossing the ocean. The ultimate movement, on the scale of billions of years, is shaped by chemical rules. One of these rules is that phosphorus makes good DNA, while arsenic does not. To reach this conclusion, we have to start where the arsenic life story started. The home of the purported arsenic- using bacteria that caused all this trouble is in a remote spot of California called Mono Lake. McFarland, Ben. A World from Dust : How the Periodic Table Shaped Life, Oxford University Press, Incorporated, 2016. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/gcu/detail.action?docID=4413924. Created from gcu on 2021-03-26 08:27:58. C op yr ig ht © 2 01 6. O xf or d U ni ve rs ity P re ss , I nc or po ra te d. A ll rig ht s re se rv ed . 2 A Wor l d f rom   Du s t Mono Lake sits at the bottom of a basin just east of Yosemite, at the foot of Mount Conness. It is Article The Fossil Record of the Cambrian Explosion: Resolving the Tree of Life^ ß. Miller The Cambrian explosion has been the focus of extensive scientific study, discussion, and debate for decades. It has also received considerable attention by evolution critics as posing challenges to evolution. In the last number of years, fossil discoveries from around the world, and particularly in China, have enabled the reconstruction of many of the deep branches within the invertebrate animal tree of life. Fossils representing sister groups and stem groups for living phyla have been recognized within the latest Precambrian (Neoproterozoic) and Cambrian. Important transitional steps between living phyla and their common ancestors are preserved. These include the rise of mollusks from their common ancestor with the annelids, the evolution of arthropods from lobopods and priapulid worms, the likely evolution of brachiopods from tommotiids, and the rise of chordates and echinoderms from early deuterostomes. With continued new discoveries, the early evolutionary record of the animal phyla is becoming ever better resolved. The tree of life as a model for the diversification of life over time remains robust, and strongly supported by the Neoproterozoic and Cambrian fossil record. T he most fundamental claim of bio- logical evolution is that all living organisms represent the outer tips of a diversifying, upward-branching tree of life. The Tree of Life is an extreme- ly powerful metaphor that captures the essence of evolution. Like the branches of a tree, as we trace individual lines of descent (lineages) back into the past (down the tree), they converge with other lineages toward their common ancestors. Similarly, these ancient lineages them- selves converge with others back in time. Thus, all organisms, both living and ex- tinct, are ultimately cormected by an unbroken chain of descent with modifica- tion to a common ancestral trunk among single-celled organisms in the distant past. This tree metaphor applies as much to the emergence of the first representatives of the major groups of living invertebrates (such as snails, crabs, or sea urchins) as it does to the first appearance and diversi- fication of dinosaurs, birds, or mammals. This early diversification of invertebrates apparently occurred around the time of the Precambrian/Cambrian boundary over a time interval of a few tens of millions of years. This period of rapid evolutionary diversification has been called the Cam- brian Explosion. The Cambrian explosion has been the focus of extensive scientific study, dis- cussion, and debate for decades, and is increasingly receiving attention in the popular media. It has also received con- siderable recent attention by evolution Keith B. Miller Keith Miller is a fellow of the ASA and current member of the Executive Council. He received his PhD in geology from the University of Rochester and has been teaching at Kansas State University si