Is This Ancient, Bag-like Sea Creature Our Earliest Ancestor

Alyssa Lee

Mr. Ippolito

Biology 10H

20 April 2017

Strickland, Ashley. "Is This Ancient, Bag-like Sea Creature Our Earliest Ancestor?" CNN. Cable News Network, 03 Feb. 2017. Web. 20 Apr. 2017. <http://www.cnn.com/2017/01/30/health/earliest-human-ancestor-deuterostome-saccorhytus-history-study/index.html>.

The article that I chose to read is called “Is This Ancient, Bag-like Sea Creature Our Earliest Ancestor?” by Ashley Strickland. It discusses the discovery of the Saccorhytus, a “tiny, bag-like creature” only one millimeter long that thrived approximately 540 million years ago. The Saccorhytus is an organism that has been categorized in the broad and wide-ranging category of deuterostomes, a group of smaller organisms from which many of the larger, more advanced organisms of today can trace their origins back to. Some organisms that fall into this category include starfish and sea urchins. When the scientists at the University of Cambridge in England and Northwest University in China first decided to investigate the origins of human existence and evolution, it is therefore no surprise that they turned their search to the deuterostomes, being responsible for many of the current lifeforms on Earth today. Upon deep excavation near shallow waters, the researchers found exactly what they were looking for: the Saccorhytus, appearing as “tiny black specks” in the three tons of excavated limestone, the researchers decided to examine their samples of Saccorhytus under the microscope. They found that the Saccorhytus “had an elliptical body with bilateral symmetry, evidence of musculature and a thin yet flexible skin.” However, the most defining feature of the Saccorhytus was its expandable mouth, incredibly large when compared to the span of its body. The most important discovery made was that the Saccorhytus had suggested the idea of a “molecular clock”- an idea that suggests that “the origination of the main groups of animals significantly predate what the fossil record would indicate”. In other words, the actual time of origination differs from what is suggested from the fossil evidence, pointing to the fact that the deuterostome from which human life may have evolved from to be the Saccorhytus. Due to the fact that the earliest small animals such as the Saccorhytus were unlikely to survive and be found fossilized, they not only shed light on the possibility of a strange human ancestor, but also offered rich, unprecedented insight into a “long and cryptic history”.

The existence of the Saccorhytus sheds an incredible amount of light onto the mystery surrounding our earliest human ancestors, even beyond our simian counterparts and hominids. Due to the fact that many of our ancient relatives are shrouded in the unknown, this discovery offers a hint of not only one of the origins of intelligent human life, but also on the time period in which it lived, over half a billion years ago. With the Saccorhytus, scientists and researchers can observe its anatomical structure and use their observations to form conclusions concerning the status of life on Earth at the time. This is especially essential to our studies today in that we can catch a glimpse of Earth in an era where we did not yet exist, and thereby see the changes that have occurred to animal lifeforms that have adapted over time to environmental pressure. Its discovery also reveals to us the amount of change that can happen over the course of hundreds of millions of years- if the Saccorhytus is indeed a distant relative of humanity, it is certainly awe-inspiring as to how such a queer, primitive looking creature could have any possible relevance to what homo sapiens look like today. This demonstrates the astounding fact that a significant amount of change that can occur to an organism during the course of evolution that has truly shaped the organisms alive on Earth today.

This article was very well-written in that it stated the facts simply and colloquially, making it not too difficult a read. The author does an especially excellent job describing the significance and the background on the Saccorhytus, as well as the tedious process used to find them. In addition, the topic itself was very interesting to me in that I was able to discover and learn more about our human ancestors, a subject that I find intriguing. However, I believe that there were some weaknesses to this article. The most prominent weakness that I could find was the author’s explanation of how they determined the Saccorhytus to be a human ancestor. Although the author explains that many deuterostomes have been discovered to be the ancestors of organisms today, I did not fully understand the link between the Saccorhytus and humans; as far as I understood, the only aspect that connected the two was the fact that the Saccorhytus was a deuterostome in the same tree of life as humanity, but even this is not explained. Therefore, I believe that further elaboration was needed in order to fully specify the reasoning behind this essential connection.