New+Findings--Afterward

Place your questions and answers for New Findings (The Afterward) here.

A: The arctic is such a great place to find and explore for fossils because of how barren the arctic is. Although many people are unaware of this, the arctic is considered to be a desert. Also, having a lack of people, trees, and building around the arctic is another fortunate thing about this location. You must tread carefully because of how easy it is to miss a major discovery of a fossil. The line between seeing a fossil is so fine that just having the wrong lighting can cause someone to miss the biggest discovery of their life. (J. Speelman)
 * Q: Why is the Arctic a good place to find rare fossils such as the //Tiktaalik// and why must we "tread carefully" when exploring them? (I. Perler)**

A: The operculum is a bone that covers the gills in most bony fish. In aquatic animals, the operculum moves water across the gills in a push-pull action. The water enters the mouth and throat and when the water goes to leave the throat the operculum has to open in order for the water to leave. The loss of the operculum allowed for a neck to develop. A neck is necessary for land animals to support itself on land. A neck is necessary when doing pushups (per the book), moving the head up and down, and when moving the head left and right to see surroundings. (T Gebhart)
 * What is the operculum, and what is the importance of it (or the loss of it) in //Tiktaalik?// How does a neck benefit us as humans? Name a few activities when a neck is necessary. (J. terHorst)**
 * Q: What role does the operculum play in organisms in which it can be found? Do you think //Tiktaalik// was the first organism in the bridge from water to land that did not have an operculum? Why or why not? (M. Blanchard)**

The Gill-flap bone in fishes is called the Operculum. It was is a mechanism that fishes use to breath via a push and pull system. //Tiktaaliki// is the "found link" between organisms with and without this bone. This allowed for not only greater head movement that is advantageous for adapting to live on land, but also allowed it to rely mostly on mouth breathing, which was a crucial step to evolving to live on land( this organism already had both true gills and lungs, and it had evolved to more efficiently use its true lungs)(C.King)
 * Q: Identify the name of the gill-flap bone in fishes, and explain what //Tiktaalik// gained from not having it. (P. Oakes)**
 * Q: How are we able to reconstruct the relationship of long dead animals and the bodies and genes of recent animals? (A. Schmidt)**

A. The hyomandibula is a large rod-shaped bone that connects the upper jaw to the braincase. this large bone morphed into a small bone in the inner ear of a human known as the stapes. this bones aids in hearing and is therefore incredibly advantageous. (E.Olson)
 * Q: What new discoveries of** **//Tiktaalik's// head and neck confirm that it is one of the first steps toward amphibians, and eventually mammals? Why are these advantageous? (C.Nikolai)**

Shubin does not believe that //Tiktaalik// is the missing link, he just believes it is one in a series of found links. I agree with Shubin. There is still a huge amount of time between love finned fish and land living animals, and the //Tiktaalik// just shows us what one of the animals looked like partly through the shift from water to land. There are many other organisms that were part of that shift, and we just haven't discovered them yet. Basically, it is not THE missing link, but it was one of many missing links that we have now found, and now we just need to look for others. (A. Nolan)
 * Q: Is //Tiktraalik// the missing link? Explain what Shubin thinks. Do you agree with him? (L. Bentley)**

Back when //Tiktaalik// were alive, the Arctic climate was very different from what it was today. It was a tropical area with warm water and fish, perfect for //Tiktaalik//, being a fish/primitive land animal. With a warm environment, there would have also been other organisms alive that //Tiktaalik// could use as a food source. Since then, the climate has changed and glaciers have shifted so that the Arctic has become the cold environment we all know. (C. Sanders)
 * Q: How did the //Tiktaalik// manage to survive in the Arctic climate? Propose another suggestion why the //Tiktaalik// was found where it was? (H. Schwarz)**

A: The underside of the skull of //Tiktaalik// shows how intermediate //Tiktaalik// was because of its size. This bone, known as the stapes, started out in the gill arch series. Overtime, it gradually decreased from a large bone in the skull in fish to a tiny bone in the ear. //Tiktaalik// comes in as having this bone smaller than one of the earliest fish but larger than one of the earliest amphibians. This intermediate structure could have been advantageous because it allowed these organisms to have some form of an auditory system. This auditory system would have aided in hunting, feeding, and finding a mate. (O. Heltman)
 * Q: What was intermediate about the underside of //Tikaalik?// What was advantageous about this intermediate structure? (C. Hurst)**

A: During the late(ish) Denovian period, the approximate time period in which Tiktaalik lived, North America was located approximately around the equatorial line. This means that the climate during this period would have been much warmer, likely consisting of shallow streams, rivers and forests. This is in stark contrast to the modern day location of it's fossil, which is located within the arctic circle. The vastly different climate makes sense, as unless specially adapted, most fish cannot live within such cold environments. In addition, it would be unlikely for any environment of that climate to have the necessary requirements to facilitate the evolution of tetrapods. These changes in environment support the idea of continental drift, or the idea that the tectonic plates, and the landmasses they carry, slowly move or drift relative to each other. Otherwise, it would be difficult to explain the vastly different climates of fossils (M. Purdon).
 * Q: Shubin mentions that the climate of the Arctic Tundra was not always as cold and desolate as it is now. What type of climate did the Arctic used to be and why does this make sense, knowing that the //Tiktaalik// was found here? What do these changes in climate suggest about the geological patterns of the Earth? (R. Heis)**

A: Following the publication of Your Inner Fish, people often questioned whether Tiktaalik was the "missing link" in the study of evolution. However, Shubin addresses how it is merely part of a series of found links that all work together to connect fish and underwater organisms to land organisms. There are so many other artifacts to discover and fossils that will provide more informations meaning Tiktaalik is not the one thing that will link the two together, but among many organisms that will help do this. Personally, I am just curious to see how our knowledge and study of evolution will change during my lifetime. I am curious to see if any big discoveries will be made or any specific processes will come about to answer many of the unsolved questions that remain. (M. McKinney)
 * Q: What development regarding Tiktaalik was made following the initial publication of Your Inner Fish? How has this augmented our understanding of evolution? Are there any questions regarding evolution that are you personally anxious to learn more about? (N. Sarkar) **

A: It is important as it essentially is the link that connects aquatic organisms to those which live on land, inheriting traits from fish, but also having traits that are specialized for life on land which have been inherited by all currently living land animals. This helps uncover information about human evolution as it is the best candidate for whom we got certain traits from, which are absent from fish, but are had by every other animal living on land (such as arm, hand, and digit anatomy/bone structure). (N. Braun)
 * Q: What makes //Tiktaalik// one of the most important fossil findings, especially when it comes to its use in uncovering information about human evolution? (A. Gatje) **


 * Q: In what way does Tiktaalik outshine all other "candidates" for most likely being the organism to be the bridge between land and aquatic animals? Based on what you know about the Tiktaalik and using applictions from past biology could you infer if this organism would spend more time out of the water and on land? Or in water more often than on land? (T. McDaniel) **

The lack of movement of the joint in the middle of the braincase in Tiktaalik shows the evolution from lobe-finned fish and early amphibians, because lobe finned fish contained this type of joint in exactly the same place as where it is in the Tiktaalik. Early amphibians did not have this; instead, bones that are firmly sutured together. The presence of this (restricted moving) joint in the Tiktaalik suggest that the Tiktaalik is a species that existed as fish slowly evolved into amphibians, and the transition from water to land. (L. Bercz)
 * Q: ** **How does the lack of movement in the Tiktaalik's joint in the middle of the braincase show a connection between fish and amphibians? (T. Russell) **