Ever since the movie “Jurassic Park” debuted, the world has wanted to know if dinosaurs can be genetically mutated from birds of today. Unfortunately, these experiments are not for creating dinosaurs, but to focus on a single trait to test a specific hypothesis on the evolution of development (Universidad De Chile 2016). Chickens have a reduced, splinter-like fibula that no longer connects to the ankle and is shorter than the tibia. This is the iconic drumstick of the chicken that we all have enjoyed at one point in time. While the chicken is developing in the embryo, it has been observed that birds develop a tubular fibula that is also and observed trait in dinosaurs. The lengthwise growth of the epiphysis occurs if the bone retains a cartilaginous …show more content…
As it continues to develop, the bone becomes spinter-like and the tibia continues to grow past it. To understand this transformation, Joao Botelho conducted two experiments: One focused on the fibular reduction in birds while the other focused on the development and evolution of the perching digit of birds.
In terms of fibular reduction, Botelho and his team studied the timing of reduction and ossification in several species of birds (Chicken, Mallard duck, and Chilean tinamou) (Botelho, 2016). They specifically looked at the molecular development of cartilage maturation and growth plate formation in the tibia and fibula. The key protein being Indian hedgehog (IHH) that was originally found in hedgehogs codes is produced by prehypertrophic chondrocytes. Its main role is endochondral ossification in most animals. It stimulates immature chondrocytes transition to hypertrophic chondrocytes that favor that replacement of cartilage to bone in the diaphysis. IHH has a negative feedback loop with Parathyroid hormone-related protein (PTHrP) that maintains the coordinated differentiation of immature chondrocytes in the growth plate (Botelho, 2016). If PTHrP is genetically inactivated,
Ceratopsians and Pachycephalosaurs are closely related in their characteristics. Ceratopsians processed a saddle-shaped boney frill that extended from the skull to the neck and typically had horns over the nose and eyes. The most popular was the triceratops, which could reach over 26 feet and weigh in excess of twelve metric tons. Their frills served as two major functions. It protected the vulnerable neck from being harmed. The second major function that the frill provided was due to the fact that the frill contained a network of blood vessels on its underside, which were used as a means to get rid of excess heat. The Pachycephalosaurs were considered to be bipedal. They were also found to have thick skulls, flattened bodies, and tail that were covered in an array of body rods. Pachycephalosaurs were thought to have been more than fifteen feet long and processed a skull that was surrounded by a rounded dome of solid bone. It was thought that they used their heads in combat or mating contests, but that was disproved fairly recently, which I will discuss later in the paper. Both Ceratopsians and Pachycephalosaurs were “bird-hipped” and both of these suborders contained a backwards pubic bone. Both were Marginocephilia, or “fringed heads”, which is one of three clads under the Orinthiscia order. They were also herbivore dinosaurs that inherited their fringe at the back of the skull from earlier ancestors.(2) Their classi...
There is common plan for all limbs: one bone, followed by two bones, then a bunch of little bones, and finally digits. This array of bones is seen in many species including, but not restricted to bats, whales, and lizards. But how do these limbs develop and why do they all look similar? Shubin explains it by conveying that there are certain genetic switches that help assemble who we are. When scientists went looking for this genetic switch in limbs, they found a couple tissue areas in the limbs that allow this body plan to occur. “A strip of tissue at the extreme end of the limb bud is essential for all limb development…This patch of tissue was named the zone of polarizing activity (ZPA).” ZPA allows humans to have opposable thumbs and pinkies. In other organisms, it differentiates the “thumb” side from the “pinky” side. Scientists then wanted to discover the molecule that allowed this changen in the ZPA, the answer is Sonic hedgehog. Shubin points out that every limbed animal h...
developed by means of longer legs and arched heels - two traits seen in H. naledi fossils.
Paul, Gregory S. (2002). "Looking for the True Bird Ancestor". Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Baltimore: Johns Hopkins University Press. pp. 171–224. ISBN 0-8018-6763-0.
...vejoy, the team’s anatomy expert, hypothesized that the bone crushed and fossilized misshapen, causing the position of the bones to seem as if they “flared up like a chimp’s.” This initial conclusion might have been the correct one, but Lovejoy was part of Johanson’s team, and as such, his analysis was done under Johanson’s influence. Johanson concluded that this chimp-like bone was an illusion, and the reconstruction that followed resulted in a bipedal pelvis. It is unclear how certain the researchers can be that the final result was the original shape of the bone, but one thing is clear – the reconstruction was done under the influence of the initial and final conclusion. When the assembly and analysis of the bones are done by a team of researchers already pre-disposed to a specific hypothesis, it is little wonder that the evidence ends up fitting the hypothesis
I visited the Oriental Institute of Chicago Museum, which contains various artifacts, I choose a Model Hippopotamus from Egypt. The hippopotamus is dated to Egypt’s Middle Kingdom, circa 1878 BC. According to wall text at the Oriental Institute of Chicago, hippopotamuses in Egyptian culture represented the enemies of the ruler. I was attracted to the Model Hippopotamus based on its size/shape, lines, texture, and the color.
Feder and Park present a list of traits that are used by paleoanthropologists to distinguish the appearance of skeletal features and characterize these changes over time. Th...
Aggressive individuals often act in ways that will result in having personal gain, rather than focusing what impact they have on others. Aggression is pervasive. It affects the rich as well as the poor, the upper and lower classes, it defines us. This means that most sole individuals will behave in certain ways to promote their well being, instead of how they affect others. Michael Crichton uses characters in Jurassic Park to portray the negative physical, social and intellectual impact they can have on society. This is evident in everyday life because society has molded individuals into looking out for their well being with no considerations of the impact that it has on others.
Christopher Johnson McCandless was a hiker who also went by the name Alexander Supertramp and ventured into the Alaskan wilderness in April 1992 with a bit of food and equipment, hoping to live in isolation. Almost four months later, McCandless's body was found, weighing only 30kg. His story shocked many people and got the attention of magazine writer Jon Krakauer. At First he wrote a small article in the magazine Outside that sparked a lot of controversy with the readers. Since Krakauer got a lot of attention from his article, he decided to do more investigation on McCandless’s journey. Krakauer end up writing the book named Into the Wild and explains with plenty of detail McCandless’s life before his journey to the wilderness. Now a days, most teenager or young adult would never give up the life they have, because the way were so attach to electronics and our surroundings, for Chris McCandless is a different story he gave everything he had in life to go out and live a life in seclusion that caused him his death.
Michael Crichton’s classic novel Jurassic Park sparked controversy among scientists, excited science-fiction fans, and captivated paleontologists as Chrichton proposed the idea that dinosaurs could be cloned. The plot elicited criticism from scientists around the world, but support from others. Cloning a dinosaur was made possible in the fictional text: take some amber, fill in missing DNA, obtain an ostrich egg, keep the egg in a controlled environment, then a dinosaur is born. Unfortunately, each of the steps are of intricate design.
Marzluff, J., Angell, T. & Elliot, B. (2013, May. - Jun.). Birds: Brains over brawn. Audubon, 115(3), 40-41.
Modern-day genetic technology has granted mankind with the opportunity to bring back extinct species from the dead. If humans have come to possess the DNA from an extinct animal population, it is possible to create an identical clone of the animal in question, effectively “bringing it back from the dead”. Many ethical dilemmas surround the practice of de-extinction, and rightfully so. Recreating an extinct species could produce groundbreaking scientific breakthroughs, generating exciting opportunities for future genetics-based research. However, there could also be monumental consequences: the newly revived, once-extinct species might destroy the ecological equilibrium of modern Earth
When these alterations are helpful, they grow to be fixed in a population and can result in the evolution of new phyla. Evo-devo seeks to figure out how new groups happen by understanding how the method of development has evolved in different lineages. In other word, evo-devo explains the interaction between phenotype and genotype (Hall, 2007). Explanation of morphological novelty of evolutionary origins is one of the middle challenges in current evolutionary biology, and is intertwined with energetic discussion regarding how to connect developmental biology to standard perspectives from the theory of evolution (Laubichler, 2010). A large amount of theoretical and experiential effort is being devoted to novelties that have challenged biologists for more than one hundred years, for instance, the basis of fins in fish, the fin-to-limb change and the evolution of feathers.
nuclei was then inactivated and substituted with dead nuclei from the extinct frog. Some eggs started to grow and divide to early embryo stage (a tiny ball of m...
Reptiles are vertebrate, or backboned animals constituting the class Reptilia and are characterized by a combination of features, none of which alone could separate all reptiles from all other animals.The characteristics of reptiles are numerous, therefore can not be explained in great detail in this report. In no special order, the characteristics of reptiles are: cold-bloodedness; the presence of lungs; direct development, without larval forms as in amphibians; a dry skin with scales but not feathers or hair; an amniote egg; internal fertilization; a three or four-chambered heart; two aortic arches (blood vessels) carrying blood from the heart to the body, unlike mammals and birds that only have one; a metanephric kidney; twelve pairs of cranial nerves; and skeletal features such as limbs with usually five clawed fingers or toes, at least two spinal bones associated with the pelvis, a single ball-and-socket connection at the head-neck joint instead of two, as in advanced amphibians and mammals, and an incomplete or complete partition along the roof of the mouth, separating the food and air passageways so that breathing can continue while food is being chewed. These and other traditional defining characteristics of reptiles have been subjected to considerable modification in recent times. The extinct flying reptiles, called pterosaurs or pterodactyls, are now thought to have been warm-blooded and covered with hair. Also, the dinosaurs are also now considered by many authorities to have been warm-blooded. The earliest known bird, archaeopteryx, is now regarded by many to have been a small dinosaur, despite its covering of feathers The extinct ancestors of the mammals, the therapsids, or mammallike reptiles, are also believed to have been warm-blooded and haired.