Advancements Of Modern Technology : Ct And Mri

We use fossils to compare and contrast how and organism has evolved over a long period of time and how it has adapted to new changes.

fossil bones and teeth have been found, the way of life of these creatures, and

Fossils let us know how species have changed crosswise over long stretches of the Earth's history. For example, in 1998, researchers discovered a fossil demonstrating a creature at the move from ocean animal to land animal. This tetrapod had a hand-like balance, affirming a forecast of transformative science. In spite of the fact that the fossil record does exclude each plant and creature that ever lived, it gives considerable proof to the normal plunge of life by means of advancement. The fossil record is a noteworthy present for the investigation of nature. That is the reason the greater part of the proof for advancement originates from the fossil record. Fossils demonstrate how much, or how little, living beings have changed after some time. One of the issues with the fossil record is that it contains holes. Not all life forms fossilize well, and there will be numerous fossils that have been wrecked by the developments of the Earth, or just not yet been

Ichnology, the study of trace fossils, is the principal study in following and learning about trace fossils and how these fossil types indicate habitats. Ichnologists can use trace fossils, such as a track way and walking patterns of dinosaurs, to determine the specific area a dinosaur walked on, which can express a dinosaur species preferred habitat. By examining sedimentary layers and structures, ichnologists can use fossilized tracks to determine what specific habitat a species of dinosaur lived in. The use of uniformitarianism can be used to conclude what specific environment a dinosaur lived in through sedimentary structures. Ichnology uses tracks to determine what habitat a dinosaur inhabited by the pattern that a dinosaur walked in. With nests, Ichnologists can use information to determine what habitat a species of dinosaur lived in to ensure a safe environment for the eggs. Ichnologists can determine if a species of dinosaur stayed in a specific environment by studying the walking patterns of track ways and the indications of dinosaur nests. Ichnologists use track ways and nests to determine preferred habitats due to a plethora of trace fossils that a species of dinosaur can make in its

From both the title of the chapter and the introduction by Dr. Shubin, this chapter begins with a focus on teeth. Because the function of teeth is to break down food before it enters the esophagus, the different shapes of teeth can represent many different things about the organism it belongs to including what type of eater it was (carnivore, herbivore, or omnivore). Teeth are the hardest tissue (not bone) in the human body and therefore fossilize well. As Dr. Shubin stated in chapter one, there must be many points that permit a fossil to make any kind of scientific conclusion. Obviously, the state of their presence is important, so the fact that teeth preserve well allows for them to be great specimens for analysis. Dr. Shubin and his team analyzed fossilized teeth in areas as different as Nova Scotia and the Arizona desert. Studying different fossils in these diverse regions allowed the team to see that mammalian and reptilian teeth are very different. For example, mammalian teeth differ from organism to organism to fit with the organisms need (Cheetahs that eat only meat will have different teeth than deer who are herbivores) and are replaced only once in the lifetime of the organism while reptilian teeth are usually sharp and are constantly replaced if damaged. These differences allowed scientists to characterize fossils as either a reptile or a mammal. Similar to Tiktaalik discussed in chapter one, the discovery of fossils that were part reptile and part mammal allowed the researchers to see that mammals evolved from reptiles, and further supported the theory of evolution. Further studies yielded even more

The reading states that the researchers deliberately broke open the Tyrannosaurus rex's leg bone and found remains of blood vessels, red blod cells, and collagen matrix and provides three reasons of support. However, the professor states that it's skeptical that T.rex has all of structures and refutes each of the authors' reasons.

Youg, Ed (2009, April 30) Dinosaur proteins, cells and blood vessels recovered from Brachylophosaurus. Retrieved from http://news.nationalgeographic.com/

Fossils give us evidence about past life, and they give valuable information about many organisms and their evolution history. There are trace fossils and body fossils. Body fossils are body parts of organisms that were kept preserved, and trace fossils are only marks or impressions left by organisms. Body fossils provide more information because not only they tell us about their activity, but also about their anatomy and body function.

The curious is that those remains were found in a beach that is visited by thousand of tourists every summer. The scientists think the place was a swamp or a flooded area of shallow depth about 100.000 years ago. Also, they found footprints of a running bird called Rheidae about 4.92 ft high, footprints of Hidrochoeridae, a sort of big mouse about 4.26 ft long; and finally, three toes from a paw that scientists suppose they could be compatible with the ones of the Macraucheniidae, that were similar the current camels. The article doesn't say what prehistoric animals the bones belong to.

Animal fossils usually provide little information to study. Recently, there is a discovery that the T rex’s leg bone insides reveal some materials that seem to be remain of blood vessels, red blood cells and collage matrix. The lecture and reading passage discuss if the materials are blood vessels, red blood cells and collagen marix. The lecture puts forward three points and effectively contradicts the opinions of the reading passage.

Trace fossils are known as preserved evidence that have been left behind from an animals action.Trace fossils capture the movement of ancient animals. For example, when the animals leave their footprints behind, it creates an impression in the soft mud, silt and sand. The soil then hardens into rock therefore preserving a trace of the animal.

The joint could “lock”, suggesting the animal could walk upright. This was an important discovery showing an ancient bipedal creature. If the bones’ age was consistent with Johanson’s hypothesized “missing link”, it would serve as supporting evidence to Johanson’s theory.

A new prehistoric relative to modern day crocodiles, Ieldraan melkshamensis, has recently been identified. The fossilized remains of this 10 foot long ancient reptile has been in Londons Natural History Museum’s archive for almost 150 years and was classified as a new species due to the many unique features of it cranial anatomy. The primary characteristics that distinguishes this fossil for all the other known prehistoric species are the features of its skull, lower jaw, and most importantly its teeth. These features are thought to have allowed this predator to feed on large prey, such as squid, making it one of the top predators in the oceans of jurassic Britain. It was originally thought that this family of prehistoric crocodiles were present during the late jurassic period between 152 and 157 million years ago, but this fossil has been dated back 163 million years, making it millions of years older than this family was previously thought to be. This discovery is incredibly important for our understanding of the evolution of these ancient animals and how they impacted their marine ecosystem.

The passage and the lecture offer two opposing views on the source that made the pattern of fine lines in the fossil of a dinosaur. While the passage lists some reasons to refutes that the lines are evidence for the idea that the dinosaur had feathers, The professor counters those points and support that idea.

Magnetic resonance imaging (MRI) is a powerful medical imaging modality which gives high spatial resolution images without radiation risk. MRI acquires signals from hydrogen protons of subject. Under external static magnetic field (B0), the spins of hydrogen protons precess with a Larmor frequency, while they align parallel to the direction of B0. The spins align antiparallel to the direction of B0 when additional radio-frequency (RF) pulse with the Larmer requency is ap-plied. After RF pulse is removed, the protons relax through the recovery of mag-netization parallel to the direction of B0 (longitudinal or T1 relaxation) and the de-cay of transverse magnetization caused by the de-phasing of the spins (transverse or T2 relaxation) [4]. The tissue specific parameters of proton density, T1 relaxa-tion, and T2 relaxation gives contrast to the MR images. Due to this principle, MRI gives great spatial resolution for soft tissues which contain more water molecules. The major drawback of this technique is its relatively poor sensitivity, due to the weak signal from protons [5]. T1 and T2 contrast agents which shorten relaxation times have been developed to overcome its poor sensitivity and improve specifici-ty. Gd(III) chelates are the most widely used T1 contrast agents in clinical applica-tions [6]. Although Gd(III) chelates have good paramagnetic property and short-en T1 relaxation, the toxicity of gadolinium ions and their rapid renal clearance limit their use [7]. To reduce