Evolution And Evolution Of Evolution

Fossils grant us opportunity of understanding about species which no longer exist on Earth- that are extinct. The prehistoric remains inform us about plants and

In the following space, explain the role of fossils in developing the Geologic column. Your explanation must be between 200 and 300 words.

Paleontology or paleobiology is the study of plant, animal, and microorganism fossils found on the earth. Paleobotany focuses on algae, fungi, mosses, ferns, seed plants

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

_______1. A type of fossil that forms when sediments fill in the cavity left by a decomposed organism.

Layers of soil are laid down on dead animals or plants embalming them. The minerals replace the organic matter creating the fossil.

Fossil preservation has always been the most accurate way to determine what species lived during a specific time period. Through correlations and radiometric dating, time periods

Fossils provide a record of how organisms have evolved overtime, as they contain the remains of life trapped in sediment, ice or amber and preserved for over millions of years. Transitional fossils, which provide evidence for evolutionary change, have features that show the transition of characteristics of organisms from ancestors to descendents. An example is Archaeopteryx, which featured reptilian features, including teeth and skeleton, however, also had feathers and a wishbone sternum (used to attach muscles for flying). The evidence of the fossil shows the evolutionary transition between dinosaurs and

Fossil Record are a good way to show the evolution process. They provide scientist with snapshots of the past that, when assembled, illustrate a panorama of

1. The author chose to focus on 375 million year old rock because the transition from fins to necks and limbs occurred then. The scientists knew that any time later than this and they would find lots of animals with limbs. But if they searched earlier than this time then there are only fish without necks. When the fish were evolving they evolved necks before they evolved limbs so this was a good sign in chronology. Sedimentary rocks are the best types of rocks for fossil due to their gradual pressure and low amounts of heat. Sedimentary rock is also found in lake beds and streams, where fish and aquatic wildlife are most likely to live.

Introduction: Fossils are defined as a physical trace or evidence of life from a prior geological time period which has been preserved. Examples of fossils include burrows, indentations or bite marks, footprints or other impressions, coprolites, hard animal body parts such as bone, shells or horns or mineralized plant remains embedded in stratified rock.

The author and his colleagues chose to focus on 375 million year old rocks in their search for fossils because amphibians that look dissimilar to fish were discovered in 365 million year old rocks, while fish without amphibian characteristics were discovered in 385 million year old rocks. Thus, it is possible that the evolutionary intermediary, or the “missing link” between fish and amphibians, would be discovered in 375 million year old rocks, between the two time periods. The rocks examined were sedimentary in composition, as the gradual and relatively gentle formation of sedimentary rock under conditions of mild pressure and low heat are conducive to the fossilization of animal remains. Sedimentary rock is also often formed in rivers and seas, where animals are likely to live. This site provides a resource that describes means by which fossils are formed and how the fossil record may be interpreted, and shows some examples of fossils demonstrating evolution through geological periods: http://www.fossilmuseum.net/fossilrecord.htm. In 2004, Shubin and his colleagues were looking for fossils on Ellesmere Island, in northern Canada. This location was chosen because of its lack of human development, as well as of obstructing natural formations and life forms such as trees, which

The fossil record is evidence of evolution. Fossils are often fingerprints of evolution. They help scientists track how species evolved

: Fossils are the remains or traces of ancient organisms which have been preserved. For example, a fossil can exist as skeletal remains or even as a footprint. Such organisms are subjected to a slow rate of decaying since they have been rapidly buried under conditions that facilitate this. It is common for fossils to occur as hard-bodied organisms as these are more resistant to environmental influences. Fossils are usually found embedded in rock. The layers of rock are of different age and makeup. Hence fossils found in one layer would vary in characteristics from those found in another layer. They can be observed and analyzed through visual as well as radiometric means so that the age and morphology can be determined. These features indicate

It is a journal that discusses fossils of early life and evolution. It gives facts and information pertaining to the timelines, type and the formation of fossils.