Himanshu answered on
Jul 12 2021
July 12, 2020
Fossils – Evidence of Evolution and Its Dating
Paleontology is the study of origins of life on Earth on the basis of fossils. Fossils are the remnants of plants, animals, fungal, bacterium and single-celled life objects in rock or rock preserved organisms. Fossil remains are used by paleontologists to explain different aspects of organisms extinct and living. Individual fossils can provide details on the life and environment of an organism. For instance, the rings of a tree mean one year of life, in the same way the oyster rings on its surface tells its age. To research the oyster fossils, paleontologists will find out how long and under what circumstances the oyster lived.
Fossils are used, researched and understood in various ways throughout human history. Fossils were used for aesthetic or religious purposes in early civilizations, but where they originated, was never understand. Few ancient Greek and Roman scientists have recognized that fossils are the remnants of living beings; while some scholars have thought and related that fossil is evidence of the creatures of mythology, for e.g. dragons. Fossils were commonly seen as the creations of the Devil or of a higher force between the middle ages and in1700s.
In the 1700s, the era called as the Age of Enlightenment, the systematic study of paleontology, — the collection and the analysis of fossils began. Scientists started describing, mapping and classifying rock formations. Geologists have found that rock deposits are not caused by particular events or catastrophes, but by long sedimentary cycles. In the 19 century, paleontologists - Georges Cuvier and William Smith found that - layers in rocks can be measured and matched in different areas based on the fossils they were made of.
The works of Charles Lyell and Charles Darwin profoundly affected the manner in which humanity viewed the world's past and its species later that century. Lyell's Geology Concepts suggested that the fossils in one layer of rock are identical, while the other layers of rock have different fossils. This sequence can be used to illustrate connections between equally distinguished rock layers.
Darwin's theory on the Origin of Species in the living world has been somewhat similar. Darwin proposed a time-long evolution of new species. The hypothesis of Darwin stated that the species living in the far past were distinct and often joined up with those existing today. This theory permitted paleontologists, for insights into fossil evidence, to examine living organisms.
With the discovery of radioactivity in the end of 19 century the determination of layers of rock and fossils was revolutionized. Using the technique called radiometric dating, age of a rock layer could be evaluated by analyzing the number of atoms in the rock that have been varied since the rock formation. When the atoms varies, the radioactivity varies. Variation in radioactivity is natural and can be measured in time units. By calculating and comparing radioactive element with a new sample in an old sample, scientists will measure how long it has been. Radiometric data allow to assign the age of the layers of the rock, which can be determined by the age of the fossils.
Modern paleontologists have a number of methods to locate, study and identify fossils. Paleontologists can study minutest descriptions of smaller fossils using electron microscopes. The internal structures of Fossil X-ray machines and CT Scanners are shown. The advanced computer programs are enabled to analyze fossil evidence, recreate skeletons and depict extinct organisms' bodies and movements.
Determining the ages of Fossils
Paleontology is the study of how life has changed geologically. Various methods exist for determining the fossil age, including:
1. Stratigraphy- The study of the sedimentary record strata or layers is known as the stratigraphy. The strata are characterized by their various colors or compositions and exposed on cliffs, canyons and banks of the river. Such rocks typically form relatively horizontal parallel layers and form on the top of these layers. The fossil age is believed to be in between the two common layers of the rock of which the period is known. Due to discontinuity between rock series it may be separated by erosion or faults.
2. Biostratigraphy- This is the technique in which the short lived species are used to match the isolated rocks. For example, in the period of Middle Ordovician, the...