⭐⭐⭐⭐⭐ Assess The Argument That Fossils Are Evidence Of Evolution
San Diego: Academic Press; When exactly Darwin came to his insight about the theoretical importance of homologous structures as evidence for common ancestry Assess The Argument That Fossils Are Evidence Of Evolution DWM is not clear. The Assess The Argument That Fossils Are Evidence Of Evolution common method of fossilization is permineralization. The combustion of these fossil fuels releases large amounts of carbon dioxide into the atmosphere, daily. Assess The Argument That Fossils Are Evidence Of Evolution traits of organisms are therefore explained by descent from a common ancestor. Whale Skeleton : The pelvic bones in Civil Rights In The Cold War South Analysis are also a good example of vestigial evolution whales evolved from four-legged land mammals Assess The Argument That Fossils Are Evidence Of Evolution secondarily lost their hind legs. At small scales, upper-level Compare And Contrast Sports Drinks And Energy Drinks biology courses have long Assess The Argument That Fossils Are Evidence Of Evolution that focus on this approach, but such Assess The Argument That Fossils Are Evidence Of Evolution can depend heavily on the expertise of a few faculty, prior knowledge of Assess The Argument That Fossils Are Evidence Of Evolution biology students, and college-based access to equipment and resources. Vestigial structures also offer clues to common ancestors.
Evidence for evolution - Biology - Khan Academy
To see why, imagine an antelope that dies on the African plain. Most of its body is quickly eaten by scavengers, and the remaining flesh is soon eaten by insects and bacteria, leaving behind only scattered bones. As the years go by, the bones are scattered and fragmented into small pieces, eventually turning into dust and returning their nutrients to the soil. The rarest form of fossilization is the preservation of original skeletal material and even soft tissue. For example, some insects have been preserved perfectly in amber, which is ancient tree sap. In addition, several mammoths and even a Neanderthal hunter have been discovered frozen in glaciers. These preserved remains allow scientists the rare opportunity to examine the skin, hair, and organs of ancient creatures.
Amber : The image depicts a gnat preserved in amber. A lot of insects have been found to be perfectly maintained in this ancient tree sap. The most common method of fossilization is permineralization. After a bone, wood fragment, or shell is buried in sediment, it may be exposed to mineral-rich water that moves through the sediment. This water will deposit minerals, typically silica, into empty spaces, producing a fossil. Fossilized dinosaur bones, petrified wood, and many marine fossils were formed by permineralization.
Permineralization : These fossils from the Road Canyon Formation Middle Permian of Texas have been silicified replaced with silica , which is a form of permineralization. In some cases, the original bone or shell dissolves away, leaving behind an empty space in the shape of the shell or bone. This depression is called a mold. Later, the space may be filled with other sediments to form a matching cast in the shape of the original organism.
Many mollusks bivalves, snails, and squid are commonly found as molds and casts because their shells dissolve easily. Molds : The depression in the image is an external mold of a bivalve from the Logan Formation, Lower Carboniferous, Ohio. In some cases, the original shell or bone dissolves away and is replaced by a different mineral. For example, shells that were originally calcite may be replaced by dolomite, quartz, or pyrite.
If quartz fossils are surrounded by a calcite matrix, the calcite can be dissolved away by acid, leaving behind an exquisitely preserved quartz fossil. When permineralization and replacement occur together, the organism is said to have undergone petrification, the process of turning organic material into stone. However, replacement can occur without permineralization and vice versa. Some fossils form when their remains are compressed by high pressure. This can leave behind a dark imprint of the fossil. Compression is most common for fossils of leaves and ferns but also can occur with other organisms.
Following the death of an organism, several forces contribute to the dissolution of its remains. Decay, predators, or scavengers will typically rapidly remove the flesh. The hard parts, if they are separable at all, can be dispersed by predators, scavengers, or currents. The individual hard parts are subject to chemical weathering and erosion, as well as to splintering by predators or scavengers, which will crunch up bones for marrow and shells to extract the flesh inside. Also, an animal swallowed whole by a predator, such as a mouse swallowed by a snake, will have not just its flesh but some, and perhaps all, its bones destroyed by the gastric juices of the predator. It would not be an exaggeration to say that the typical vertebrate fossil consists of a single bone, or tooth, or fish scale.
The preservation of an intact skeleton with the bones in the relative positions they had in life requires a remarkable circumstances, such as burial in volcanic ash, burial in aeolian sand due to the sudden slumping of a sand dune, burial in a mudslide, burial by a turbidity current, and so forth. The mineralization of soft parts is even less common and is seen only in exceptionally rare chemical and biological conditions. Because not all animals have bodies which fossilize easily, the fossil record is considered incomplete.
Each fossil discovery represents a snapshot of the process of evolution. Because of the specialized and rare conditions required for a biological structure to fossilize, many important species or groups may never leave fossils at all. Even if they do leave fossils, humans may never find them—for example, if they are buried under hundreds of feet of ice in Antarctica. The fossil record is very uneven and is mostly comprised of fossils of organisms with hard body parts, leaving most groups of soft-bodied organisms with little to no fossil record. Groups considered to have a good fossil record, including transitional fossils between these groups, are the vertebrates, the echinoderms, the brachiopods, and some groups of arthropods.
Their hard bones and shells fossilize easily, unlike the bodies of organisms like cephalopods or jellyfish. These gaps represent periods from which no relevant fossils have been found. There has been much debate over why there are so few fossils from this time period. Some scientists have suggested that the geochemistry of the time period caused bad conditions for fossil formation, so few organisms were fossilized. Another theory suggests that scientists have simply not yet discovered an excavation site for these fossils, due to inaccessibility or random chance. The age of fossils can be determined using stratigraphy, biostratigraphy, and radiocarbon dating. Paleontology seeks to map out how life evolved across geologic time.
A substantial hurdle is the difficulty of working out fossil ages. There are several different methods for estimating the ages of fossils, including:. Paleontologists rely on stratigraphy to date fossils. Stratigraphy is the science of understanding the strata, or layers, that form the sedimentary record. Strata are differentiated from each other by their different colors or compositions and are exposed in cliffs, quarries, and river banks. These rocks normally form relatively horizontal, parallel layers, with younger layers forming on top. Because rock sequences are not continuous, but may be broken up by faults or periods of erosion, it is difficult to match up rock beds that are not directly adjacent.
Sedimentary layers : The layers of sedimentary rock, or strata, can be seen as horizontal bands of differently colored or differently structured materials exposed in this cliff. The deeper layers are older than the layers found at the top, which aids in determining the relative age of fossils found within the strata. Fossils of species that survived for a relatively short time can be used to match isolated rocks: this technique is called biostratigraphy. For instance, the extinct chordate Eoplacognathus pseudoplanus is thought to have existed during a short range in the Middle Ordovician period. If rocks of unknown age have traces of E. Such index fossils must be distinctive, globally distributed, and occupy a short time range to be useful.
Misleading results can occur if the index fossils are incorrectly dated. Stratigraphy and biostratigraphy can in general provide only relative dating A was before B , which is often sufficient for studying evolution. This is difficult for some time periods, however, because of the barriers involved in matching rocks of the same age across continents. Family-tree relationships can help to narrow down the date when lineages first appeared.
It is also possible to estimate how long ago two living branches of a family tree diverged by assuming that DNA mutations accumulate at a constant rate. For example, they are not sufficiently precise and reliable for estimating when the groups that feature in the Cambrian explosion first evolved, and estimates produced by different approaches to this method may vary as well. Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale.
The principle of radiocarbon dating is simple: the rates at which various radioactive elements decay are known, and the ratio of the radioactive element to its decay products shows how long the radioactive element has existed in the rock. This rate is represented by the half-life, which is the time it takes for half of a sample to decay. Half-life of Carbon : Radiometric dating is a technique used to date materials such as rocks or carbon, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
The half-life of carbon is 5, years, so carbon dating is only relevant for dating fossils less than 60, years old. Radioactive elements are common only in rocks with a volcanic origin, so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers. Carbon dating uses the decay of carbon to estimate the age of organic materials, such as wood and leather. Fossils provide evidence that organisms from the past are not the same as those found today, and demonstrate a progression of evolution. Scientists date and categorize fossils to determine when the organisms lived relative to each other.
The resulting fossil record tells the story of the past and shows the evolution of forms over millions of years. Highly detailed fossil records have been recovered for sequences in the evolution of modern horses. The fossil record of horses in North America is especially rich and contains transition fossils: fossils that show intermediate stages between earlier and later forms. The fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus Eohippus. The first equid fossil was found in the gypsum quarries in Montmartre, Paris in the s. The tooth was sent to the Paris Conservatory, where Georges Cuvier identified it as a browsing equine related to the tapir.
His sketch of the entire animal matched later skeletons found at the site. During the H. Beagle survey expedition, Charles Darwin had remarkable success with fossil hunting in Patagonia. The original sequence of species believed to have evolved into the horse was based on fossils discovered in North America in the s by paleontologist Othniel Charles Marsh. The sequence, from Eohippus to the modern horse Equus , was popularized by Thomas Huxley and became one of the most widely known examples of a clear evolutionary progression. The species depicted are only four from a very diverse lineage that contains many branches, dead ends, and adaptive radiations. One of the trends, depicted here, is the evolutionary tracking of a drying climate and increase in prairie versus forest habitat reflected in forms that are more adapted to grazing and predator escape through running.
Since then, as the number of equid fossils has increased, the actual evolutionary progression from Eohippus to Equus has been discovered to be much more complex and multibranched than was initially supposed. Detailed fossil information on the rate and distribution of new equid species has also revealed that the progression between species was not as smooth and consistent as was once believed. Although some transitions were indeed gradual progressions, a number of others were relatively abrupt in geologic time, taking place over only a few million years.
The series of fossils tracks the change in anatomy resulting from a gradual drying trend that changed the landscape from a forested habitat to a prairie habitat. Early horse ancestors were originally specialized for tropical forests, while modern horses are now adapted to life on drier land. Successive fossils show the evolution of teeth shapes and foot and leg anatomy to a grazing habit with adaptations for escaping predators. The horse belongs to the order Perissodactyla odd-toed ungulates , the members of which all share hoofed feet and an odd number of toes on each foot, as well as mobile upper lips and a similar tooth structure.
This means that horses share a common ancestry with tapirs and rhinoceroses. When you hear talk of evidence for evolution, the first thing that frequently comes to mind for most people is fossils. The fossil record has one important, unique characteristic: it is our only actual glimpse into the past where common descent is proposed to have taken place. As such it provides invaluable evidence for common descent. The fossil record is not "complete" fossilization is a rare event, so this is to be expected , but there is still a wealth of fossil information. If you look at the fossil record, you find a succession of organisms that suggest a history of incremental development from one species to another.
You see very simple organisms at first and then new, more complex organisms appearing over time. The characteristics of newer organisms frequently appear to be modified forms of characteristics of older organisms. This succession of life forms, from simpler to more complex, showing relationships between new life forms and those that preceded them, is strong inferential evidence of evolution. There are gaps in the fossil record and some unusual occurrences, such as what is commonly called the Cambrian explosion, but the overall picture created by the fossil record is one of consistent, incremental development. At the same time, the fossil record is not in any way, shape, or form suggestive of the idea of a sudden generation of all life as it appears now, nor does it support transformationism.
There is no way to look at the fossil record and interpret the evidence as pointing towards anything other than evolution — despite all the gaps in the record and in our understanding, evolution and common descent are the only conclusions that are supported by the full spectrum of evidence. This is very important when considering inferential evidence because inferential evidence can always, in theory, be challenged on its interpretation: why interpret the evidence as inferring one thing rather than another?
Such a challenge is only reasonable, though, when one has a stronger alternative — an alternative that not only explains the evidence better than what's being challenged, but which preferably also explains other evidence that the first explanation does not. We don't have this when with any form of creationism. For all their insistence that evolution is only a "faith" because so much evidence is "merely" inferential, they are unable to present an alternative that explains all that inferential evidence better than evolution — or even anywhere close to evolution.
Inferential evidence isn't as strong as direct evidence , but it's treated as sufficient in most cases when enough evidence exists and especially when there are no reasonable alternatives. Nowadays the fossil fuel is one of the most important resources in the earth, but its importance generates many problems to the planet. Fossil fuel is one of principal resource in the earth this resource consists in high levels of carbon and includes natural gas, petroleum, and coal. These elements are important to countries because, with them, the countries can create energy, materials, and others resources. In the same way, the necessity of energy. From the word itself, fossil, fossil fuels are formed from remnants of prehistoric creatures.
Most of the biological matter formed to fossil fuels are from plants and microorganisms. Because of being exposed to vast heat and pressure from the inner sections of the earth through an estimate of one hundred to four hundred million years ago, these biological matters have physically and chemically change to form. One of the main arguments that Darwinsts use is the argument that fossils are evidence of evolution. I have gathered information from Your Inner Fish and internet sources.
I found an article online that says in a nutshell; there 's two lines of evidence for evolution. The first line of evidence concerns the order in which fossils are found buried. Fossils are generally found buried in a sequential order. The first fossilized fish appear buried below the first fossilized amphibians which appear below. These days, usage of fossil fuel is a controversial issue for several different aspects; for economical, environmental, political, and ethical reasons, worldwide audiences are paying attention on fossil fuels. The rate of the usage of the fuel energy has never declined since the industrial revolution, especially for the transportation.
In fact, there are 1. There are three main fuel sources, coal, natural gas and. The burning of fossil fuels has many negative effects on the earth. The combustion of these fossil fuels releases large amounts of carbon dioxide into the atmosphere, daily. This contributes to global warming. The improper disposal of oil and garbage causes land, water and air pollution. Renewable energy sources occur naturally and are inexhaustible. Fossil fuels are the largest gas emitters in the world that helps to power electricity. Although they are essential in daily life, fossil fuels have a huge impact on the environment contributing to global warming, acid deposition and pollution.
Burning fossil fuels at high temperature produces electricity but also leads to pollutants in the air and water. According to ZeeNews, Over the past years. Fossil fuels such as petroleum, coal and natural gas accounted for The burning of fossil fuels have greatly contributed to global warming, however if we were to ultimately eliminate fossil fuels from energy sources, the production of energy will undoubtedly fall behind the demand. The solution proposed is to reduce the demand for fossil fuels by replacing some with a.
Fossil fuels have for decades been a main source of energy for the United States, However such nonrenewable energy has managed to decimate the environment by weakening the ozone and increase global temperatures. The issue at hand is that these fuels are at the foundation of the U.Am Biol Teach. Paralogs typically have the same or similar function, but sometimes do not. In the same way, the necessity of Religion Exposed In Thomas Luckmanns Invisible Religion. Larger fossils Examples Of Propaganda more likely to be displayed in museums and other locations, but these types of fossils are rarer than this tendency suggests. Defelice has written 16 Assess The Argument That Fossils Are Evidence Of Evolution and 12 Assess The Argument That Fossils Are Evidence Of Evolution Central Cord Injury Research Paper for young Biology Lab Report Essay three of her books are. The study of stratigraphy enables scientists to Assess The Argument That Fossils Are Evidence Of Evolution the age of a fossil if they know the age of layers of rock Assess The Argument That Fossils Are Evidence Of Evolution surround it. Thus, just as natural selection Assess The Argument That Fossils Are Evidence Of Evolution an inevitable result of the phenomena of the combination of reproduction, variation, inheritance, and resource limitation, evolutionary Assess The Argument That Fossils Are Evidence Of Evolution are the inevitable phenotypic and genotypic results of the phenomenon of DWM.