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The theory of evolution pdf
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Introduction
Evolution is the idea of a living organism adapting or mutating to gain beneficial physiological, psychological and structural features. The genetic makeup of all living things is constantly changing, due to DNA replication errors or outside factors, some of these changes impact drastically on the organism changing it for the better or worse. Typically when an organisms genetic code is changed for the better and it reproduces and outlives its unchanged counterparts this process is called evolution.
Evolution can happen to any living organism, and is constantly happening. For a species to be “evolved” no major physical characteristics need to be changed, an evolutionary trait can be anything from changed certain cellular size or a drastic change such as the forming of a tail. Certain activities can affect a species long term also. For instance a fish that needs to escape a predator might jump out of the water, over melena of the species doing this they will develop a higher lung capacity.
There are many explanations for why this happens the two most known explanations are Darwin’s theory of evolution and Lamarck’s theory of evolution, Darwin’s theory of evolution focuses on natural selection and the idea traits in organism are constantly changing and that positive traits will outlast those with no traits or bad traits. Lamarckian evolution focuses on an organism being able to change its genetic makeup by repeatedly doing a certain action, once this has been done over many generations the latest generation will look different from the first.
Pleistocene Organism
The procoptodon was a kangaroo predecessor that lived in the Pleistocene era, the procoptodon had many adaptations, including; structural adaptations, such as i...
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... reach. Any number of environmental changes could have caused this to happen, Darwin’s theory states that at least one procoptodon had to have had a small portion of grass in its diet and could digest it, therefore when the shrubs and trees died out a portion of the procoptodons were able to survive on the grass.
Conclusion
In conclusion Darwin’s theory of evolution best describes how the changes like; the two extra-long fingers on each paw, the long horse hoof like extra toe on each foot and the short snout and flat face all developed into an equal finger paw, equal toe length feet, and a longer snout. Darwin’s theory provides a solid reason why the procoptodon developed into the red kangaroo, based on the changing food supply. Compared to Lamarckian theory where the animals could change their digestive system on a genetic level to accept grass as a food source.
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...
Biological evolution is a change in the characteristics of living organisms over generations (Scott, 2017). A basic mechanism of evolution, the genetic drift, and mutation is natural selection. According to Darwin's theory of evolution, natural selection is a process in nature in which only the organisms best adapted to their environmental surroundings have a higher chance of surviving and transmitting their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated. There has been many experimental research projects that relate to the topic of natural selection and evolution.
comes from and how they evolved in the manner that they did. This type of
What is evolution? Evolution in modern terms is fairly easy to understand. Evolution is the theory that life on earth began with a single celled organism that lived more that 3.5 billion years ago that slowly evolved into many diverse creatures over time. When you break down this theory into sections you get 6 factors: evolution, gradualism, speciation, common ancestry, natural selection and nonselective mechanisms of evolutionary change.
"On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life," usually shortened to "the Origin of Species," is the full title of Charles Darwin's book, first published in 1859, in which Darwin formalized what we know today as the Theory of Evolution. Although Darwin is the most famous exponent of this theory, he was by no means the first person to suspect the workings of evolution. In fact, Charles owed a considerable debt to his grandfather Erasmus, a leading scientist and intellectual, who published a paper in 1794, calledZoonomia, or, The Laws of Organic Life. This set down many of the ideas that his grandson elaborated on 70 years later.
Anyone with even a moderate background in science has heard of Charles Darwin and his theory of evolution. Since the publishing of his book On the Origin of Species by Means of Natural Selection in 1859, Darwin’s ideas have been debated by everyone from scientists to theologians to ordinary lay-people. Today, though there is still severe opposition, evolution is regarded as fact by most of the scientific community and Darwin’s book remains one of the most influential ever written.
Evolution in general, is a hard concept to grasp. There are multiple factors that effect the outcome a species, for example: genetics, nurture, nature, and the environment all play an important role. It was once said that species do not survive due to the fact that they are the strongest or the most intelligent, but because that species is the most responsive to change.
Evolution is a on going process and the evolution is made up of many different processes. It allows species to become what they are, how they act, and what they will become. It also allows species to be able to survive. It produces new and different species through ancestral populations of organisms and moves them to new population. Both natural selection and genetic drift decrease genetic variation. If they were the only mechanisms of evolution, populations would eventually become homogeneous and further evolution would be impossible. There are, however, mechanisms that replace variation depleted by selection and drift (Colby).
The fossil record shows us that tarsiers have developed very elongated tarsals, and hind limbs (Rasmussen et al 1998). When comparing the fossil morphology to that of extant lineages of tarsier we can infer that these exaggerated features observed in the post crania have allowed for a powerful, quick movement that is highly adaptive and advantageous to predation avoidance strategies in the tarsier lineage.
In order for a species to survive, its population has to evolve. Evolution is the process of gradual change driven by natural selection to improve survival. Evolution is the explanation of how life got to its current state. Before the idea of evolution, the Bible gave the explanation of how things came to be, the Theory of Creation. Charles Darwin is credited for developing the theory of evolution.
Microscopic analysis has shown that the bones of some dinosaurs grew at a rate comparable to the modern mammals and have many more features in common with them. -Some researchers had studied
First, the period depicted in this tale takes place about 20,000 years ago. A time when dinosaurs no longer roamed the earth but megafauna, large vertebrates, was abundant. Vertebrates in this group inc...
With the studies that Charles Darwin obtained he published his first work, “The Origin of Species.” In this book he explained how for millions of years animals, and plants have evolved to better help their existence. Darwin reasoned that these living things had gradually changed over time to help themselves. The changes that he found seemed to have been during the process of reproduction. The traits which would help them survive became a dominant trait, while the weaker traits became recessive. A good example of what Darwin was trying to explain is shown in giraffes. Long-necked giraffes could reach the food on the trees, while the short-necked giraffes couldn’t. Since long necks helped the giraffes eat, short-necked giraffes died off from hunger. Because of this long-necks became a dominant trait in giraffes. This is what Charles Darwin would later call natural selection.
The evolutionary theory is the concept that species evolve over time through the mechanism of natural selection of survival and reproduction. Natural selection means acting on the assumption that various living organisms were produced by genetic diversity and mutation. The evolution theory may also be referred to as the philosophizing science. This theory states that all phenomena are derived from natural causes and can be explained by scientific laws without reference to a plan or purpose.
Evolution is the complexity of processes by which living organisms established on earth and have been expanded and modified through theorized changes in form and function. Human evolution is the biological and cultural development of the species Homo sapiens sapiens, or human beings. Humans evolved from apes because of their similarities. This can be shown in the evidence that humans had a decrease in the size of the face and teeth that evolved. Early humans are classified in ten different types of families.