Evolution is a theory that argues that all organisms alive on earth today share a common ancestor. It is thought that through generations, specific changes or adaptations were established in species in order to help them survive, reproduce, and raise offspring. But how are we certain that these changes occurred? Today, there is an abundant amount of research evidence that suggests that anatomical and physiological alterations occurred to species that caused them to turn from aquatic animals to terrestrial animals, allowing them to survive different environmental conditions. The following are several gradual changes an aquatic organism must go through in order to move to land and adjust to its new terrestrial habitat: circulatory and most importantly respiratory systems must be improved, structural adaptations should be modified, development of a skeletal system to protect the body and organs, and an adjustment of the senses must also occur.
The evolution from water to land was a major event in the vertebrates. Species respiratory, circulation, and reproduction system show how they evolved and adapted to the environment. Vertebrates who belong the phylum Chordata had at least at some point of their life, a dorsal hollow nerve cord, a notochord, pharyngeal pouches, and a tail that extends beyond the anus. It is said that fishes were amongst the first vertebrates. The earliest fish to appear in the fossil record were jawless, covered with bony plates, gills, scales, but no fins. According to Arreola, they later evolved by adapting to their environment and began to form jaws and paired fins. The jaws were useful with their muscles and teeth, which helped them eat a wider variety of food, and were even able to defend themselves by bi...
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...is a form of evidence that shows how life has changed throughout the years and how species today are connected way back to a common ancestor. Paleontologists look for features from one way of life to another. They create a tree of life that separates species according to their common structure. Fossils show how tetrapod legs evolved from fins and genes studies show how mutation and natural selection resulted into long limb bones from the fins (Hoff). In this case, they have uncovered how a species that lives on water transitioned to a terrestrial way of life.
Perhaps descendants found land a source of abundant food and a haven from competition. Over millions of years through variation and selection, fins became legs, rear legs appeared, and bodies created fur and took the familiar shape the animals we have on land. These species had to evolve and change the way
One hundred and fifty million years ago, large aquatic species of reptile such as the Plesiosaur dominated the ocean, and were pre-eminent predators of the sea. The branch of now extinct Plesiosaurs, or ‘near lizards’, evolved into variant closely related species specialised to take different niches in the food chain. Such species of Plesiosaur include the phenotypically similar Plesiosauroid and Pliosauroid. The physiological adaptations of the long necked variant, the Plesiosauroid, as it relates to deep sea diving, will be addressed in depth.
In the book, Your Inner Fish, by Neil Shubin he presents the notion of evolution and how we can trace parts that make up the human body back to jellyfish, worms, and even fish. The book not only discusses how we arose to be what we are today, but also the implications our ancestors had on our current body plan. In this essay, I will demonstrate that I have digested the entirety of Shubin’s book by convincing you (dear reader) that everything in our bodies is based on simple changes to already existing systems. To make this case, I will use the evidence of limb development in a vast array of organisms, the four arches found in the embryological stage of development, the structures inside our noses, and how our ears have come about all due to modifications.
If you were to live during the tertiary period, this would be one of the things you would often see. All of the mammals that existed during that time period were terrestrial. They all were land dwelling mammals. Before J. G. M. Thewissen and colleagues’ discovery in Pakistan, many scientists believed, since the constant new discoveries twenty years ago, in what the numerous fossils from North America, Pakistan, and Egypt have revealed, “…these early cetaceans had mobile elbows and external hind limbs with articulated knees. However, they were fully aquatic, except for Ambulocetus, which was amphibious-much like sea lions” (Walking with Whales).
Feder and Park present a list of traits that are used by paleoanthropologists to distinguish the appearance of skeletal features and characterize these changes over time. Th...
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.
According to The Princeton Guide of Evolution, evolution refers to change through time as species become modified and diverge to produce multiple descendant species (Losos et al. 2013). Charles Darwin proposed the idea of evolution as “decent with modification” in his book On the Origin of Species in 1859. He introduced the theory that natural selection was the mechanism of decent with modification. Individuals with certain heritable characteristics survive and reproduce at a higher rate than other individuals. Natural selection increases the adaptation of organisms to their environment over time. In this lab, the evolution of Anolis
Liubicich, D.M., et al. 2009. Knockdown of Parhyale Ultrabithorax recapitulates evolutionary changes in crustacean appendage morphology. PNAS 106 (33): 13892-13896
The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.
The Axolotl, a crucially endangered neotenous species of mole salamander, has adapted to fit its environment so it can easily catch food and evade predators. The Axolotl’s habitat is the lake system of Xochimilco that is near Mexico City, Mexico. This shallow, fresh water lake complex has a temperature range of 6- 20°C and a pH of 7- 12. The complex also has the Axolotl’s primary food sources of mollusk, insect larvae, and other crustaceans. However, with the introduction of foreign species such as the Asian Carp and the African Tilapia, the Axolotl now has predators that may eat and threaten it, and it has competition for the animals it usually eats. Fortunately, the Axolotl has developed adaptations that aid it in catching food and evading predators. To help it catch food the Axolotl’s teeth are shaped like cones, so that its “vacuum” action of sucking in as much water in order to also eat food is aided by the shape of the teeth, which allow it to grip, rather than chew. To aid them in avoiding predators they are able to metamorphose so that they use their lungs more than their gill, which allows them to leave very toxic waters and the predators within. Another adaption that helps them deflect any predator is that they are able to regenerate body parts that have been lost, allowing them to stay as strong as possible. Axolotl’s have adaptations that aid their survival from predators in the lake complex Xochimilco that they reside in.
Many scientists in the past, such as Aristotle and Plato, believed that there were no changes in populations; however, other scientists, such as Darwin and Wallace, arose and argued that species inherit heritable traits from common ancestors and environmental forces drives out certain heritable traits that makes the species better suited to survive or be more “fit” for that environment. Therefore, species do change over a period of time and they were able to support their theory by showing that evolution does occur. There were four basic mechanisms of evolution in their theory: mutation, migration, genetic drift, and natural selection. Natural selection is the gradual process by which heritable traits that makes it more likely for an organism to survive and successfully reproduce increases, whereas there is a decline in those who do have those beneficial heritable traits (Natural Selection). For example, there is a decrease in rain which causes a drought in the finches’ environment. The seeds in the finches’ environment would not be soft enough for the smaller and weaker beak finches to break; therefore, they cannot compete with the larger and stronger beak finches for food. The larger and stronger beak finches has a heritable trait that helps them survive and reproduce better than others for that particular environment which makes them categorized under natural selection (Freeman, 2002).
Since the earth has changed so much, many organisms must evolve to survive. Since the earth is constantly changing and creating for landforms over time. The certain animals that live in an area must evolve to be able to live in the new environment from the landform. For example, natural selection is when “only the strong survive so that organism continues to evolve”.(ISN) Many organisms must adapt to their new environment over time. A landform can cause animals to evolve because they have a new
Evolution can be found among almost every type of creature, if not all living creatures. Indeed, there are many articles and research being done about evolution in sea organisms. Seeing as evolution is based on abilities to obtain food and shelter, the end results usually ended up with an animal or organism evolving to better obtain either of these. For example, the head of a dwarf seahorse was found to have evolved to better catch their prey, the copepod (Ornes, 2013). The shape of the head causes the water in front of the nose to be still as to be able to avoid being detected (Ornes, 2013). With sea creatures evolution also may cause other changes like the loss of a stomach (Milius, 2013). The puffer fish does not “need” the acids to digest its meal and instead used the stomach free area to be able to “puff” up and seem unappetizing (Milius, 2013). Not only is there changes in animals, but also in coral reefs. Instead of having to rely on the green algae to get its food, cold water coral has evolved to become able to get energy from the small creatures that it would catch. It has evolved that way because it is very dark where the coral reefs are found in cold water areas (Earth Sky, 2014). Evolution doesn't just happen within land organisms.
Without evolution, and the constant ever changing environment, the complexity of living organisms would not be as it is. Evolution is defined as a process that results in heritable changes in a population spread over many generations (8).Scientists believe in the theory of evolution. This belief is based on scientific evidence that corroborates the theory of evolution. In Figure 1 the pictures of the skulls depict the sequence of the evolution of Homo-sapiens. As the figure shows, man has evolved from our common ancestor that is shared by homo-sapiens. The change of diet of homo-sapiens over time has thought to contribute to the change in jaw structure and overall skull shape.
The Occurence of Evolution Evolution is defined as genetically based change from generation to generation. IF and ONLY if you look exactly the same as both your parents and they look exactly the same as your grandparents and so on back to the beginning of life (however you define that beginning) can you say that evolution has not occurred. Since I assume you are an organism born on this planet, and that you are a human being, rather than some clonal organism (one that reproduces by budding or similar method), I assume you do not look exactly like both your parents and that they do not look exactly like their parents, and that the differences are, at least in part, genetically based. Therefore, within your own family, evolution has occurred.