Abstract
An adaptation or adaptive trait is a trait/characteristic that has evolved in a population of organisms which provides a functional advantage. Adaptations increase the biological fitness of a population. Fitness is defined as the ability to survive and pass genes on to subsequent generations.
For the purposes of this assignment, it has been chosen an adaptive trait common to more than one species. For example, birds and bats both have wings.
This essay describes what makes this trait an adaptation and how evidence supports it. It briefly describes how the trait evolved; e.g., mutation, genetic drift, migration and/or natural selection.
This essay also describes what is the difference between homologous and analogous traits and how
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Physiological adaptations refer to the metabolic processes and to the relatedness and similarities of DNA sequence between the same species. As it is easily understood, fossils are one of the best living proof of evolution, because they reveal similarities and differences traits between species over long periods, and eventually revealing a common ancestor. In the case of the Polar bear, it can be observed similar traits with the
Grizzle Bear, revealing how each evolved differently overtime, and depending on the bear's environment.
Biochemistry studies similarities at DNA, ATP, and enzymes. DNA sequence and proteins resemblance shared by different organisms show evidence of advancements in the understanding of evolution. (The
Big Bear Project, n.d.). As stated by Futoyma (2009), “Selection at the level of genes or organisms is likely to be the most important because the numbers and turnover rates of these entities are greater than those of populations or species”.
ADAPTIVE TRAITS 5
References
Futuyma, D. (2009). Chapter 11: Natural Selection and Adaptation. Evolution, 2nd edition. Sinauer
Associates. Retrieved from
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.
Darwin: A Norton Critical Edition, Second Edition ; ed. by Philip Appleman; copyright 1979, 1970 by W.W. Norton & Company, Inc.
...or maintenance of traits that enhance the individuals overall fitness, as stated by ______. For males some of this fitness, which is influenced by the condition of the individual, goes into the expression of sexually selected traits, such as mating calls. This has a indirect result for other traits such as foraging behavior or increasing the risk of predation. This trait then becomes costly, resulting in the evolution of condition dependence, as shown by Price et al. 1993; Anderson 1994; and Johnstone 1995. Individuals in higher conditions have an advantage over others as they have a larger pool to allocate among their competing demands. This means that "condition dependence is expected to arise because individuals in higher condition are better able to pay higher marginal costs of further exaggeration than those in lower conditions”, as stated by Rowe and Houle.
This is because the theory suggested that the traits would be more common through generations if the environment did not make it less common. In other w...
Work Cited Colby, Chris. A. Web. " An Introduction to Evolutionary Biology." 28 August 2015.
“Animals are adapted to their conditions in subtle and marvelous ways (Boyd, R., & Silk, J. 1997:2).” It is commonly recognized that Darwin identified adaptations through Natural Selection: traits that are advantageous to survival will be retained in the population through reproduction. Natural Selection further indicates that traits will survive when they are most beneficial to an individual’s fitness. While Natural Selection and Mutation effectively explains adaptive fitness qualities and variance among populations, it fails to explain species beautiful ornamental traits that are not necessarily beneficial to fitness. The extravagant tails of a male peacocks, the neck of a giraffe, and bright colored plumage of birds are attributes designed to maximize reproductive success. Muscularity, sexual dimorphism (general size difference between sexes), male beards, penis size, calculated fat storage (in the breasts and hips for women), and co-parenting are adaptations in humans explained through sexual selection: specifically, through competition. Natural and Sexual Selection are competing and paralleling factors that define human evolution. While Natural Selection may define the necessity to impart certain genes, Sexual Selection quickly allows adaptations to occur through competition. Evolution
Genes are expected to give offspring hereditary similarities to the parent. However, this was not known and Gregory Mendel asked himself what was passed on by parents to their offspring that is the basis for similarity. Mendel would go on through experiments with pea plants to answer short questions. The answers were short as well as to say that the passing of characteristics from parents to the offspring is throug...
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.
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 comparative method is a species that can be studied and compared to the search of understanding human behavior. The physiological outlook elucidate the performance of how the nervous system and hormones reacts to the body, what precedent of the transformations in the structure can affect one’s behavior, and how the brain operates. For example, when a cardiologist operate on someone’s heart. He has the expectation of extending that individual's life (Thomas Spray). Another comparative method utilized is the investigation of inheritance. This technique engages a species inheriting genes from its parents. For instance, when the offspring with dark skin complexion begat blue eyes this trait is hereditary. Each of these biological aspects consisting of the comparative, physiological and the genetic systems explicates human behavior. This dissertation will focus on the brain, the nervous system, and the ways in which these physiological mechanisms interrelate.
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).
The next type of adaptation is also genetic, but does not involve the changing of the genes themselves, but rather how they are expressed. Because humans possess a remarkable amount of ‘genetic plasticity’, developmental adjustments can occur by turning particular genes on or off to adapt to the current environmental conditions at birth and through adolescence.
So, it would seem that human beings are able to adapt to a wide range
more than half the variation was found to be due to heredity. Among these traits were
Natural selection is based on the concept “survival of the fittest” where the most favourable individual best suited in the environment survive and pass on their genes for the next generation. Those individual who are less suited to the environment will die.