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What is Free Evolution? Free evolution is the idea that the natural processes of organisms can lead to their development over time. Going On this page includes the emergence and development of new species. This is evident in many examples, including stickleback fish varieties that can be found in salt or fresh water, and walking stick insect varieties that have a preference for particular host plants. These mostly reversible traits permutations do not explain the fundamental changes in basic body plans. Evolution through Natural Selection Scientists have been fascinated by the development of all the living creatures that inhabit our planet for many centuries. The most widely accepted explanation is Darwin's natural selection process, an evolutionary process that is triggered when more well-adapted individuals live longer and reproduce more successfully than those who are less well-adapted. Over time, the population of well-adapted individuals grows and eventually creates a new species. Natural selection is an ongoing process that involves the interaction of three elements that are inheritance, variation and reproduction. Sexual reproduction and mutations increase genetic diversity in an animal species. Inheritance refers to the passing of a person's genetic characteristics to their offspring that includes recessive and dominant alleles. Reproduction is the process of producing viable, fertile offspring, which includes both asexual and sexual methods. All of these factors have to be in equilibrium for natural selection to occur. If, for instance the dominant gene allele causes an organism reproduce and live longer than the recessive allele The dominant allele is more prevalent in a population. But if the allele confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. The process is self reinforcing which means that an organism that has an adaptive trait will live and reproduce far more effectively than one with a maladaptive characteristic. The higher the level of fitness an organism has which is measured by its ability to reproduce and survive, is the more offspring it produces. People with desirable characteristics, such as a long neck in Giraffes, or the bright white color patterns on male peacocks are more likely than others to survive and reproduce, which will eventually lead to them becoming the majority. Natural selection is only a force for populations, not individuals. This is a crucial distinction from the Lamarckian theory of evolution, which states that animals acquire traits through usage or inaction. If a giraffe stretches its neck to reach prey, and the neck becomes longer, then its offspring will inherit this trait. The differences in neck length between generations will continue until the neck of the giraffe becomes too long that it can not breed with other giraffes. Evolution by Genetic Drift Genetic drift occurs when alleles of one gene are distributed randomly in a population. Eventually, only one will be fixed (become common enough to no longer be eliminated through natural selection), and the other alleles will diminish in frequency. In the extreme this, it leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity decreases to zero. In a small number of people this could lead to the complete elimination of recessive gene. This scenario is called the bottleneck effect. It is typical of an evolutionary process that occurs whenever an enormous number of individuals move to form a group. A phenotypic bottleneck may also occur when the survivors of a disaster such as an outbreak or mass hunt event are confined to a small area. The survivors will carry a dominant allele and thus will share the same phenotype. This could be caused by earthquakes, war, or even plagues. Going On this page , if it remains vulnerable to genetic drift. Walsh, Lewens and Ariew define drift as a departure from the expected values due to differences in fitness. They cite the famous example of twins that are genetically identical and share the same phenotype. However one is struck by lightning and dies, whereas the other is able to reproduce. This kind of drift could be vital to the evolution of the species. It's not the only method for evolution. The most common alternative is a process called natural selection, where phenotypic variation in the population is maintained through mutation and migration. Stephens argues there is a significant distinction between treating drift as an actual cause or force, and treating other causes such as migration and selection mutation as forces and causes. He argues that a causal-process explanation of drift lets us differentiate it from other forces and this differentiation is crucial. He also claims that drift has a direction: that is it tends to reduce heterozygosity. It also has a magnitude, which is determined by the size of population. Evolution by Lamarckism In high school, students take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 – 1829). His theory of evolution, also referred to as “Lamarckism, states that simple organisms transform into more complex organisms by inheriting characteristics that are a product of the use and abuse of an organism. Lamarckism can be demonstrated by the giraffe's neck being extended to reach higher branches in the trees. This could cause giraffes to pass on their longer necks to offspring, who would then become taller. Lamarck was a French Zoologist. In his opening lecture for his course on invertebrate Zoology at the Museum of Natural History in Paris on 17 May 1802, he presented a groundbreaking concept that radically challenged the conventional wisdom about organic transformation. According Going In this article , living organisms evolved from inanimate matter through a series gradual steps. Lamarck wasn't the first to propose this however he was widely thought of as the first to offer the subject a comprehensive and general treatment. The most popular story is that Charles Darwin's theory of natural selection and Lamarckism were rivals during the 19th century. Darwinism eventually triumphed and led to the development of what biologists today call the Modern Synthesis. The theory argues that acquired traits can be passed down through generations and instead argues that organisms evolve through the selective influence of environmental factors, such as Natural Selection. Lamarck and his contemporaries believed in the notion that acquired characters could be passed down to future generations. However, this concept was never a key element of any of their theories about evolution. This is partly because it was never scientifically validated. It has been more than 200 year since Lamarck's birth, and in the age genomics, there is a growing evidence base that supports the heritability of acquired traits. This is sometimes called “neo-Lamarckism” or, more frequently, epigenetic inheritance. This is a model that is just as valid as the popular neodarwinian model. Evolution by the process of adaptation One of the most commonly-held misconceptions about evolution is that it is being driven by a struggle for survival. This notion is not true and overlooks other forces that drive evolution. The fight for survival can be more accurately described as a struggle to survive within a specific environment, which can be a struggle that involves not only other organisms but also the physical environment. To understand how evolution operates it is beneficial to understand what is adaptation. The term “adaptation” refers to any specific feature that allows an organism to survive and reproduce in its environment. It could be a physiological structure, such as feathers or fur or a behavioral characteristic such as a tendency to move into shade in hot weather or stepping out at night to avoid cold. The capacity of an organism to extract energy from its surroundings and interact with other organisms, as well as their physical environment, is crucial to its survival. The organism must possess the right genes to produce offspring and to be able to access sufficient food and resources. Furthermore, the organism needs to be capable of reproducing at a high rate within its niche. These elements, along with mutations and gene flow can result in an alteration in the ratio of different alleles in a population’s gene pool. This change in allele frequency could lead to the development of novel traits and eventually new species as time passes. Many of the characteristics we appreciate in animals and plants are adaptations. For instance the lungs or gills which extract oxygen from the air feathers and fur for insulation and long legs to get away from predators and camouflage to conceal. To comprehend adaptation, it is important to discern between physiological and behavioral traits. Physiological adaptations like the thick fur or gills are physical characteristics, whereas behavioral adaptations, like the desire to find friends or to move to shade in hot weather, are not. It is also important to remember that a lack of planning does not cause an adaptation. A failure to consider the implications of a choice, even if it appears to be rational, may cause it to be unadaptive.