What is Free Evolution?<br /><br />Free evolution is the concept that natural processes can cause organisms to evolve over time. This includes the creation of new species and the alteration of the appearance of existing species.<br /><br />This has been proven by many examples, including stickleback fish varieties that can live in fresh or saltwater and walking stick insect varieties that have a preference for particular host plants. These mostly reversible trait permutations, however, cannot be the reason for fundamental changes in body plans.<br /><br />Evolution through Natural Selection<br /><br />The evolution of the myriad living creatures on Earth is a mystery that has intrigued scientists for many centuries. Charles Darwin's natural selection is the most well-known explanation. This happens when people who are more well-adapted survive and reproduce more than those who are less well-adapted. Over time, a population of well adapted individuals grows and eventually becomes a new species.<br /><br />Natural selection is an ongoing process and involves the interaction of 3 factors that are: reproduction, variation and inheritance. Sexual reproduction and mutation increase the genetic diversity of an animal species. Inheritance is the passing of a person's genetic traits to his or her offspring that includes recessive and dominant alleles. Reproduction is the process of generating viable, fertile offspring. This can be done through sexual or asexual methods.<br /><br />Natural selection is only possible when all of these factors are in harmony. If, for example, a dominant gene allele causes an organism reproduce and survive more than the recessive allele, then the dominant allele is more common in a population. However, if the gene confers a disadvantage in survival or reduces fertility, it will disappear from the population. The process is self-reinforcing meaning that an organism with an adaptive trait will survive and reproduce much more than one with a maladaptive characteristic. The more offspring an organism produces the more fit it is, which is measured by its capacity to reproduce itself and survive. People with desirable traits, like having a longer neck in giraffes and bright white patterns of color in male peacocks, are more likely to be able to survive and create offspring, and thus will make up the majority of the population in the future.<br /><br />Natural selection only affects populations, not individual organisms. This is a major distinction from the Lamarckian evolution theory which holds that animals acquire traits either through usage or inaction. If a giraffe extends its neck in order to catch prey, and the neck becomes longer, then its offspring will inherit this characteristic. The length difference between generations will continue until the giraffe's neck gets too long to no longer breed with other giraffes.<br /><br />Evolution through Genetic Drift<br /><br />Genetic drift occurs when alleles of one gene are distributed randomly in a population. In the end, only one will be fixed (become common enough that it can no more be eliminated through natural selection) and the other alleles drop in frequency. In the extreme, this leads to dominance of a single allele. The other alleles are virtually eliminated and heterozygosity decreased to a minimum. In a small population it could result in the complete elimination of recessive gene. This scenario is called the bottleneck effect. It is typical of an evolutionary process that occurs whenever the number of individuals migrate to form a group.<br /><br />A phenotypic bottleneck may also occur when survivors of a disaster like an outbreak or a mass hunting event are confined to a small area. The survivors will carry a dominant allele and thus will share the same phenotype. This situation might be caused by conflict, earthquake or even a cholera outbreak. The genetically distinct population, if left vulnerable to genetic drift.<br /><br />Walsh Lewens, Walsh and Ariew define drift as a deviation from the expected value due to differences in fitness. They give the famous example of twins who are both genetically identical and share the same phenotype. However, one is struck by lightning and dies, whereas the other continues to reproduce.<br /><br />This kind of drift could play a very important part in the evolution of an organism. However, it's not the only way to develop. Natural selection is the primary alternative, in which mutations and migrations maintain the phenotypic diversity of the population.<br /><br />Stephens argues there is a significant difference between treating drift like a force or cause, and considering other causes, such as migration and selection mutation as causes and forces. Stephens claims that a causal process explanation of drift lets us separate it from other forces and that this distinction is crucial. He argues further that drift is both direction, i.e., it tends to eliminate heterozygosity. It also has a size which is determined by population size.<br /><br />Evolution through Lamarckism<br /><br /><br /><br />When students in high school take biology classes, they are frequently introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is commonly known as "Lamarckism" and it states that simple organisms develop into more complex organisms by the inherited characteristics that are a result of the natural activities of an organism, use and disuse. 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 their offspring, who then get taller.<br /><br />Lamarck Lamarck, a French Zoologist, introduced an idea that was revolutionary in his opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on organic transformation. In his view living things evolved from inanimate matter through a series of gradual steps. Lamarck was not the first to propose this, but he was widely considered to be the first to give the subject a thorough and general overview.<br /><br />The popular narrative is that Lamarckism grew into an opponent to Charles Darwin's theory of evolution through natural selection, and that the two theories battled out in the 19th century. Darwinism ultimately won and led to what biologists refer to as the Modern Synthesis. This theory denies acquired characteristics can be passed down through generations and instead argues organisms evolve by the selective influence of environmental factors, including Natural Selection.<br /><br />While Lamarck endorsed the idea of inheritance through acquired characters, and his contemporaries also paid lip-service to this notion but it was not a central element in any of their evolutionary theorizing. This is due to the fact that it was never tested scientifically.<br /><br />It's been more than 200 year since Lamarck's birth and in the field of genomics there is a growing evidence base that supports the heritability of acquired traits. It is sometimes called "neo-Lamarckism" or more frequently epigenetic inheritance. <a href="https://evolutionkr.kr/">Evolution KR</a> is a variant that is as reliable as the popular neodarwinian model.<br /><br />Evolution by adaptation<br /><br />One of the most common misconceptions about evolution is that it is being driven by a struggle for survival. In fact, this view is inaccurate and overlooks the other forces that determine the rate of evolution. The fight for survival can be more precisely described as a fight to survive within a particular environment, which could involve not only other organisms but also the physical environment.<br /><br />To understand how evolution operates it is beneficial to consider what adaptation is. Adaptation refers to any particular characteristic that allows an organism to live and reproduce in its environment. It could be a physiological structure such as fur or feathers, or a behavioral trait like moving to the shade during the heat or leaving at night to avoid the cold.<br /><br />An organism's survival depends on its ability to extract energy from the environment and interact with other living organisms and their physical surroundings. The organism should possess the right genes to produce offspring and to be able to access sufficient food and resources. The organism must be able to reproduce at the rate that is suitable for its specific niche.<br /><br />These elements, in conjunction with mutation and gene flow can result in a change in the proportion of alleles (different varieties of a particular gene) in a population's gene pool. This change in allele frequency can lead to the emergence of novel traits and eventually new species as time passes.<br /><br />A lot of the traits we admire in animals and plants are adaptations, for example, lung or gills for removing oxygen from the air, fur or feathers for insulation long legs to run away from predators, and camouflage for hiding. However, a complete understanding of adaptation requires paying attention to the distinction between physiological and behavioral characteristics.<br /><br />Physical traits such as thick fur and gills are physical traits. Behavior adaptations aren't like the tendency of animals to seek out companionship or retreat into shade during hot temperatures. Furthermore it is important to note that lack of planning does not mean that something is an adaptation. In fact, failing to consider the consequences of a decision can render it unadaptive, despite the fact that it may appear to be sensible or even necessary.<br /><br />