What is Free Evolution?
Free evolution is the concept that the natural processes of living organisms can cause them to develop over time. This includes the emergence and development of new species.
A variety of examples have been provided of this, including various varieties of fish called sticklebacks that can live in fresh or salt water and walking stick insect varieties that are attracted to particular host plants. These reversible traits do not explain the fundamental changes in the body's basic plans.
Evolution through Natural Selection
The evolution of the myriad living organisms on Earth is an enigma that has fascinated scientists for decades. Charles Darwin's natural selectivity is the best-established explanation. This is because those who are better adapted are able to reproduce faster and longer than those who are less well-adapted. Over time, the population of well-adapted individuals becomes larger and eventually forms a new species.
Natural selection is a process that is cyclical and involves the interaction of three factors that are: reproduction, variation and inheritance. Sexual reproduction and mutations increase the genetic diversity of a species. Inheritance refers to the transmission of genetic characteristics, which includes recessive and dominant genes, to their offspring. Reproduction is the generation of fertile, viable offspring which includes both sexual and asexual methods.
All of these elements have to be in equilibrium for natural selection to occur. If, for instance, a dominant gene allele causes an organism reproduce and last longer than the recessive allele The dominant allele becomes more prevalent in a population. But if the allele confers a disadvantage in survival or decreases fertility, it will disappear from the population. The process is self reinforcing which means that the organism with an adaptive characteristic will live and reproduce far more effectively than one with a maladaptive characteristic. The more offspring that an organism has the more fit it is that is determined by its ability to reproduce and survive. People with desirable traits, like a longer neck in giraffes or bright white colors in male peacocks are more likely survive and have offspring, which means they will eventually make up the majority of the population over time.
Natural selection is an aspect of populations and not on individuals. This is a crucial distinction from the Lamarckian theory of evolution that states that animals acquire traits through usage or inaction. For example, if a animal's neck is lengthened by reaching out to catch prey and its offspring will inherit a larger neck. The differences in neck size between generations will continue to increase until the giraffe is no longer able to reproduce with other giraffes.
Evolution by Genetic Drift
Genetic drift occurs when the alleles of one gene are distributed randomly in a group. At some point, one will reach fixation (become so common that it cannot be eliminated through natural selection), while other alleles will fall to lower frequencies. This can result in a dominant allele at the extreme. The other alleles are basically eliminated and heterozygosity has decreased to zero. In a small group, this could lead to the complete elimination of recessive alleles. This is called a bottleneck effect, and it is typical of the kind of evolutionary process that occurs when a large number of people migrate to form a new group.
A phenotypic bottleneck may occur when the survivors of a disaster such as an epidemic or mass hunt, are confined within a narrow area. The survivors will be largely homozygous for the dominant allele which means they will all share the same phenotype and therefore share the same fitness characteristics. This may be caused by war, earthquake or even a cholera outbreak. The genetically distinct population, if left, could be susceptible to genetic drift.
Walsh Lewens, Walsh, and Ariew define drift as a departure from the expected value due to differences in fitness. They give a famous instance of twins who are genetically identical and have the exact same phenotype and yet one is struck by lightning and dies, while the other lives and reproduces.
This kind of drift can play a very important part in the evolution of an organism. However, it is not the only method to evolve. Natural selection is the primary alternative, in which mutations and migration maintain the phenotypic diversity of the population.
Stephens asserts that there is a huge difference between treating drift like an actual cause or force, and treating other causes such as migration and selection mutation as forces and causes. Stephens claims that a causal process account of drift permits us to differentiate it from other forces, and this distinction is vital. He further argues that drift has a direction: that is it tends to reduce heterozygosity. He also claims that it also has a magnitude, that is determined by population size.
Evolution through Lamarckism
Biology students in high school are often introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is commonly referred to as "Lamarckism" and it states that simple organisms develop into more complex organisms via the inherited characteristics which result from the natural activities of an organism, use and disuse. Lamarckism is typically illustrated by a picture of a giraffe that extends its neck to reach leaves higher up in the trees. This would cause giraffes to pass on their longer necks to their offspring, who then become taller.
Lamarck the French zoologist, presented a revolutionary concept in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. 무료에볼루션 challenged conventional wisdom on organic transformation. In his view, living things had evolved from inanimate matter via an escalating series of steps. Lamarck wasn't the only one to propose this, but he was widely thought of as the first to give the subject a comprehensive and general treatment.
The predominant story is that Charles Darwin's theory on evolution by natural selection and Lamarckism were competing in the 19th century. Darwinism eventually won, leading to the development of what biologists now refer to as the Modern Synthesis. The theory argues the possibility that acquired traits can be inherited, and instead argues that organisms evolve by the symbiosis of environmental factors, like natural selection.
special info and his contemporaries believed in the idea that acquired characters could be passed on to the next generation. However, this idea was never a key element of any of their theories about evolution. This is partly due to the fact that it was never tested scientifically.
However, it has been more than 200 years since Lamarck was born and in the age of genomics, there is a large amount of evidence that supports the heritability of acquired characteristics. This is also known as "neo Lamarckism", or more often epigenetic inheritance. It is a form of evolution that is as valid as the more popular neo-Darwinian model.
Evolution by Adaptation
One of the most widespread misconceptions about evolution is that it is driven by a sort of struggle to survive. This is a false assumption and overlooks other forces that drive evolution. The struggle for existence is better described as a fight to survive in a certain environment. This could be a challenge for not just other living things, but also the physical environment.
To understand how evolution functions it is beneficial to understand what is adaptation. Adaptation is any feature that allows a living thing to live in its environment and reproduce. It can be a physiological structure, such as fur or feathers, or a behavioral trait, such as moving to the shade during hot weather or stepping out at night to avoid cold.
The survival of an organism is dependent on its ability to extract energy from the surrounding environment and interact with other living organisms and their physical surroundings. The organism must have the right genes for producing offspring and to be able to access enough food and resources. Moreover, the organism must be able to reproduce itself in a way that is optimally within its niche.
These elements, along with mutations and gene flow can cause an alteration in the ratio of different alleles within the gene pool of a population. The change in frequency of alleles could lead to the development of new traits, and eventually, new species over time.
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 to provide insulation, long legs for running away from predators and camouflage to hide. However, a complete understanding of adaptation requires attention to the distinction between physiological and behavioral traits.
Physiological adaptations like thick fur or gills, are physical traits, whereas behavioral adaptations, such as the tendency to search for companions or to move to shade in hot weather, aren't. Additionally it is important to understand that a lack of thought does not mean that something is an adaptation. In fact, failure to consider the consequences of a choice can render it unadaptive even though it may appear to be reasonable or even essential.