The Top Free Evolution Gurus Do 3 Things
What is Free Evolution?
Free evolution is the idea that natural processes can lead to the development of organisms over time. This includes the evolution of new species and the alteration of the appearance of existing ones.
Many examples have been given of this, such as different varieties of fish called sticklebacks that can be found in salt or fresh water, and walking stick insect varieties that prefer specific host plants. These mostly reversible traits permutations do not explain the fundamental changes in the basic body plan.
Evolution through Natural Selection
Scientists have been fascinated by the development of all the living organisms that inhabit our planet for ages. Charles Darwin's natural selection is the most well-known explanation. This is because people who are more well-adapted have more success in reproduction and survival than those who are less well-adapted. Over time, a population of well-adapted individuals increases and eventually becomes a new species.
Natural selection is a cyclical process that involves the interaction of three factors: variation, inheritance and reproduction. Variation is caused by mutations and sexual reproduction, both of which increase the genetic diversity within the species. Inheritance is the term used to describe the transmission of a person’s genetic traits, including both dominant and recessive genes to their offspring. Reproduction is the process of producing fertile, viable offspring, which includes both sexual and asexual methods.
Natural selection only occurs when all of these factors are in harmony. If, for example, a dominant gene allele allows an organism to reproduce and last longer than the recessive allele then the dominant allele will become more common in a population. But if the allele confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. This process is self-reinforcing meaning that an organism with a beneficial trait will survive and reproduce more than one with an unadaptive trait. The greater an organism's fitness which is measured by its ability to reproduce and endure, is the higher number of offspring it can produce. Individuals with favorable traits, like a long neck in giraffes, or bright white color patterns on male peacocks, are more likely than others to survive and reproduce and eventually lead to them becoming the majority.
Natural selection is only an element in the population and not on individuals. This is a major distinction from the Lamarckian theory of evolution which argues that animals acquire traits through use or disuse. For 에볼루션 코리아 , if a animal's neck is lengthened by stretching to reach prey and its offspring will inherit a more long neck. The differences in neck length between generations will continue until the giraffe's neck becomes so long that it can not breed with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when alleles of one gene are distributed randomly in a group. In the end, one will attain fixation (become so widespread that it can no longer be removed through natural selection), while other alleles fall to lower frequency. In extreme cases, this leads to dominance of a single allele. The other alleles are basically eliminated and heterozygosity has decreased to zero. In a small group this could result in the complete elimination of the recessive allele. This is known as a bottleneck effect and it is typical of the kind of evolutionary process when a large number of individuals migrate to form a new population.
A phenotypic bottleneck may also occur when survivors of a disaster such as an outbreak or mass hunting incident are concentrated in the same area. The survivors will have an dominant allele, and will share the same phenotype. This can be caused by earthquakes, war, or even plagues. Whatever the reason the genetically distinct population that remains could be susceptible to genetic drift.
에볼루션 무료체험 , Walsh, and Ariew define drift as a departure from the expected values due to differences in fitness. They give a famous instance of twins who are genetically identical, share the exact same phenotype and yet one is struck by lightening and dies while the other lives and reproduces.
This kind of drift can play a very important part in the evolution of an organism. But, it's not the only way to develop. Natural selection is the most common alternative, where mutations and migration maintain the phenotypic diversity in the population.
Stephens asserts that there is a huge distinction between treating drift as a force or cause, and considering other causes, such as selection mutation and migration as forces and causes. He claims that a causal mechanism account of drift allows us to distinguish it from other forces, and this distinction is crucial. He argues further that drift has both a direction, i.e., it tends towards eliminating heterozygosity. It also has a size, that is determined by the size of the population.
Evolution by Lamarckism
In high school, students study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution is often referred to as "Lamarckism" and it states that simple organisms grow into more complex organisms through the inherited characteristics that are a result of the organism's natural actions use and misuse. Lamarckism is usually illustrated with a picture of a giraffe stretching its neck to reach the higher branches in the trees. This causes the longer necks of giraffes to be passed onto their offspring who would then grow even taller.
Lamarck the French Zoologist, introduced a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. In his view living things evolved from inanimate matter through the gradual progression of events. Lamarck was not the first to suggest that this could be the case but the general consensus is that he was the one having given the subject his first comprehensive and comprehensive analysis.
The most popular story is that Charles Darwin's theory of evolution by natural selection and Lamarckism fought in the 19th Century. Darwinism eventually prevailed, leading to the development of what biologists call the Modern Synthesis. This theory denies acquired characteristics can be passed down and instead argues that organisms evolve through the selective influence of environmental elements, like Natural Selection.
Although Lamarck endorsed the idea of inheritance by acquired characters and his contemporaries also spoke of this idea, it was never a major feature in any of their evolutionary theories. This is partly because it was never scientifically validated.
However, it has been more than 200 years since Lamarck was born and in the age of genomics there is a huge amount of evidence to support the heritability of acquired characteristics. This is also known as "neo Lamarckism", or more commonly epigenetic inheritance. This is a variant that is just as valid as the popular neodarwinian model.
Evolution by Adaptation
One of the most widespread misconceptions about evolution is that it is driven by a sort of struggle to survive. In reality, this notion is inaccurate and overlooks the other forces that drive evolution. The fight for survival can be more precisely described as a fight to survive within a particular environment, which may include not just other organisms but also the physical environment.
To understand how evolution operates it is beneficial to understand what is adaptation. 에볼루션 코리아 is a feature that allows a living organism to survive in its environment and reproduce. It could be a physical feature, like feathers or fur. It could also be a behavior trait, like moving towards shade during the heat, or moving out to avoid the cold at night.
The capacity of a living thing to extract energy from its surroundings and interact with other organisms as well as their physical environments is essential to its survival. The organism must have the right genes to create offspring, and be able to find enough food and resources. In addition, the organism should be capable of reproducing itself at an optimal rate within its environment.
These factors, along with mutation and gene flow, lead to a change in the proportion of alleles (different varieties of a particular gene) in a population's gene pool. This shift in the frequency of alleles could lead to the development of new traits and eventually new species over time.
A lot of the traits we appreciate in animals and plants are adaptations. For example lung or gills that extract oxygen from air feathers and fur as insulation, long legs to run away from predators and camouflage to conceal. To understand adaptation it is crucial to differentiate between physiological and behavioral traits.
Physiological adaptations, such as the thick fur or gills are physical characteristics, whereas behavioral adaptations, such as the desire to find companions or to retreat to shade in hot weather, are not. Additionally, it is important to note that lack of planning does not make something an adaptation. Failure to consider the implications of a choice even if it appears to be rational, may cause it to be unadaptive.