What is Free Evolution?
Free evolution is the notion that the natural processes that organisms go through can lead to their development over time. This includes the appearance and development of new species.
A variety of examples have been provided of this, including various kinds of stickleback fish that can live in fresh or salt water and walking stick insect varieties that are attracted to specific host plants. These are mostly reversible traits, however, cannot explain fundamental changes in basic body plans.
Evolution by Natural Selection
The development of the myriad of living organisms on Earth is an enigma that has intrigued scientists for decades. 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. As time passes, the number of well-adapted individuals becomes larger and eventually forms a new species.
Natural selection is an ongoing process and involves the interaction of 3 factors: variation, reproduction and inheritance. Variation is caused by mutations and sexual reproduction both of which enhance the genetic diversity of the species. Inheritance refers the transmission of genetic traits, including both dominant and
에볼루션 코리아 recessive genes and their offspring. Reproduction is the process of producing viable, fertile offspring, which includes both sexual and asexual methods.
Natural selection is only possible when all of these factors are in balance. If, for example, a dominant gene allele allows an organism to reproduce and last longer than the recessive gene, then the dominant allele will become more prevalent in a population. If the allele confers a negative survival advantage or lowers the fertility of the population, it will go away. The process is self-reinforcing, which means that an organism with an adaptive trait will live and reproduce more quickly than those with a maladaptive feature. The more offspring an organism can produce the more fit it is which is measured by its capacity to reproduce and survive. People with good traits, like having a long neck in the giraffe, or bright white patterns on male peacocks are more likely than others to live and reproduce which eventually leads to them becoming the majority.
Natural selection only acts on populations, not on individual organisms. This is a significant distinction from the Lamarckian evolution theory that states that animals acquire traits due to use or lack of use. For instance,
에볼루션 블랙잭 if a giraffe's neck gets longer through stretching to reach prey its offspring will inherit a longer neck. The length difference between generations will persist until the neck of the giraffe becomes too long to no longer breed with other giraffes.
Evolution through Genetic Drift
In the process of genetic drift, alleles within a gene can attain different frequencies within a population through random events. Eventually, one of them will reach fixation (become so common that it can no longer be removed through natural selection), while other alleles fall to lower frequencies. This can lead to an allele that is dominant in extreme. The other alleles are eliminated, and heterozygosity decreases to zero. In a small population it could lead to the complete elimination of recessive allele. This scenario is known as a bottleneck effect and it is typical of evolutionary process when a large amount of individuals migrate to form a new population.
A phenotypic bottleneck may also occur when the survivors of a catastrophe such as an outbreak or mass hunting incident are concentrated in a small area. The survivors are likely to be homozygous for the dominant allele which means they will all share the same phenotype and will therefore have the same fitness characteristics. This could be caused by war, earthquakes or even a plague. Whatever the reason, the genetically distinct population that is left might be susceptible to genetic drift.
Walsh Lewens,
바카라 에볼루션 Lewens, and Ariew utilize a "purely outcome-oriented" definition of drift as any departure from expected values for different fitness levels. They cite the famous example of twins who are genetically identical and share the same phenotype, but one is struck by lightning and dies, but the other is able to reproduce.
This type of drift can play a very important part in the evolution of an organism. However, it is not the only method to progress. The primary alternative is to use a process known as natural selection, where the phenotypic diversity of a population is maintained by mutation and migration.
Stephens asserts that there is a significant difference between treating drift like an actual cause or force, and treating other causes such as migration and selection mutation as causes and forces. He claims that a causal-process model of drift allows us to distinguish it from other forces, and
에볼루션 바카라 this differentiation is crucial. He further argues that drift has a direction, i.e., it tends to reduce heterozygosity. It also has a size which is determined based on the size of the population.
Evolution by Lamarckism
Biology students in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution, commonly called "Lamarckism is based on the idea that simple organisms develop into more complex organisms through inheriting characteristics that are a product of the use and abuse of an organism. Lamarckism is typically illustrated with an image of a giraffe stretching its neck further to reach leaves higher up in the trees. This would cause giraffes to pass on their longer necks to offspring, who then get taller.
Lamarck, a French Zoologist from France, presented an idea that was revolutionary in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the traditional thinking about organic transformation. According to Lamarck, living creatures evolved from inanimate material through a series of gradual steps. Lamarck wasn't the first to make this claim but he was regarded 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 competing in the 19th century. Darwinism ultimately won which led to what biologists refer to as the Modern Synthesis. The theory argues that acquired traits can be passed down and instead, it claims that organisms evolve through the selective influence of environmental elements, like Natural Selection.
Lamarck and his contemporaries supported the notion that acquired characters could be passed down to the next generation. However, this concept was never a central part of any of their theories on evolution. This is partly due to the fact that it was never validated scientifically.
But it is now more than 200 years since Lamarck was born and in the age of genomics, there is a large amount of evidence to support the heritability of acquired characteristics. It is sometimes referred to as "neo-Lamarckism" or more often epigenetic inheritance. It is a variant of evolution that is as relevant 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 type of struggle to survive. In reality, this notion misrepresents natural selection and ignores the other forces that are driving evolution. The fight for survival can be more accurately described as a struggle to survive in a certain environment. This could include not just other organisms but also the physical environment.
Understanding adaptation is important to understand evolution. It is a feature that allows a living thing to live in its environment and reproduce.
