How To Choose The Right Free Evolution On The Internet
What is Free Evolution?
Free evolution is the concept that natural processes can cause organisms to evolve over time. This includes the creation of new species and transformation of the appearance of existing ones.
A variety of examples have been provided of this, including various varieties of stickleback fish that can live in salt or fresh water, and walking stick insect varieties that prefer particular host plants. These reversible traits cannot explain fundamental changes to the body's basic plans.
Evolution through Natural Selection
Scientists have been fascinated by the evolution of all living organisms that inhabit our planet for ages. The most well-known explanation is Darwin's natural selection process, which occurs when individuals that are better adapted survive and reproduce more successfully than those less well-adapted. Over time, a population of well-adapted individuals increases and eventually creates a new species.
Natural selection is an ongoing process and involves the interaction of 3 factors including reproduction, variation and inheritance. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within the species. Inheritance is the term used to describe the transmission of a person's genetic traits, which include both dominant and recessive genes to their offspring. Reproduction is the process of generating viable, fertile offspring. This can be accomplished via sexual or asexual methods.
All of these variables must be in harmony for natural selection to occur. If, for instance the dominant gene allele causes an organism reproduce and last longer than the recessive allele, then the dominant allele is more common in a population. However, if the gene confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. This process is self-reinforcing meaning that the organism with an adaptive trait will live and reproduce far more effectively than those with a maladaptive feature. The greater an organism's fitness as measured by its capacity to reproduce and survive, is the more offspring it produces. People with good characteristics, like longer necks in giraffes and bright white color patterns in male peacocks are more likely to be able to survive and create offspring, and thus will make up the majority of the population over time.
Natural selection is only a force for populations, not individual organisms. This is a crucial distinction from the Lamarckian theory of evolution that states that animals acquire traits through use or lack of use. For instance, if the giraffe's neck gets longer through stretching to reach prey and its offspring will inherit a larger neck. The length difference between generations will continue until the neck of the giraffe becomes too long that it can no longer breed with other giraffes.
Evolution through Genetic Drift
In genetic drift, alleles within a gene can attain different frequencies within a population through random events. In the end, only one will be fixed (become common enough to no longer be eliminated by natural selection) and the other alleles drop in frequency. This can lead to dominance in extreme. The other alleles have been essentially eliminated and heterozygosity has diminished to zero. In a small population this could result in the complete elimination of recessive allele. This scenario is known as a bottleneck effect and it is typical of evolutionary process that occurs when a large amount of individuals move to form a new group.
A phenotypic 'bottleneck' can also occur when the survivors of a catastrophe like an outbreak or mass hunt event are concentrated in a small area. The survivors will carry an dominant allele, and will have the same phenotype. This could be the result of a conflict, earthquake or even a cholera outbreak. Regardless of the cause the genetically distinct group that is left might be susceptible to genetic drift.
Walsh Lewens, Lewens, and Ariew utilize Lewens, Walsh and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values of differences in fitness. They give the famous example of twins who are genetically identical and have exactly the same phenotype. However, one is struck by lightning and dies, whereas the other lives to reproduce.
This kind of drift can be crucial in the evolution of the species. This isn't the only method for evolution. The most common alternative is a process known as natural selection, in which the phenotypic variation of the population is maintained through mutation and migration.
Stephens claims that there is a significant difference between treating drift as a force or an underlying cause, and treating other causes of evolution such as selection, mutation, and migration as forces or causes. He argues that a causal-process model of drift allows us to distinguish it from other forces, and this differentiation is crucial. 에볼루션 바카라 argues that drift is both a direction, i.e., it tends to eliminate heterozygosity. It also has a size which is determined based on the size of the population.
Evolution through Lamarckism
Biology students in high school are frequently introduced to Jean-Baptiste Lamarck's (1744-1829) work. His theory of evolution is commonly known as "Lamarckism" and it states that simple organisms grow into more complex organisms by the inheritance of characteristics which result from the organism's natural actions usage, use and disuse. Lamarckism is usually illustrated with the image of a giraffe that extends its neck to reach leaves higher up in the trees. This could cause the longer necks of giraffes to be passed onto their offspring who would then grow even taller.
Lamarck was a French zoologist and, in his lecture to begin his course on invertebrate zoology at the Museum of Natural History in Paris on 17 May 1802, he introduced an original idea that fundamentally challenged the conventional wisdom about organic transformation. According to Lamarck, living creatures evolved from inanimate materials through a series gradual steps. Lamarck was not the first to propose this but he was regarded as the first to provide the subject a thorough and general explanation.
The predominant story is that Charles Darwin's theory on natural selection and Lamarckism were rivals in the 19th Century. Darwinism eventually triumphed and led to the development of what biologists today call the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead argues that organisms evolve through the selective influence of environmental factors, such as Natural Selection.
While Lamarck believed in the concept of inheritance by acquired characters, and his contemporaries also spoke of this idea however, it was not a central element in any of their evolutionary theorizing. This is due to the fact that it was never scientifically validated.
It's been more than 200 years since Lamarck was born and in the age of genomics there is a vast amount of evidence to support the heritability of acquired traits. This is referred to as "neo Lamarckism", or more generally epigenetic inheritance. This is a version that is as valid as the popular neodarwinian model.
Evolution through the process of adaptation
One of the most commonly-held misconceptions about evolution is its being driven by a struggle for survival. This is a false assumption and overlooks other forces that drive evolution. The fight for survival can be more effectively described as a struggle to survive within a specific environment, which can involve not only other organisms but as well the physical environment.
To understand how evolution works it is important to consider what adaptation is. Adaptation is any feature that allows a living thing to live in its environment and reproduce. It could be a physical feature, like feathers or fur. Or it can be a trait of behavior, like moving to the shade during hot weather or escaping the cold at night.
An organism's survival depends on its ability to draw energy from the surrounding environment and interact with other living organisms and their physical surroundings. The organism must have the right genes to produce offspring, and must be able to access enough food and other resources. Moreover, the organism must be capable of reproducing itself at a high rate within its niche.
These elements, along with mutations and gene flow, can lead to an alteration in the ratio of different alleles within the gene pool of a population. This change in allele frequency can result in the emergence of new traits, and eventually, new species in the course of time.
Many of the features we admire in plants and animals are adaptations. For instance lung or gills that extract oxygen from the air feathers and fur as insulation and long legs to get away from predators, and camouflage to hide. However, a complete understanding of adaptation requires a keen eye to the distinction between the physiological and behavioral traits.
Physical traits such as thick fur and gills are physical traits. The behavioral adaptations aren't like the tendency of animals to seek companionship or move into the shade in hot weather. It is important to keep in mind that lack of planning does not cause an adaptation. Failure to consider the effects of a behavior even if it appears to be logical, can make it unadaptive.