15 Best Documentaries On Free Evolution
What is Free Evolution?
Free evolution is the idea that the natural processes of living organisms can lead them to evolve over time. This includes the creation of new species and transformation of the appearance of existing species.
A variety of examples have been provided of this, including different kinds of stickleback fish that can live in salt or fresh water, and walking stick insect varieties that favor specific host plants. These are mostly reversible traits, however, cannot explain fundamental changes in body plans.
Evolution by Natural Selection
The development of the myriad of living creatures on Earth is a mystery that has intrigued scientists for centuries. The most widely accepted explanation is Charles Darwin's natural selection, an evolutionary process that occurs when individuals that are better adapted survive and reproduce more effectively than those that are less well-adapted. Over time, a community of well-adapted individuals increases and eventually becomes a new species.
Natural selection is a cyclical process that involves the interaction of three elements including inheritance, variation, and reproduction. Sexual reproduction and mutations increase genetic diversity in a species. Inheritance refers to the passing of a person's genetic traits to their offspring which includes both recessive and dominant alleles. Reproduction is the process of creating fertile, viable offspring. This can be achieved via sexual or asexual methods.
Natural selection is only possible when all the factors are in balance. For example the case where the dominant allele of the gene allows an organism to live and reproduce more frequently than the recessive allele the dominant allele will be more common within the population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will go away. The process is self reinforcing which means that the organism with an adaptive trait will live and reproduce far more effectively than those with a maladaptive trait. The higher the level of fitness an organism has as measured by its capacity to reproduce and endure, is the higher number of offspring it will produce. Individuals with favorable traits, like longer necks in giraffes or bright white patterns of color in male peacocks, are more likely to survive and have offspring, which means they will become the majority of the population in the future.
Natural selection is only an aspect of populations and not on individuals. This is a significant distinction from the Lamarckian theory of evolution which claims that animals acquire traits through use or disuse. For instance, if a Giraffe's neck grows longer due to stretching to reach for prey and its offspring will inherit a larger neck. The differences in neck length between generations will continue until the neck of the giraffe becomes too long to not breed with other giraffes.
Evolution by Genetic Drift
In the process of genetic drift, alleles within a gene can be at different frequencies in a population through random events. At some point, one will attain fixation (become so common that it can no longer be removed through natural selection) and the other alleles drop to lower frequencies. This can lead to dominance in extreme. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small group it could lead to the total elimination of recessive alleles. 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 population.
A phenotypic bottleneck could occur when survivors of a catastrophe such as an epidemic or a mass hunting event, are condensed in a limited area. The survivors will have an allele that is dominant and will share the same phenotype. This could be caused by war, earthquakes, or even plagues. 에볼루션 카지노 , if it is left susceptible to genetic drift.
Walsh, Lewens, and Ariew utilize Lewens, Walsh and Ariew employ a "purely outcome-oriented" definition of drift as any departure from the expected values of variations in fitness. They cite the famous example of twins who are both genetically identical and share the same phenotype. However one is struck by lightning and dies, but the other continues to reproduce.
This kind of drift can play a very important role in the evolution of an organism. However, it's not the only method to progress. Natural selection is the main alternative, in which mutations and migration keep phenotypic diversity within the population.
Stephens asserts that there is a vast distinction between treating drift as an agent or cause and considering other causes, such as selection mutation and migration as forces and causes. Stephens claims that a causal process explanation of drift lets us separate it from other forces and this distinction is crucial. He argues further that drift has an orientation, i.e., it tends to reduce heterozygosity. It also has a size, that is determined by the size of the population.
Evolution through Lamarckism
When students in high school study biology, they are often introduced to the work of Jean-Baptiste Lamarck (1744 - 1829). His theory of evolution, commonly referred to as "Lamarckism is based on the idea that simple organisms develop into more complex organisms inheriting characteristics that result from an organism's use and disuse. Lamarckism is usually illustrated with an image of a giraffe that extends its neck further to reach leaves higher up in the trees. This could cause giraffes' longer necks to be passed on to their offspring who would then grow even taller.
Lamarck, a French Zoologist, introduced a revolutionary concept in his opening lecture at the Museum of Natural History of Paris. He challenged conventional wisdom on organic transformation. According Lamarck, living organisms evolved from inanimate materials through a series of gradual steps. Lamarck was not the first to suggest this however he was widely considered to be the first to give the subject a thorough and general explanation.
The dominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were competing in the 19th century. Darwinism ultimately prevailed which led to what biologists call the Modern Synthesis. This theory denies acquired characteristics can be passed down and instead argues organisms evolve by the selective action of environment elements, like Natural Selection.
Lamarck and his contemporaries endorsed the notion that acquired characters could be passed down to the next generation. However, this concept was never a key element of any of their evolutionary theories. This is partly due to the fact that it was never tested scientifically.
It's been more than 200 years since the birth of Lamarck, and in the age genomics, there is a growing body of evidence that supports the heritability of acquired traits. This is often referred to as "neo-Lamarckism" or more frequently epigenetic inheritance. It is a variant of evolution that is as valid as the more popular Neo-Darwinian model.
Evolution through the process of adaptation
One of the most widespread misconceptions about evolution is that it is a result of a kind of struggle for survival. In fact, this view is inaccurate and overlooks the other forces that drive evolution. The struggle for existence is better described as a struggle to survive in a particular environment. This could include not just other organisms, but also the physical environment itself.
Understanding adaptation is important to comprehend evolution. Adaptation is any feature that allows a living thing to survive in its environment and reproduce. It can be a physiological structure, like feathers or fur or a behavioral characteristic, such as moving into the shade in hot weather or stepping out at night to avoid cold.
The capacity of an organism to extract energy from its environment and interact with other organisms, as well as their physical environments, is crucial to its survival. The organism should possess the right genes for producing offspring and to be able to access enough food and resources. The organism must also be able to reproduce itself at an amount that is appropriate for its niche.
These factors, together with gene flow and mutation result in changes in the ratio of alleles (different varieties of a particular gene) in the gene pool of a population. Over time, this change in allele frequencies could lead to the emergence of new traits and ultimately new species.
Many of the features we appreciate in plants and animals are adaptations. For instance, lungs or gills that draw oxygen from air feathers and fur for insulation long legs to run away from predators and camouflage to conceal. However, a thorough understanding of adaptation requires attention to the distinction between behavioral and physiological traits.
Physiological adaptations like the thick fur or gills are physical traits, while behavioral adaptations, such as the tendency to seek out friends or to move to shade in hot weather, are not. In 에볼루션 코리아 , it is important to note that a lack of thought does not mean that something is an adaptation. In fact, failing to think about the implications of a behavior can make it unadaptive even though it appears to be reasonable or even essential.
