15 Best Documentaries On Free Evolution

What is Free Evolution?

Free evolution is the concept that natural processes can cause organisms to evolve over time. This includes the appearance and growth of new species.

Many examples have been given of this, including different varieties of fish called sticklebacks that can be found in salt or fresh water, and walking stick insect varieties that are attracted to particular host plants. These reversible traits, however, cannot be the reason for fundamental changes in body plans.

Evolution by Natural Selection

Scientists have been fascinated by the evolution of all living creatures that inhabit our planet for many centuries. The most well-known explanation is that of Charles Darwin's natural selection process, a process that is triggered when more well-adapted individuals live longer and reproduce more effectively than those that are less well-adapted. Over time, the population of individuals who are well-adapted grows and eventually develops into a new species.

Natural selection is a cyclical process that is characterized by the interaction of three elements: variation, inheritance and reproduction. Variation is caused by mutation and sexual reproduction both of which enhance the genetic diversity within a species. Inheritance refers the transmission of a person's genetic traits, which include recessive and dominant genes and their offspring. Reproduction is the process of generating viable, fertile offspring. This can be accomplished through sexual or asexual methods.

Natural selection can only occur when all these elements are in equilibrium. For example, if a dominant allele at one gene causes an organism to survive and reproduce more often than the recessive allele the dominant allele will become more prevalent in the population. If the allele confers a negative survival advantage or decreases the fertility of the population, it will be eliminated. This process is self-reinforcing, which means that the organism with an adaptive trait will survive and reproduce more quickly than those with a maladaptive trait. The higher the level of fitness an organism has, measured by its ability reproduce and survive, is the more offspring it can produce. Individuals with favorable characteristics, such as a long neck in giraffes, or bright white color patterns on male peacocks, are more likely than others to live and reproduce and eventually lead to them becoming the majority.

Natural selection is only a force for populations, not on individual organisms. This is a crucial distinction from the Lamarckian theory of evolution that states that animals acquire traits due to the use or absence of use. For instance, if a giraffe's neck gets longer through stretching to reach for prey, its offspring will inherit a longer neck. The difference in neck length between generations will persist until the neck of the giraffe becomes too long to not breed with other giraffes.

Evolution by Genetic Drift

In genetic drift, the alleles within a gene can reach different frequencies within a population by chance events. In the end, one will attain fixation (become so common that it can no longer be removed by natural selection), while other alleles will fall to lower frequency. In the extreme this, it leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small number of people this could lead to the complete elimination of recessive gene. This scenario is called the bottleneck effect and is typical of the evolution process that occurs when a large number individuals migrate to form a group.

A phenotypic 'bottleneck' can also occur when survivors of a disaster like an outbreak or a mass hunting incident are concentrated in the same area. The remaining individuals will be mostly homozygous for the dominant allele, meaning that they all have the same phenotype, and consequently share the same fitness characteristics. This can be caused by war, earthquakes or even a plague. The genetically distinct population, if it remains vulnerable to genetic drift.

Walsh Lewens, Walsh, and Ariew define drift as a departure from the expected value due to differences in fitness. They cite the famous example of twins that are genetically identical and share the same phenotype, but one is struck by lightning and dies, but the other lives to reproduce.

This kind of drift could be crucial in the evolution of a species. But, it's not the only way to evolve. Natural selection is the primary alternative, where mutations and migrations maintain phenotypic diversity within the population.

Stephens asserts that there is a significant difference between treating drift as a force or as a cause and treating other causes of evolution like mutation, selection and migration as forces or causes. He argues that a causal-process explanation of drift lets us separate it from other forces and that this distinction is essential. He argues further that drift has both direction, i.e., it tends towards eliminating heterozygosity. It also has a size, which is determined by the size of the population.

Evolution through Lamarckism

Biology students in high school are frequently introduced to Jean-Baptiste Lemarck's (1744-1829) work. His theory of evolution is generally referred to as "Lamarckism" and it states that simple organisms grow into more complex organisms by the inheritance of characteristics that result from the natural activities of an organism use and misuse. Lamarckism is typically illustrated by the image of a giraffe that extends its neck further to reach leaves higher up in the trees. This would cause giraffes to pass on their longer necks to offspring, which then grow even taller.

Lamarck the French Zoologist, introduced an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged previous thinking on organic transformation. According to Lamarck, living creatures evolved from inanimate materials by a series of gradual steps. Lamarck was not the only one to suggest that this might be the case but the general consensus is that he was the one having given the subject his first comprehensive and comprehensive treatment.

The most popular story is that Charles Darwin's theory on natural selection and Lamarckism were competing in the 19th century.  에볼루션 무료 바카라  prevailed and led to what biologists call the Modern Synthesis. This theory denies acquired characteristics are passed down from generation to generation and instead argues organisms evolve by the influence of environment factors, including Natural Selection.

Lamarck and his contemporaries supported the idea that acquired characters could be passed down to future generations. However, this concept was never a central part of any of their theories about evolution. This is due to the fact that it was never tested scientifically.

It has been more than 200 years since the birth of Lamarck and in the field of age genomics there is a growing evidence-based body of evidence to support the heritability of acquired traits. This is sometimes called "neo-Lamarckism" or, more frequently epigenetic inheritance. It is a variant of evolution that is just as valid as the more well-known Neo-Darwinian theory.

Evolution by the process of adaptation

One of the most widespread misconceptions about evolution is that it is driven by a sort of struggle to survive. This view is inaccurate and overlooks other forces that drive evolution. The fight for survival is more accurately described as a struggle to survive in a specific environment. This could include not just other organisms as well as the physical environment itself.

To understand how evolution works, it is helpful to consider what adaptation is. It is a feature that allows a living organism to survive in its environment and reproduce. It can be a physical feature, like fur or feathers. Or it can be a behavior trait that allows you to move into the shade during hot weather, or escaping the cold at night.

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 possess the right genes to create offspring and to be able to access sufficient food and resources. In addition, the organism should be capable of reproducing itself at a high rate within its niche.

These factors, together with gene flow and mutations can result in changes in the proportion of different alleles within a population’s gene pool. This change in allele frequency can result in the emergence of novel 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 that extract oxygen from air feathers and fur for insulation, long legs to run away from predators, and camouflage to hide. However, a proper understanding of adaptation requires attention to the distinction between the physiological and behavioral characteristics.

Physiological adaptations, like thick fur or gills are physical traits, while behavioral adaptations, like the tendency to search for companions or to retreat to shade in hot weather, are not. It is important to note that lack of planning does not make an adaptation. A failure to consider the implications of a choice even if it appears to be rational, could cause it to be unadaptive.