Why All The Fuss Over Free Evolution?

What is Free Evolution?

Free evolution is the idea that natural processes can cause organisms to develop over time. This includes the development of new species as well as the alteration of the appearance of existing ones.

Many examples have been given of this, such as different kinds of stickleback fish that can live in salt or fresh water, and walking stick insect varieties that prefer specific host plants. These are mostly reversible traits can't, however, explain fundamental changes in body plans.

Evolution through Natural Selection

Scientists have been fascinated by the development of all living organisms that inhabit our planet for many centuries. The best-established explanation is Charles Darwin's natural selection process, an evolutionary process that occurs when individuals that are better adapted survive and reproduce more effectively than those less well-adapted. Over time, a community of well-adapted individuals expands and eventually creates a new species.

Natural selection is a process that is cyclical and 에볼루션 바카라 체험 - Evolutionkr.kr - involves the interaction of three factors that are: reproduction, variation and inheritance. Sexual reproduction and mutations increase genetic diversity in an animal species. Inheritance is the transfer of a person's genetic traits to the offspring of that person, which includes both dominant and recessive alleles. Reproduction is the process of generating viable, fertile offspring. This can be achieved by both asexual or sexual methods.

Natural selection only occurs when all these elements are in harmony. For instance the case where an allele that is dominant at a gene can cause an organism to live and reproduce more often than the recessive one, the dominant allele will become more prominent within the population. If the allele confers a negative advantage to survival or decreases the fertility of the population, it will go away. This process is self-reinforcing, which means that an organism with an adaptive trait will survive and reproduce more quickly than one with a maladaptive characteristic. The greater an organism's fitness which is measured by its ability to reproduce and endure, is the higher number of offspring it will produce. Individuals with favorable traits, such as longer necks in giraffes or bright white colors in male peacocks are more likely to survive and produce offspring, so they will eventually make up the majority of the population over time.

Natural selection is only a factor in populations 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 instance, if a animal's neck is lengthened by stretching to reach for prey, its offspring will inherit a more long neck. The length difference between generations will persist until the giraffe's neck gets too long to no longer breed with other giraffes.

Evolution through Genetic Drift

In the process of genetic drift, alleles within a gene can reach different frequencies within a population by chance events. In the end, only one will be fixed (become widespread enough to not longer be eliminated by natural selection) and the other alleles diminish in frequency. This can lead to dominance in the extreme. The other alleles are eliminated, and heterozygosity is reduced to zero. In a small number of people, this could result in the complete elimination of recessive gene. This scenario is called the bottleneck effect and is typical of an evolutionary process that occurs when a large number individuals migrate to form a population.

A phenotypic 'bottleneck' can also occur when survivors of a disaster like an outbreak or a mass hunting event are concentrated in an area of a limited size. The survivors will share an allele that is dominant and will share the same phenotype. This could be caused by earthquakes, war or even plagues. The genetically distinct population, if it is left vulnerable to genetic drift.

Walsh Lewens, Walsh and Ariew define drift as a deviation from the expected values due to differences in fitness. They cite the famous example of twins who are genetically identical and have exactly the same phenotype. However one is struck by lightning and dies, while the other is able to reproduce.

This kind of drift can play a crucial role in the evolution of an organism. This isn't the only method of evolution. Natural selection is the primary alternative, in which mutations and migration keep the phenotypic diversity in a population.

Stephens argues that there is a big difference between treating the phenomenon of drift as a force or as a cause and treating other causes of evolution, such as selection, mutation, and migration as forces or causes. He claims that a causal-process explanation of drift lets us differentiate it from other forces and that this distinction is essential. He also argues that drift is both an orientation, i.e., it tends to eliminate heterozygosity. It also has a size, which is determined by population size.

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 commonly called "Lamarckism" and it states that simple organisms grow into more complex organisms through the inherited characteristics which result from the organism's natural actions, use and disuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher branches in the trees. This could cause the longer necks of giraffes to be passed to their offspring, who would then grow even taller.

Lamarck the French zoologist, presented an innovative idea in his 17 May 1802 opening lecture at the Museum of Natural History of Paris. He challenged the conventional wisdom on organic transformation. According to Lamarck, living creatures evolved from inanimate material by a series of gradual steps. Lamarck wasn't the first to make this claim, but he was widely thought of as the first to offer the subject a comprehensive and general explanation.

The dominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were competing during the 19th century. Darwinism eventually won, leading to the development of what biologists refer to as the Modern Synthesis. This theory denies acquired characteristics can be passed down and instead argues organisms evolve by the selective influence of environmental factors, such as Natural Selection.

Although Lamarck endorsed the idea of inheritance through acquired characters and his contemporaries also offered a few words about this idea, it was never a central element in any of their theories about evolution. This is due to the fact that it was never tested scientifically.

However, it has been more than 200 years since Lamarck was born and, in the age of genomics there is a vast body of evidence supporting the heritability of acquired characteristics. It is sometimes referred to as "neo-Lamarckism" or more frequently, epigenetic inheritance. This is a variant that is as reliable as the popular Neodarwinian model.

Evolution by adaptation

One of the most common 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 fight for survival is more accurately described as a struggle to survive in a specific environment. This can include not just other organisms as well as the physical environment itself.

Understanding how adaptation works is essential to understand evolution. The term "adaptation" refers to any specific feature that allows an organism to survive and reproduce in its environment. It can be a physiological structure like feathers or fur or a behavior, such as moving into the shade in the heat or leaving at night to avoid cold.

The ability of an organism to draw energy from its environment and interact with other organisms as well as their physical environments, is crucial to its survival. The organism must possess the right genes to generate offspring, and must be able to find enough food and other resources. Furthermore, the organism needs to be able to reproduce itself at an optimal rate within its niche.

These elements, in conjunction with gene flow and mutation, lead to an alteration in the percentage of alleles (different forms of a gene) in the population's gene pool. This shift in the frequency of alleles can result in the emergence of new traits, and eventually, new species in the course of time.

Many of the features we admire in animals and plants are adaptations. For example, lungs or gills that draw oxygen from air feathers and fur for insulation long legs to run away from predators and camouflage for hiding. However, a proper understanding of adaptation requires attention to the distinction between the physiological and behavioral traits.

Physical characteristics like the thick fur and gills are physical characteristics. Behavior adaptations aren't like the tendency of animals to seek companionship or move into the shade in hot weather. Additionally, it is important to note that lack of planning does not make something an adaptation. Inability to think about the implications of a choice even if it appears to be logical, can make it unadaptive.