What is Free Evolution?

Free evolution is the concept that natural processes can cause organisms to evolve over time. This includes the evolution of new species as well as the change in appearance of existing ones.

A variety of examples have been provided of this, 에볼루션 바카라 such as different varieties of stickleback fish that can live in salt or fresh water, as well as walking stick insect varieties that favor particular host plants. These reversible traits do not explain the fundamental changes in basic body plans.

Evolution by Natural Selection

Scientists have been fascinated by the evolution of all living creatures that live on our planet for centuries. Charles Darwin's natural selection theory is the best-established explanation. This is because people who are more well-adapted survive and reproduce more than those who are less well-adapted. Over time, a population of well adapted individuals grows 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 of a species. Inheritance refers to the transmission of a person’s genetic traits, including recessive and dominant genes to their offspring. Reproduction is the production of viable, fertile offspring, which includes both sexual and asexual methods.

All of these elements must be in balance to allow natural selection to take place. If, for instance, a dominant gene allele makes an organism reproduce and last longer than the recessive allele then the dominant allele becomes more prevalent in a group. However, if the allele confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. This process is self-reinforcing meaning that a species with a beneficial trait is more likely to survive and reproduce than one with a maladaptive characteristic. The more offspring an organism produces the more fit it is which is measured by its ability to reproduce and survive. People with good traits, like having a longer neck in giraffes and bright white color patterns in male peacocks, are more likely to survive and produce offspring, and thus will become the majority of the population over time.

Natural selection only affects populations, not individual organisms. This is a crucial distinction from the Lamarckian theory of evolution which holds that animals acquire traits through usage or inaction. If a giraffe expands its neck to reach prey and the neck grows longer, then the offspring will inherit this trait. The differences in neck size between generations will increase until the giraffe is no longer able to reproduce with other giraffes.

Evolution through Genetic Drift

In genetic drift, alleles within a gene can be at different frequencies in a population by chance events. At some point, only one of them will be fixed (become common enough to no more be eliminated through natural selection) and the other alleles decrease in frequency. In the extreme this, it leads to one allele dominance. Other alleles have been virtually eliminated and heterozygosity diminished to a minimum. In a small population it could result in the complete elimination of the recessive gene. This is known as a bottleneck effect and it is typical of the kind of evolutionary process that occurs when a large number of people migrate to form a new population.

A phenotypic bottleneck can also occur when the survivors of a disaster such as an outbreak or mass hunting event are concentrated in the same area. The survivors will carry an dominant allele, and will have the same phenotype. This may be the result of a war, an earthquake or even a disease. The genetically distinct population, if it remains 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 a famous instance of twins who are genetically identical, share identical phenotypes but one is struck by lightening and dies while the other lives and reproduces.

This kind of drift can be very important in the evolution of an entire species. However, it is not the only way to develop. Natural selection is the most common alternative, in which mutations and migration keep the phenotypic diversity in the population.

Stephens argues that there is a significant distinction between treating drift as a force or as an underlying cause, and considering other causes of evolution such as mutation, selection and migration as forces or causes. He argues that a causal-process model of drift allows us to distinguish it from other forces and that this differentiation is crucial. He also argues that drift has a direction, i.e., it tends towards eliminating heterozygosity. It also has a size, that is determined by the size of the population.

Evolution by Lamarckism

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

Lamarck was a French Zoologist. 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 previous understanding of organic transformation. According to him, living things had evolved from inanimate matter through the gradual progression of events. Lamarck wasn't the only one to suggest this, but he was widely thought of as the first to offer the subject a comprehensive and general explanation.

The predominant story is that Charles Darwin's theory of natural selection and Lamarckism were rivals in the 19th Century. Darwinism ultimately prevailed and led to what biologists call the Modern Synthesis. The Modern Synthesis theory denies that traits acquired through evolution can be inherited and instead, it argues that organisms develop through the action of environmental factors, including natural selection.

While Lamarck endorsed the idea of inheritance by acquired characters and his contemporaries paid lip-service to this notion however, it was not an integral part of any of their evolutionary theories. This is partly because it was never scientifically tested.

But it is now more than 200 years since Lamarck was born and, in the age of genomics there is a huge amount of evidence that supports the possibility of inheritance of acquired traits. This is often referred to as "neo-Lamarckism" or, more commonly, epigenetic inheritance. This is a version that is as valid as the popular Neodarwinian model.

Evolution through Adaptation

One of the most commonly-held misconceptions about evolution is being driven by a fight for survival. In fact, this view misrepresents natural selection and ignores the other forces that are driving evolution. The fight for survival can be better described as a fight to survive in a specific environment. This may include not only other organisms as well as the physical environment itself.

To understand how evolution functions it is important to consider what adaptation is. Adaptation is any feature that allows a living organism to live in its environment and reproduce. It could be a physiological structure such as fur or feathers or a behavioral characteristic such as a tendency to move into the shade in hot weather or coming out at night to avoid the cold.

The survival of an organism depends on its ability to extract energy from the environment and interact with other living organisms and their physical surroundings. The organism must have the right genes to produce offspring and to be able to access enough food and resources. Moreover, the organism must be able to reproduce itself in a way that is optimally within its environment.

These factors, in conjunction with mutations and gene flow, can lead to a shift in the proportion of different alleles within the population's gene pool. As time passes, this shift in allele frequency can result in the development 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, fur and feathers as insulation and long legs to get away from predators and camouflage for hiding. To understand adaptation it is essential to differentiate between physiological and behavioral traits.

Physical traits such as thick fur and gills are physical traits. Behavioral adaptations are not like the tendency of animals to seek companionship or retreat into shade during hot temperatures. It is also important to note that insufficient planning does not result in an adaptation. In fact, a failure to think about the implications of a choice can render it unadaptable even though it appears to be reasonable or even essential.