10 Healthy Free Evolution Habits
What is Free Evolution?
Free evolution is the concept that natural processes can cause organisms to develop over time. This includes the evolution of new species and change in appearance of existing species.
This is evident in many examples, including stickleback fish varieties that can thrive in saltwater or fresh water and walking stick insect types that are apprehensive about particular host plants. These typically reversible traits do not explain the fundamental changes in basic body plans.
Evolution through Natural Selection
Scientists have been fascinated by the evolution of all the living organisms that inhabit our planet for many centuries. Charles Darwin's natural selectivity is the best-established explanation. This happens when people who are more well-adapted are able to reproduce faster and longer than those who are less well-adapted. Over time, a population of well-adapted individuals increases and eventually becomes a new species.
Natural selection is an ongoing process that is characterized by the interaction of three factors that are inheritance, variation and reproduction. Sexual reproduction and mutation increase genetic diversity in a species. Inheritance is the transfer of a person's genetic traits to the offspring of that person, which includes both recessive and dominant alleles. Reproduction is the production of fertile, viable offspring, which includes both asexual and sexual methods.
All of these variables have to be in equilibrium for natural selection to occur. If, for example an allele of a dominant gene allows an organism to reproduce and live longer than the recessive allele, then the dominant allele is more prevalent in a group. But if the allele confers an unfavorable survival advantage or decreases fertility, it will be eliminated from the population. The process is self reinforcing which means that an organism that has an adaptive trait will live and reproduce more quickly than one with a maladaptive characteristic. The more offspring an organism produces the better its fitness which is measured by its ability to reproduce itself and live. People with good characteristics, such as a long neck in the giraffe, or bright white color patterns on male peacocks, are more likely than others to survive and reproduce, which will eventually lead to them becoming the majority.
Natural selection is only a force for populations, not individual organisms. This is a major distinction from the Lamarckian theory of evolution, which claims that animals acquire traits by use or inactivity. If a giraffe expands its neck to catch prey, and the neck becomes longer, then the offspring will inherit this characteristic. The differences in neck length between generations will persist until the neck of the giraffe becomes so long that it can 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 group due to random events. In the end, one will reach fixation (become so widespread that it can no longer be removed by natural selection) and the other alleles drop to lower frequency. 에볼루션 사이트 can result in dominance in extreme. The other alleles are essentially eliminated, and heterozygosity falls to zero. In a small population this could result in the complete elimination of recessive alleles. This scenario is called the bottleneck effect. It is typical of the evolution process that occurs when a large number individuals migrate to form a population.
A phenotypic bottleneck may happen when the survivors of a disaster, such as an epidemic or a massive hunting event, are condensed in a limited area. The remaining individuals will be mostly homozygous for the dominant allele which means that they will all have the same phenotype, and consequently share the same fitness characteristics. This can be caused by earthquakes, war or even a plague. 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, whereas the other continues to reproduce.
This kind of drift could be crucial in the evolution of a species. However, it's not the only way to develop. The most common alternative is a process called natural selection, in which the phenotypic diversity of an individual is maintained through mutation and migration.
Stephens claims that there is a huge difference between treating drift like an actual cause or force, and considering other causes, such as selection mutation and migration as causes and forces. Stephens claims that a causal process model of drift allows us to differentiate it from other forces and that this differentiation is crucial. He argues further that drift has both a direction, i.e., it tends to eliminate heterozygosity. It also has a size that 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, commonly referred to as “Lamarckism” is based on the idea that simple organisms develop into more complex organisms through adopting traits that result from the organism's use and misuse. Lamarckism is typically illustrated by the image of a giraffe stretching its neck to reach the higher branches in the trees. This could result in giraffes passing on their longer necks to offspring, who would then become taller.
Lamarck was a French zoologist and, in his opening lecture for his course on invertebrate Zoology at the Museum of Natural History in Paris on 17 May 1802, he presented an innovative concept that completely challenged previous thinking about organic transformation. In his view living things evolved from inanimate matter through the gradual progression of events. Lamarck was not the first to suggest that this could be the case, but the general consensus is that he was the one being the one who gave the subject its first general and comprehensive treatment.
The dominant story is that Charles Darwin's theory of evolution by natural selection and Lamarckism were rivals in the 19th Century. Darwinism eventually prevailed, leading to the development of what biologists now refer to as the Modern Synthesis. The Modern Synthesis theory denies that traits acquired through evolution can be inherited and instead suggests that organisms evolve by the symbiosis of environmental factors, like natural selection.
While Lamarck supported the notion of inheritance through acquired characters and his contemporaries paid lip-service to this notion but it was not a central element in any of their evolutionary theories. This is largely due to the fact that it was never validated scientifically.
It's been more than 200 years since Lamarck was born and in the age genomics there is a vast amount of evidence to support the heritability of acquired characteristics. This is also referred to as "neo Lamarckism", or more often epigenetic inheritance. It is a version of evolution that is as valid as the more popular Neo-Darwinian theory.
Evolution through Adaptation
One of the most widespread misconceptions about evolution is that it is a result of a kind of struggle to survive. 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 particular environment. This may include not only other organisms but also the physical surroundings themselves.
To understand how evolution functions, it is helpful to think about what adaptation is. It is a feature that allows a living organism to survive in its environment and reproduce. It can be a physiological feature, like feathers or fur or a behavioral characteristic, such as moving into the shade in hot weather or coming out 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 environment, is crucial to its survival. The organism needs to have the right genes to create offspring, and it should be able to locate sufficient food and other resources. Moreover, the organism must be capable of reproducing at a high rate within its environmental niche.
These factors, together with gene flow and mutations can result in a shift in the proportion of different alleles in the gene pool of a population. Over time, this change in allele frequencies can lead to the emergence of new traits, and eventually new species.
Many of the characteristics we admire about animals and plants are adaptations, for example, the lungs or gills that extract oxygen from the air, feathers or fur for insulation and long legs for running away from predators, and camouflage to hide. However, a proper understanding of adaptation requires attention to the distinction between behavioral and physiological characteristics.
Physiological adaptations like thick fur or gills, are physical traits, whereas behavioral adaptations, such as the tendency to seek out friends or to move to the shade during hot weather, are not. Furthermore it is important to remember that lack of planning does not mean that something is an adaptation. In fact, failure to think about the consequences of a behavior can make it unadaptive even though it may appear to be reasonable or even essential.