What is Free Evolution?
Free evolution is the idea that natural processes can cause organisms to evolve over time. This includes the appearance and development of new species.
This has been proven by many examples such as the stickleback fish species that can thrive in saltwater or fresh water and walking stick insect species that are apprehensive about particular host plants. 무료에볼루션 are mostly reversible traits, however, cannot explain fundamental changes in basic body plans.
에볼루션 무료 바카라 by Natural Selection
The development of the myriad of living organisms on Earth is a mystery that has fascinated scientists for centuries. Charles Darwin's natural selection is the best-established explanation. This process occurs when individuals who are better-adapted have more success in reproduction and survival than those who are less well-adapted. As time passes, a group of well adapted individuals grows and eventually becomes a new species.
Natural selection is a process that is cyclical and involves the interaction of 3 factors: variation, reproduction and inheritance. Mutation and sexual reproduction increase the genetic diversity of a species. Inheritance refers to the passing of a person's genetic traits to his or her offspring which includes both recessive and dominant alleles. Reproduction is the production of fertile, viable offspring which includes both sexual and asexual methods.
All of these variables have to be in equilibrium for natural selection to occur. If, for example an allele of a dominant gene makes an organism reproduce and survive more than the recessive gene then the dominant allele is more common in a population. However, if the gene confers a disadvantage in survival or decreases fertility, it will be eliminated from the population. This process is self-reinforcing, which means that an organism that has an adaptive trait will live and reproduce much more than those with a maladaptive trait. The more offspring an organism produces the better its fitness, which is measured by its ability to reproduce itself and live. People with desirable traits, like having a long neck in Giraffes, or the bright white color patterns on male peacocks are more likely than others to survive and reproduce which eventually leads to them becoming the majority.
Natural selection only affects populations, not individual organisms. This is a major distinction from the Lamarckian theory of evolution which holds that animals acquire traits through the use or absence of use. If a giraffe stretches its neck to reach prey and its neck gets longer, then its offspring will inherit this characteristic. The difference in neck length between generations will continue until the giraffe's neck gets too long that it can no longer breed with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when alleles from the same gene are randomly distributed in a group. Eventually, only one will be fixed (become widespread enough to not longer be eliminated through natural selection) and the rest of the alleles will decrease in frequency. In the extreme this, it leads to one allele dominance. The other alleles are essentially eliminated, and heterozygosity is reduced to zero. In 에볼루션 슬롯게임 , this could result in the complete elimination of the recessive gene. Such a scenario would be called a bottleneck effect, and it is typical of evolutionary process when a lot of individuals move to form a new population.
A phenotypic 'bottleneck' can also occur when the survivors of a disaster like an outbreak or a mass hunting event are confined to a small area. The survivors will carry an dominant allele, and will share the same phenotype. This could be the result of a conflict, earthquake, or even a plague. The genetically distinct population, if it is left vulnerable to genetic drift.
Walsh, Lewens and Ariew define drift as a deviation from expected values due to differences in fitness. They give a famous example of twins that are genetically identical, have identical phenotypes and yet one is struck by lightening and dies while the other lives and reproduces.
This type of drift can play a crucial part in the evolution of an organism. It's not the only method of evolution. Natural selection is the most common alternative, in which mutations and migrations maintain the phenotypic diversity in the population.
Stephens argues there is a significant difference between treating drift like an agent or cause and considering other causes, such as migration and selection as forces and causes. He claims that a causal-process model of drift allows us to distinguish it from other forces and that this distinction is crucial. He argues further that drift has a direction, i.e., it tends towards eliminating heterozygosity. It also has a size which is determined based on population size.
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, often referred to as “Lamarckism” which means that simple organisms develop into more complex organisms by taking on traits that result from the use and abuse of an organism. Lamarckism is illustrated through the giraffe's neck being extended to reach higher levels of leaves in the trees. This could result in giraffes passing on their longer necks to offspring, who would then become taller.
Lamarck the French zoologist, presented an innovative idea in his opening lecture at the Museum of Natural History of Paris. He challenged traditional thinking about organic transformation. According to Lamarck, living things evolved from inanimate materials by a series of gradual steps. Lamarck wasn't the first to suggest this, but he was widely thought of as the first to provide the subject a comprehensive and general overview.
The predominant story is that Charles Darwin's theory of natural selection and Lamarckism fought in the 19th century. Darwinism eventually triumphed, leading to the development of what biologists now call the Modern Synthesis. This theory denies that acquired characteristics can be inherited, and instead, it argues that organisms develop through the selective action of environmental factors, including natural selection.
Lamarck and his contemporaries believed in the notion that acquired characters could be passed down to the next generation. However, this notion was never a key element of any of their theories about evolution. This is largely due to the fact that it was never validated scientifically.
It has been more than 200 year since Lamarck's birth and in the field of genomics there is a growing evidence base that supports the heritability of acquired traits. This is referred to as "neo Lamarckism", or more generally epigenetic inheritance. This is a variant that is just as valid as the popular Neodarwinian model.
Evolution through 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 ignores other forces driving evolution. The struggle for existence is better described as a struggle to survive in a certain environment. This can include not only other organisms but also the physical environment itself.
Understanding the concept of adaptation is crucial to comprehend evolution. Adaptation is any feature that allows a living thing to live in its environment and reproduce. It could be a physiological structure, such as feathers or fur, or a behavioral trait, such as moving to the shade during hot weather or stepping out at night to avoid the cold.
The survival of an organism depends on its ability to draw energy from the surrounding environment and interact with other living organisms and their physical surroundings. The organism needs to have the right genes to generate offspring, and it should be able to locate sufficient food and other resources. Furthermore, the organism needs to be capable of reproducing itself at a high rate within its environment.
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. As time passes, this shift in allele frequency can lead to the emergence of new traits and eventually new species.
Many of the features we find appealing in animals and plants are adaptations. For instance the lungs or gills which draw oxygen from air, fur and feathers as insulation, long legs to run away from predators, and camouflage to hide. To understand adaptation, it is important to differentiate between physiological and behavioral traits.
Physiological traits like large gills and thick fur are physical characteristics. Behavioral adaptations are not, such as the tendency of animals to seek out companionship or retreat into shade in hot temperatures. It is also important to keep in mind that the absence of planning doesn't cause an adaptation. Inability to think about the consequences of a decision, even if it appears to be logical, can cause it to be unadaptive.