What is Free Evolution?
Free evolution is the concept that natural processes can cause organisms to evolve over time. This includes the development of new species and transformation of the appearance of existing species.
Numerous examples have been offered of this, such as different kinds of stickleback fish that can live in either salt or fresh water, and walking stick insect varieties that are attracted to particular host plants. These typically reversible traits are not able to explain fundamental changes to the body's basic plans.
Evolution by Natural Selection
Scientists have been fascinated by the evolution of all living organisms that inhabit our planet for many centuries. Charles Darwin's natural selection theory is the best-established explanation. This is because people who are more well-adapted are able to reproduce faster and longer than those who are less well-adapted. As time passes, a group of well adapted individuals grows and eventually creates a new species.
Natural selection is a process that is cyclical and involves the interaction of three factors including reproduction, variation and inheritance. Sexual reproduction and mutation increase the genetic diversity of a species. Inheritance refers to the transmission of a person's genetic characteristics, which includes both dominant and recessive genes, to their offspring. Reproduction is the process of generating fertile, viable offspring. This can be achieved through sexual or asexual methods.
All of these variables must be in harmony to allow natural selection to take place. If, for instance an allele of a dominant gene causes an organism reproduce and survive more than the recessive gene allele The dominant allele becomes more prevalent in a group. If the allele confers a negative survival advantage or reduces the fertility of the population, it will disappear. The process is self reinforcing meaning that the organism with an adaptive trait will live and reproduce more quickly than one with a maladaptive characteristic. The more offspring an organism can produce the better its fitness, which is measured by its ability to reproduce and survive. Individuals with favorable traits, like longer necks in giraffes, or bright white patterns of color in male peacocks are more likely to be able to survive and create offspring, which means they will eventually make up the majority of the population over time.
Natural selection is a factor in populations and not on individuals. This is a significant distinction from the Lamarckian evolution theory which holds that animals acquire traits through usage or inaction. For instance, if a animal's neck is lengthened by reaching out to catch prey, its offspring will inherit a larger neck. The length difference between generations will persist until the giraffe's neck gets so long that it can no longer breed with other giraffes.
Evolution through Genetic Drift
Genetic drift occurs when the alleles of one gene are distributed randomly within a population. In the end, one will reach fixation (become so widespread that it is unable to be eliminated through natural selection) and other alleles fall to lower frequencies. In the extreme this, it leads to one allele dominance. The other alleles have been basically eliminated and heterozygosity has been reduced to a minimum. In a small population it could lead to the complete elimination of recessive alleles. This scenario is called the bottleneck effect and is typical of an evolution process that occurs when an enormous number of individuals move to form a group.
A phenotypic bottleneck may occur when the survivors of a catastrophe such as an epidemic or mass hunt, are confined into a small area. click the following article will share a dominant allele and thus will have the same phenotype. This can be caused by earthquakes, war or even plagues. Regardless of the cause the genetically distinct population that is left might be prone to genetic drift.
Walsh, Lewens, and Ariew employ Lewens, Walsh, and Ariew use a "purely outcome-oriented" definition of drift as any departure from the expected values for variations in fitness. They cite a famous example of twins that are genetically identical and have identical phenotypes and yet one is struck by lightning and dies, while the other lives and reproduces.
This kind of drift can play a significant role in the evolution of an organism. However, it is not the only way to evolve. The main alternative is a process called natural selection, in which phenotypic variation in a population is maintained by mutation and migration.
Stephens claims that there is a significant distinction between treating drift as an agent or cause and considering other causes, such as selection mutation and migration as causes and forces. Stephens claims that a causal mechanism account of drift permits us to differentiate it from these other forces, and that this distinction is essential. He also argues that drift has both an orientation, i.e., it tends towards eliminating heterozygosity. It also has a size which is determined based on population size.
Evolution by 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 called "Lamarckism is based on the idea that simple organisms evolve into more complex organisms by taking on traits that result from the organism's use and misuse. Lamarckism can be demonstrated by an giraffe's neck stretching to reach higher leaves in the trees. This could cause the longer necks of giraffes to be passed to their offspring, who would then become taller.
Lamarck Lamarck, a French zoologist, presented an idea that was revolutionary in his opening lecture at the Museum of Natural History of Paris. He challenged the previous thinking on organic transformation. According to him living things evolved from inanimate matter through a series of gradual steps. Lamarck wasn't the only one to make this claim however he was widely regarded as the first to offer the subject a thorough and general overview.
The prevailing story is that Lamarckism grew into a rival to Charles Darwin's theory of evolution by natural selection and that the two theories fought each other in the 19th century. Darwinism eventually prevailed, leading to the development of what biologists now refer to as the Modern Synthesis. The theory argues that acquired traits can be passed down through generations and instead argues organisms evolve by the selective influence of environmental factors, such as Natural Selection.
Lamarck and his contemporaries supported the notion that acquired characters could be passed down to the next generation. However, this idea was never a central part of any of their evolutionary theories. This is due to the fact that it was never tested scientifically.
But it is now 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 often, epigenetic inheritance. It is a form of evolution that is just as valid as the more popular neo-Darwinian model.
Evolution through the process of adaptation
One of the most common misconceptions about evolution is being driven by a struggle to survive. This view is a misrepresentation of natural selection and ignores the other forces that drive evolution. The fight for survival can be more precisely described as a fight to survive in a specific environment, which may involve not only other organisms but also the physical environment.
Understanding adaptation is important to understand evolution. The term "adaptation" refers to any characteristic that allows a living organism to survive in its environment and reproduce. It can be a physical structure such as feathers or fur. Or it can be a trait of behavior such as moving into the shade during hot weather, or coming out to avoid the cold at night.
The survival of an organism depends on its ability to extract energy from the surrounding environment and interact with other organisms and their physical environments. The organism must have the right genes for producing offspring, and be able to find enough food and resources. The organism must also be able reproduce itself at an amount that is appropriate for its niche.
These factors, together with mutation and gene flow result in a change in the proportion of alleles (different forms of a gene) in the population's gene pool. This change in allele frequency could lead to the development of new traits, and eventually, new species in the course of time.
Many of the characteristics we admire about animals and plants are adaptations, such as the lungs or gills that extract oxygen from the air, fur or feathers for insulation long legs to run away from predators, and camouflage to hide. To understand the concept of adaptation it is crucial to distinguish between behavioral and physiological traits.
Physical characteristics like large gills and thick fur are physical traits. Behavior adaptations aren't like the tendency of animals to seek out companionship or move into the shade during hot temperatures. It is important to note that the absence of planning doesn't cause an adaptation. A failure to consider the implications of a choice even if it appears to be logical, can cause it to be unadaptive.