Natural selection cannot fashion perfect organisms •There are at least four reasons why natural selection cannot produce perfection -Organisms are limited by historical constraints -Adaptations are often compromises -Chance and natural selection interact -Selection can only edit existing variations
Natural selection is not able to produce the perfect organism because evolution is limited by historical constraints. Evolution is not able to build new complex structures from scratch. Instead, it must adapt existing structures to new situations, and these resulting adaptations may not be perfect. Also, adaptations are often compromises as organisms must do many different things. Chance and natural selection interact and prevent natural selection from fashioning perfect organisms because chance events can affect a population's subsequent evolutionary history, especially as not all the alleles in a founding population's gene pool are better than those that were "left behind." Furthermore, selection can edit only existing variations as natural selection only favors the fittest phenotypes that currently exist in a population; these alleles are not necessarily the "ideal alleles." Thus, due to the above-mentioned constraints, natural selection, which operates on a "better than" basis, cannot produce the perfect organism.
The environment is extremely dynamic; changing one thing makes everything else change to some degree. So any adaptation for the current situation will invariably change what the situation is, and make those changes out of date; it's a never-ending cycle.
Because evolutionary processes are tinkerers that need to use the material, organisms and their phenotypes/genotypes, that is at hand. Evolution does not build from the top down, like an engineer would, but tinkers from the ground up and comes up with adaptive solutions that are just good enough to be adaptive to the immediate environment.
Natural selection over long periods of time leads to a fitter and more reproductively successful group of organisms thus becoming more common in a population. It will lead to evolution.
Evolution is the change in allele frequency (genotype) over time in a population of organisms resulting in alterations of the phenotype. Change over time gives rise to the diversity of species.The theory of evolution by natural selection is the nonrandom survival and reproductive success of randomly varying organisms. This is the main adaptive driver of evolution and can lead to speciation. All organisms are variations and the environment, the natural selector, preferentially chooses those with beneficial traits to be reproductively successful in the immediate environment at a greater rate than their fellow population members. As their descendents possess these traits, the alleles shift in the population gene pool and evolution occurs. Gene flow and genetic drift also cause evolution, especially in small populations, but they are not adaptive drivers.Basically, theory of evolution is the theory that explains the diversity of life. Many believe the father of evolution was Comte de Buffon, a French naturalist. However, he was unable to come up with a reasonable mechanism that drives evolution. Charles Darwin later came up with natural selection as the mechanism that drives evolution and wrote about it in his book On the Origin of Species.
Natural selection works via a simple mechanism: certain organisms, though mutation, will be better-equipped for survival than others of their species. Over time, the better-adapted organisms will have a higher survival rate and, through interbreeding and simply outliving the competition, will eventually replace them. If there was no variation (mutation) in the population, there would be no better-adapted individuals, and no change. This has been the case with some species. Alligators, for example, have been around virtually unchanged (except for size) for nearly 100 million years. They are well-adapted adapted for survival in their environment as it is, and thus there is really no need for improvements that would lead to major evolutionary change.
Micro evolution can lead to macroevolution
Genetics is the study of genes, heredity and variation of living organisms in biology. Molecular genetics supports evolution as its processes work in combination with the environment and experiences of an organism to influence their development and behavior.
The environment is extremely dynamic; changing one thing makes everything else change to some degree. So any adaptation for the current situation will invariably change what the situation is, and make those changes out of date; it's a never-ending cycle.
The organisms that are better adapted to their immediate environment and have greater reproductive success leave a greater representation of their genes in the gene pool of those organisms. Over time the reproductively successful have the majority representation of genes in the gene pool and with this frequency shift evolution has taken place. Evolution is the change in allele frequency over time in a population of organisms. Sometimes, with the proper beneficial mutations and right immediate environment, speciation can take place.
Organisms don't evolve , species do. Also - many proteins are enzymes, and their manufactured as directed by DNA. A change in DNA may or may not lead to changes which can be described as evolution.
small changes add up over time
Convergent evolution can lead to quite different organisms evolving similar body structures. This makes it difficult for taxonomists to decide how the organisms should be classified.
Convergent evolution can lead to quite different organisms evolving similar body structures. This makes it difficult for taxonomists to decide how the organisms should be classified.
Adaptions that lead to greater survivability and reproductive success in the immediate environment of the individual organisms under selection pressure.
Convergent evolution can lead to quite different organisms evolving similar body structures. This makes it difficult for taxonomists to decide how the organisms should be classified.
speiciation
what evolution as a result of acquired characteristics
Natural selection over long periods of time leads to a fitter and more reproductively successful group of organisms thus becoming more common in a population. It will lead to evolution.
The rise of photosynthetic organisms will not ever lead to a decrease in oxygen. The use of these organisms will always lead to an increase.