Selection? Natural selection drives evolution on the basis of fitness, whereas genetic drift causes evolution by random chance owing to sampling error. A good example of selection is found in nature; the fittest individuals are most likely to reproduce. Those that aren't as fit may reproduce but also die before reproducing.
Randomness? Genetic drift can cause evolutionary changes by randomly selecting certain genes over others. This can happen if some of a population's members are born with two copies of a gene that causes disease, for example. The healthy members of the population will be more likely to have children than those who don't carry the disease-causing allele. Over time, this will result in a change in the frequency of the allele across the population.
Natural selection is when organisms with different traits survive and reproduce more or less often. This leads to the evolution of those traits in the surviving populations. For example, if the only animals that can swim well enough to escape a river are those with thicker skin, then over time this will lead to all the animals in the river evolving thickened skins. This is natural selection because it is an important factor in determining which animals survive to pass on their genes to the next generation.
Genetic drift is the random variation in gene frequencies among a population.
Common blunders and misunderstandings Natural selection is an evolutionary method or cause. Adaptations are physical or behavioral characteristics that help an organism adapt to its surroundings. Heritable variance is caused by random mutations. The origin of new heritable features is due to random mutations. Most mutations are harmful, so over time they disappear from the population. Some mutations are beneficial, so they survive to reproduce today. Natural selection operates on individuals who are capable of producing more offspring than others. It favors those individuals whose children are more likely to survive to reproductive age. This process creates evolutionary changes in populations.
Mutation is a spontaneous error occurring in DNA during reproduction or replication. A mutation can be either beneficial or detrimental depending on what effect it has on the survival and reproduction of the individual carrying it. Mutations can also create new genetic variations that allow organisms to evolve into different species. Natural selection does not cause mutations; instead, it selects for those individuals who are better able to reproduce.
Summary: Natural selection is an evolutionary force that acts on individuals who are capable of producing more offspring than others. Mutation is a spontaneous error occurring in DNA that can be beneficial or detrimental depending on what effect it has on the survival and reproduction of the individual carrying it.
Genetic drift is defined as a random shift in allele frequency. These erratic fluctuations in allele frequency might add up over time. Smaller samples can differ more significantly from the broader sets from which they are drawn than bigger samples, hence genetic drift is more strong in smaller populations. > span>
The smaller the population, the faster this process will happen. For example, if we look at a population of 100 individuals, on average one person will be chosen at random to reproduce each generation, but if that same population consisted of only 10 people then all of them would be expected to have an impact on future generations.
Drift becomes even more important when you consider how many mutations are needed for evolution to occur speedily. If the mutation rate is very high, such as 1 in 1000 genes, then over thousands or millions of years this could result in significant evolutionary change. But if the rate is much lower, such as 1 in 100,000 genes, then it takes much longer. The number of mutations needed depends on the size of the population so, all else being equal, smaller populations will evolve more quickly.