The Pros And Cons Of Biological Evolution

What is Evolution? Based off Berkeley, biological evolution is the descent of life with modification. It entails small-scale evolution, the small changes in gene frequency within a population between generations, and large-scale evolution, “the descent of different species from a common ancestor over many generations.” Evolution helps people of current time understand the history of life dating to the beginning of life. (Berkeley)

Evolution is not a simple idea of change over time. Tons of things variate over time: “trees lose their leaves, mountain ranges rise and erode,” but these are not instances of biological evolution due to how they don 't “involve descent through genetic inheritance.” The primary idea of biological evolution is “all

These genetic differences are heritable and can be passed on to the next generation — which is what really matters in evolution: long term change.” (Berkeley) Without genetic variation, some of the basic evolutionary changes cannot happen. There are three primary sources of genetic variation. First, Mutations are changes in DNA. A single mutation can have a large effect, but in many cases, evolutionary change is the accumulation of many mutations. Secondly, Gene flow is any movement of genes from one population to another and is an important source of genetic variation. Thirdly, Sex can introduce new gene combinations into a population. This genetic shuffling is another important source of genetic

An organism 's DNA affects how it looks, how it behaves, and its physiology within all aspects of life. Therefore, a change in an organism 's DNA can cause changes in all aspects of its life. Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not "try" to supply what the organism "needs." In this respect, mutations are random — whether a particular mutation happens or not is unrelated to how useful that mutation would be. Since all cells in our body contain DNA, there are lots of places for mutations to occur. The mutations that matter to large-scale evolution are the ones that are capable of being passed through the offspring. These occur in reproductive cells like eggs and sperm, referred to as the germ line mutations. A single germ line mutation has a range of effects. Some mutations don 't have any noticeable effect on the phenotype of an organism. A phenotype is the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment. This can happen in many situations: perhaps the mutation occurs in a stretch of DNA with no function, or perhaps the mutation occurs in a protein-coding region, but ends up not affecting the amino acid sequence of the protein. A small change in the phenotype can cause something like a single mutation in an organism that could cause a harmless small change in a life form, such as curved back ears.