Process of Natural Selection – Darwin’s Theory of Evolution

Process of Natural Selection  

Introduction

NATURAL SELECTION AND EVOLUTION  

• According to Darwin’s Theory of Evolution, the two causes of evolution are branching descent and natural selection. Climate, temperature, resource availability, and other environmental conditions all had a significant influence on the evolutionary process. 
• Another factor that might contribute to natural selection is inheritance. Two creatures are fighting for the same resource. If one can multiply significantly quicker than the other, they will have an advantage. Thus, the hereditary gene in organisms aids in selection and evolution. In other words, the more you adapt to a changing environment, the more likely it is that you will be chosen by nature. 
• Inadequate weather variations, natural resources, predators, competition, and so forth are great obstacles provided by nature to pick the fittest. The one with more inherited adaptations will have a better chance of surviving, while others will not thrive.  
• Nature’s chosen ones thrive and breed, and a new population emerges at the expense of others. As a result, we may conclude that ‘survival of the fittest’ occurs during evolution. 

PROCESS OF NATURAL SELECTION  

• The process by which forms of life with traits that allow them to better adapt to specific environmental pressures, such as predators, climate change, or competition for food or mates, tend to survive and reproduce in greater numbers than others of their kind, ensuring the perpetuation of those favorable traits in succeeding generations. 
• Mutation, migration, and genetic drift modify gene frequencies regardless of whether such changes boost or reduce the probability of an organism surviving and reproducing in its environment. They are all random processes.  

NATURAL SELECTION  

• Natural selection can result in speciation, which occurs when one species develops a new and separate species. As a result, this mechanism promotes evolution and helps to explain the diversity of life on Earth. 
• Few types of genes are supported under positive Darwinian natural selection because they enhance the likelihood of reproduction or survival, resulting in an increase in the pace of evolution. 

DARWIN’S THEORY  

• The process of natural selection and vast quantities of evidence for evolutionary change from many sources were Darwin’s original contributions. He also gave detailed explanations of how evolution affects our knowledge of life’s past and contemporary biological variety. 
• Species (interbreeding populations of organisms) evolve through time and space. Today’s representatives of species differ from those that existed in the recent past, and populations in various geographic locations differ somewhat in shape or behavior. 
• All creatures have ancestors in common with other species. Populations may split over time into separate species that share a common ancestor. If you go far enough back in time, any two species will have a common ancestor. The shared ancestry of organisms explains their similarities: their similarities reflect the inheritance of features from a common ancestor. 

COMPONENTS OF NATURAL SELECTION  

Natural selection happens in response to a variety of conditions: 

• Inherited Diversity – Within a population, there is a genetic variation that may be inherited. 
• Competition – A fight for survival exists (species tend to produce more offspring than the environment can support). 
• Selection – Environmental forces cause unequal reproduction within a population. 
• Adaptations – Individuals with advantageous characteristics are more likely to survive and pass these characteristics on to their children. 
• Evolution – There is a shift in allele frequency within the population gene pool throughout time. 

There are four components of the natural selection process:  

1. Variation: Individual differences in appearance and behavior exist among organisms (within populations). Body size, hair color, face marks, voice characteristics, and the number of children are all examples of differences. On the other hand, other features, such as the number of eyes in vertebrates, exhibit little to no variation among individuals. 

2. Inheritance: Some characteristics are handed down from father to offspring. Such qualities are heritable, but others are heavily impacted by environmental factors and have low heritability. 

3. Rapid population growth: Most populations produce more offspring each year than local resources can support, resulting in competition for resources. Each generation loses a large number of people. 

4. Differential survival and reproduction: Individuals with qualities that are best suited to the competition for local resources will produce more offspring for the following generation. 

FACTORS THAT AFFECT THE PROCESS OF NATURAL SELECTION  

1. Reproduction: Natural selection can only work on a population if it reproduces in order to produce a new generation. Individuals with features that are best suited to their environment tend to reproduce more than those who do not. As a result, natural selection works to increase the number of people with those favorable features while decreasing the number of individuals with less desirable qualities. The higher a population’s reproduction rate, the greater the competitive strain on an individual to survive. Because of this pressure, only the most suited members survive, while the weaker members perish. As a result, the population will soon be brimming with people who display the features that provide the species a higher chance of survival. 

2. Variation in Characteristics: Natural selection may occur within a population only when individuals of the population differ in their individual qualities. A study of natural selection on color within a population, for example, necessitates distinct individuals having various hues. There are no features for nature to “select” over others if there is no variety in attributes. 

3. Heredity: Heredity and reproduction go hand in hand because the genes of the parents unite to form the DNA of their child. Natural selection must occur if parents with favorable features pass those traits on to their kids. Otherwise, the genes that cause the beneficial features would perish with the parents and not be passed on to the next generation. Speciation happens when individuals of a species are geographically separated and exposed to different conditions, allowing for unconnected lines of heredity. Over time, characteristics in each group continue to diverge in order to better adapt to varied settings. Advantageous genes for one environment start to differ from those for another, and the two groups start to diverge. 

4. Variation in Fitness: Fitness refers to an organism’s capacity to live and reproduce as much as feasible. Natural selection requires varying degrees of fitness in individuals of a population. Some people must have characteristics that enable them to live and reproduce more frequently than others. Otherwise, natural selection cannot generate more people with advantageous features and fewer with less useful traits.