Often, natural processes are examined in the study of evolution. Evolution is the process of changes in innate attributes in a population of organisms that occur over subsequent generations. Charles Lyell was the first to use ‘evolution’ in modern biology. Life arose on Earth roughly 4 billion years ago. Since then, the meaning of evolution has been evolving continuously.  

1. The biological and cultural factors in human evolution.
2. The history of evolution.
3. Various theories associated.

With knowledge about these, we can understand this concept.

Natural Selection

• The main force of evolution is natural selection. It is responsible for the diversity and complexity of life. It accounts for the species that have survived on the Earth
• Natural selection is the process where species in a naturally variable population adapt, change, survive and reproduce
• Charles Darwin gave an understanding of the concept of natural selection. He was an acclaimed English naturalist, biologist, and geologist
• According to this, some species have adaptive traits which are more suited to their natural environment. Thus, giving them an increase in the portion of beneficial characteristics
• It provides the advantage of being more likely to survive and reproduce. These traits are passed to coming generations from parents to their offspring
• This force explains how different varieties of life forms came into existence from a common ancestor on the Earth
• The five types of natural selection are

1. Stabilising Selection
2. Directional Selection
3. Disruptive Selection
4. Artificial Selection
5. Sexual Selection

Biassed Mutation

Mutations are caused by:

1. Errors in copying and dividing DNA.
2. Radiation exposure.
3. Exposure to chemicals or infectious viruses.

Bias in mutation is a paradigm where certain mutation types happen more habitually than others. 

This happens under certain conditions.  There can be the following three effects of genetic mutations:

1. Beneficial.
2. Having no effects.
3. Dangerous consequences.

It leads to natural selection favouring better conversion. It helps the species to survive and thrive in its natural environment. Often, the regularity of mutation bias under natural conditions is extremely low. It can be improved under certain circumstances.

Gene Flow

It is the active or passive and slow distribution of genes. It happens between different species in a population of organisms. This changes the genetic composition of the receiving population. Hence, it promotes adaptive evolution. Therefore, increasing the irregularity within a population. It is also known as gene migration. The flow of genetic material between various species causes a change in gene frequency. It can be positive or negative. It is positive if it helps a species to survive better in its natural environment. Moreover, it is harmful if it introduces disadvantageous genes to the receiving population of species. It can happen amongst the same species through vertical gene (parent to offspring)  transfer and between different species by horizontal gene transfer(lower level organism to higher-level organism).

Genetic Drift

It is known as the changes in the comparative recurrence of gene variants in a population of organisms. It can happen purely by chance over time. Usually, this occurs in a small population. A few consequences of genetic drift are listed below:

1. Loss of rare gene variants.
2. Reduction in the gene pool.
3. Genetic differences between the current and coming generations.

Types of genetic drift:

• When the size of the population rapidly becomes extremely small or the bottleneck effect
• When a few individuals separate from a larger population to make their colony. It is called the founder effect

Non-Random Mating

Non-random mating acts as an accelerating process for natural selection to cause evolution. The choice of mates is made by phenotypic differences based on the existing genotypic differences. Types of non-random mating are

• Outbreeding: This is when mating takes place between distant relatives
• Inbreeding: This is when mating takes place between close relatives

One example of non-random mating is sexual selection. In some species, females choose more attractive males for mating. It can play a role of a barrier to mating between closely related species.

Human Interference In Biological Evolution

Various human activities affecting the biological and cultural factors in human evolution is

• The continuous development of new pesticides and antibiotics
• Selection of mating species
• Fishing and hunting
• Urbanisation steals away the natural environment
• Habitat fragmentation
• Biological invasions
• A drastic change in the climate. It causes various individuals to shift to new favourable locations

Conclusion

Here, we studied the diverse natural and cultural factors in human evolution. We learned about their causes and consequences. Human interference and its effects on evolution were also studied. Various industrial activities are responsible for the changes in natural evolution. We came across some interesting facts on evolution. These forces interact dynamically with each other. Thus, making the evolution process way more complex. Detailed knowledge on the five points of evolution: natural selection, gene flow, genetic drift, biassed mutation, and non-random mating can be acquired through variously reliable and credible online platforms for biological and cultural factors in human evolution anthropology UPSC.