The concept of coalescence, which has its origin in the Latin word coalescens, is the property of things to merge or unite. Coalescing substances or materials are those that can be united in a single body.

For chemistry, coalescence involves a process through which two phase domains of essentially identical composition come into contact and form a larger phase domain. The materials, in this way, establish an optimization of their surface to minimize energy expenditure.

An example of coalescence is produced by mixing water and oil and shaking the container. We will soon see how the drops begin to merge to form a single large drop that represents the final separation between the two substances.

According to DigoPaul, coalescence also occurs when welding of metals occurs. A applying thermal energy (heat), fusion welding achieves coalescence through casting, forming a single crystal system. The molten metal is in contact with the edges of the joint surfaces, which are partially molten.

On the other hand, in the field of medicine the use of the word that we are now analyzing is also used. Thus, we speak of coalescence to refer to the adherence of two surfaces that are in contact. A clear example of this would be scars.

All this without forgetting that, in the field of speech therapy, reference is also made to that same word. In his case, they are used to define what is the assimilation of two differentiated sounds and that originate, precisely because of this “union”, a totally new sound.

Specifically, we can further qualify and explain that this action is one of the phonological processes that are part of children’s language and that they develop basically with the intention of simplifying speech. Moreover, in that case coalescence is included as a process that refers to the formation of the syllable.

The phenomenon of coalescence can be observed in geography when a river that comes from a mountain range reaches the bottom of a tectonic valley. This watercourse carries a significant amount of sediment that forms debris cones and overlaps each other. The action of rainfall and the various floods mean that, over time, the valley has interspersed deposits that generate a cross stratification.

In addition to all the above, we would have to point out the existence of what has been called the theory of coalescence. This becomes a technique or mechanism that was devised with the clear objective of being able to carry out the study and analysis of genetic variation. To do this, it is based on the history of genetic variants in the past.

It should be emphasized that this has great value, since it has been considered to have been the most important advance achieved in the last thirty years regarding what is known as population genetics.