What is evolution in biology? Driving forces, laws, examples
Today we will talk about what is evolution inbiology, what value does it have. Of course, speaking about this topic, we can not ignore the evolutionary theory of Charles Darwin, who offered it to the world, which exists to this day.
So, what is evolution in biology? Under this concept it is customary to understand the gradual changes that are not very evident. But as a result of this process, there are fundamental changes. Evolution in biology can lead even to the formation of new species of living beings or to the cardinal change and adaptation of the old. What is the significance of evolution in natural science? Certainly, the key. You will understand this when you finish reading this work.
Now let's talk a little about the most important conceptof our article. What is evolution in biology? It is important to understand that this phenomenon is irreversible and directly related to the historical process, the development of living nature. It is possible to consider the evolution of separate parts of the biosphere or, in general, all living things of our planet. Remember that only a living organism can evolve.
Previously, evolution opposed this concept,as a "revolution". But in the course of diligent study of these two processes it turned out that evolution and revolution are rather difficult to distinguish from each other. Why? Evolution can last millions of years or pass quickly. So the boundaries between these two processes are greatly eroded.
Some people think that the person is the resultevolution, that is, we descended from ancient monkeys. This theory was put forward by the famous scientist Charles Darwin. And the theory was called evolutionary. Believe it or not, everyone decides on their own, because now there are a lot of other possible hypotheses. But since the speech in our work has gone about evolution, we can not ignore the theory of Darwin. We propose to start it right now.
Theory of Darwin
Charles Darwin was the first to explainhumanity, what is evolution in biology. Let us also mention that his theory was based on the works of T. Malthus, who presented to the world in 1778 his "Treatise on Population." After studying this work, Charles Darwin was able to formulate the basic laws, the forces that drive evolution. What is the work of T. Malthus? He explained what would have happened to us if population growth was not restrained by any factors.
Note also that Darwin shifted the theoryMalthus to other living systems, his main contribution to science is the explanation of how evolution takes place. He first introduced the concept of "natural selection". It may be mentioned that another scientist (AR Wallace) was able to reach the same conclusion. Then Darwin and Wallace united and spoke together at a meeting in 1858 with a joint report, and already in 1859 Charles Darwin presented the world with the work "The Origin of Species."
So, what is evolution in biology, the definitionaccording to the theory of Charles Darwin, we have already provided. But there is also a modern (it is also called synthetic) theory of evolution. We propose to review it briefly.
The theory of neo-Darwinism is a theory of Darwin-Wallace renewed as far back as the 20th century. This was the result of updating and adding new data in the areas:
- molecular biology;
Why is this theory called synthetic? Precisely because it is a synthesis of the basic positions presented by Charles Darwin.
Laws of Evolution
Before we designate the basic laws,suggest that you consider what evolution is in biology, an example in this will be a good helper. Take the blue butterfly that lives in the Samoan Islands. They began to exterminate parasites, which were dangerous for males. In just a year of such an attack, the number of males increased to 40 percent. No, the parasites still existed in the neighborhood, only butterflies they were not already a hindrance. So evolution looks.
- the rate of evolution is not the same;
- the formation of new species occurs in simple forms;
- cases of regressive evolution are noted;
- evolution occurs due to some factors (mutations, natural selection, drift of genes).
We learned about evolution in biology and itsessence. Let's now talk about the factors. They were received as a result of studying and systematization of all the accumulated knowledge concerning evolution. This is the only way to see and understand the driving forces that allow many species (less adapted to survival) to remain on our planet.
So, there are only three main factors:
Forms of selection
Speaking of evolution, we can distinguish several forms of natural selection:
The first type is aimed at maintaining sustainabilityspecific type. Let's consider an example on sparrows. During a violent storm, 136 dying birds were found. 64 of them died, because they had either short or long wings. Individuals with an average size survived, as they were more enduring.
Driving is manifested as follows: the disappearance of limbs in snakes or eyes in cave animals, fingers in ungulates and so on. That is, the organ (or its part), which is not needed by the animal, simply disappears.
An example of a disruptive selection may be a snail (more precisely, their color). If the soil is brown, then the shell has a brown or yellow tinge.