Environmental factors can accelerate the process of extinction

In general, the extinction phenomenon of animals is a natural process. For some reason, an estimated 99.9% of all species that once lived on Earth today are extinct.

However, the reason why extinct species is so complex, different and has many changes. Since humans appeared on Earth 100,000 years ago, the rate of extinction has shown signs of increasing - by an estimate of up to 1,000 times - putting people in the midst of modern extinction called the Holocene extinction event.

Why is the population of species on Earth extinct? It is a difficult question with almost no answer.Ecologists, biologists, physicists, and other experts are investigating the cause of extinction to try to find the inner factors involved, which is extremely necessary for improvement of natural conservation management process.

Recently, how a group of physicists have studied how random noise in the environment (from factors such as climate and other sources) affects the population's extinction faster and faster , this event is called 'extinction' by scientists (MTE). Physicists Alex Kamenev and Boris Shklovskii of Minnesota University together with Baruch Meerson of the University of Jerusalem have published their research in Physical Review Letters.

According to scientists, environmental noise is considered to be a factor affecting the birth and death rates of species, sometimes reducing the size of the population and accelerating their disappearance. Previous theoretical studies have assumed that environmental noises are 'white' - that is, random changes of the environment do not interact with each other.But recently, researchers who have discovered more real environmental changes are having an interactive relationship, or 'colored' than white.

The dove, once the most popular bird in North America, was hunted until extinction between the 1800s and 1900s. (Photo: Research organization of direct evolution in the Dove (1920)). 'In a broader sense, the noise in the environment includes unusual environmental changes related to population changes,' said Meerson in PhysOrg.com magazine. ' For example, changes in temperature, drought, flood, disease and eating meat together.' If these random variations in the environment do not interact with each other, they can be described in a white sound pattern. However, changes in the actual environment always affect each other. For example, during epidemics, predators may appear for a certain period of time. And like that, the white sound pattern will gradually change to the color sound pattern.

Meerson and his colleagues asked how the color of environmental sounds affects the extinction rate of species, which has not been discovered for many years. They found that the weaker the environmental sound, the faster the extinction took place.In general, the larger the population size, the more likely it is that the population will survive longer. However, the researchers point out that sound colors can change this proportional relationship, depending on how long the sound level interacts with each other.

Meerson remarked: 'The most important result from this study is that environmental sound is capable of promoting the risk of extinction of species populations. Among these surprises there is a forecast of environmental change (reflected in the time independence of the species' birth and death rates), leading to species extinction. It turns out that this change depends greatly on sound colors. '

For a long period of interaction of environmental sounds, the population size has almost no effect on the MTE period, since it was still strong enough at that time. In this situation, the population size is gradually decreasing.Sound color does not directly cause extinction, but it makes the population change abnormally. Accordingly, with adverse changes that make the species weaken to extinction (for example, due to reduced fertility), it is very likely that the population of that species will disappear completely.

On the other hand, during the short interactive period of environmental sound, the MTE period has changed the size of the population in an exponential proportion.With the sound interacting for a short period of time that could have caused a disaster for such a population, such as reducing birth rates to such an extent that there is no way to save the population anymore.

In general, physicists hope to understand how the environmental change that interacts with each other can lead to extinction in the future, helping them to know the impending consequences for ecosystems and conservation. species survival.During the mid-era of this extinction, understanding the motivating factor in the extinction process can help people become more fully aware of whether they are affecting the natural population change as how.