Why are dogs not a separate species? About species and subspecies

Dogs are not an independent species, they are just a subspecies of wolves. You can refer to the article "Dogs and wolves have the same number of chromosomes, but dogs are not an independent species."

Can you tell which one is a wolf and which one is a dog in the two pictures above?

In the mysterious biological world, "species" and "subspecies" are the key to unlocking the door to biodiversity. They are not only the important cornerstones of biological taxonomy, but also carry the wonderful process of biological evolution.

一、Species: the basic unit of biological classification

In the vast system of biological classification, "species" is the most basic unit. It is composed of a group of biological individuals with similar morphology and physiological characteristics, which can naturally mate and produce fertile offspring (this is the most important sign to judge a species). In simple terms, members of the same species have similar appearances and internal structures and functions, and can successfully reproduce.

二、Subspecies: Geographical isolation within a species

So, what is a subspecies? When the same species of organism has stable differences in morphology, physiology, behavior, etc. between populations due to geographical isolation, ecological environment differences, etc., but has not formed reproductive isolation, these populations with obvious differences are divided into subspecies. Simply put, subspecies are like different branches in the big family of species. Although they all belong to the same family, each branch has its own unique "personality".

Take tigers as an example. There are many subspecies of tigers in existence. For example, the majestic Siberian tiger is a subspecies of tiger. It lives in the cold northeast region. It is huge in size and has lighter fur. Its thick fur and huge body help it maintain its body temperature and catch prey in the ice and snow. The agile Sumatran tiger is also a subspecies of tiger. It lives on the island of Sumatra in Indonesia. It is relatively small in size and has denser stripes on its body, which enables it to better hide and move in the dense tropical rainforest.

三、Classification criteria: revealing the differences between species and subspecies

（一）Species classification criteria

The most critical criterion for determining whether organisms belong to the same species is reproductive isolation. If two populations of organisms cannot naturally mate, or cannot produce fertile offspring after mating, then they belong to different species. For example, although horses and donkeys look similar and can mate and give birth to mules, mules are infertile, which indicates that horses and donkeys are different species.

（二）Subspecies classification criteria

For animals, if two populations of the same species are distributed in different areas, and there are obvious differences in classification between them, and the difference in individuals accounts for at least 75% of the total population, then the two populations can be considered different subspecies. Moreover, two subspecies of the same species cannot occupy the same distribution area (referring to the breeding area). For example, wolves in different regions may have darker fur colors, lighter fur colors, and different body shapes and habits. When these differences reach a certain level, they are classified as different subspecies.

Plant subspecies are generally defined as subspecies when a plant has large variations in stems, leaves, flowers or fruits and has a certain distribution area (or special growth environment), but the changes do not exceed the scope of the original species and are not enough to establish a new species. For example, some plants growing in mountainous areas may have variations such as short plants and thick leaves due to the harsh environment. These variations are stably inherited and confined to a specific area, forming a subspecies of the plant.

四、Naming rules: unique biological "identity card"

In order to accurately identify and distinguish different species and subspecies, scientists have developed a set of strict naming rules. The scientific name of a species uses binomial nomenclature, which consists of the genus name and the specific epithet, with the genus name first and the first letter capitalized; the specific epithet is in lowercase. For example, the scientific name of humans is Homo sapiens, where Homo is the genus name and sapiens is the specific epithet. This naming method is concise and ensures that each species has a unique scientific identifier.

五、Significance and Value

The study of species and subspecies is of great significance and value. From the perspective of scientific research, they are important clues to explore the evolution of organisms. By comparing the morphology, genes and other characteristics of different species and subspecies, scientists can trace the evolutionary path of organisms and understand how organisms adapt to the environment and differentiate and develop over a long period of time.

In terms of biodiversity conservation, the study of species and subspecies also plays a key role. Each species and subspecies is an important part of biodiversity and plays a unique role in the ecosystem. Understanding their distribution, number, ecological needs and other information will help us formulate scientific and reasonable conservation strategies to protect these precious biological resources and maintain ecological balance.

In addition, the research results of species and subspecies are also widely used in agriculture, medicine, industry and other fields. In agriculture, by studying the species and subspecies characteristics of crops and livestock, better varieties can be cultivated to improve yield and quality; in the field of medicine, the study of medicinal plants and microbial species and subspecies helps to discover new drug ingredients and treatment methods; in industry, the use of different species and subspecies of microorganisms for fermentation, biodegradation, etc. can produce a variety of useful products and promote the development of green industry.

Species and subspecies are a mysterious area in the biological world. They not only show the diversity and wonder of life, but also provide an important basis for us to understand nature, protect biodiversity, and promote the development of science and technology. With the continuous advancement of science and technology, our understanding of species and subspecies will continue to deepen. I believe that in the future, they will reveal more mysteries of life to us.

Why wolves are recognized as a separate species：

Independent evolutionary process - In the long process of natural evolution, wolves have formed a unique evolutionary path to adapt to various natural environments. They occupy a specific ecological niche in the ecosystem and live by preying on other animals. They are typical carnivores. Their behavioral patterns and physiological characteristics have evolved to adapt to survival in the wild and predatory life.

Reasons why dogs are not a separate species：

Originated from wolves - dogs were domesticated from wolves. During the domestication process, although the appearance and behavior of dogs have undergone some changes, from a genetic point of view, the genes of dogs and wolves are extremely similar. They have the same number of chromosomes and belong to the same species biologically.

No independent evolutionary path - After being domesticated, the evolution and development of dogs were largely influenced by humans and relied on the food and living environment provided by humans. They did not form an evolutionary path and unique ecological niche independent of wolves that were fully adapted to the natural environment.

Therefore, based on many factors such as evolutionary history, genetic characteristics and ecological niche, wolves are considered to be an independent species, while dogs are a subspecies of wolves, not an independent species.

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