Concept of Species- Evolutionary And Biological Species Concept

Aug 03, 2023, 16:45 IST

If you are looking for a concept of species, you have come to the right place!

We’ll discuss concepts of species in this article. The primary classification unit in biology and biodiversity is the species. A big group of organisms in which two individuals of opposing sexes can successfully procreate is commonly referred to as "spices." Additionally, species types are recognized and distinguished based on their morphology, ecological niche, and DNA sequences.

Introduction

Biologists have attempted to define the meaning of the term "species" for millennia. However, any attempt to explain this concept raises new issues. The term "species concept" refers to these efforts to define what a species is and what its limiting conditions should be. Various species theories are being researched right now. Microtaxonomy is the study of the species problem.

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What is the Concept of Species?

The fundamental method for classifying biological organisms is through species. These are substantial, extensive portions of organisms in which sexual reproduction occurs between two identical family members of the same species. Karyotypes, appearance, DNA sequences, and other characteristics found in the categorization modes aid in defining and separating different biological entities within a species.

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Essential Concepts of Species

There are various types of organisms on this planet. However, they can be broadly divided into six notions, which are as follows:

• Biological species concept:
  • In 1942, Ernst Mayr introduced the idea of a biological species. Its foundation is reproductive seclusion.
  • Currently, it is the species notion that is used the most.
  • Mayr famously describes it as "groups of actual or potentially breeding natural populations, which are reproductively isolated from other such groupings."
  • According to the biological species idea, if two related populations of organisms coexist, they will recognize them as belonging to two different species if they can reproduce sexually and give birth to sterile children.
  • This idea has the drawback of being unsatisfactorily applied to creatures that reproduce asexually.
• Morphological species concept:
  • The morphological species idea, as its name suggests, makes species distinctions based on their morphological (anatomical) traits.
  • Regan defined a species as "a community or several related communities, whose distinctive morphological traits are, in the judgment of a competent systematist, sufficiently definite to entitle it or them to a special designation."
  • The idea of morphological species has certain benefits. Even species that reproduce asexually can be categorized using this criterion.
  • Paleontologists may classify species using fossils; this technique for identifying populations is useful.
  • Regan's description clarifies that this type of classification is up to "expert" judgment. In other words, there is a chance that the distinctions will be more subjective than objective.
• Ecological species concept:
  • According to Valen's definition, a species is a lineage (or a group of lineages that are closely related) that inhabits an adaptation zone that is minimally unique from that of any other lineage within its range and that evolves independently from all other lineages.
  • However, Colinvaux clarifies it: "A species is a collection of closely related populations, whose members compete more with those of their kind than with those of other species."
  • In other words, a species is a population or a collection of closely linked individuals whose needs are met. They are, therefore, more likely to acquire identical traits and fill the same ecological niche.
• Evolutionary species concept:
  • A unique lineage of ancestor-descendant populations of organisms that preserves its identity from other similar lineages [in space and time] and has its evolutionary tendencies and historical fate is referred to as a species in this idea.
  • This idea was designed primarily for species that could not be categorized by the biological species idea, such as asexual species and species found in fossils.
• Cohesion species concept:
  • A lineage of evolution that acts as the field of play for fundamental microevolutionary forces such as gene flow (where appropriate), genetic drift, and natural selection.
  • Because it emphasizes the existing phenotypic similarities among species, it differs from the evolutionary definition of species.
• Pluralistic concept of species:
  • The notion of species is a challenging and complex process, as shown by the classifications above.
  • Too many variables are in flux for any single collection of distinguishing elements to be determined.
  • Due to this, a pluralistic species idea was required.
  • Basically, this implies combining all of the species notions we have available.
  • The "most significant determinants for the cohesion of individuals as a species vary," according to Campbell and Reece.
  • These characteristics can be assessed using species notions, which are most persuasive in each scenario.

Types of Species

• Taxonomic Species: It consists of a collection of creatures with related morphologies.
• Microspecies: A single parent provides the population.
• Biological Species: It includes the population of those capable of sexual reproduction.
• Evolutionary Species: It consists of uniparental organisms, phyletic lineages, and sexually reproducing organisms.
• Successional Species: A tree species that takes the place of a more shade-intolerant pioneer or other successional tree species in a forest. Successional seedlings can develop into the dominant species by growing in the understory's shade.

What is Species Diversity?

It is described as the total number of species and their population in a given ecosystem. Species richness refers to the diversity of species present there. On Earth, there are 1.8 million distinct species that have been identified. About a million of the total species are insect-related. Every year, new species are found. According to scientists, there may be 5 to 30 million species that exist in reality on Earth.

Importance of Species Diversity

The following is a list of some of the significant importance:

• Numerous species contribute to the improvement of soil fertility, climatic stability, water purification, air purification, and several other environmental aspects.
• It supports a thriving ecosystem. Because every species has a unique connection to a diverse ecosystem.
• The more species there are, the more productive the ecosystem will be, resulting in a stable ecology.
• The capacity to avert any catastrophe will be the specific justification.
• The ability of species to adapt to environmental disasters like drought will increase with species variety.
• People can obtain various goods, including fruits, cereals, meat, timber, and fiber, because of the great diversity of species.
• About 20% of the oxygen in the atmosphere comes from the Amazon rainforest.
• They preserve ecosystems' soil fertility.
• Symbiotic relationships, decomposition, and pollination play notable roles in the ecosystem.
• The survival of humanity depends on healthy biodiversity.
• Other advantages include leisure and tourism, education, and research, in addition to these.
• They are popular tourist destinations as well.

Threats to Species Diversity

The Evil Quartet, four primary factors that contribute to the loss of diversity.

• Overexploitation: Excessive damage or exploitation of natural resources results in the loss of numerous biodiversity species. An illustration of this is the overfishing of marine life, which causes its extinction.
• Loss of Habitat: Because of industrialization and urbanization, many species have lost their places and food sources, leading to the extinction of many species.
• New Species Introduction: When new species are introduced, they harm existing species, leading to their extinction.
• Co-extinction: Coextinction and threatened are terms used to describe the phenomenon in which the extinction or decline of one species, the host species, results in the end or endangerment of another species, the dependent species, and may have cascading effects across trophic levels.

Steps Taken for Conservation of Biodiversity

The government takes several actions to preserve biodiversity because it is disappearing daily. The following are the government's most significant efforts:

• In-situ conservation is preserving areas with high biodiversities, such as biosphere reserves, national parks, and sanctuaries. This conservation method shields various endangered animals from extinction in their natural habitats. Such would be the local Royal Bengal tiger, primarily protected in national parks and biosphere reserves.
• Areas with high biodiversity contain a variety of species. The key factors used to identify these places are endemism, habitat threat, species richness, and level of exploitation. There are a total of 34 hotspots on the planet. As an illustration, India has two biodiversity hotspots: the Western Ghats and Eastern Himalayas.
• Diverse holidays are observed in India to protect and plant trees. The Chipko movement is one of the well-known ones among them.
• Threatened species' gametes are preserved using cryopreservation procedures in various lab and research settings.
• Ex-situ conservation refers to providing threatened and endangered species with complete protection and care outside their natural habitat.

Concept Of Species: FAQs

Q1. Where does the concept of species come from?

Ans. According to the Biological Species Concept, a species taxon is a collection of creatures that may effectively interbreed and give birth to fertile offspring. That idea holds that interbreeding within a species and reproductive barriers between animals of various species help to protect the integrity of a species.

Q2. How many species of life have scientists identified?

Ans. Only 14% of the species alive today have been cataloged by scientists. The precise number of living species in the globe is unknown to scientists. In actuality, just 14% of extant species have been accurately described by scientists despite their best efforts over many generations.

Q3. Which species concept is most effective?

Ans. The biological species concept, put out by evolutionary biologist Ernst Mayr, is the most well-known species theory. According to the biological species idea, a species is a collection of naturally occurring populations reproductively isolated from one another and actually or potentially interbreeding.

Q4. What are the two key characteristics of a species?

Ans. A group of organisms that may interbreed and produce fertile offspring is referred to as a species. If two organisms can reproduce and have children, their offspring are also of the same species as their parents.

Q5. Who came up with the idea of species?

Ans. Ernst Mayr is the originator of one of the most well-known of the many alternative definitions of the species category and significantly contributed to the development of the broad concept of species as metapopulation lineages.