Among the animal on the planet, the species rich group making more than 70% is ________.
Insects
Understanding Animal Species Richness
The question asks about the animal group that represents more than 70% of all animal species found on Earth. Species richness refers to the number of different species present in a particular area or group. When we look at the diversity of life, animals form a massive part, and within the animal kingdom, different groups have vastly different numbers of described species.
Comparing Major Animal Groups
Let's consider the approximate number of described species for the animal groups mentioned in the options, along with some others for context:
| Animal Group | Approximate Number of Described Species | Percentage of Total Animal Species (Rough Estimate) |
|---|---|---|
| Insects | Over 1 million (potentially millions more undiscovered) | > 70% |
| Fishes | Around 34,000 | ~ 2-3% |
| Mammals | Around 6,500 | < 1% |
| Reptiles | Around 11,000 | < 1% |
| Birds | Around 10,000 | < 1% |
| Other Animal Groups (e.g., Molluscs, Crustaceans, Worms, etc.) | Hundreds of thousands | Remaining Percentage |
Identifying the Dominant Animal Group
Based on the estimated numbers, it is clear that insects dominate the animal kingdom in terms of species count. The vast majority of described animal species are insects. While estimates vary and many species remain undiscovered, particularly insects, the proportion that insects represent is overwhelmingly large, significantly exceeding 70% of all animal species.
This incredible diversity in insects is attributed to several factors, including their small size, rapid reproduction rates, ability to occupy diverse habitats, and co-evolution with plants.
Considering the options provided:
- Fishes: While diverse, fishes do not constitute over 70% of animal species.
- Mammals: Mammals are a relatively small group in terms of species number compared to the total animal diversity.
- Insects: Insects are the most species-rich group by a large margin, accounting for well over 70% of described animal species.
- Reptiles: Reptiles also represent a small fraction of the total animal species diversity.
Therefore, the animal group making up more than 70% of species is Insects.
Revision Table: Key Animal Group Diversity
| Animal Group | Species Count (Approx.) | Relative Species Richness |
|---|---|---|
| Insects | > 1,000,000 | Extremely High (> 70% of animals) |
| Fishes | ~ 34,000 | Moderate |
| Mammals | ~ 6,500 | Low |
| Reptiles | ~ 11,000 | Low |
Additional Information: Biodiversity and Animal Classification
Biodiversity refers to the variety of life in the world or in a particular habitat or ecosystem. It includes species diversity, genetic diversity, and ecosystem diversity. Species diversity is often measured by species richness (the number of species) and species evenness (the relative abundance of each species).
Animals are classified into various groups based on their characteristics. Major groupings within the Animal Kingdom include phyla like Arthropoda (which includes insects, spiders, crustaceans), Chordata (which includes vertebrates like fishes, amphibians, reptiles, birds, and mammals), Mollusca (like snails, clams, squids), Annelida (segmented worms), etc.
Insects belong to the class Insecta within the phylum Arthropoda. Arthropoda itself is the largest phylum in the animal kingdom, and insects are the largest class within Arthropoda, containing more species than all other animal classes combined.
Important Questions from Biodiversity and Conservation
Which of the following is not the cause of biodiversity loss?
Select the statements that are CORRECT regarding patterns of biodiversity.
(A) Species diversity increases as we move away from the equator towards the poles
(B) The tropical Amazon rain forest in South America has the greatest biodiversity on Earth.
(C) There is more solar energy available in the temperate region than tropics.
(D) Tropical environments are less seasonal, relatively more constant and predictable
(E) A. Humboldt observed that within a region, species richness decreases with increasing explored area, up to a limit.
Choose the correct answer from the options given below:
Who was the leader of Chipko movement?
Which commission/summit gave the concept of sustainable development for the first time?
Tropical evergreen forests are found in which of the following States of India?
