The classification system have undergone several changes over a period of time, why?

Options

A. Because the criteria for classification changed, now they are based to trace the developmental history.
B. Because over time an attempt has been made to evolve such classification which are based on phylogeny
C. Because over time an attempt has been made to evolve such classification system which are based only on human evolution mainly
D. Because over time an attempt has been made to evolve such system which are based on histological and cytological studies

Answer

### Step-by-Step Text Solution:

1. **Introduction to Classification Systems**:
- Classification systems in biology are frameworks used to categorize and organize living organisms based on shared characteristics and evolutionary relationships.

2. **Historical Context**:
- The classification system has evolved over time due to advancements in scientific understanding and technology. Initially, organisms were classified simply into two groups: animals and plants, primarily based on observable traits like the presence of red blood.

3. **Criteria for Classification**:
- The criteria for classification have changed significantly. Early systems relied on visible characteristics, while modern systems incorporate genetic and molecular data. This shift reflects a deeper understanding of the relationships between organisms.

4. **Developmental History and Phylogenetics**:
- Modern classification is heavily influenced by the concept of developmental history, which examines how organisms have evolved over time. Phylogenetic analysis is a key tool in this process, allowing scientists to study the evolutionary relationships between different species.

5. **Molecular Techniques**:
- Advances in molecular biology, particularly in DNA and RNA sequencing, have provided new insights into the genetic similarities and differences among organisms. This genomic data allows for a more accurate classification based on evolutionary lineage.

6. **Conclusion**:
- In summary, the classification system has undergone changes due to the evolving criteria for classification, which now includes phylogenetic analysis and molecular data. This evolution reflects a more comprehensive understanding of biological diversity and evolutionary relationships.