Biology and the Living World

Biology is the science of life and living processes, focusing on the diversity of living organisms.

• Early humans differentiated between inanimate objects and living beings, often deifying some.
• Systematic studies led to identification, nomenclature, and classification of organisms.
• Recognition of similarities and relationships among organisms led to biodiversity conservation efforts.

Chapters Overview

1. The Living World
2. Biological Classification
3. Plant Kingdom
4. Animal Kingdom

Ernst Mayr

• Born on July 5, 1904, Ernst Mayr was a significant evolutionary biologist, often called "The Darwin of the 20th century."
• Contributed to ornithology, taxonomy, zoogeography, evolution, systematics.
• Defined modern understanding of biological species.
• Received prestigious awards such as the Balzan Prize, International Prize for Biology, Crafoord Prize.
• Passed away in 2004.

The Living World

Diversity in the Living World

• Wide range of habitats: mountains, forests, oceans, deserts.
• Biodiversity refers to the number and types of organisms on earth, with 1.7-1.8 million species identified.
• Importance of standardized naming for global communication about organisms – known as nomenclature.

Taxonomic Categories

• Nomenclature: Naming organisms based on agreed principles, e.g., International Code for Botanical and Zoological Nomenclature.
• Binomial Nomenclature: Two-part naming system, e.g., Mangifera indica.
• Classification: Grouping organisms into categories or taxa based on observable characteristics.

Taxonomic Hierarchy

• Hierarchical steps include species, genus, family, order, class, phylum/division, and kingdom.
• Species: Group of organisms with fundamental similarities.
• Genus: Group of related species.
• Family: Group of related genera.
• Order: Assemblage of families.
• Class: Includes related orders.
• Phylum: Includes classes with common features.
• Kingdom: Highest category, e.g., Kingdom Animalia and Plantae.

Systematics

• The systematic arrangement of organisms considering evolutionary relationships.

Summary

• Millions of organisms are known, but many remain undiscovered.
• Taxonomy: science of classification based on taxonomy principles and international codes.
• Hierarchical classification from species to kingdom helps understand and organize biological diversity.

Exercises

1. Importance of classifying living organisms.
2. Changes in classification systems over time.
3. Criteria for classifying people.
4. Learning from identification of individuals and populations.
5. Correct scientific name for mango: Mangifera indica.
6. Define taxon with examples.
7. Correct sequence of taxonomic categories.
8. Understanding the concept of species.
9. Definitions of taxonomic categories: phylum, class, family, order, genus.
10. Illustrate taxonomic hierarchy with examples.

This document provides a foundational understanding of biological classification, the importance of taxonomy, and the renowned work of Ernst Mayr in evolutionary biology.