Introduction to Biological Classification

1. Keshav Bhatia, Academic Content Writer at Edumarz

Humankind has tried numerous times to categorize organisms they see around them. Before Aristotle, classification was based on an organism’s use. Aristotle was the first one to classify

organisms scientifically; he grouped

Plants into trees, shrubs, and herbs

He categorized animals into those without blood and those with red blood.

Then came Carolus Linnaeus, who made striking changes in scientific classification. His exemplary work earned him the title of “Father of Taxonomy”.

He divided organisms into two kingdoms: Plantae and Animalia. 

All organisms had to fit into this two-kingdom classification.

But his system had flaws.

Many organisms didn’t fit into either category.

There were a lot of species that didn’t fit into either group. As a result, the long-used two-kingdom categorization was determined to be insufficient. Aside from gross appearance, there was a need to include additional features such as cell structure, wall nature, manner of nutrition, habitat, reproductive strategies, evolutionary relations, and so on.

As a result, classification systems for living creatures have experienced several alterations over time.

It did not make a distinction between;

                    1.  Eukaryotes and prokaryotes

                    2.  Unicellular and multicellular organisms

                    3.  Photosynthetic and non-photosynthetic organisms 

The Plantae and Animalia kingdoms have stayed in the future classification systems. The quantities and qualities of kingdoms, as well as groups included within these kingdoms, have changed over the years as our understanding of organisms has improved and better classification systems have evolved.

R.H Whittaker is the scientist who proposed a five-kingdom classification for living organisms. 

The Kingdoms described by him are:

• Monera 
• Protista
• Fungi 
• Plantae 
• Animalia