Which is the correct order of increasing geological time scale for a hypotehtical vertebrate evolution?

Options

A. Cenozoic, Mesozoic, Paleozoic, Proterozoic
B. Cenozoic, Palaeozoic, Mesozoic, Proterozoic
C. Proterozoic, Cenozoic, Palaeozoic, Mesozoic
D. Proterozoic, Palaezoic,Mesozoic,Cenozoic

Answer

To determine the correct order of increasing geological time scale for hypothetical vertebrate evolution, we need to understand the major geological eras and the evolution of vertebrates within those eras. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Geological Eras
The geological time scale is divided into several eras. For vertebrate evolution, the key eras are:
- Proterozoic
- Paleozoic
- Mesozoic
- Cenozoic

### Step 2: Understand the Characteristics of Each Era
- **Proterozoic Era**: This is the earliest era where life was simple and primitive. It marks the beginning of life on Earth.
- **Paleozoic Era**: This era saw significant diversification of life. It includes the evolution of jawless vertebrates in the Silurian period and the age of fishes in the Devonian period. Amphibians evolved during the Carboniferous period, and reptiles began to appear towards the end of this era.
- **Mesozoic Era**: Known as the age of reptiles, this era includes the Triassic, Jurassic, and Cretaceous periods. Dinosaurs dominated during this time, and it ended with their extinction.
- **Cenozoic Era**: This is the era of mammals and birds. It follows the extinction of the dinosaurs and marks the rise of higher forms of life.

### Step 3: Arrange the Eras in Ascending Order
To answer the question, we need to arrange these eras in the order they occurred, from the earliest to the most recent:
1. **Proterozoic**
2. **Paleozoic**
3. **Mesozoic**
4. **Cenozoic**

### Conclusion
The correct order of increasing geological time scale for hypothetical vertebrate evolution is:
**Proterozoic → Paleozoic → Mesozoic → Cenozoic**

### Final Answer
**Option D**: Proterozoic, Paleozoic, Mesozoic, Cenozoic.

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