Answer:
**Characteristics of a Scientific Theory:**
1. **Explanation:** A scientific theory provides an explanation for a phenomenon, based on a body of evidence and observations.
2. **Predictive Power:** It can make accurate predictions about future events or outcomes.
3. **Falsifiability:** A theory must be testable and capable of being proven false through experimentation or observation.
4. **Supported by Evidence:** It is supported by a substantial body of evidence, including experimental data, observations, and research.
5. **Consistency:** A theory is consistent with existing scientific knowledge and doesn't contradict established facts.
6. **Generality:** It has broad applicability and can explain a range of related phenomena.
7. **Refinement:** Scientific theories are subject to refinement and improvement based on new evidence, technology, or insights.
**Difference between a Hypothesis and a Theory:**
A **hypothesis** is a testable, tentative explanation for an observation or phenomenon. It is a proposed idea that is often formulated based on initial observations or prior knowledge. Hypotheses are specific and are designed to be tested through experiments or further observations.
A **scientific theory**, on the other hand, is a well-substantiated explanation for a range of phenomena. It has passed multiple tests and is supported by substantial evidence. It goes beyond a single explanation and has predictive power. Unlike hypotheses, theories have a much higher level of confidence and generality, being the result of extensive research and observation.
**Example of a Refined Scientific Theory:**
The theory of **evolution** is an excellent example of a scientific theory that has been refined and improved since it was first established. Charles Darwin proposed the theory of evolution by natural selection in the 19th century to explain how species change over time. Since then, the theory has been supported by an overwhelming amount of evidence from various fields, including genetics, paleontology, and comparative anatomy.
Over the years, advancements in genetics, molecular biology, and the fossil record have led to refinements of the theory. For instance, the modern synthesis of evolutionary biology combines Darwin's theory with the understanding of genetics, clarifying how variation and inheritance occur. Additionally, discoveries such as the understanding of DNA and the molecular mechanisms of inheritance have enriched our understanding of how evolution works at the genetic level.
These refinements have strengthened the theory of evolution, making it a cornerstone of modern biology while highlighting the dynamic nature of scientific theories as they adapt to new knowledge and evidence.