Select the correct statement(s).

Options

A. Single-celled organisms evolved slowly into multicellular organisms
B. Invertebrates evolved around 500 million years ago
C. Jawless fish must have evolved around 350 million years ago.
D. All of the above

Answer

To solve the question of selecting the correct statement(s), we will analyze each option provided in the video transcript step by step.

### Step 1: Analyze the First Statement
The first statement claims that "single cell organisms evolved into multi-cell organisms." This is a widely accepted concept in evolutionary biology, known as the transition from unicellular to multicellular life. It is generally understood that multicellular organisms evolved from simpler, single-celled ancestors over a long period of time.

**Hint for Step 1:** Consider the evolutionary process and the time it takes for organisms to develop complexity.

### Step 2: Analyze the Second Statement
The second statement mentions that "invertebrates evolved around 500 million years ago." This aligns with the fossil record, which indicates that invertebrates, such as early arthropods, began to diversify significantly during the Cambrian period, approximately 500 million years ago.

**Hint for Step 2:** Look into the timeline of major evolutionary events and the appearance of different life forms in the fossil record.

### Step 3: Analyze the Third Statement
The third statement states that "wireless fish must have evolved 350 million years ago." This is likely referring to the evolution of early fish, particularly the transition from lobe-finned fish to tetrapods, which occurred around this time. The term "wireless fish" seems to be a miscommunication, but the evolution of fish is indeed a significant event in evolutionary history.

**Hint for Step 3:** Research the evolution of fish and the timeline of vertebrate evolution to clarify any terminology used.

### Step 4: Analyze the Fourth Statement
The fourth statement claims that "all of these are correct statements." Since we have established that the first three statements are correct based on current scientific understanding, this statement would also be true.

**Hint for Step 4:** Consider the implications of the previous statements being true when evaluating the correctness of this statement.

### Conclusion
After analyzing all statements, we conclude that all the statements provided are correct. Therefore, the answer to the question is that all of the statements are correct.

### Final Answer
All of the statements are correct.