<think>
Okay, I need to figure out the answers to these six questions about the pathway enrichment analysis in the provided scientific article. Let me start by going through the Methods section again to see where they mention the analysis.

Looking at the "Positive Selection Analysis" subsection under Methods, the last paragraph says: "GO category enrichment among positively selected genes was performed with the STRING database online software (101)." So the tool used is STRING's online software. 

1. The tool is STRING database online software. 

The citation is reference 101, which in the references would be the STRING 11.0 version, as listed under Software Versions: "STRING 11.0". So the version is 11.0. 

2. Yes, the version is 11.0.

For the gene set library, since they mention GO categories, that's Gene Ontology. So the library is GO.

3. Gene Ontology (GO).

The question about background gene list: The Methods don't explicitly state whether a background list was defined. They just mention using the positively selected genes against the GO categories in STRING. Maybe STRING uses its own background by default, but since the paper doesn't specify, I should note it's not described.

4. Not described.

Statistical test used: The paragraph doesn't specify the test. STRING typically uses hypergeometric tests for enrichment, but since the user is asking for what's in the article, and they don't mention it, I have to say not described.

5. Not described.

FDR correction: The question is whether they used FDR. The text doesn't mention any multiple testing correction except in the phylogenetic part where they say no correction was done for the alternate consensus runs. For the GO analysis, since it's via STRING and no mention is made, maybe they didn't, but the user's instructions say to note if not described. So answer is not described.

6. Not described.
</think>

1. **Tool used for pathway enrichment analysis?**  
   STRING database online software  

2. **Tool version number provided?**  
   Yes, version 11.0  

3. **Gene set library queried?**  
   Gene Ontology (GO)  

4. **Background gene list defined?**  
   Not described  

5. **Statistical test used?**  
   Not described (likely hypergeometric test, but not specified in the article)  

6. **False discovery rate (FDR) correction used?**  
   Not described  

---

### Summary Table:
| Question | Answer |
|----------|--------|
| 1. Tool for pathway enrichment analysis? | STRING database online software |
| 2. Tool version number? | Yes (STRING 11.0) |
| 3. Gene set library (e.g., GO, KEGG)? | Gene Ontology (GO) |
| 4. Background gene list defined? | Not described |
| 5. Statistical test used? | Not described |
| 6. FDR correction used? | Not described |