User:HaskelleTW/Earliest known life forms/Brinaluvsrocks Peer Review

General info
HaskelleTW
 * Whose work are you reviewing?


 * Link to draft you're reviewing
 * User:HaskelleTW/Earliest known life forms
 * Link to the current version of the article (if it exists)
 * Earliest known life forms:

Evaluate the drafted changes
(Compose a detailed peer review here, considering each of the key aspects listed above if it is relevant. Consider the guiding questions, and check out the examples of what feedback looks like.)

LEAD

The lead paragraphs of your article have been significantly improved to encompass the main points of this topic. It would be good to also add a line just summarising the evidence. You have most but could add lipid biomarkers and carbon isotopes.

CONTENT

I think you've done a good job adding to this page, especially seeing what was lacking in the original one. These are all the most convincing, yet debated, pieces of evidence for early life, which makes for a very interesting article.

Some teeny suggestions :)

- The graphite showed a δ13C signature consistent with biogenic carbon on Earth. The earliest evidence of life found in THE rock record is from the Akilia Sequence and the Isua Supracrustal Belt in Greenland.

- I would add a couple words in the final line of the first geochem evidence paragraph about carbon isotopes. Just saying that they can record biological fractionation. You mention in further down but might not be as obvious to some readers so it's nice to state it at the first mention of carbon isotopes.

- In the final line of the geochemical evidence section you mention that 'these findings are supplemented by direct evidence'. I would just join this with the first line in the fossil evidence section and say that direct = fossil.

- The Dresser Formation stromatolites are chert, not sandstone, i think. I would double check this though.

- I would expand a bit on the last line in the microfossils section as to what the chemical preservations are.

- It might be good to change the biomarker section header to molecular biomarkers.

- Is the last addition to the biomarker section just an overview paragraph? I know this is still the sandbox and it will probably look different once you have moved it over, but just making sure :)

TONE AND BALANCE

You've done a great job not biasing your article. Didn't see anything that would convince me of one particular 'starting point' and all evidence has good explanations and justifications. Nothing seems underrepresented, even with such little evidence existing in the first place of when life first appeared. Good job stating the counterargument to things like stromatolite morphology and d13C signals.

SOURCES AND REFERENCES

All sources look good. Reference [30] has multiple sources which I didn't really understand. What does the link do in that case?

ORGANIZATION

The structure has been greatly improved with appropriate headers. There is one extra line break in the biomarker section that could be changed - will be once in main article i think. Paragraphs are not too long which keeps the reader engaged. Great job splitting the evidence into clear sections.

IMAGES AND MEDIA

Good examples of stromatolites and lipid biomarkers added. Might be good to add what a note saying that the lipids in the photo are specific examples of photosynthesis indicators. Cited correctly.