Talk:History of life/Archive 2

Years ago abbreviations
The use of the abbreviation Ga. to mean billion years ago is obtuse and makes the page unnecessarily hard to read. Wikipedia’s own page explaining this abbreviation https://en.m.wikipedia.org/wiki/Billion_years also lists Bya, billion years ago, as another way to abbreviate the same thing. This would be far superior in several respects.

1) no one uses the term Giga-annum. I am a very well read science fan, and I’ve never run across giga-annum. We don’t talk about National budgets in giga dollars. We don’t reference the astronomical distances in giga-kilometers. 2) elsewhere in the page in full, unabbreviated text, the term “billion years” is used several times. Switching back and forth between billion years and giga-annum is silly. And clearly in full text the preference for billion over giga is clear. 3) without the “y” the abbreviation makes no sense for years ago. It is either Billion years ago (Bya) or apparently it might be giga years ago (Gya) or even Giga-annum ago (Gaa) but it is not (By) billion years or (Ga) giga-annum if the intent is years prior to right now. Mckennagene (talk) 05:44, 5 April 2019 (UTC)

I attempted to at least define the term since the link to year looks like maybe at one point deep-linked to Gigaannum but some bot broke the link when the anchor was removed. I agree the article would be much more legible if it simply said "billion years." Lukeschlather (talk) 15:18, 21 September 2020 (UTC)

A single last universal ancestor? Maybe — but maybe not.
The first paragraph of the section begins
 * Biologists reason that all living organisms on Earth must share a single last universal ancestor ...

The second paragraph is a bit longer, beginning ...
 * According to a different scenario, a single last universal ancestor ... has never existed.

So the reader is presented with two competing theories, each covered in more detail in the rest of the section. It is not Wikipedia's place to favor one view held by respected scientists over a competing view favored by other such scientists. A glance at the footnotes reveals that the "different scenario" was advocated by Otto Kandler, an author of papers in major journals and the recipient of many awards including the Order of Merit of the Federal Republic of Germany.

Accordingly, on March 1, I changed "Biologists" to "Some biologists", arguing that the section shouldn't start "Biologists reason that ..." when the ensuing clause represents the view only of one group of biologists while respected biologists (including Kandler) disagree.

reverted my change, writing that "It is the consensus view, but there may be the odd dissenter". See the exchange here. I don't think it appropriate to lump proponents of the "different scenario" as odd dissenters. I would like to change the text back to "Some biologists", but I welcome other ideas.

Peter Brown (talk) 02:53, 13 April 2023 (UTC)