Comment by jujube3 | Hacker News Reader

Comment by jujube3 | Hacker News Reader

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  > End-Permian seems tied to the Siberian Traps basaltic eruption,
  > but that eruption had been going for thousands of years before
  > the dieoff started.

The eruptions probably hadn't been "going for thousands of years." We can't "see" time periods as small as a few thousands years from a vantage point of 250 million years later.

Biologists like to proclaim that things are gradual when they're really more likely sudden. This often reflects mathematical ignorance. For example, if the last specimin of a certain rare fossil is found in a stratum slightly older than the K-T stratum, does that mean it went extinct earlier than the K-T event? Probably not; it just means the fossil is rare so your sampling error is larger.

I'm massively summarizing the book but he talks a lot about the history of the timeline for end-Permian.

At the time of writing of the book it was "less than 60k years" which seems like a long time, but when the extinction was first discovered it was believed to be a very gradual change taking place over 10 million years, turns out that it was believed that end-Permian and end-Guadalupian were the same event.

As isotope dating has gotten more and more accurate, the length of time for end-Permian has gotten shorter and shorter. There's also other evidence that it was a very sudden event, evidence of fungal explosions for instance during the event suggesting massive amounts of decomposition.

In any case, as I said the P-T took "no more than 60k years" but the Siberian traps were erupting for at least 120k years before, so there's at least 60k years unaccounted for between the start of the eruptions and the start of the extinction.

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