[Steve Van Doorn]

TwilightDog said, "how did these isotopes of manganese and iron traverse the distance between the earth and this supernova in a timeframe that would make it contemporaneous with the supernova event?

There is growing evidence it was a micro nova from our sun.

said, "Cosmic rays are produced from massive galactic events like a supernovae and consist of matter particles like Fe or Mn that have additional neutrons making them radioactive"

This has not been studied that I'm aware of. The two major near extinction of humans bottle necks of human population of 70,000 years ago and 12,800 years ago also had the effect of a Y Chromosome(Males) bottleneck right after the both events. Y Chromosome are more radiosensitive then the X chromosomes. As a result for thousands of years after both these events the female/male ratio was 6 to 1 and 17 to 1 respectively.

I'm suggesting a micro-nova from our sun could be that trigger.

[Campion]

They're pretty sure that the 70kya bottleneck was caused by the eruption of the Toba supervolcano in Indonesia.

As a result for thousands of years after both these events the female/male ratio was 6 to 1 and 17 to 1 respectively.

Cue Dr. Strangelove reference ... "It vould not be difficult, mein Führer! ... I mean, Mr. President".

[dsc]

“As a result for thousands of years after both these events the female/male ratio was 6 to 1 and 17 to 1 respectively.”

I wonder if those events resulted in a genetic predisposition toward male promiscuity.