Earlier quoted context omitted.
My argument isn't that because something happens in nature it's OK. But rather it is closer to the argument that the Large Hadron Collider will not create a black hole that the whole planet will be sucked into. In the case of the LHC, we know that particles collide at the speeds planned all the time, yet this does not lead to black holes erupting everywhere. In the case of the gene transfers currently done, we know p…
LHC's website states: "Whatever the LHC will do, Nature has already done many times over during the lifetime of the Earth and other astronomical bodies." This case is not analogous because in this planet's history there have been 6 different extinction events. So in order for it to be analogous, they would have to say that we know a few times in the past this has caused a black hole, but this is totally different. Pa…
There are two mass extinction events that have a clear biological origin. Minor extinction events are a permanent feature of evolution.
The first is the evolution of photosynthesis causing the Great Oxygenation Event[0]. In this, cyanobacteria converted CO2 into water and oxygen on a massive scale. This lead to a cooling of the planet due to reduced CO2 levels and the precipitation of iron oxides into massive deposits worldwide, today visible as "banded iron formations" [1].
The second mass extinction with a clear biological origin is the current one, where Homo sapiens is converting a massive quantity of carbon previously sequestered during the carboniferous back into CO2 and warming the planet as a result. In addition, this species destroys the habitats of many other species.