Humans generally believe they have catalogued the forms and orders of life on Earth exhaustively enough to ‘know what’s here’. This is not only impossible, it would need a huge upgrade just to get to ‘wrong’. Our catalogues are vastly less dependable and complete than we commonly suppose.

I mean, the categories with which we refer to biological phenomena are missing crucial elements that, without them… well, that’s another topic.

Additionally, our ideas do not account for any kind of life that arrives here … from elsewhere … and becomes then indigenous. But I have good reason to suspect our world is colonized, at least occasionally, by interlopers from elsewhere. I suspect that, over the past 20 or so years, this has occurred at least once.

I also speculate that some changes in Earth’s temperature, atmosphere or other variables… may both catalyze and inhibit such events.