As if mushrooms weren't trippy enough
You may be asking yourself why the hell anybody would think mushrooms are an alien life form. Or maybe you entirely agree! Either way, I am going to present some observations that suggest that they very well could have been sent here from another planet to probe Earth for life.
Mushrooms can talk
Everyone has heard of psychedelic mushrooms. When consumed, they can produce profound experiences. These experiences include the notion that "something" is communicating to you; like they are trying to show you something. It is not in any language we as humans are familiar with and it may not even be audible. However, there are numerous reports of psychedelic mushrooms inducing a sense of communication from extraterrestrial beings. This could also very well be nature "talking" to us which I believe is a valid perspective as well. Nonetheless, some form of communication is perceived.
Mushrooms may have catalyzed human evolution
There is a theory out there that states just that. It is called the stoned ape theory and was cooked up by a man named Terence Mckenna. It speculates that mushrooms gave us an evolutionary advantage and permitted our species to survive and thus evolve. When psychedelic mushrooms are consumed they can induce states of elevated consciousness, increased intelligence and self-awareness, community bonding, vivid reliving of dreams and very commonly, enhanced ability to recall memories, especially from childhood. Enhanced creativity and communication, emotional recognition, problem solving, decision making, (as in life decisions after the experience, maybe not during haha) are all effects of the psychedelic mushroom experience as well, both during the experience and sometimes for many years after. These experiences could have promoted the evolution of the frontal lobe in humans or the area of the brain where many of the aforementioned abilities occur. Mushrooms also increase visual acuity thus allowing for a species who consumed them to hunt & gather better. They enhance peripheral vision allowing for the spotting of predators sooner. They can increase libido or the desire to reproduce. All these things considered, could they have played a role in potentiating our evolution as a species? Quite possibly.
Mushroom spores can travel through space
Mushroom spores are made of something called chitin, one of the toughest substances on Earth. Spores are also able to survive in vacuums. Although I do not know if this is entirely true or not, I have read that the outer casing of spores has the ability to deflect UV rays. Spores would therefore be an ideal space pod. Were they sent here to catalyze the evolution of our species? To communicate something to us? To show us something we cannot see? How many licks does it take to get to the center of a tootsie pop? The world may never know.