Exactly my point. Us in our current state are very different, less aligned with the cycle of things in nature opposed to the former. Unlike the rest of the animal kingdom we manipulate the earths natural resources. Once we became homosapien-sapien our numbers gradually shot into the millions and over the past five to six thousand years we've gained enormous ground over the earth. We don't even need major cataclysm like meteorites to befall us like the dinosaurs. We have human cataclysms like world wars. Our growth, control or dominance depends purely upon an artificial cycle opposed to the natural state of things. Humans go against one another, we feed a market. The rest of the world is our play thing (or at least they entertain or feed us on a steady chain). I really do need to check out the San Diego Zoo this year. 

Back to the point...

Scientists have always been obsessed with the missing link in our evolution. Its the reason why people entertain theories like these. We seek to find a common ancestor in our evolution which could have buried their dead and made tools like us.

We have similar DNA to other wildlife... so yes, as long as we brought all the other mammals with us. :P


Wait a minute.... NOAHS ARK!!! Oh my god!!!

The random particles that were always there and decided one day to randomly explode, randomly created consciousness and lifeforce because that's made of protons, neutrons and electrons.... probably. The random explosion also gave us the ability to Appreciate Music, Humor, Art, the ability to Love, to imagine, to dream and to contemplate life.

The universe is a cold immoral place, there is no purpose, no morality and no universal Justice and everything lives suffers and then dissapears forever, life is meaningless.

It makes perfect sense and is something everyone should believe in because reasons.

Kinda thinking about it backwards.  What defines a "breathable atmoshphere" is simply whatever is in the atmosphere of the environment that promoted the organic chemistry originating in that environment to thrive, not what WE consider to be a breathable atmosphere for US.  An oxygen rich athmosphere is going to give rise to organic molecules that favor oxygen because anything else is going to die.  Likewise with other atmospheres.

And complex life doesn't just randomly turn into other complex life.  Genetic mutations take millions of years to guide evolution of species.

And yes, those random genetic mutations happen ALL THE TIME.  Biological CRC errors basically.

Aliens... I'm getting Xenogears vibes. I love panspermia and other types of third party creation stories, especially ones that are combined with manmade religions. Eg: gods DID exist and all the biblical stuff was true but they were just aliens with advanced technology, etc. Stargate, Xenogears, etc

Our own galaxy, let alone the entire observable and unobservable universe, is just so vast, the possibilities are truly endless.

Xenogears has to take the cake though... most amazing story I've ever experienced.

The only case you might have is some microorganims somehow surviving entry into the athmosphere (wich would have had a very diffrent composition back then), crash landing in the ocean and evolving from there.
In that case nearly all life on earth would be alien, or have alien admixture.

For everything else Darwin and genetics have you covered. Aliens wiping out dinosours to have the planet to themselves is very unlikely, to put it mildly.

First of all; apes did not evolve into humans, but the theory (if I´m right) is that we share one or more ancestors.

Second, we share to much of our DNA with other species in order for us to be something completely seperate. We also have traits and behavior that is very similar to most other mammals.

Humanity as a species is not that much different from any other, only that we have developed in some areas far above most other species. But it doesn´t make us unique, just a little bit more specialized.

Sadly I know a lot of people that thinks otherwise, ironically or not :).

We have a fossil record showing the steps that primates took to evolve into us.

And something similar to primates did not show up until millions and millions of years after the dinosaurs were gone. humans didn't arrive just after the dinosaurs died. The mammals of that time were small and rat-like. It took millions upon millions of years for them to branch out into different species and for one of the branches to evolve onto apes.

everyone already covered, that humans with 100% certainty are related to all the other lifeforms on earth and if we weren't we probably couldn't even digest them (there goes that "aliens want to eat us" myth)

but I'd like to add this:

The human physiology is extremely bad for space travel, just days in lowered gravity starts to decay our bones/muscles and put enormous stress on our organism unless we spend hours in fitness training each day. Sure, a highly advanced species could have technology to make up for these weaknesses, but in my opinion this kind of species should very easily be able to adjust it's genetics to allow for much easier space travel - hell, we are on the verge of this ourselves.

That we are unable to survive months or years outside of a gravity and magnetic field is very telling that our species is bound to a planet and wasn't traveling through the interstellar medium for generations to reach earth (even at/close to lightspeed it's highly likely you'd at least need hundreds to thousends of years). Explaining this with "we've since evolved/re-adjusted to live on earth" is nonsense.