Thread For Scientific / Logical Blunders

I can suspend my disbelief, but only to a point. When logic and common sense itself is violated, it makes it very difficult. Please post flaws you found, I am curious to know who else saw these, or if there were others. GROSS ERRORS OF SCIENCE: 1. Taking off your helmet on a foreign environment, despite a breathable atmosphere. You are on a foreign planet. There is biological material around you. You are in a space suit. The atmosphere reads "breathable"...so LETS TAKE OFF OUR HELMETS! No scientist would EVER even THINK about doing this. It is just so absurd. The smallest biological organism, harmless on that planet, could be a devastating pandemic to human beings who lack the evolutionary resilliency to it. When I saw all these "scientists" take off their helmets simply due to breathability, it made my skin crawl it was so idiotic. Bad writing!! 2. Lets put the head of an alien being on a table, without environmental quarrantine, and without face masks, without bodily protection, and let me get right up to it so i can smell it. Are you serious? What if this thing died of....get ready...A DISEASE! We already knew these beings died en masse, bodies piled up. For all we know, they died of a horrible disease. Yet she just touches it and smells it and breathes it...no problem. (she even said "he stinks") 3. Dumping my DNA into a river, and that somehow leads to the first human. Cmon. The premise of this movie is what is called "panspermia", ok thats totally fine. We got here from another world. But consider that if human DNA is floating around in water, then how did a human being "come out" of it? Are you saying that what came out of it was an amoeba, and then a slug, and then a jellyfish, and then a snail, and then a lizard-->bird-->dog-->ape--man? So much for the entire premise of the movie then (that we did not evolve according to darwinian theory, but instead were created) Human DNA in a river --> human being. Someone explain this to me in a way that is plausible. 4. Human DNA in river --> Cave paintings pointing towards star system. And just how am I supposed to believe this? The beginning of the movie, at least how I interpret it, shows that human beings came about because human DNA evolved into a non-human amoeba, which evolved into non-human animals, which evolved into humans...and those first humans somehow "knew" the exact location of the engineers in space. Yea, right! This is just so full of holes.