the way i understood the movie was that the oil thing was what created carbon based lifeforms! However it can be used to control the dna in the mean time.

Instead of using... Crude oil... as a life enchancer... it was used as a weapon of destruction. It was used as a terraforming poison to subtlity repopulate any infected world when the time that the Oil genes were rebuilded!

It reacts on heat and drasticly transform anything it touch with Reptilian Characteristics.

In the movie the x-files:fight the future in 1998. we see a similar plot with a black oilly alien virus that have the same specs!

To understand the purpose of this... watch District 9! You may have to watch it twice.

The aliens that are trying to escape are extremly evil! The movie is portraying that as innoncent aliens just being attacked by humans, just to make you beleive that humans are bad!

check the symbolism on the alien weapons and the black oily thing that infect the principal actor. (dont remember his name.)

Also Check Crysis 2 introduction... Pay attention to the first statement of the commentators! They mentions 3 cities.

In the game extermination. there was a clip mentioning an ancient virus that was locked up under antartica which uses water as a medium to grow.. Also in the game the virus react to heat! The reason the virus react to water is becase artic waters are reknown to be very salty waters!!

By the end of the game you discover the source of the virus is a 60,000 years old chunk of meat that crash landed on earth... Just before the final boss, there is a cinematic showing you that this thing is Black Oilly slime being.

Here. i can not show the video addendum i made on prometeus, becasue it has been taken down by fox... However this video is still up and i suggest you watch full screen and pay attention to most annotations!