Meaning of "given"

I found the following sentence from a book. However, I cannot understand the meaning of the "given" in the following sentence. Therefore, I would really appreciate it if someone could let me know what type of construction it is. Furthermore, please give me some websites to learn about this types of constructions and what is the grammatical name of this.

Even today, Aborigines see the Rainbow Serpent as a symbol of creation which is understandable given the increase in vegetation and the new life forms that featured when the image first appeared.