Subdue

1:28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.

Oddly enough, people are blessed much like fish.

This repeats the dominion, but it leaves out cattle and "all the earth".  I don't know about the cattle, but this makes me lean toward interpreting "all the earth" as just meaning all the animals.

The phrase "replenish the earth" is parallel to the fish's "fill the waters".  I think it's just a third way of saying "reproduce".  So "Be fruitful" = "Reproduce" and "multiply" = "reproduce".  Which makes the blessing start "Reproduce, reproduce, reproduce."  Perhaps that was considered important.

But the "subdue it" phrase is new and very interesting.  People are charged with subduing the earth.  I get two pieces of information from this.  First is "There's no such thing as a free lunch"; God will give the earth to people, but they still have to work to control it.  Second, this can basically be read as people being commanded to develop agriculture.  That surely sounds like a fundamental purpose for a group of farmers.