What does Gen. 6:4 mean “and also afterward.?

Genesis 6:4 says, "The giants were on the earth in those days - and also afterward."

We begin by the basis that those days means as the full text further reads…  

“when the sons of God came in to the daughters of men and they bore children to them.”

 This the time period the author is speaking of, all the way up to the flood which ended the era.

It also tells us then the Lord saw the wickedness of man. This started to occur BEFORE Noah began building the ark.  From the time Noah began to build the ark until the flood was 120 years. So this is the span of those days and afterward is referring to.

Why does this statement “and afterward” not refer to after the flood? Would that not explain there were giants in the Land when Moses was there?

 Here is why. Because the Bible explicitly states only 8 survived the flood. All that had breath which would include the giants would have died. Only those on the ark survived.

 Just because one finds the word giants (Nephillim) later in history, it does not mean it is the same giants as the offspring of the Sons of God before the flood.

Without trying to complicate the issue, the word giants is strictly from the Septuagint, the Greek translation of the Hebrew. Giants is not the best direct translation of the Hebrew word Nephilim which means fall, or in the plural fallen ones. So many have understood this as giant in size, where it may mean giant in intellect and power.

Regardless, whether they were giants the Hebrew spies encountered (or as some propose they lied), it does not mean these are the same giants before the flood. Logically and biblically they can’t be if all that had breath that was not on the ark died.