No, they do not.
What? You want more? Seriously? Sigh. OK.
As you know, young-earth creationist organizations believe the literal view of Genesis is virtually all-important — worth risking even the gospel of Christ. The problem is that, in order to get the support they want and need from their conservative religious base, they have to convince them that their beliefs are based on scripture, and unfortunately, there’s just not that much scriptural basis for many of the foundational planks in their theological worldview. If anything, there is at least as much biblical evidence that goes against their ideas as there is that might support them.
That means that YEC proponents cannot be selective in making their case. They have to use absolutely every Bible verse that can even remotely be offered to prop up their exegesis — no matter how questionably out-of-context and reaching it may be — and, of course, they have to ignore the contrary evidence and the the blatant contradictions their views create.
This strategy can take them to some pretty bizarre conclusions, like their insistence that carnivorous animals are some sort of mutated aberration God sent to punish us, and it can and has led them to make enemies of many perfectly innocuous things (like science, for example). Another enemy they have is, apparently, thorns.
Yes, you read that right. Inside the brains of Answers in Genesis’ Ken Ham and the Institute for Creation Research’s John Morris, thorns and thistles are powerful evidence against the theory of evolution. K-Ham writes:
Fossil thorns are found in rock layers that secularists believe to be hundreds of millions of years old, so supposedly they existed millions of years before man. However, the Bible makes it clear that thorns came into existence after the curse: “Then to Adam He said, ‘Because … you have eaten from the tree of which I commanded you, saying, “You shall not eat of it”: Cursed is the ground for your sake. … Both thorns and thistles it shall bring forth for you'” (Genesis 3:17–18).
Powerful evidence indeed: A single ambiguous passage of scripture, in which a talking snake is also similarly “cursed.” That’s more than enough reason to reject the consistent and repeatedly confirmed findings from many independent lines of empirical inquiry regarding the ancient age of the earth. But, just for fun, let’s look at the verses in question a bit closer.
For starters, do they even say what K-Ham claims they do — “that thorns came into existence after the curse”? Hardly. The passage does not necessarily describe thorns and thistles as a new part of the created order. Indeed, the fact that God apparently did not see any need to explain what thorns and thistles were would indicate, if anything, that Adam and Eve were plenty familiar with the garden nuisances (this is all, of course, presuming that we are taking the passage literally).
Other than the brief introductory segment that concerns the serpent, the “curse” passage is entirely human-centered. It describes the consequences of sin as it pertains directly to the sinners. In other words, it describes what has changed or will soon be changing for them. Notice the strange and seemingly unnecessary qualification in verse 18: “Both thorns and thistles it shall bring forth for you.” Were scripture describing the appearance of something entirely new, which would now afflict all of creation, it seems a more straightforward directive would have been preferable. Something echoing the language of Genesis 1, like “Thorns and thistles the ground shall now bring forth.” Period.
I think the fact that the text includes the clause “for you” speaks to the idea that the passage is describing what will be changing for the sinners — rather than what is changing in the world. In this case, Adam and his wife are being evicted from the garden of Eden. They are being removed from an orchard planted and sustained by God, and kicked out into a world where good food comes from the ground only by hard toil and the sweat of one’s brow. Apologies to K-Ham and J-Mo, but Genesis 3 simply doesn’t say that thorns and thistles didn’t exist in creation until God spoke a mysterious curse over the ground; it says that — unlike in the garden — thorns and thistles were now things Adam would have to deal with on a daily basis.
So — even if you want to read the text literally — I see absolutely no need to take this passage as “clearly teaching” the idea that human sin predated thorny plants. Especially when the clear evidence in the other book God authored — the book of nature — says just the opposite.