Today’s second glitch:
Change the comma after invented to a period.
*sigh* A sword is a blade, kids. Add other after and in the second sentence to show that you’re not saying swords and blades are separate categories.
That takes care of the grammar-and-punctuation stuff, but the concept in this writing prompt is just bad (or at least not expressed well).
Blade weapons are like sharks: they’ve been around since forever because they’re so efficient in form and function. If you look at pictures, based on fossil remains, of what sharks looked like millions of years ago, you’ll see that they’re pretty much like sharks now, except perhaps slightly less streamlined. Sharks haven’t become more complex; they’ve become more refined, all the extraneous detail stripped away to leave the very essence of Shark-ness. Blades are like that, too. If you compare a modern knife made of some special steel alloy to a stone blade from the Clovis period (shut up — I live less than fifteen miles from Blackwater Draw, the Clovis site, and I can use whatever examples I want), you’ll see that the basic form and function are the same, and that the only real changes are improvements in materials and specific shape. A blade is a blade is a blade, as a shark is a shark is a shark. In a world where guns (projectile weapons in general, I suppose, because you don’t need gunpowder to have damn fine crossbows) are never invented (even though the concept of a ranged/projectile weapon is old, too — there’s a thing called an atlatl, used for increasing range and power for a thrown spear, that dates from the time of those Clovis points I mentioned), swords won’t become more complex; they’ll become more efficient. They won’t develop into all sorts of weird shapes, because a blade doesn’t need a weird shape; a blade just needs a sharp edge and a shape that makes it easy to wield effectively.
Anyway, here’s the corrected (as much as it can be) version of the original:
Guns were never invented. Instead, swords and other blades became increasingly complex and powerful.