It is a common situation to have two or more nodes created representing the same thing or idea. This can be due to spelling/capitalization (eg. "exaptive" vs. "Exaptive") or due to using different words that mean the same thing (eg. "flora" vs. "plants").
Merging these elements together can be accomplished in a view. In the following example we have two elements "something" and "Something", each with two properties. We can merge them together by searching for them in a view, selecting both (via command/control clicking each or using shift to drag a selection) and using the merge feature on the right detail panel.
There are two types of merging, simple and advanced. Simple is best when you have nodes without properties that you want to merge. In this case, if the "Somethings" had no properties, we could just choose simple and then select the one to keep.
In advanced you are shown a screen with the properties on both nodes. In this example, lower case "something" has properties "Foo" and "Bar" while upper case "Something" has "lorem" and "ipsum". We can use advanced merge to see those properties and even select a combination of them for the resulting merged node.
You can see here I've scrolled to the right so that I can select "Foo" from lower case "something" to use in the new node.
After submitting the merge (and this can take a while if you are merging many elements with many connections), I'm left with the new node with the chosen properites.