Pecans were definitely there before cultivated varieties, they are a native Texas tree which covers a large area of Texas.
The scientific name refers to any pecan, both cultivated and wild, which would include pecan trees from anywhere in the native range.
A pecan from the midwest is not going to be as well adapted to Texas compared to one that is from your local area. Even a tree from East Texas will not be as well adapted to areas of Central Texas.
The more local (or at least more similar to your specific growing conditions) the source of your tree is, the better your tree will be adapted.