There isn’t a setting to change the order per se, but once you start reading a topic, if you are logged in, the system will remember where you left off and return you directly to where you left off.
Also, the summary information in the first first post has a link to the very last post. So if you find yourself at the beginning, the last post is a click away.
Finally, you have the green slider to the left. You can do a couple of different things with it. First, you can click on the date at the top of the slider (in this case May 31), or the date at the bottom of the slider (in this case, 2d ago), to move directly to the post made on those date. You can also click and drag the green slider up and down to quickly move through a very long topic.
Hopefully that sheds a bit more light on how reading and topic/post navigation works. We really think you have many options just a click or drag away.
Let us know if you have any other questions. Thanks!