the Chinese script have evolved, but one can still look at inscriptions from thousands of years ago and understand it.
it might be hard for people to understand different dialects in China but they all use the same writing system, standardized in the Qin dynasty.
Same with the borrowed Chinese characters in Japanese and Korean. A native Chinese speaker would have little problem reading those, although the pronounciations might be a little different
'ȝ' becomes 'g', 'Ð' becomes 'D', and we still use 'æ' today, which is also a rune, and they even used 'W'!
Also, the number of characters in Chinese has also drastically changed over time. So while many characters have a 1:1 lineage, far more characters simply did not exist 1 or 2 thousand years ago.
The only commonality is that they are based on pictographs and have a traceable etymology, although that's true for all languages.
The Japanese pronunciation of Chinese characters is absolutely nothing like the Chinese pronunciation of them, and the meaning is sometimes different too. (The Kanji for "letter" (as in a piece of paper you write a letter on) means "toilet paper" in Chinese.)
Are you Indiana Jones?
With some training, people can read seal script inscriptions because the structure is already fairly close to regular script which is what people use today.
The radicals are written in slightly different styles from today. It actually makes sense. Seal script is a very artistic form of calligraphy, so people use it for their seals hence the name.
An example of the "drum" character: http://www.guoxuedashi.com/zixing/yanbian/11208mb/ The horizontal arrow is the time line, starting from oracle bone script. The 4th one of the first row is seal script and the last regular script.
The idea depicted here is hitting a decorated drum on a rack with a drum stick holding in the hand.
https://en.wikipedia.org/wiki/Seal_script
If you look at the picture on the upper right, you can make out "tian xia" and "wang" -- all under heaven (i.e. the world) and king (the character for emperor isn't invented yet)
Hmm it's right there。 The 4th “皇” and 5th “帝”。 And the combined form “皇帝” - a title invented by the First Emperor himself。