• Elements

Activating Evolution is a book written by Chandra Suresh. It describes Suresh's discoveries and predictions about the emergence of humans evolved with special abilities. It has constantly appeared in the series and, less predominately, in the Heroes graphic novels. Excerpts from the book can also be viewed on a website by the same name.

Appearances include:
- Peter Petrelli brings the book to the attention of Nathan, his brother, when researching human flight.
- Mohinder Suresh, Chandra Suresh's son, finds a copy of the book in Sylar's apartment.
- Zach gives a copy of the book to Claire to help her understand her powers.
- West leaves Claire a copy of the book.
- Maya and Alejandro Herrera are on the run to find the book's author to cure Maya's 'plague.' Maya carries around a Spanish copy of the book, Activando la Evolución.

The helix is a symbol that appears quite frequently throughout the series. The helix symbol consists of an "S" shape from which three lines extend, with two on the left and one on the right. Michael Green explained that the symbol is simply known within the writers' room as "the helix".

The symbol frequently appears as a pattern formed by mundane objects, but it also recurs on certain plot-significant items and on several characters:
- On various paintings by Isaac Mendez.
- On Jessica's back whenever she surfaces as Niki's alternate personality.
- On the front of Dr. Chandra Suresh's book, Activating Evolution.

In addition to being the series logo, a solar eclipse has been a recurring image in the series itself. A terrestrial eclipse (an eclipse in which the Earth covers the Sun, as viewed from some observation point away from the Earth) is used in the series' title sequence.

So far, the solar eclipse has appeared as:
- The background of the title card of the series.
- A painting by Isaac Mendez.
- A "global event" in "Genesis"(at the end, during the last minute or so it shows the characters across the world seeing it above them.
- A future event referenced in a newspaper.
- A picture in Mohinder Suresh's apartment.
- The reflection of a light in a hospital waiting room in "Six Months Ago".
- An event during Hiro Nakamura's visit back to 17th century Japan in "How to Stop an Exploding Man" and "Four Months Later...".

A mark consisting of two black parallel lines has been shown close to the neck of multiple super-powered characters. The mark is the scar left by the two-pronged needle of a pneumatic injection device, which, as revealed in a biography of Hana Gitelman in the Heroes 360 experience, injects a radioisotope to allow tracking. All of the marked characters have had encounters with Mr. Bennet and/or the Haitian.

The following have displayed it:
- Matt Parkman in "Nothing to Hide"
- Ted Sprague in "Nothing to Hide"
- Hana Gitelman in Graphic Novel "Wireless, Part 4"
- Claude in "Unexpected"
- Isaac Mendez in "Unexpected"
- West in "Kindred"