> ## Content Index
> Fetch the complete content index at: https://www.cascadepbs.org/llms.txt
> Use this file to discover other available public pages before exploring further.

# Episode 4 Preview
- URL: https://www.cascadepbs.org/show/human-footprint/trailers/episode-4-preview-ahu9l1/
- Published: 2024-04-02T22:51:32.000Z
- Updated: 2025-08-20T18:49:10.000Z
- Description: Shane meets five species that made allies of humans.
- Author: Cascade PBS Staff
- Tags: Human Footprint, #ZZZ_Show_920c28e7-cc8d-4bd4-a6a1-1d54d80cf6c8, #geo-us, #v1.5, #ZZZ_Trailer_5cd81c8a-edd2-438c-b904-b2d27e3e2a1e, #trailer

Shane explores the surprising science and unexpected histories of “The Replacements”: five animal and plant species that made allies of humans, grew to dominate the planet alongside us, and changed their destinies (and our own) forever.