Evidence for evolution: hybridization and weak species barriers 

This video describes how what we think are different species can often interbreed. This is strong evidence for evolution since it shows that different species are related - and being related is because you share a history. Several examples of hybrids and ring species are described.
Examples used in the video include horses, donkeys, mules, salamanders, Larus gulls, greenish warblers, wheat, rye, triticale, hawks, macaques, and humans.
========academic citations========
Article about hawk hybrids:
doi.org/10.3356/0892-1016-54.1.74
Aticle about Larus gulls:
doi.org/10.1098/rspb.2004.2679
Article about Ensatina salamanders:
doi.org/10.1073/pnas.94.15.7761
Article about macaque hybrids:
doi.org/10.1016/0047-2484(74)90178-X
Article about macaque phylogeny:
doi:10.1016/j.gene.2009.05.013.
========music and video credits========
All music and video is believed to be in the public domain, available under a CC-0 or CC-by-SA license, or obtained under paid license from audioblocks.com or videoblocks.com.
Sources/credits for music:
From Audioblocks: Simplicity by Zac Nelson
Sources/credits for video:
From Videoblocks: gull flying
========image credits========
All non-original images are believed to be in the public domain, available under a CC-0 or CC-by-SA license, or obtained under paid license from storyblocks.com. Additional images used under a "fair use" interpretation
Images from storyblocks.com: tiger
Images from Pixabay:
Lion (/photos/lion-wildcat-safari-africa-515030/), hyena (/photos/hyena-africa-wildlife-nature-wild-3426693/)
Public domain: tigon (commons.wikimedia.org/wiki/File:Tigon.jpg), Chimpanzee (www.publicdomainpictures.net/pictures/190000/velka/chillin-chimp.jpg)
Fair use: liger (listed as cc by 2.0 at www.flickr.com/photos/alismith44/269850516), hawk hybrids (open access article), Red-shouldered hawk (listed as cc by 2.0 at commons.wikimedia.org/wiki/File:Red-shouldered_Hawk_(Buteo_lineatus)_-_Blue_Cypress_Lake,_Florida.jpg), Common black hawk (listed as cc by 4.0 at commons.wikimedia.org/wiki/File:Buteogallus_anthracinus_subtilis.jpg), Wheat (listed as cc by 3.0 at en.wikipedia.org/wiki/Wheat#/media/File:Wheat_close-up.JPG), triticale (listed as cc by 3.0 at en.wikipedia.org/wiki/Triticale#/media/File:Triticale.jpg), Rye (listed as cc by 3.0 at en.wikipedia.org/wiki/Rye#/media/File:Ear_of_rye.jpg), Larus distribution (listed as cc by 3.0 at en.wikipedia.org/wiki/Larus#/media/File:Ring_species_seagull.svg), green warbler (en.wikipedia.org/wiki/Greenish_warbler#/media/File:Greenish_Warbler_Sikkim_India_11.05.2014.jpg) and distribution (public domain at en.wikipedia.org/wiki/Greenish_warbler#/media/File:Greenish_warbler_ring.svg), Ensatina distribution (listed as cc by 3.0 at en.wikipedia.org/wiki/Ring_species#/media/File:Ensatina_eschscholtzii_ring_species.jpg), Southern pig-tailed macaque (listed as cc by 4.0 at en.wikipedia.org/wiki/Southern_pig-tailed_macaque#/media/File:(Macaca.nemestrina-1-PragueZOO.jpg), Celebes crested macaque(listed as cc by 2.0 at commons.wikimedia.org/wiki/File:Kuifmakaak_(8721744168).jpg).