Author: Khan Academy via YouTube
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Evolution is the change in heritable traits that occurs in a group of organisms over multiple generations.

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Credits:
“Composite image showing the diversity of birds” by Klow (CC BY-SA 3.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Bird_Diversity_2013.png

“Bald Eagle (Haliaeetus leucocephalus) Kachemak Bay, Alaska” by Andy Morffew (CC BY 2.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Bald_Eagle_(Haliaeetus_leucocephalus)_Kachemak_Bay,_Alaska.jpg

“A Congo African Grey Parrot in Herborn Bird Park, Germany” by Quartl (CC BY-SA 3.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Psittacus_erithacus_qtl1.jpg

“Costa’s hummingbird by Pete Gregoire” by Pete Gregoire (CC BY 2.0), via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Costa%27s_hummingbird_by_Pete_Gregoire_(10127567666).jpg

“A mallard duck stood up from its nap on a log at Riverwood Farms Lake” by Jeremy Bishop, via Unsplash:
https://unsplash.com/photos/Mdkrvid9l8s

“Adeliepinguin (Pygoscelis adeliae), fotografiert auf der chilenischen Antarktisstation Eduardo Frei auf King Georges Island” by Nanosmile / Reinhard Jahn (CC BY-SA 2.0 DE), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Adeliepinguin-01.jpg

“A photo quilt composed of bird photos taken on National Wildlife Refuges in Region 6, Mountain Prairie Region, USFWS” by Tom Koerner/USFWS [Public domain], via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Bird_Quilt_(25903314073).jpg

“Dancing peacock” by Montasim Jawar (CC BY-SA 4.0), via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Peacock_safari.jpg

“Bald eagle talons” by Tim Evanson (CC BY-SA 2.0), via Flickr:

“Gräsand, Mallard, Anas platyrhynchos” by Bengt Nyman (CC BY-SA 2.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:A7R09569_(52153200658).jpg

“Wisdom Returns to Midway” by USFWS [Public domain], via Flickr:

“Wisdom’s 2011 chick, marked with band number N333” by Dan Rapp/USFWS, via ACAP:
https://www.acap.aq/latest-news/4283-wisdom-the-world-s-oldest-known-albatross-gets-a-grandchick

“A feral pigeon about to land” by Claudio Gennari (CC BY 2.0), via Flickr:

“Close-up of the head of a feral pigeon (Columba livia) in Parc Georges-Valbon, France” by Alexis Lours (CC BY 4.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Feral_pigeon_2022_03_20.jpg

“Columba livia, Roncone (Sella Giudiarie, Trentino, Italy)” by Syrio (CC BY-SA 4.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Columba_livia_Roncone_02.jpg

“A feral rock pigeon (Columba livia), taken in Santa Barbara, California, USA” by Dori (CC BY-SA 3.0 US), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Pigeon_portrait_4861.jpg

“Saint Pio of Pietrelcina Chapel Bagumbayan, Quezon City” by Judgefloro (CC0 1.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:03730jfSaint_Pio_of_Pietrelcina_Chapel_Bagumbayan,_Quezon_Cityfvf_12.jpg

“Feral pigeon (Columba livia) in Parc Georges-Valbon, France” by Alexis Lours (CC BY 4.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Feral_pigeon_2022_03_18_02.jpg

“Hill Pigeon (Columba rupestris)” by Imran Shah (CC BY-SA 2.0), via Flickr:

“Animal diversity October 2007” by Justin (CC BY-SA 3.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Animal_diversity_October_2007.jpg

“Corythoraptor life restoration” by Zhao Chuang (CC BY 4.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Corythoraptor_life_restoration.png

“Terrestrial Dorygnathus” by Mark P. Witton (CC BY 4.0), via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Terrestrial_Dorygnathus.png

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