Uploaded July 2023 | Updated September 2026, 1 hour ago

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You can find all my A Level Biology videos fully indexed at freesciencelessons.co.uk/a-level-revision-videos/a-level-biology

In this video, we look at the evidence for evolution by natural selection. First we explore Darwin's theory of evolution and how he developed this. We also look at Alfred Russel Wallace. We then look at how Darwin's theory of evolution is supported by evidence from fossils, comparative anatomy (including the pentadactyl limb) and comparative biochemistry.

Image credits:

Large Ground Finch
commons.wikimedia.org/wiki/File:Large_ground_finch_(4229035966).jpg
Peter Wilton, CC BY 2.0 creativecommons.org/licenses/by/2.0, via Wikimedia Commons

Medium Ground Finch
commons.wikimedia.org/wiki/File:Female_Gal%C3%A1pagos_medium_ground_finch.jpg
Charles J. Sharp, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Small Tree Finch
commons.wikimedia.org/wiki/File:Camarhynchus_parvulus.jpg
Mike Comber, CC BY-SA 2.0 creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons

Green Warbler Finch
commons.wikimedia.org/wiki/File:Certhidea_olivacea_-_Green_Wabler_Finch.jpg
2000 - Paul McFarling, Charles Darwin Foundation, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Charles Darwin
commons.wikimedia.org/wiki/File:Charles_Darwin_aged_51.jpg
Messrs. Maull and Fox, Public domain, via Wikimedia Commons

Everest
commons.wikimedia.org/wiki/File:Everest,_Himalayas.jpg
© Vyacheslav Argenberg / vascoplanet.com/, CC BY 4.0 creativecommons.org/licenses/by/4.0, via Wikimedia Commons

Xiphactinus Fossil
commons.wikimedia.org/wiki/File:Xiphactinus_fossil_SI.jpg
Chip Clark, Smithsonian, National Museum of Natural History, Public domain, via Wikimedia Commons

Galapagos Islands
commons.wikimedia.org/wiki/File:Galapagos-satellite-2002.jpg
Jacques Descloitres, MODIS Rapid Response Project at NASA/GSFC, Public domain, via Wikimedia Commons

Alfred Russel Wallace
commons.wikimedia.org/wiki/File:Alfred-Russel-Wallace-c1895.jpg
London Stereoscopic and Photographic Company (active 1855-1922), Public domain, via Wikimedia Commons

Fossil of Germanodactylus
commons.wikimedia.org/wiki/File:Germanodactylus_spec_01.JPG
H. Zell, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Opossum
commons.wikimedia.org/wiki/File:Opossum_2.jpg
Cody Pope, CC BY-SA 2.5 creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons

Agama Sinaita
commons.wikimedia.org/wiki/File:AgamaSinaita01_ST_10_edit.jpg
by Ester Inbar, available from commons.wikimedia.org/wiki/User:ST., Attribution, via Wikimedia Commons

Earthworm
commons.wikimedia.org/wiki/File:Earthworm.JPG
Aruna at ml.wikipedia, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Volcano
commons.wikimedia.org/wiki/File:Erickson_Banzuela_Balderama_-_Mayon_Volcano_Up-close.jpg
Erickson Banzuela Balderama, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Pentadactyl limb
commons.wikimedia.org/wiki/File:Evolution_pl.png
Mcy jerry at the English-language Wikipedia, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Cytochrome C
commons.wikimedia.org/wiki/File:Cytochrome_C.png
Vossman, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Chimpanzee
commons.wikimedia.org/wiki/File:Chimpanzees_eat_nuts.jpg
Herusutimbul, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Woman
commons.wikimedia.org/wiki/File:Woman_1.jpg
Owlsmcgee, Public domain, via Wikimedia Commons

Rock containing fossilised bacteria
commons.wikimedia.org/wiki/File:Morania_fragmenta_(fossil_bacteria)_(Wheeler_Formation,_Middle_Cambrian;_Millard_County,_Utah,_USA)_1.jpg
James St. John, CC BY 2.0 creativecommons.org/licenses/by/2.0, via Wikimedia Commons

Fossil skull of mammal
commons.wikimedia.org/wiki/File:Hypisodus_cf._Hypisodus_ringens_fossil_mammal_skull_(Oligocene,_Wyoming,_USA)_(32256798985).jpg
James St. John, CC BY 2.0 creativecommons.org/licenses/by/2.0, via Wikimedia Commons