Uploaded July 2023 | Updated September 2026, 50 minutes 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 phylogeny and phylogenetic trees. First we explore what is meant by phylogeny. We then look at how to interpret a phylogenetic tree, including what is meant by a node and sister groups. Finally, we look at the benefits of phylogeny over taxonomic classification.

Image credits:

Clownfish
commons.wikimedia.org/wiki/File:Amphiprion_ocellaris_(Clown_anemonefish)_by_Nick_Hobgood.jpg
Nick Hobgood, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Geranium
commons.wikimedia.org/wiki/File:Geranium_02.JPG
Dominicus Johannes Bergsma, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Bacillus cereus
commons.wikimedia.org/wiki/File:Bacillus_cereus_SEM-cr.jpg
Mogana Das Murtey and Patchamuthu Ramasamy, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Fungi
commons.wikimedia.org/wiki/File:Fungi,_Belfast_-_geograph.org.uk_-_3668913.jpg
Fungi, Belfast by Albert Bridge, CC BY-SA 2.0 creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons

Amoeba
commons.wikimedia.org/wiki/File:Collection_Penard_MHNG_Specimen_18-1-4_Amoeba_granulosa.tif#file
Dalinda Bouraoui CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/deed.en , via Wikimedia Commons

Golden Hamster
commons.wikimedia.org/wiki/File:Golden_hamster_front_1.jpg
Adamjennison111 at English Wikipedia, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

Chinese hamster
commons.wikimedia.org/wiki/File:Chinesedsaffa.jpg
Tristanspotter, Public domain, via Wikimedia Commons

Prairie vole
commons.wikimedia.org/wiki/File:Prairie_vole.gif
United States National Park Service, Public domain, via Wikimedia Commons

DiGangi Deermouse (prairie deer mouse)
commons.wikimedia.org/wiki/File:DiGangi-Deermouse.jpg
6th Happiness, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Brown Rat
commons.wikimedia.org/wiki/File:Brown_Rat_(Rattus_norvegicus).jpg
Dunpharlain, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

House mouse
commons.wikimedia.org/wiki/File:Mouse_white_background.jpg
Unknown authorUnknown author (original) / Ilmari Karonen (editing), Public domain, via Wikimedia Commons

Phylogenetic tree of rodentia (modified)
commons.wikimedia.org/wiki/File:Phylogenetic_Tree_of_Rodentia.jpg
M ralser, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Vulpes vulpes
commons.wikimedia.org/wiki/File:Vulpes_vulpes_ssp_fulvus.jpg
Joanne Redwood, CC0, via Wikimedia Commons

Border terrier
commons.wikimedia.org/wiki/File:Border_Terrier_Kamu.jpg
Petteri Sulonen from Helsinki, Finland, CC BY 2.0 creativecommons.org/licenses/by/2.0, via Wikimedia Commons

Grey wolf
commons.wikimedia.org/wiki/File:Eurasian_wolf_2.jpg
User:Mas3cf, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons


Anthemis April 2009
commons.wikimedia.org/wiki/File:Anthemis_April_2009-1.jpg
Alvesgaspar, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Glebionis February 2008
commons.wikimedia.org/wiki/File:Glebionis_February_2008-1.jpg
Alvesgaspar, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Cichorium intybus alvesgaspar1
commons.wikimedia.org/wiki/File:Cichorium_intybus-alvesgaspar1.jpg
Alvesgaspar, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons