Uploaded August 2023 | Updated September 2026, 10 hours ago
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 stabilising selection and directional selection. First we explore stabilising selection, using the example of birth weight in humans. We then look at directional selection, including the presence of antibiotic resistance.
Image credits:
Basketball
commons.wikimedia.org/wiki/File:Spain_national_basketball_team_2011_01.jpg
Christopher Johnson, CC BY-SA 2.0 creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons
Bird
commons.wikimedia.org/wiki/File:Fringilla_coelebs_chaffinch_male_edit2.jpg
MichaelMaggs – Edited (sharpened, down-sampled, contrast corrected, noise removed) by: Arad, CC BY-SA 2.5 creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons
Staph A
commons.wikimedia.org/wiki/File:Staphylococcus_aureus_VISA_2.jpg
Content Providers(s): CDC/ Matthew J. Arduino, DRPH Photo Credit: Janice Haney Carr, Public domain, via Wikimedia Commons
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 stabilising selection and directional selection. First we explore stabilising selection, using the example of birth weight in humans. We then look at directional selection, including the presence of antibiotic resistance.
Image credits:
Basketball
commons.wikimedia.org/wiki/File:Spain_national_basketball_team_2011_01.jpg
Christopher Johnson, CC BY-SA 2.0 creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons
Bird
commons.wikimedia.org/wiki/File:Fringilla_coelebs_chaffinch_male_edit2.jpg
MichaelMaggs – Edited (sharpened, down-sampled, contrast corrected, noise removed) by: Arad, CC BY-SA 2.5 creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons
Staph A
commons.wikimedia.org/wiki/File:Staphylococcus_aureus_VISA_2.jpg
Content Providers(s): CDC/ Matthew J. Arduino, DRPH Photo Credit: Janice Haney Carr, Public domain, via Wikimedia Commons
