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Biopedia

Biopedia

By Vince's Podcasts
Biology is a fascinating subject which is well worth exploring. Its scope stretches from individual DNA strands and viruses to blue whales, metapopulations and the biosphere. We will shine the spotlight on a different biological concept in every episode. Topics I've covered in the past include the origins of cell theory, Dollo's law and the Anthropocene; however, there is still plenty more to discover. Our focus will range from the very smallest scales to the very largest; from virions to the Gaia hypothesis. So come and explore the fascinating world of biology, one episode at a time!
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57- Benedict's Test
Today's topic is a return to the world of biochemistry with a discussion of Benedict's test- used to test for reducing sugars and, with some modifications, non-reducing sugars. We won't be discussing the precise methodology- and the subtle differences in methods/reagents between the sources I accessed- but we'll discuss what exactly a reducing sugar is and introduce the topic of food tests along the way. Sources for this episode: 1) Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press. 2) Hine, R. (2019), A Dictionary of Biology (Oxford Quick Reference), 8th edition, Oxford, Oxford University Press. 3) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 4) Author unknown, Wikipedia (date unknown), Benedict's reagent (online) [Accessed 12/03 and 02/04/2022]. 5) Author unknown, Wikipedia (date unknown), Stanley Rossiter Benedict (online) [Accessed 12/03/2022].
03:31
April 10, 2022
Bonus- Darwin Day 2022
As of February 12th 2022, it's been 113 years since Charles Robert Darwin was born. As such, we're back with another Darwin Day episode! This time around, we turn our attention to His Majesty's Ship Beagle, which Darwin would famously sail on. However, most people probably don't know a lot about the ship besides this fact. So, let's explore the Beagle's past and its possible connection to the present... Sources for this episode: 1) Burchett, M. (1996), Oceanography and Marine Biology: Water Movements and Oceanic Circulation Patterns. In: Waller, G. (ed.), Dando, M. and Burchett, M. (principal contributors) (1996), SeaLife: A Complete Guide to the Marine Environment. Pica Press: Smithsonian Institution Press. 2) Darwin, C. R. (1945), The Voyage of the Beagle. The Temple Press Letchworth: J. M. Dent & Sons Ltd. 3) Dubowsky, N., and Dubowsky, S. M. (1994), The final mission of HMS Beagle: clarifying the historical record. BJHS 27: 105-111. 4) The Editors, Encyclopaedia Britannica (2014), Arafura Sea (online) [Accessed 09/02/2022]. 5) Goodin, M. M., Zaitlin, D., Naidu, R. A. and Lommel, S. A. (2008), Nicotiana benthamiana: Its History and Future as a Model for Plant–Pathogen Interactions. Molecular Plant-Microbe Interactions 21(8): 1015-1026. 6) Thomson, K. S., Encyclopaedia Britannica (2019), Beagle (online) [Accessed 03/02/2022]. 7) Author unknown, National Geographic (date unknown), HMS Beagle: Darwin's trip around the World (online) [Accessed 05/02/2022]. 8) Author unknown, Royal Museums Greenwich (date unknown), HMS Beagle: Discover more about the ship that took Darwin around the world (online) [Accessed 03/02/2022]. 9) Author unknown, Wikipedia (date unknown), Beagle Channel (online) [Accessed 07/02/2022]. 10) Author unknown, Wikipedia (date unknown), Beagle Gulf (online) [Accessed 09/02/2022]. 11) Author unknown, Wikipedia (date unknown), HMS Beagle (online) [Accessed 03/02/2022]. 12) Author unknown, Wikipedia (date unknown), Robert FitzRoy (online) [Accessed 07/02/2022]. Darwin Day: Author unknown, Galapagos Conservation Trust (2015), Darwin Day Comic Strip (online) [Accessed 06/02/2022].
17:13
February 12, 2022
56- Three Types of Selection
Natural selection is not just one phenomenon, but can be spliced into different types depending on what its action results in. Today's episode will examine disruptive selection, stabilising selection and directional selection; what they are, what their effects on populations are and some examples we see in the natural world. Sources for this episode: 1) Allaby, M., (2020), A Dictionary of Zoology (Oxford Quick Reference), 5th edition, Oxford, Oxford University Press. 2) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd 3) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 4) Hine, R. (2019), A Dictionary of Biology (Oxford Quick Reference), 8th edition, Oxford, Oxford University Press. 5) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd.
05:39
December 26, 2021
55- Hybridomas
Cultured cells are useful, but have their limitations. For instance, B cells- white blood cells which produce antibodies- have a limited lifespan in vitro, meaning their use for making antibodies commercially is limited. The solution to this is the topic of today's episode: the hybridoma. Sources for this episode: 1) Fullick, A. and Coates, A. (ed. Ryan, L.) (2016), GCSE AQA Biology (Third Edition). Oxford: Oxford University Press. 2) Madigan, M. T., Martinko, J. M., Dunlap, P. V. and Clark, D. P. (2009), Brock Biology of Microorganisms (12th Edition, International Edition), San Francisco: Pearson Benjamin Cummings Ltd. 3) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd.
04:40
October 24, 2021
54- Bonsai Trees
Perhaps you've never thought much about bonsai trees. However, their existence does raise some biologically relevant questions. For instance, how is a bonsai tree created? Moreover, as we'll see in today's episode, they have also been considered as a tool in conservation... Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) The Editors, Encyclopaedia Britannica (2021), Bonsai (online) [Accessed 15/06/2021, 18/08/2021 and 19/08/2021]. 3) Joshi, A. R. and Joshi, K. (2009), Bonsai: A Technique for Conservation of Species, Bonsai and Conservation 1(1): 3-4. 4) Perrott, R., Synge, P. M. and Herklots, G. A. C., Encyclopaedia Britannica (2020), Gardening (online) [Accessed 18/08/2021]. 5) Wyman, D. (1954), Japanese dwarfed trees. Arnoldia 14(1): 1-7. 6) Author unknown, RHS Gardening (date unknown), Bonsai (online) [Accessed 15/06/2021 and 18/08/2021].
05:45
October 17, 2021
53- Grolar Bears
We're going to explore a particular kind of hybridisation today- the kind that produces grolar bears. As the name might suggest, this refers to the offspring of a grizzly bear and a polar bear. Its existence- and that of cases like it- also allow us to put something called the biological species concept under scrutiny... Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Callaway, E., New Scientist (2010), Neanderthal genome reveals interbreeding with humans (online) [Accessed 03/08/2021]. 3) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 4) Cooke, F., Dingle, H., Hutchinson, S., McKay, G., Schodde, R., Tait, N. and Vogt, R. (2008), The Encyclopedia of Animals: A Complete Visual Guide (p.370). Sydney: Weldon Owen Pty Ltd. 5) Wei-Haas, M., National Geographic (2018), Ancient Girl's Parents Were Two Different Human Species (online) [Accessed 03/08/2021]. 6) Author unknown, BBC Newsround (2021), Have you ever heard of a 'pizzly' bear? (online) [Accessed 02/08/2021]. 7) Author unknown, Understanding Evolution (berkeley.edu), (date unknown), Misconceptions about evolution (online) [Accessed 03/08/2021].8) Author unknown, WWF (date unknown), Top 10 facts about polar bears (online) [Accessed 03/08/2021].
03:43
October 10, 2021
52- Great American Interchange
Back in episode 49, I mentioned the Great American Interchange, which took place three million years ago when North America and South America collided and were connected by the isthmus of Panama. However, I largely glossed over it as it was only of tangential relevance to the topic of the Wallace Line. So, today, let's correct that oversight and explore the Great American Interchange... Sources for this episode: 1) Domingo, L., Tomassini, R. L., Montalvo, C. I., Sanz-Pérez, D. and Alberdi, M. T. (2020), The Great American Biotic Interchange revisited: a new perspective from the stable isotope record of Argentine Pampas fossil mammals, Scientific Reports 10(1): 1608. 2) Marshall, L. G., Webb, S. D., Sepkoski, J. J. and Raup, D. M. (1982), Mammalian Evolution and the Great American Interchange, Science 215(4538): 1351-1357. 3) Weir, J. T., Bermingham, E. and Schluter, D. (2009), The Great American Biotic Interchange in birds, Proceedings of the National Academy of Sciences 106(51): 21737-21742. 4) Author unknown, Wikipedia (date unknown), Great American Interchange (online) [Accessed 15/06/2021 and 13/08/2021]. 5) Author unknown, Wikipedia (date unknown), δ13C (online) [Accessed 10/08/2021]. 6) Author unknown, Wikipedia (date unknown), δ18O (online) [Accessed 10/08/2021].
12:15
October 03, 2021
51- RuBisCO, C4 and CAM
Photosynthesis has proven a useful tool in life's arsenal, but it isn't perfect. This is because one of its enzymes- RuBisCo for short- is not equipped to deal with our oxygenated world and as such sometimes creates toxic by-products which the organism then has to expend energy to deal with. However, some plants have evolved strategies to deal with this issue. Instead of simply working with vanilla-flavoured C3 photosynthesis, they have switched to alternative strategies known as C4 or CAM photosynthesis... Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 3) Hirst, K. K., ThoughtCo (Updated 13/11/2019), Adaptations to Climate Change in C3, C4 and CAM Plants (online) [Accessed 27/07/2021]. 4) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd.
10:16
September 26, 2021
50- Kin Selection and Hamilton's Rule
Altruism- or actions by organisms which ultimately provide a benefit to other organisms- have been puzzling evolutionary scientists since Darwin's time. As such, attempts have been made to explain how this phenomenon comes about. One of these explanations is the subject of today's episode- kin selection and Hamilton's rule. Now, I am not going to go into the arguments and evidence for and against it, which is probably a topic for future episodes. For now, it's probably best to say that my previous studies on the topic have taught me that there is a tangible divide within biology on this topic... Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) Dugatkin, L. A. (2007), Inclusive Fitness Theory from Darwin to Hamilton, Genetics 176(3): 1375- 1380. 3) The Editors, Encyclopaedia Britannica (2018), Kin selection (online) [Accessed 18/06/2021]. 4) Herron, J. C. and Freeman, S. (2015), Evolutionary Analysis (Fifth Edition, Global Edition). Harlow: Pearson Education Limited. 5) Oshaka, S., OUPblog (Oxford University Press, 2015), Kin selection, group selection and altruism: a controversy without end? (online) [Accessed 17/06/2021]. 6) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd.
06:45
September 19, 2021
49- The Wallace Line
If Alfred Russell Wallace (1823- 1913) is thought of at all, he is an after-thought to his far more famous counterpart Charles Darwin and the theory of natural selection. However, he has also had an impact in other fields. Today, we'll be exploring the Wallace Line and Wallace's contribution to zoogeography. Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Camerini, J. R., Encyclopaedia Britannica (2021), Alfred Russell Wallace (online) [Accessed 10/06/2021]. 3) The Editors, Encyclopaedia Britannica (2019), Wallace Line (online) [Accessed 10/06/2021]. 4) Marshall, M., New Scientist (2021), The other humans: The emerging story of the mysterious Denisovans (online) [Accessed 11/06/2021]. 5) Scoville, H., ThoughtCo (2020), What Is the Wallace Line? (online) [Accessed 10/06/2021]. 6) Smithsonian Tropical Research Institute, Phys (2016), Recent connection between North and South America reaffirmed (online) [Accessed 10/06/2021]. 7) Tang, C. M., Encyclopaedia Britannica (2018), Tethys Sea (online) [Accessed 11/06/2021]. 8) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 9) University of Adelaide, Phys (2013), Mysterious ancient human crossed Wallace's Line (online) [Accessed 10/06/2021]. 10) Author unknown, Understanding Evolution (Berkeley, date unknown), Biogeography: Wallace and Wegener (online) [Accessed 11/06/2021]. 11) Author unknown, Wikipedia (date unknown), Wallacea (online) [Accessed 11/06/2021].
05:52
September 12, 2021
48- The Creation of Chromosome 2
It's a well-known fact that humans have 23 pairs of chromosomes- 46 chromosomes in total. However, chimpanzees have 48 chromosomes, as do the other 'great apes'. Why is this? Well, it centres around human chromosome 2. Sources for this episode: 1) Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press. 2) IJdo, J.W., Baldini, A., Ward, D. C., Reeders S. T. and Wells, R. A. (1991) Origin of human chromosome 2: an ancestral telomere-telomere fusion, Proceedings of the National Academy of Sciences of the United States of America 88(20): 9051-9055. 3) Willey, J. M., Sherwood, L. M. And Woolverton, C. J. (2017), Prescott’s Microbiology, 10th edition (International Edition). New York, McGraw-Hill Education. 4) Young, W. J., Merz, T., Ferguson-Smith, M. A. and Johnston, A. W. (1960), Chromosome Number of the Chimpanzee, Pan troglodytes, Science 131(3414): 1672-1673. 5) Author unknown, Wikipedia (date unknown), Chimpanzee genome project (online) [Accessed 02/06/2021]. 6) Author unknown, WWF (date unknown) Great apes (online) [Accessed 06/06/2021].
09:03
September 05, 2021
47- Sibling Species
Moving away from previous topics somewhat, we're going to dive back into ecological theory and discuss the concept of sibling species. What is a sibling species? Well, they're species which appear broadly very similar, but do have some differences when you get up close. As we'll see in today's episode, sibling species are essentially part of the process of speciation.. Sources for this episode: 1) Eisenmann, E., Amadon, D., Banks, R. C., Blake, E. R., Howell, T. R., Johnson, N. K., Lowery, G. H., Parkes, K. C. and Storer, R. W. (1973), Thirty-Second Supplement to the American Ornithologists' Union Check-List of North American Birds, Auk 90(2): 411-419. 2) Gittleman, J. L., Encyclopaedia Britannica (2019), Species (online) [Accessed 29/05/2021]. 3) Nelson, D., OSU Bio Museum (2015), Examples of sibling species (online) [Accessed 02/06/2021]. 4) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 5) Author unknown, Wikipedia (date unknown), Alder flycatcher (online) [Accessed 02/06/2021].
04:41
August 29, 2021
46- Ediacaran Biota
Today, we're going to be discussing the Ediacaran fauna. This is a faunal assemblage that came before the Cambrian Explosion (535-525 Mya) but is less well known. Unlike the Cambrian Explosion- which saw the creation of most of the phyla we know today- the Ediacaran biota is much less familiar. It also appears to be quite confusing in terms of what category its constituent organisms fall under... Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) Ebling, F. J. G., Encyclopaedia Britannica (2017), Integument (online) [Accessed 29/05/2021]. 3) Flannery, T. F., Encyclopaedia Britannica (2019), Cambrian explosion (online) [Accessed 27/05/2021]. 4) Grazhdankin, D. (2011), Ediacaran Biota. In: Reitner J. and Thiel, V. (eds) Encyclopedia of Geobiology. Encyclopedia of Earth Sciences Series. Springer, Dordrecht. 5) Herron, J. C. and Freeman, S. (2015), Evolutionary Analysis (Fifth Edition, Global Edition). Harlow: Pearson Education Limited. 6) Rafferty, J. P., Encyclopaedia Britannica (2018), Ediacaran Period (online) [Accessed 28/05/2021]. 7) Shen, B., Dong, L., Xiao, S. and Kowalewski, M. (2008), The Avalon Explosion: Evolution of Ediacara Morphospace, Science 319(5859): 81-84. 8) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 9) Virginia Tech, ScienceDaily (2008), Two Explosive Evolutionary Events Shaped Early History Of Multicellular Life (online) [Accessed 28/05/2021]. 10) Windley, B. F., Encyclopaedia Britannica (2019), Ediacara fauna (online) [Accessed 28/05/2021]. 11) Author unknown, Wikipedia (date unknown), Ediacaran biota (online) [Accessed 28/05/2021]. 12) Author unknown, Wikipedia (date unknown), Marinoan glaciation (online) [Accessed 28/05/2021].
07:39
August 22, 2021
45- The DNA of Louis XVI
Almost no French king is more famous than Louis XVI, reigning during the turbulent times of the French Revolution at the tail-end of the eighteenth century. Previous studies have attempted to characterise his Y-chromosomal single tandem repeat (STR) profile, but were ultimately unsuccessful due to contradictions. So, today, let's explore a 2016 study which analysed a loyalist-owned lock of hair and compared it to three living male-line relatives. Sources for this episode: 1) Lucotte, G., Thomasset, T. and Wen, S. (2016), The DNA Y-STRs Profile of Louis XVI (1754-1793). International Journal of Sciences 5(4): 68-93. 2) Popkin, J. D. and Goodwin, A., Encyclopaedia Britannica (2021), Louis XVI (online) [Accessed 16/05/2021]. 3) Author unknown, Wikipedia (date unknown), Family tree of French monarchs (simplified) (online) [Accessed 15/08/2021]. 4) Author unknown, Wikipedia (date unknown), Karl Wilhelm Naundorff (online) [Accessed 16/05/2021 and 06/09/2021].
06:30
August 14, 2021
44- Point Mutations and Almonds
Point mutations can have a huge impact on the genome depending on where in the genetic code they occur. To illustrate this, we're going to be looking at a case study in the form of almonds- formerly poisonous nuts which had their metaphorical fangs taken out by a single base change... Sources for this episode: 1) Hardy, E. R., Encyclopaedia Britannica (2021), Saint Basil the Great (online) [Accessed 22/05/2021]. 2) Herron, J. C. and Freeman, S. (2015), Evolutionary Analysis (Fifth Edition, Global Edition). Harlow: Pearson Education Limited. 3) Leman, J., Scientific American (2019), The Bitter Truth: Scientists Sequence the Almond Genome (online) [Accessed 18/05/2021]. 4) Petruzzello, M., Encyclopaedia Britannica (2021), almond (online) [Accessed 18/05/2021]. 5) Sánchez-Pérez, R., Pavan, S., Mazzeo, R., Molodovan, C., Cigliano, R. A., Del Cueto, J., Ricciardi, F., Lotti, C., Ricciardi, L., Dicenta, F., López-Marquéz, R. L. and Møller, B. L. (2019), Mutation of a bHLH transcription factor allowed almond domestication, Science 364(6445): 1095-1098. 6) Author unknown, Wikipedia (date unknown), Almond (online) [Accessed 18/05/2021].
04:44
August 08, 2021
43- Two-Component Systems
Bacteria are far simpler in molecular terms than eukaryotes. However, they still need to be able to sense and respond to their environment. How do they do this? Enter the two-component system; a two-protein system which allows stimuli to be detected and gene expression altered using phosphate transfer. Sources for this episode: 1) Madigan, M. T., Martinko, J. M., Dunlap, P. V. and Clark, D. P. (2009), Brock Biology of Microorganisms (12th Edition, International Edition), San Francisco: Pearson Benjamin Cummings Ltd. 2) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 3) Willey, J. M., Sherwood, L. M. and Woolverton, C. J. (2017), Prescott's Microbiology (10th Edition, International Edition), Singapore: McGraw Hill Education Ltd. 4) Author unknown, Wikipedia (date unknown), Osmotic concentration (online) [Accessed 27/05/2021].
05:30
August 01, 2021
42- The Quagga
No, the episode name isn't a typo. Rather, it's the name of a subspecies of zebra we're going to be discussing today. Along the way, we will explore  clines, the purpose of zebra stripes and an attempt to breed back the quagga from its zebra cousins. Why don't we hear more about it? Well, because it no longer exists... Sources for this episode: 1) Bryden, H. A. (1889), Kloof and karroo: Sport, legend and natural history in Cape Colony, with a notice of the game birds, and of the present distribution of antelopes and larger game, London and New York: Longmans, Green and Co. Available at: Internet Archive [Accessed 14/05/2021]. 2) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 3) Davis, N., The Guardian (2019), Why the zebra got its stripes: to deter flies from landing on it (online) [Accessed 14/05/2021]. 4) Douglas, G. (1821), A Communication of a Singular Fact in Natural History, Philosophical Transactions of the Royal Society of London (1776-1886) 111: 20–22. Available at Internet Archive [Accessed 14/05/2021]. 5) The Editors, Encyclopaedia Britannica (2018), Quagga (online) [Accessed 14/05/2021]. 6) Heywood, P. (2020), Sexual dimorphism of body size in taxidermy specimens of Equus quagga quagga Boddaert (Equidae), Journal of Natural History 53(45-46): 2757-2761. 7) Author unknown, The Quagga Project (date unknown), Home (online) [Accessed 14/05/2021]. 8) Author unknown, Wikipedia (date unknown), Quagga (online) [Accessed 14/05/2021].
06:58
July 25, 2021
41- Gruinard Island
Biological warfare has been around for centuries. However, it itself isn't the topic of today's episode. Rather, today we're going to talk about experiments conducted with anthrax on Gruinard Island in the United Kingdom. Sources for this episode: 1) Johnson, M. P., Pye, S. and Allcock, L. (2008), Dispersal mode and assessments of recovery on the shores of Gruinard, the 'anthrax island', Biodiversity Conservation 17: 721-732. 2) Madigan, M. T., Martinko, J. M., Dunlap, P. V. and Clark, D. P. (2009), Brock Biology of Microorganisms (12th Edition, International Edition), San Francisco: Pearson Benjamin Cummings Ltd. 3) Riedel, S. (2004), Biological warfare and bioterrorism: a historical warfare, BUMC Proceedings 17: 400-406. 4) Author unknown, BBC News (2001), Britain's 'Anthrax Island' (online) [Accessed 21/05/2021]. 5) Author unknown, Gov.uk (date unknown), The Truth About Porton Down (online) [Accessed 21/05/2021]. 6) Author unknown, Wikipedia (date unknown), Gruinard Island (online) [Accessed 26/04/2021].
06:12
July 18, 2021
40- Two Views on Communities
Today is more of a follow-up episode building on episode 39. Specifically, we're going to examine two different schools of thought about plant succession, known as the Gleasonian and Clementsian models... Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Hagen, J., Encyclopaedia Britannica (2020), Frederic Edward Clements (online) [Accessed 25/04/2021]. 3) Author unknown, Wikipedia (date unknown), Henry A. Gleason (botanist) (online) [Accessed 25/04/2021].
03:44
July 11, 2021
39- Succession and Climax Communities
Our discussion this week is going to head back into ecology and focus on succession- a change in the species composition of a community across space or time. Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 3) Thompson, J. N., Encyclopaedia Britannica (2018), Ecological succession (online) [Accessed 10/04/2021]. 4) Author unknown, Encyclopaedia.com (updated 2018), Plagioclimax (online) [Accessed 10/04/2021].
05:52
July 04, 2021
38- Haemophilia
Haemophilia is a genetic condition which is characterised by one of the blood clotting factors, usually encoded for on the X chromosome, not being encoded for properly for various reasons- whether it's a mobile genetic element inserting itself into the gene or a simple mutation. On the show today, we describe the cause and symptoms of haemophilia, as well as using the case study of Queen Victoria to show that new mutations are a surprisingly common root cause... Sources for this episode: 1) Francioli, L. C., et al. (2015), Genome-wide patterns and properties of de novo mutations in humans. Nature Genetics 47(7): 822- 826. 2) Mannucci, P. M. and Tuddenham, E. G. D. (2001), The Haemophilias- From Royal Genes to Gene Therapy. The New England Journal of Medicine 344(23): 1773- 1779. 3) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 4) Author unknown, The Haemophilia Society (date unknown), Bleeding Disorders > Haemophilia (online) [Accessed 08/04/2021]. 5) Author unknown, Wikipedia (date unknown), Factor VIII (online) [Accessed 08/04/2021]. 6) Author unknown, Wikipedia (date unknown), Queen Victoria (online) [Accessed 08/04/2021].
05:05
June 27, 2021
37- Metapopulations
We're all familiar with populations, but what about a metapopulation? Put simply, these are populations of populations. Thanks to our sources and also my interpretation of the subject from back when I studied the concept, that's the notion we're going to unravel today... Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (Second Edition). Sunderland, Massachusetts, Sinauer Associated Ltd. 2) Thompson, J. N., Encyclopaedia Britannica (2016), Metapopulation (online) [Accessed 17/04/2021]. 3) Wu, J., Encyclopaedia Britannica (2019), Patch dynamics (online) [Accessed 18/04/2021]. 4) In this episode, I use an analogy from how I understood the concept from back when I was taught the concept at university, which I've signposted.
04:39
June 20, 2021
36- Hardy-Weinberg Equilibrium
Back in the early 20th century, an English mathematician and a German scientist both independently came up with an equation to portray the frequency of different phenotypes in a hypothetical population. As we'll see today, this equation rests on some pretty big assumptions which effectively exclude evolution. Why is this useful? Well, because we can use it to see if evolution might be occurring... Sources for this episode: 1) Chen, B., Cole, J. W. and Grond-Ginsbach, C. (2017), Departure from Hardy Weinberg Equilibrium and Genotyping Error. Frontiers in Genetics 8(167). 2) Herron, J. C. and Freeman, S. (2015), Evolutionary Analysis (Fifth Edition, Global Edition). Harlow: Pearson Education Limited. 3) TED-Ed, YouTube (2012), Five fingers of evolution- Paul Anderson (online) [Accessed 18/04/2021]. 4) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. 5) Author unknown, Wikipedia (date unknown), G. H. Hardy (online). 6) Author unknown, Wikipedia (date unknown), Wilhelm Weinberg (online).
07:29
June 13, 2021
35- Five Kingdoms, Three Domains
Today, we're going to discuss classification. We're going to briefly skim over how people historically used to organise life, before the establishment of the prokaryote-eukaryote division which would stay in place until an American scientist called Carl Woese rocked the taxonomic boat... Sources for this episode: 1) Craine, A. G., Encyclopaedia Britannica (2020), Carl Woese (online) [Accessed 10/04/2021]. 2) Author unknown, Wikipedia (date unknown), Taxonomy (online) [Accessed 10/04/2021]. 3-4) Some of the discussion is based on my previous education on the subject and my completion of a Massive Open Online Course 'Emergence of Life' covering this topic in 2018.
04:45
June 06, 2021
34- The Tuatara
On the show today, we discuss the tuatara- two (or possibly only one) species of reptile which are the final representatives of an ancient lineage. I didn't really go into it in the main episode, but there appears to be some debate about whether or not the tuatara is one species or two. All the sources I'd used in this week's episode list two species, but I afterwards discovered an article from the journal 'Conservation Genetics' which concluded that the tuatara should probably be thought of as one species instead of two. I might come back to it in a future episode. The paper in question is: Hay, J. M., Sarre, Stephen D., Lambert, D. M., Allendorf, F. W. and Daugherty, C. H. (2010), Genetic diversity and taxonomy: a reassessment of species designation in tuatara (Sphenodon: Reptilia), Conservation Genetics 11: 1063-1081. Sources for this episode: 1) Blythe, C. A., Encyclopaedia Britannica (2021), New Zealand (online) [Accessed 28/03/2021]. 2) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 3) Cooke, F., Dingle, H., Hutchinson, S., McKay, G., Schodde, R., Tait, N. and Vogt, R. (2008), The Encyclopedia of Animals: A Complete Visual Guide (p.370). Sydney: Weldon Owen Pty Ltd. 4) Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. 5) Author unknown, Wikipedia (date unknown), Rhynchocephalia (online) [Accessed 28/03/2021].
03:05
May 30, 2021
33- Lethal Alleles
At A Level, we are taught that dominant: recessive traits are in a 3:1 ratio for any trait in which only one gene encodes for it. However, it's not always that simple. Enter lethal alleles... Sources for this episode: 1) Gao, Z., Waggoner, D., Stephens, M., Ober, C. and Przeworski, M. (2015), An Estimate of the Average Number of Recessive Lethal Mutations Carried by Humans. Genetics 199: 1243- 1254. 2) Roos, R. A. C. (2010), Huntingdon's disease: a clinical review. Orphanet Journal of Rare Diseases 2010 5:40. 3) Author unknown, Wikipedia (date unknown), Lethal allele (online) [Accessed 26/03/2021]. 4) Author unknown, Wikipedia (date unknown), Manx cat (online) [Accessed 27/03/2021].
03:43
May 23, 2021
32- Trisomies and Non-Disjunction
Usually, we get two copies of each chromosome. However, the finely tuned process of meiosis and fertilisation can go awry such that a new zygote ends up with three copies. Depending on the chromosome, this can have serious consequences... Sources for this episode: 1) For an explanation of non-disjunction which I found helpful when I was at sixth form, see: Amoeba Sisters, YouTube (2017), Meiosis (Updated) (online) [Accessed 25/03/2021]. 2) Xu, X., Zhang, X., Han, J.-W., Adamu, Y. and Zhang, B. (2020), Potential Increased Risk of Trisomy 18 Observed After a Fertilizer Warehouse Fire in Brazos County and TX. International Journal of Environmental Research and Public Health 17: 2561- 2571. 3) Author unknown, NHS (date unknown), Edwards' syndrome (trisomy 18) (online) [Accessed 25/03/2021].
05:20
May 16, 2021
31- Choanoflagellates
We often think about animals as an insular group. However, as with any genetic grouping, animals do have close relatives. On the show today, we discuss choanoflagellates- considered the closest relatives to animals today, and possibly a good candidate for what the common ancestor of all animals would have looked like. Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) The Editors, Encyclopaedia Britannica (2021), Choanoflagellate (online) [Accessed 13/03/2021]. 3) Holland, S. M., Encyclopaedia Britannica (2021), Ordovician Period (online) [Accessed 13/03/2021]. 4) Marshall, M., New Scientist (2009), Timeline: The evolution of life (online) [Accessed 13/03/2021]. 5) Philippe, H., et al. (2009), Phylogenomics Revives Traditional Views on Deep Animal Relationships. Current Biology 19: 706- 712.
05:16
May 09, 2021
30- Measures of Diversity
Biodiversity is often mentioned as one concept in popular culture. However, it can be split into different components depending on who you ask. Today, we're going to explore two different ways of chopping biodiversity up. Sources for this episode: 1) Cain, M. L., Bowman, W. D. and Hacker, S. D. (2011), Ecology (2nd edition). Sunderland: Sinauer Associates Ltd. 2) Author unknown, Wikipedia (date unknown), Gamma diversity (online) [Accessed 06/03/2021]. There are ways of working out biodiversity values, which we won't discuss in this episode. For a formula for the Shannon-Weiner index of biodiversity (which I'm going to try and discuss in a future episode), see: Thain, M. and Hickman, M. (2014), Dictionary of Biology (Eleventh Edition). London: Penguin Books Ltd. For Simpson's biodiversity index, see: Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press.
03:33
May 02, 2021
29- Sympatric Speciation
This week, we're going to discuss sympatric speciation- the counterpart to allopatric speciation where no physical barrier is needed. Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. 3) Author unknown, National Geographic (date unknown), Speciation (online) [Accessed 28/02/2021]. 4) Author unknown, Understanding Evolution (date unknown), Sympatric speciation (online). Available at: 'berkeley.edu' [Accessed 28/02/2021].
04:48
April 25, 2021
Bonus- William Darwin's Development
Bonus episode! Today, I'm going to focus on a less well-known story from the Darwin family. Specifically, let's look at William Erasmus Darwin, the eldest child of the family. In 1877, Darwin published an article about his observations of William's development. Sources for this episode: 1) Darwin, C. R. (1877), A biographical sketch of an infant. Scientific American Supplement 86: 1373- 1374 (online). Available at: Internet Archive [Accessed 25/03/2021]. 2) Author unknown, Wikipedia (date unknown), William Erasmus Darwin (online) [Accessed 25/03/2021]. 3) Author unknown, Wikipedia (date unknown), The Descent of Man (online) [Accessed 26/03/2021].
04:26
April 24, 2021
28- Speciation and the Great Wall of China
The Great Wall of China is one of the most imposing monuments humanity has ever created- after all, it's not for nothing that the claim goes around that you can see it from space. However, it's not just an effective barrier for humans. In fact, a 2003 study indicates that it's causing speciation in the region... Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) The Editors, Encyclopaedia Britannica (2021), Great Wall of China (online) [Accessed 19/02/2021]. 3) Oltermann, P., et al., The Guardian/Observer (2010), The Ancient World (booklet series), Day 6: China. Associated with the British Museum. 4) Su, H., Qu., L.-J., He, K., Zhang, Z., Wang, J., Chen, Z. and Gu, H. (2003), The Great Wall of China: a physical barrier to gene flow? Heredity 90: 212- 219.
04:55
April 18, 2021
27- Twin Types
We're always taught that twins can either be identical or non-identical. But what is the basis for this? And is there ever a situation where twin type is not quite so binary? Sources for this episode: 1) Davis, N., the Guardian (2019), Scientists stunned by discovery of 'semi-identical' twins (online) [Accessed 07/02/2021]. 2) Author unknown, BBC (2019), Semi-identical twins 'identified for only the second time' (online) [Accessed 07/02/2021]. 3) Author unknown, Wikipedia (date unknown), Twin (online) [Accessed 08/02/2021].
06:00
April 11, 2021
26- The Anthropocene
The term 'Anthropocene' (roughly translated as 'Age of Man') is a term that is sometimes thrown about on the radio or in science. But what is it exactly? As we'll see today, the concept itself is relatively simpler, but nailing down the specifics is somewhat harder than it seems... Sources for this episode: 1) Ashley, S., National Trust (date unknown), What is the Anthropocene? (online) [Accessed 30/01/2021]. 2) Author unknown, Encyclopaedia Britannica (2020), Anthropocene Epoch (online) [Accessed 30/01/2021]. 3) Author unknown, Wikipedia (date unknown), Chinese industralization (online) [Accessed 02/02/2021].
05:07
April 03, 2021
25- Dollo's Law
Science has to change with the evidence if it is to be trusted. One example of this comes with Dollo's Law, named after the French Belgian biologist Louis Dollo. His original theory was that evolution would never, under any circumstances, retrace its path. However, as we're going to see on the podcast today, that isn't always the case. With new evidence came the need for a revamp of Dollo's Law... Sources for this episode: 1) The Editors, Encyclopaedia Britannica (2018), Peppered moth (online) [Accessed 27/01/2021]. 2) Zimmer, C., National Geographic (2003), Recoil from Dollo's Law (online) [Accessed 24/01/2021]. 3) Author unknown, Encyclopaedia Britannica (2018), Dollo's Law (online) [Accessed 24/01/2021]. 4) Author unknown, Wikipedia (date unknown), Dollo's Law of irreversibility (online) [Accessed 24/01/2021]. NOTE: I think I get a bit mixed up in my speech at one point with the gastropod example. What I should have said is that shells started out coiled, uncoiled itself and then recoiled on at least two occasions.
04:26
March 28, 2021
24- Rewind: Dominant and Recessive
In our third Rewind episode, I'm going to go back over the concept of dominant vs. recessive as a mechanism of genetic inheritance, which I've touched upon before but not really in any great detail. Sources for this episode: 1) Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press. 2) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. 3) Author unknown, Wikipedia (date unknown), Eye color (online) [Accessed 19/01/2021].
03:45
March 21, 2021
23- How Many Species?
This episode is really going to do what it says on the tin- discuss the question of how many species there are in the world. This might seem a simple question, but a simple answer has eluded the scientific community for some years now. On the show today, I'm going to go through some of the methods past research has used to answer this question and what figures they came up with. Sources for this episode: 1) Latty, T. and Lee, T., 'Phys.org' (2019), How many species on Earth? A simple question that's hard to answer (online) [Accessed 16/01/2021]. 2) Mora, C., Tittensor, D. P., Adl, S., Simpson, A. G. B. and Worm, B. (2012), How Many Species Are There on Earth and in the Ocean? PLOS Biology 9(8): e1001127.  NOTE- at one point I mention seven taxonomic levels, but I should have said six.
05:29
March 14, 2021
Introducing- After Alexander
Hi everyone, just a quick plug for my other show- After Alexander. This is a history podcast where we examine what happened between Alexander the Great's death in 323 and the destruction of the last of the Hellenistic kingdoms by the Romans and Parthians. Specifically, it focuses on the Seleucid dynasty, descended from Seleucus I Nicator and eventually rulers over most of Alexander's old empire in their glory days. If that sounds like it might be for you, feel free to head over and join us! Regular content resumes next week.
02:07
March 07, 2021
22- The Central Indo-Pacific
The Central Indo-Pacific (or CIP if you're stuck for time) is a highly diverse region of the ocean. But how did it get to be this way? It's this question which is the topic for today's episode. Sources for this episode: 1) Ivany, L. C., Patterson, W. P. and Lohmann, K. C. (2000), Cooler winters as a possible cause of mass extinctions at the Eocene/Oligocene boundary. Nature 407: 887- 890. 2) Jones, K. R., Klein, C. J., Halpern, B. S., Venter, O., Grantham, H., Kuempel, C. D., Shumway, N., Friedlander, A. M., Possingham, H. P. and Watson, J. E. M. (2018), The Location and Protection Status of Earth’s Diminishing Marine Wilderness. Current Biology 28: 2506- 2512. 3) Miller, E.C., Hayashi, K. T., Song, D., Wiens, J. J., (2018) Explaining the ocean’s richest biodiversity hotspot and global patterns of fish diversity. Proceedings of the Royal Society B 285: 20181314. 4) Renema, W., Bellwood, D. R., Braga, J. C., Bromfield, K., Hall, R., Johnson, K. G., Lunt, P., Meyer, C. P., McMonagle, L. B., Morley, R. J., O'Dea, A., Todd, J. A., Wesselingh, F. P., Wilson, M. E. J. and Pandolfi, J. M. (2008), Hopping Hotspots: Global Shifts in Marine Biodiversity. Science (321): 654- 657. 5) Siqueira, A. C., Bellwood, D. R. and Cowman, P. F. (2019), Historical biogeography of herbivorous coral reef fishes: The formation of an Atlantic fauna. Journal of Biogeography. 6) Author unknown, Wikipedia (date unknown), Coral (online) [Accessed 17/01/2021]. 7) Author unknown, Wikipedia (date unknown), Eocene (online) [Accessed 17/01/2021].
04:18
February 28, 2021
21- The Black Queen Hypothesis
Building on our discussion of the Red Queen hypothesis last week, we're going to go through a theorem which is similarly chess-themed but goes against our hypothesis from episode 20. This theory holds that, rather than continual evolution being necessary for a species to survive, natural selection can sometimes allow genes to be lost from the gene pool. Sources for this episode: 1) Allen, R. C., Popat, R., Diggle, S. P. and Brown, S. P. (2014), Targeting virulence: can we make evolution-proof drugs? Nature Reviews Microbiology 12(4): 300- 308. 2) Morris, J. J., Lenski, R. E. and Zinser, E. R. (2012), The Black Queen Hypothesis: Evolution of Dependencies through Adaptive Gene Loss. mBio 3(2): e00036-12. 3) Willey, J. M., Sherwood, L. M. and Woolverton, C. J. (2017), Prescott's Microbiology (Tenth Edition, International Edition). New York: McGraw Hill Education. 4) Author unknown, Wikipedia (date unknown), Black Queen hypothesis (online) [Accessed 15/01/2021].
05:26
February 21, 2021
20- The Red Queen Hypothesis
This week, I'm going to discuss the Red Queen Hypothesis, which sounds intimidating but is actually rather straightforward. Not only is it an evolutionary theory, but it's also a reminder that biologists really like finding obscure reasons to name things... Sources for this episode: 1) Scoville, H., ThoughtCo (updated 2019), What Is the Red Queen Hypothesis? (online) [Accessed 14/01/2021]. 2) Thain, M. and Hickman, M. (2004), The Penguin Dictionary of Biology (11th edition). London: Penguin Books Ltd. 3) Author unknown, Wikipedia (date unknown), Red Queen Hypothesis (online) [Accessed 14/01/2021].
02:57
February 14, 2021
Bonus- Darwin Day 2021
Happy Darwin Day! On the anniversary of Darwin’s birthday on 12th February 1809, I thought it would be fun to release a special episode covering some aspect of Darwin’s life or theories. Today, we’re going to discuss the health of Darwin’s children and of Darwin’s immediate family. Sources for this episode: 1) Hayman, J., Álvarez, G., Ceballos, F. C. and Berra, T. M. (2017), The illnesses of Charles Darwin and his children: a lesson in consanguinity. Biological Journal of the Linnean Society 121: 458- 468. 2) Information on the immediate family of Charles Darwin can also be found on Wikipedia, whether his article or the article on the Darwin-Wedgewood family.
05:41
February 12, 2021
19- How Evolution Works
This week, I’m going to do something a little different and talk through a process we hear a lot about, but which isn’t often discussed as a process outside biology classrooms very much- evolution. This episode will be a little different from my usual, as it’s mainly going to be me talking rather than drawing on sources. Instead, this discussion is going to be based on my biological education so far.
05:44
February 07, 2021
18- Apoptosis
Apoptosis is the phenomenon by which cells commit suicide in an orderly and programmed fashion. But why is it important? And what happens if it goes wrong? Today, we're just going to introduce the topic briefly and give some examples of why it is biologically useful. Sources for this episode: 1) Alberts, Johnson, Lewis, Raff, Roberts, and Walter (2008), Molecular Biology of the Cell, Fifth Edition. Abingdon: Garland Science, ‘Taylor and Francis Group LLC’. 2) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group.
04:10
January 31, 2021
17- How To Make An Eye Colour
Eye colour is one of the first examples of genetic inheritance talked about in schools across the country. But what is it that these genes really do? What causes eye colour from a functional perspective? As we'll see on the podcast today, it's all to do with the pigment melanin... Sources for this episode: 1) Alberts, Johnson, Lewis Raff, Roberts, and Walter (2008), Molecular Biology of the Cell, Fifth Edition. Abingdon: Garland Science, Taylor and Francis Group LLC. 2) Sturm, R. A. and Frudakis, T. N. (2004), Eye colour: portals into pigmentation genes and ancestry. Trends in Genetics 20(8): 327- 332.
03:26
January 24, 2021
16- Assortative Mating
Assortative mating is essentially the recognition that theory isn’t always perfect and that, however desperately biologists might want some simplicity in the world, organisms don’t just encounter each other like gas molecules- it’s not a random process. In fact, it can even give evolution a helping hand… Sources for this episode: 1) Nishi, A., Alexander, M., Fowler, J. H. and Christakis, N. A. (2020), Assortative mating at loci under recent natural selection in humans. BioSystems 187 (2020) 104040. 2) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group.
03:52
January 17, 2021
Announcement- Website
Hi everyone, Vince here with a quick update- the podcast now has an accompanying website! From now on, you can head to 'www.biopedia.co.uk' to access all our episodes, as well as a blog featuring some extra content. Thank you all for continuing to listen to the show and I'm excited to add new content!
02:28
January 13, 2021
15- The Adaptive Landscape
The adaptive landscape is an important method for biologists, ecologists, and geneticists to visualise the process of evolution. But what is it, and how does it work? This week, we’re going to discuss what the adaptive landscape actually is, so while there are going to be some sources listed, there's also a bit of general discussion as well. Some sources for this episode: 1) Martin, C. H. and Wainwright, P. C. (2013), Multiple fitness peaks on the adaptive landscape drive adaptive radiation in the wild. Science 339: 208- 211. 2) Author unknown, Wikipedia (date unknown), Fitness Landscape (online) [Accessed 2021, date not known]. 3) Script writing was reinforced by my previous education on the topic.
04:35
January 10, 2021
14a- The Function of NRAMP1
Bonus episode! In the main episode on Sunday, I briefly mentioned NRAMP1, a mutation in which can influence how susceptible someone is to the leprosy bacterium, Mycobacterium leprae. But what exactly is the NRAMP1 protein and why is it important? Sources for this episode: 1) Cannone-Hergaux, F., Calafat, J., Richer, E., Cellier, M., Grinstein, S., Borregaard, N. and Gros, P. (2002), Expression and subcellular localisation of NRAMP1 in neutrophil granules. Blood 100(1): 268- 275. 2) Forbes, J. R. and Gros, P. (2003), Iron, manganese, and cobalt transport by Nramp1 (Slc11a1) and Nramp2 (Slc11a2) expressed at the plasma membrane. Blood 102(5): 1884- 1892. 3) Hennigar, S. R. and McClung, J. P. (2016), Nutritional Immunity: Starving Pathogens of Trace Minerals. American Journal of Lifestyle Medicine 10(3): 170- 173. 4) Rørvig, S., Østergaard, O., Heegaard, N. H. H. and Borregaard, N. (2013), Proteome profiling of human neutrophil granule subsets, secretory vesicles, and cell membrane: correlation with transcriptome profiling of neutrophil precursors. Journal of Leukocyte Biology 94: 711- 721. A paper that mentions cell lysis in the context of pathogens surviving phagocytosis: Natural Resistance to Infection with Intracellular Pathogens: The Nramp1 Protein Is Recruited to the Membrane of the Phagosome.
03:54
January 06, 2021
14- Leprosy and 'The Leper King'
Happy new year! In our inaugural episode of 2021, we’re going to go back to the 1100s and focus on the famous case of the Leper King Baldwin IV, who ruled as king of Jerusalem from 1174 to 1185. What exactly is leprosy, and what causes it? We’ll use the test case of Baldwin as an opening to talking a bit about the bug Mycobacterium leprae and how exactly leprosy works. Sources for this episode: 1) Abel, L., Sánchez, F. O., Oberti, J., Thuc, N. V., Van Hoa, L., Lap, V. D., Skamene, E., Lagrange, P. H. and Schurr, E. (1998), Susceptibility to Leprosy Is Linked to the Human NRAMP1 Gene. The Journal of Infectious Diseases 177: 133- 145. 2) Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press. 3) Guerrero-Peral, A. L. (2009), Neurological manifestations of the leprosy of King Baldwin IV of Jerusalem. Revista de Neurologica 49(8). 4) Turner, J. J., Hektoen International, The remarkable Baldwin IV: leper and king of Jerusalem (online). 5) Author unknown, Microbiology Society (2014), Mycobacterium leprae, the cause of leprosy (online) [Accessed 11/12/2020]
05:56
January 03, 2021
13- Rewind: Amino Acids
Proteins are often mentioned on the show, but what about the building blocks that they consist of? This week, we’re going to tackle amino acids in our second rewind episodes. There are some topics that naturally branch off from this one, such as interactions between amino acids and how DNA encodes for different ones, but they will probably be topics for future episodes. Sources for this episode: 1) Campbell, N. A., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V. and Reece, J. B. (2018), Biology: a global approach, 11th edition (Global Edition), Harlow, Pearson Education Limited. 2) Compound Interest, Compound Interest (2014), A Brief Guide to the Twenty Common Amino Acids (online) [Accessed c.2020, date not known]. 3) Fullick A., Locke, J. and Bircher, P. (2015), A Level Biology for OCR A. Oxford: Oxford University Press. 4) Ritchie, R. and Ghent, D. (2015), A Level Chemistry for OCR A. Oxford: Oxford University Press. 5) Thain, M., and Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. NOTE: In case this wasn’t clear in the audio, variable groups, R groups and side chains all refer to the same functional group- namely, the variable part of an amino acid.
04:24
December 27, 2020
12- The Wnt Signalling Network
Building on our discussion of both signalling pathways and G-protein coupled receptors from a few weeks ago, this week we’re going to discuss the Wnt signalling pathway- a pathway which is crucial in aspects of development and can have widespread impacts on the cell. It all sounds rather intimidating, but there’s actually surprisingly few steps involved in this pathway- and we’re only going to be focusing on one part of the signalling network, which makes life a lot less complicated! Sources for this episode: 1) Alberts, Johnson, Lewis, Raff, Roberts, and Walter (2008), Molecular Biology of the Cell, Fifth Edition, p.948- 950. Abingdon: Garland Science, Taylor and Francis Group LLC. 2) Janda, C. Y., Waghray, D., Levin, A. M., Thomas, C. and Garcia, K. C. (2012), Structural basis of Wnt recognition by Frizzled. Science 337: 59- 63. 3) Author unknown, National Center for Biotechnology Information (2020), PubChem Compound Summary for CID 445638, Palmitoleic acid (online) [Accessed 29/11/2020].
06:12
December 20, 2020
11- Rewind: Cell Theory
In the first of our ‘Rewind’ episodes, we go back to basics and discuss cells- where they came from and the famous cell theory of 1839, which is still present in textbooks today. There are more stories than we can cover which lead up to cell theory, so just see this as an introductory episode until when and if we can come back to these famous names and discoveries. Sources for this episode: 1) Silver (1987), Virchow, the Heroic Health Model in Medicine: Health Policy by Accolade. AJPH 77(1): 82- 88. 2) Author unknown, National Geographic, date unknown, Cell Theory (Encyclopaedic entry, online) [Accessed c.2020, date not known].
03:53
December 13, 2020
10- The Lamellipodium
As discussed in previous episodes, the actin cytoskeleton is vital to allow cells to move. But what about the specifics? In this episode, we’re going to be dissecting the lamellipodium- a meshwork actin structure that some cells use to move. Sources for this episode: 1) Alberts, Johnson, Lewis, Raff, Roberts, and Walter (2008), Molecular Biology of the Cell, Fifth Edition. Abingdon: Garland Science, Taylor and Francis Group LLC. 2) Berro, Michelot, Blanchoin, Kovar and Martiel (2007), Attachment Conditions Control Actin Filament Buckling and the Production of Forces. Biophysical Journal 92(7): 2546- 2558. 3) Kiuchi, Ohashi, Kurita and Mizuno (2007), Cofilin promotes stimulus-induced lamellipodium formation by generating an abundant supply of actin monomers. The Journal of Cell Biology 177(3): 465- 476. 4) ‘Mechanobiology Institute, Singapore’, YouTube (2013), Arp2/3 complex mediated actin nucleation (online) [Accessed 23/11/2020].
06:11
December 06, 2020
9- The Platypus’ Larger Cousin
We’re all familiar with the platypus, but it still has surprises up its sleeve. On the show today, we get to know its bumper-sized cousin- Obdurodon tharalkooschild. Sources for this episode: 1) Dell’Amore, C., National Geographic (2013), Giant Platypus Found, Shakes Up Evolutionary Tree (online) [Accessed 17/11/2020].2) Pian, R., Archer, M. And Hand, S. J. (2013), A new, giant platypus, Obdurodon tharalkooschild, sp. nov. (Monotremata, Ornithorhynchidae), from the Riversleigh, World Heritage Area, Australia. Journal of Vertebrate Paleontology 33(6): 1255- 1259.
02:52
November 29, 2020
8- Orca Population History
Killer whales are an icon of the world's oceans. However, genetic studies show that they haven't always been doing so well- especially during the last Ice Age. What's the story? And what relevance does the millennia-old plight of the orca have today? On the podcast today, we're going to use a genetic study from 2014 to explore just that. Sources for this episode: 1) Moura, A. E. et al (2014), Killer Whale Nuclear Genome and mtDNA Reveal Widespread Population Bottleneck during the Last Glacial Maximum. Molecular Biology and Evolution 31(5): 1121- 1131. 2) General dates for some of the geological epochs discussed are widely available and can be found at sources such as Wikipedia. A small housekeeping note: the lamellipodium episode is taking longer than expected and so has had to be pushed back a bit until November 25th (episode 10).
06:19
November 22, 2020
7- Localised mRNA and Cell Polarity
On the podcast today, we cover the concept of localised mRNA, which can be relevant to cell polarity. Sources for this episode: 1) Martin, K. C. And Ephrussi, A. (2009), mRNA Localisation: Gene Expression in the Spatial Dimension. Cell 136: 719- 730.
03:49
November 15, 2020
6- Persister Cells
Antibiotic resistance we’ve all heard of by now, but what about antibiotic persistence? Join us as we explore the phenomenon of persistence, which allows bacterial infections to reappear even after antibiotic treatment. And all while being genetically identical to their susceptible neighbours! Sources for this episode: 1) Balaban, N. Q., Helanie, S., Lewis, K., Ackermann, M., Aldridge, B., Andersson, D. I., Brynildsen, M. P., Bumann, D., Camilli, A., Collins, J. J., Dehio, C., Fortune, S., Ghigo, J.-M., Hardt, W.-D., Harms, A., Heinemann, M., Hung, D. T., Jenal, U., Levin, B. R., Michiels, J., Storz, G., Tan, M.-W., Tenson, T., Van Melderen, L., Zinkernagel, A. (2019), Definitions and guidelines for research on antibiotic persistence. Nature Reviews 17: 441- 448. 2) Fisher, R. A., Gollan, B. and Helanie, S. (2017), Persistent bacterial infections and persister cells. Nature Reviews Microbiology 15: 453- 464. 3) Wiley, J. M., Sherwood, L. M. and Woolverton, C. J. (2017), Prescott’s microbiology, 10th edition (International Edition), New York, McGraw-Hill Education. 4) Some of the discussion is based on my previous education on the topic.
05:39
November 08, 2020
5- A Projected Range Shift during Global Warming
It is common knowledge that bees as a whole are declining as a result of climate change, although bee decline as a larger topic is not in itself the subject of today's episode. But what about individual species? On the podcast today, we cover a 2019 study which predicted that the Australian small carpenter bee, Ceratina australensis, might go against this trend.... Sources for this episode: 1) Breeze, T. D., Roberts, S. P. M. and Potts, S. G. (2012), The Decline of England's Bees: Policy Review and Recommendations (University of Reading). Available at: Friends of the Earth (published 2017, online) [Accessed 09/09/2021]. 2) Dew, R. N., Silva, D. P. And Rehan, S. M. (2019), Range expansion of an already widespread bee under climate change. Global Ecology and Conservation 17 (2019): e00584. 3) Author unknown, Friends of the Earth (2017), What are the causes of bee decline? (online) [Accessed 09/09/2021].
03:36
November 03, 2020
4- GTPases and Actin Remodelling in Yeast
This episode builds on content covered in episode 3, so be sure to check it out if you haven’t listened to it already. This week, we explore an example of the GTPase content we discussed last time. Specifically, we look at the diploid mating of baker’s yeast in stressful environments. Source for this episode: 1) Alberts, Johnson, Lewis Raff, Roberts and Walter (2008), Molecular Biology of the Cell, Fifth Edition. Abingdon: Garland Science, Taylor and Francis Group LLC.
03:19
November 01, 2020
3- Cell Polarity and GTPases
On the podcast today, we scratch the surface of cell polarity and how enzymes known as GTPases are linked to this process. Sources for this episode: 1) Alberts, Johnson, Lewis Raff, Roberts and Walter (2008), Molecular Biology of the Cell, Fifth Edition, Abingdon: Garland Science, Taylor and Francis Group LLC. 2) Thain, M. And Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. 3) Some of the discussion is also based on my studies.
05:31
October 30, 2020
2- The Identification of Richard III
It’s genetics time! Back in 2012, a skeleton was unearthed in a car park in Leicester, which was later positively identified as Richard III of England. But how? Join us as we delve into how genetics cracked a 500 year old case wide open... Sources: 1) King, T. E., Fortes, G. G., Balaresque, P. Thomas, M. G., Balding, D., Delser, P. M., Neumann, R., Parson, W., Knapp, M., Walsh, S., Tonasso, L., Holt, J., Kayser, M., Appleby, J., Forster, P., Ekserdjian, D., Hofreiter, M., and Schürer, K. (2014), Identification of the remains of King Richard III. Nature Communications 5:5631, DOI: 10.1038/ncomms6631. 2) Shakespeare, W., Richard The Third (play), Act 1, Scene 3. 3) Author unknown, BBC news (2015), Richard III: Leicester Cathedral reburial service for king (online) [Accessed 29/10/2020]. 4) Author unknown, BBC (2018), 'The discovery of Richard III's skeleton changed my life' (online) [Accessed 29/10/2020].
05:24
October 29, 2020
1- Biofilms
Welcome to our first proper episode! This week, we tackle the problem of biofilms- an extracellular matrix which can protect the species inside it and is a source of frustration to doctors and dentists alike. Sources for this episode: 1) Lopez, D. Vlamakis, H. And Kolter, R. (2010), Biofilms. Cold Spring Harbor Perspectives in Biology 2(7): a000398. DOI: 10.1101/cshperspect.a000398. 2) Short, F. L., Murdoch, S. L. And Ryan, R. P. (2014), Polybacterial human disease: the ills of social networking. DOI: 10.1016/j.tim.2014.05.007. 3) Thain, M. And Hickman, M. (2014), The Penguin Dictionary of Biology, 11th edition. London: Penguin Publishing Group. ISBN: 978-0-141-01396-1. 4) Wiley, J. M., Sherwood, L. M. And Woolverton, C. J. (2017), Prescott’s Microbiology, 10th edition (International Edition). New York, McGraw-Hill Education. ISBN: 978-981-3151-26-0.
03:48
October 27, 2020
0- Introduction
Welcome to Biopedia! This episode is a bit of an explanation as to who I am, what the podcast is all about and some caveats about my schedule.
03:22
October 26, 2020