Charles Darwin makes his way south from Rio de Janeiro to Maldonaldo and the south of South America. Along the way, he witnesses some local activities and has time to show off technological marvels to the locals.

NOTE: I have found out since recording that St Elmo's light or fire is a weather phenomenon in which plasma appears around anything with a structure like a rod in a vehicle, such as the mast of a ship or the wing of a plane (St. Elmo's fire Wikipedia 04/11/2025). I have also discovered that $2 in 1832 money is worth $75.34 in 2025 money ($2 in 1832 → 2025 | Inflation Calculator 04/11/2025).

Sources for this episode:

TBA

In a sort of unofficial Part II to our discussion in episode 112, we are going to examine the data from the 1790 US census focussed on the towns of Danbury and Brookfield in Fairfield County, Connecticut. We will be using the data for each household to answer two questions- does the ratio between males and females deviate significantly from 50:50? And what is the average family size?

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TBA

Something a bit different today- we are going to be following up from our discussion of namesaking and looking at suffix chains! Examples of links in such chains would include people like Theodore Roosevelt VII or John Smith III. Let's look at some real-life data- including data from the 1790 US census- to ask one question: how common or rare is each new link in the chain?

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Today, we will be wiping out humanity to ask a simple question- what would happen if there really were only two people left to repopulate the planet? Let's meet our hypothetical protagonists Cornelius and Cornelia, and in the first part of this scenario we will examine how many children the pair could realistically have given certain assumptions.

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TBA

A few weeks ago in episode 108, we talked about the largest species of snake to ever exist. Well, today we are travelling to the other end of the size spectrum to talk about the smallest snake in the world. This is Tetracheilostoma carlae, the Barbados threadsnake- which was thought to have gone extinct until the year 2025...

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Throughout history, there have been several claims of unusual longevity. For example, Pliny the Elder mentions several cases of people claiming to be 140 in a first century CE census. Moreover, there is a man in England who supposedly died at the age of 169 in 1670. However, they don't quite compare to the case of Colestein Veglin from July 1876.

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Previous episodes of the podcast have established the precedent of examining specific species or taxa. On today's episode, we are going to examine a snake. Not just any snake- the biggest snake to have ever lived...

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Pascal's Triangle is a useful concept in binomial theorem. However, it also has uses in biology. Today, we use it to answer the question- if you have X number of kids in a family or randomly chosen people in a sample, what is the probability of ending up with at least Y males and/or Z females?

Sources for this episode:

TBA

Adam and Eve, Ask and Embla, Deucalion and Pyrrha... The cultures of the world seemingly love the idea of humanity descending from two founders. While this notion may not be in line with scientific thought, there are two individuals who everyone can trace either maternal or paternal ancestry to. Say hello to mitochondrial Eve and Y-chromosomal Adam...

Sources for this episode:

• Berta, P., Hawkins, J. R., Sinclair, A. H., Taylor, A., Griffiths, B. L., Goodfellow, P. N. and Fellous, M. (1990), Genetic evidence equating SRY and the testis-determining factor. Nature 348: 448- 450.
• Callaway, E. (2013), Nature News, Genetic Adam and Eve did not too far apart in time (online). (Accessed 18/10/2020).
• Chan, E. K. F., Timmermann, A., Baldi, B. F., Moore, A. E., Lyons, R. J., Lee, S.-S., Kalsbeek, A. M. F., Petersen, D. C., Rautenbach, H., Förtsch, H. E. A., Bornman, M. S. R. and Hayes, V. M. (2019), Human origins in a southern African palaeo-wetland and first migrations. Nature 575: 185- 189.
• Chiaroni, J., Underhill, P. A. and Cavalli-Sforza, L. L. (2009), Y chromosome diversity, human expansion, drift and cultural evolution. Proceedings of the National Academy of Sciences of the United States of America 190(48): 20174- 20179.
• Fleischmann, T. (2019), The Norse Creation of the Cosmos. MFA, Salem Press Encyclopedia of Literature.
• Fry, S. (2017), Mythos: The Greek Myths Retold. London: Michael Joseph Ltd (part of Penguin).
• Ingman, M., Kaessmann, H., Pääbo, S. and Gyllensten, U. (2000), Mitochondrial genome variation and the origin of modern humans. Nature 408: 708- 713.
• Nass, M. M. K. and Nass, S. (1963), Intramitochondrial fibers with DNA characteristics. The Journal of Cell Biology 10: 593- 611.
• Sykes, B. (2001), The Seven Daughters of Eve. London: Corgi Books (part of the Random House Group Ltd.
• Thain, M. and Hickman, M. (2004), The Penguin dictionary of biology, 11th edition, London, Penguin Books Ltd.
• Author unknown (2010), Holy Bible: International Children's Bible (New Century Version). Milton Keynes: Authentic Media Limited.

We know today that our planet Earth is billions of years old. However, the people of a few centuries ago would have been equally convinced it was only a few thousand years old. So what were some of these old ages, and how big a shift is it from there to the age we've arrived at today?

Sources for this episode:

TBA

It was one of the oldest individual organisms to have lived. And yet, in 2006, its story would come to an end. To find out how, come and join us on this adaptation of a post on the Biopedia website into audio format.

Sources for this episode:

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Tackling James Lovelock's most famous theorem is no easy task. However, that's exactly what we're going to do today. Join us for a breakdown of the Gaia Hypothesis, a discussion of altruism, a throwback to the Black Queen Hypothesis in episode 21 and some speculation based on an early 2000s book by Lovelock himself.

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As it turns out, Louis XIII of France and Drypetina of Pontus have something in common. They have hyperdontia, or too many teeth. Today, we go through the phenomena of hyperdontia, hypodontia and concomitant hypo-hyperdontia.

Sources for this episode:

• Ammianus Marcellinus (1956) in Three Volumes (Vol. I). Translated by J. C. Rolfe. Cambridge, Massachusetts and London: Harvard University Press and William Heinemann Ltd.
• Eshgian, N., Al-Talib, T., Nelson, S. and Abubakr, N. H. (2021), Prevalence of hyperdontia, hypodontia, and concomitant hypo-hyperdontia. Journal of Dental Sciences 16: 713-717.
• Gracco, A. L. T., Zanatta, S., Valvecchi, F. F., Bignotti, D., Perri, A. and Baciliero, F. (2017), Prevalence of dental agenesis in a sample of Italian orthodontic patients: an epidemiological study. Progress in Orthodontics 18:33.
• Littlewood, I. (2002), The Rough Guide: History of France. London: Rough Guides Ltd.
• Peker, I., Kaya, E. and Darendeliler-Yaman, S. (2009) Clinical and radio- graphical evaluation of non- syndromic hypodontia and hyperdontia in permanent dentition. Medicina Oral Patologia Oral y Cirugia Bucal 14: e393e7.
• Pliny (1961), Natural History in Ten Volumes (Volume II: Libri III- VII). Translated by H. Rackham. Cambridge, Massachusetts and London: Harvard University Press and William Heinemann, Ltd.
• Snow, P. and Macmillan, A. (2022), Kings & Queens: The Real Lives of the English Monarchs. London: Welbeck.
• Author unknown (1830), A Collection of the Most Instructive and Amusing Lives Ever Published. Volume VIII: Lord Herbert and Prince Eugene. London: Whittaker, Treacher, and Arnot.
• Author unknown, Wikipedia (date unknown), Agrippina the Younger (online) (Accessed 15/10/2024).
• Author unknown, Wikipedia (date unknown), Drypetina (online) (Accessed 15/10/2024).
• Author unknown, Wikipedia (date unknown), Louis XIII (online) (Accessed 15/10/2024).

An episode all about a suggested topic- the walrus! Let's explore how one species used to many, and the challenges the sole surviving species faces in the modern day...

Sources for this episode:

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WE DID IT! 100 episodes. It feels crazy to say that the beginning of Biopedia in late 2020 is four and a half years ago when this episode comes out. Thank you all so much for listening and I look forward to many more episodes to come!

To celebrate our milestone, we are discussing a milestone in biology- as voted for by you the community over on YouTube. Get ready for an outmoded theory about how bacteria emerge on food and huge names such as Louis Pasteur and Robert Koch!

Sources for this episode:

• Madigan, M. T., Bender, K. S., Buckley, D. H., Sattley, W. M. and Stahl, D. A. (2019), Brock Biology of Microorganisms (15th edition). Harlow: Pearson Education Limited.
• Pasteur, L. (1881), On the Germ Theory. Science os-2(62): 420-422.

Don't worry, you have not in fact stumbled onto a physics podcast. However, the Laws of Thermodynamics do have a rather significant connection to evolutionary biology. This is because, at first glance, they appear to lead to a rather startling conclusion- life should not be able to evolve at all...

Sources for this episode:

• Berg, J. M., Tymoczko, J. L. and Stryer, L. (2007), Biochemistry (6th edition). New York: W. H. Freeman and Company.
• Herron, J. C., and Freeman, S. (2015), Evolutionary Analysis. Harlow: Pearson Education Ltd.
• Masanes, L. and Oppenheim, J. (2017), A general derivation and quantification of the third law of thermodynamics. Nature Communications 8: 14538.
• Ritchie, R. and Ghent, D. (2015), A Level Chemistry for OCR A. Oxford: Oxford University Press.

Quick correction: I call the episode on sibling species episode 37 in the audio, but it's actually episode 47!

Way back in the early days of Biopedia, we discussed the concept of sibling species. Now, we're talking about cryptic species. Are these the same concept? Well, as we will see today, it's complicated...

Sources for this episode:

• Allaby, M. (editor) (2020), Oxford Dictionary of Zoology. Oxford: Oxford University Press.
• Bickford, D., Lohman, D. J., Sodhi, N. S., Ng, P. K. L., Meier, R., Winker, K., Ingram, K. K. and Das, I. (2007), Cryptic species as a window on diversity and conservation. TRENDS in Ecology and Evolution 22(3): 148-155.
• Herron, J. C., and Freeman, S. (2015), Evolutionary Analysis. Harlow: Pearson Education Ltd.
• Hine, R. (2019), A Dictionary of Biology (Oxford Quick Reference), 8th edition, Oxford, Oxford University Press.
• Author unknown, Wikipedia (date unknown), Species complex (online) (Accessed 25/07/2024).

2023 was a warm year. But let's put it into context. To do that, a 2024 study looked at temperature and tree core data to assemble summer temperatures all the way back to 1 CE. As for the result- the title speaks for itself...

Sources for this episode:

• Bianchi, G. G., & McCave, I. N. (1999). Holocene periodicity in North Atlantic climate and deep-ocean flow south of Iceland. Nature, 397(6719): 515–517.
• Büntgen, U., Myglan, V. S., Ljungqvist, F. C., McCormick, M., Di Cosmo, N., Sigl, M., Jungclaus, J., Wagner, S., Krusic, P. J., Esper, J., Kaplan, J. O., de Vaan, M. A. C., Luterbacher, J., Wacker, L., Tegel, W., & Kirdyanov, A. V. (2016). Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD. Nature Geoscience, 9(3): 231–236.
• Dull, R. A., Southon, J. R., Kutterolf, S., Anchukaitis, K. J., Freundt, A., Wahl, D. B., Sheets, P., Amaroli, P., Hernandez, W., Wiemann, M. C., & Oppenheimer, C. (2019). Radiocarbon and geologic evidence reveal Ilopango volcano as source of the colossal ‘mystery’ eruption of 539/40 CE. Quaternary Science Reviews, 222: 105855.
• Dytham, C. (2011). Choosing and Using Statistics: A Biologist’s Guide (3rd ed.). Wiley-Blackwell.
• Esper, J., Torbenson, M. and Büntgen, U. (2024), 2023 summer warmth unparalleled over the past 2,000 years. Nature 631: 94-97.
• Goosse, H., Crespin, E., Dubinkina, S., Loutre, M.-F., Mann, M. E., Renssen, H., Sallaz-Damaz, Y., & Shindell, D. (2012). The role of forcing and internal dynamics in explaining the “Medieval Climate Anomaly.” Climate Dynamics, 39(12): 2847–2866.
• Graham, N. E., Ammann, C. M., Fleitmann, D., Cobb, K. M., & Luterbacher, J. (2011). Support for global climate reorganization during the “Medieval Climate Anomaly.” Climate Dynamics, 37(5–6): 1217–1245.
• Lamb, H. H. (1965). The early medieval warm epoch and its sequel. Palaeogeography, Palaeoclimatology, Palaeoecology, 1(1): 13–37.
• Lowe, J., & Walker, M. (2015). Reconstructing Quaternary Environments (3rd ed.). Routledge.
• Mann, M. E., Zhang, Z., Rutherford, S., Bradley, R. S., Hughes, M. K., Shindell, D., Ammann, C., Faluvegi, G., & Ni, F. (2009). Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly. Science, 326(5957): 1256–1260.
• Matthews, J. A., & Briffa, K. R. (2005). The ‘little ice age’: re‐evaluation of an evolving concept. Geografiska Annaler: Series A, Physical Geography, 87(1): 17–36.
• Shi, F., Sun, C., Guion, A., Yin, Q., Zhao, S., Liu, T., & Guo, Z. (2022). Roman Warm Period and Late Antique Little Ice Age in an Earth System Model Large Ensemble. Journal of Geophysical Research: Atmospheres, 127(16): e2021JD035832.

A bit of an unusual one this year- I was recently given a Dr Who book featuring Charles Darwin. So, let's examine the historical details of this novella and see how they represented Darwin. Have they done him justice?

Sources for this episode:

TBA

Your number of ancestors double every generation. Two parents, four grandparents, and so on. If we compare these numbers to the total number of people alive on the planet as we go back in time, what do we find? And what do researchers say on the subject?

Sources for this episode:

• Bell, S., Phys (2013), Researcher uses DNA to demonstrate just how closely everyone on Earth is related to everyone else (online) (Accessed 05/07/2024).
• Berger, B. M. (1960), How Long Is a Generation? The British Journal of Sociology 11(1): 10-23.
• Hershberger, S., Scientific American (2020), Humans Are All More Closely Related Than We Commonly Think (online) (Accessed 05/07/2024).
• Matsamura, S. and Forster, P. (2008), Generation time and effective population size in Polar Eskimos. Proceedings of the Royal Society B: Biological Sciences 275: 1501-1508.
• Murdock, N. H. (1998), Teenage Pregnancy. Journal of the National Medical Association 90(3): 135.
• Author unknown, Guiness World Records (date unknown), Oldest person to give birth (online) (Accessed 05/07/2024).
• Author unknown, Our World in Data (date unknown), Population, 10,000 BCE to 2021 (online) (Accessed 05/07/2024).