Talks #7 - #12 (MAY 2022 OCT 2022)

Professor Erika Schagatay is the director of the Environmental Physiology Group (EPG) studying human performance in extreme environments, with a special focus on freediving.

Erika obtained her B.Sc. in Biology at Lund University, studied Marine Biology at Gothenburg University, and completed her PhD in Animal Physiology at Lund University in 1996, on a thesis about the human diving response. After post-doctoral work in sports physiology at August Krogh Institute in Copenhagen, Denmark, and medical sciences at the Department of Community Medicine in Malmö, Sweden, 1997-1998, she joined Mid Sweden University in 1999 as a lecturer. In 2000 she was appointed associate professor at Lund University, and 2007 professor at Mid Sweden University. She headed the interdisciplinary Sports Science Profile at Mid Sweden University 2003-2008 and Sport Sciences 2015-2019, and currently holds the chair professorship in Sport Sciences.

An active diver, her interest in physiology began when she met breath-hold divers performing far better than stated possible in the medical literature at the time. She found that good divers had a powerful diving response – and it did not make sense to her how a terrestrial animal could have developed such an effective oxygen conserving system. By coincidence she came across Elaine Morgans book “The descent of Woman” and a possible explanation appeared.

Erika has since 1988 studied the physiology of several freediving populations, including the Indonesian Bajau and Japanese Ama, and found they can work efficiently for many hours a day underwater. Later studies have focused on competitive apnea divers, to reveal what makes them able to breath-hold for over 10 minutes, swim 300 m underwater and reach 130 m depth on one breath, a feat that is impossible for other terrestrial mammals. She has found that in addition to the diving response, we share with seals a spleen response - boosting the blood with red blood cells when we dive, among many other human features beneficial for apneic diving.

She has also studied high altitude physiology and revealed that human performance can be enhanced in this hypoxic environment by learning from breath-hold diving. Erika has published over 100 original articles on freediving physiology, high altitude- and thermo-physiology. In addition to experimental laboratory work, Erika has led field expeditions to extreme environments in Indonesia, Japan, the Philippines, Egypt and the Nepali Himalayas. She has supervised ten graduate students and more than 100 Master students in their research projects. Erika has also worked with safety aspects of freediving in the Swedish Sports Diving Federation and the international diving organizations AIDA-international and CMAS, and lectured on her research on many international conferences.

See  https://www.miun.se/en/personnel/erikaschagatay/  for more information and a list of published work.

Francesca developed a passionate interest in the Aquatic Ape Theory at the age of 17 after reading Elaine Morgan’s “The Descent of Woman” and has thereafter read everything she could find by her and /or otherwise related to the subject. 

Francesca gave birth to her first child in water, inspired by AAT, Michel Odent, and her belief that it would be a more natural, easier and relatively less painful form of childbirth (it was).

Since 2015 she’s been maintaining a website (Aquatic Human Ancestor dot org) which tries to keep up with scientific discoveries in support of AAT) – many of the speakers on WHAT talks are mentioned, although she says she’s lapsed a little in recent years as she’s had little time to keep it updated.

Francesca currently works as a yacht broker/charter operator in Greece. She’s always been drawn to the sea and loves being in it, or on it, whenever she can!

She is currently researching / writing a book (working title: Semi-aquatic Human Ancestors – the Evolution of a Theory), based on the accumulating scientific evidence that supports aquatic or semi-aquatic adaptations in humans (an outline of which will be covered in the talk).

Francesca's Web Site: http://aquatic-human-ancestor.org/

Semi-Aquatic Human Ancestors

 Semi-aquatic ancestors: when, where & why?
AAT supporters agree that water has played a morphological role in the evolution of human ancestors, but there remains much debate and little consensus regarding when, where and why this might have happened. Elaine Morgan and many others talked about somewhere in East Africa, perhaps Afar or the Rift valley during the Pliocene, as this is where/when the oldest “hominins” with bipedal modifications seem to appear, but the science is very weak, with no clear answers about why what happened to human ancestors didn’t happen also to the extant great apes, and scientists to this day have still not been able to draw any definitive conclusions regarding the phylogenetic relationships between australopithecines and Homo species.   

It was these unanswered questions that prompted me to delve deeper into the prevailing scientific evidence, established facts and generally accepted paradigms concerning human evolution. To understand when, where and why our ancestors’ aquatic interlude may have occurred, I decided to start my research from the time when the first apes diverged from other primates, around 25 million years ago, and study the evidence right up to the emergence of clearly definable Homo genus, approximately 2 million years ago. What I discovered surprised me. There wasn’t a single aquatic interlude for a brief window of time – there were many, covering many millennia, and it wasn’t just Homo species that carry the scars of an aquatic history, but some of our closest cousins too. Nevertheless, the evidence I researched does point to a single defining period for when the split between Pan – the chimpanzee lineage – and Homo occurred, a location where a semi-aquatic existence wasn’t just convenient, but essential, and a geological event that may provide the answer to why this happened. 

Key papers

Roberts, E., Stevens, N., O’Connor, P. et al. Initiation of the western branch of the East

African Rift coeval with the eastern branch. Nature Geosci 5, 289–294 (2012).

https://doi.org/10.1038/ngeo1432

Stevens, N., Seiffert, E., O’Connor, P. et al. Palaeontological evidence for an Oligocene

divergence between Old World monkeys and apes. Nature 497, 611–614 (2013).

https://doi.org/10.1038/nature12161

William J. Sanders, Brian E. Bodenbender, Morphometric analysis of lumbar vertebra UMP

67-28: Implications for spinal function and phylogeny of the Miocene Moroto hominoid,

Journal of Human Evolution, Volume 26, Issue 3, 1994, Pages 203-237, ISSN 0047-2484,

https://doi.org/10.1006/jhev.1994.1012.

Filler AG (2007) Homeotic Evolution in the Mammalia: Diversification of Therian Axial

Seriation and the Morphogenetic Basis of Human Origins. PLoS ONE 2(10): e1019.

ttps://doi.org/10.1371/journal.pone.0001019

Senut, Brigitte. “Morphology and environment in some fossil Hominoids and Pedetids

(Mammalia).” Journal of anatomy vol. 228,4 (2016): 700-15. doi:10.1111/joa.12427

Kamberov YG, Guhan SM, DeMarchis A, et al. Comparative evidence for the independent

evolution of hair and sweat gland traits in primates. J Hum Evol. 2018;125:99-105.

doi:10.1016/j.jhevol.2018.10.008

Fini, M.A., Lanaspa, M.A., Gaucher, E.A. et al. Brief report: The uricase mutation in humans

increases our risk for cancer growth. Cancer Metab 9, 32 (2021).

https://doi.org/10.1186/s40170-021-00268-3

Andrew Best, Jason M. Kamilar, The evolution of eccrine sweat glands in human and

nonhuman primates, Journal of Human Evolution, Volume 117, 2018, Pages 33-43, ISSN

0047-2484,

https://doi.org/10.1016/j.jhevol.2017.12.003

Ancient Bones: Unearthing the Astonishing New Story of How We Became Human, written

by Madelaine Böhme,  Rüdiger Braun , and Florian Breier, published by Greystone Books in

September 2020 (hardback, 376 pages)

https://inquisitivebiologist.com/2020/12/27/book-review-ancient-bones-unearthing-the-

astonishing-new-story-of-how-we-became-

human/#:~:text=Ancient%20Bones%20was%20originally%20published,already%20published

%20the%20English%20translation.

Ward CV, Hammond AS, Plavcan JM, Begun DR. A late Miocene hominid partial pelvis from

Hungary. J Hum Evol. 2019 Nov;136:102645. doi: 10.1016/j.jhevol.2019.102645. Epub 2019

Sep 17. PMID: 31537304. https://doi.org/10.1016/j.jhevol.2019.102645.

Bonis, Louis & Koufos, George. (2004). Ouranopithecus et la date de séparation des

hominoïdes modernes. Comptes Rendus Palevol. 3. 257-264. 10.1016/j.crpv.2004.04.002.

Bonis, Louis & Koufos, George. (2014). First discovery of postcranial bones of

Ouranopithecus macedoniensis (Primates, Hominoidea) from the late Miocene of

Macedonia (Greece). Journal of Human Evolution. 74. 10.1016/j.jhevol.2014.05.015.

John Hawks, Keith Hunley, Sang-Hee Lee, Milford Wolpoff, Population Bottlenecks and

Pleistocene Human Evolution, Molecular Biology and Evolution, Volume 17, Issue 1, January

2000, Pages 2–22, https://doi.org/10.1093/oxfordjournals.molbev.a026233

Kaiser, Shari M, Harmit S Malik, and Michael Emerman. "Restriction of an Extinct Retrovirus

by the Human Trim5α Antiviral Protein." 2007, Science, v. 316,.5832 pp. 1756-1758.

doi: 10.1126/science.1140579

Woldegabriel, Giday & Haile-Selassie, Yohannes & Renne, R.P. & Hart, William & Ambrose,

A.H. & Asfaw, Berhane & Heiken, Grant & TD, White. (2001). Geology and Paleontology of

the Late Miocene Middle Awash Valley, Afar Rift, Ethiopia. Nature. 412. 175-178.

10.1038/35084058.

Böhme, M., Spassov, N., Majidifard, M.R. et al. Neogene hyperaridity in Arabia drove the

directions of mammalian dispersal between Africa and Eurasia. Commun Earth

Environ 2, 85 (2021). https://doi.org/10.1038/s43247-021-00158-y

Stankiewicz, P. One pedigree we all may have come from – did Adam and Eve have the

chromosome 2 fusion?. Mol Cytogenet 9, 72 (2016). https://doi.org/10.1186/s13039-016-

0283-3

All speakers opinions are their own and their participation here does not imply agreement with any model of human evolution.

John Langdon is Professor Emeritus of Biology and Anthropology at the University Indianapolis, where he taught human evolution, gross anatomy, neuroscience, and human biology for many decades.  His interest in the history and process of science led him to critique shortcomings in the AAH in several articles and conference presentations.  He is the author of six books, including Getting it Right: The Science of Human Evolution (2016 Springer Press),  The Human Strategy: An Evolutionary Perspective on Human Anatomy (2005 Oxford University Press), and The Natural History of Paradigms (JH Langdon and ME McGann, eds., 1993 University of Indianapolis Press).   Human Evolution: Bones Cultures, and Genes, is forthcoming from Springer in October.

His articles relating to the AAH:2013    Human ecological breadth: Why neither savanna hypotheses nor aquatic hypotheses hold water.  Human Evolution 28(3-4):171-200.2006  Was an aquatic diet necessary for hominid brain expansion and development? British Journal of Nutrition 96(1):7-17.1999    Parsimony in aquatic and terrestrial models: How many hypotheses do we need? Water and Evolution Symposium, University of Ghent, Ghent, Belgium.  http://allserv.UGent.be/~mvaneech/Symposium.html1997  Monolithic hypotheses and parsimony in human evolution: A critique of the aquatic ape hypothesis. Journal of Human Evolution 33:479-494. 

Wading or Waddling?
(We need good questions to get good answers)

Talk Summary

The "Aquatic Ape Hypothesis" is now a conglomeration of many hypotheses, some of which are mutually contradictory.  It is not practical to address all versions.  Instead I will focus on a single issue, bipedalism, because that is at the heart of all of them and because Elaine Morgan herself identified bipedalism as the most important trait that the AAH tries to explain.  One of the barriers to understanding the evolution of bipedalism is a poor understanding of the alternatives.  Primitive tetrapod quadrupedalism is inefficient for many reasons, and lineages that needed speed developed bipedalism more than once (e.g., archosaurs, kangaroos).  What we think of as a typical fast running quadrupedal gait is actually rare, and may only have evolved once. 

Human ancestors and close relatives were climbers, and climbing adaptations are not compatible with efficient ground locomotion.  It is easier for a climber to develop efficient terrestrial bipedalism than efficient quadrupedalism, and anthropoids have done so at least five times.  The evolution of human bipedalism was neither unique nor unlikely.  It was not a single evolutionary event, but many, occurring over millions of years.  No single explanation can be adequate to describe it, and extraordinary circumstances, such as habitat shifts to and from water, are unnecessary.  "Why are we bipedal?" is a bad question.

Sunday October 9th 2022 (9 pm West Australian Time; 2pm UK)

Potted Bio
Michael A Crawford PhD, FRSB, FRCPath

Fellow of the Royal College of Pathologists, the Royal Society of Biology. PhD

from the University of London, thesis “Influence of pH on the excretion of some

weak acids and bases”1960 at the Royal Post Graduate Medical School,

Hammersmith, London. Then head Department of Biochemistry, Makerere

University Medical College, Kampala, Uganda till 1965 but with continued

research laboratory until 1972. Wellcome visiting fellow to Prof Ernst Baranay,

Pharmacology, University of Uppsala, head, biochemistry at the Nuffield Institute

of Comparative Medicine till 1990. Director Institute of Brain Chemistry and

Human, Nutrition, Queen Elizabeth Hospital for Children, Hackney, and London

Metropolitan University. 2011-2019 was Chief Investigator for FOSS1, an RCT at

Imperial College, London, UK where he is now a visiting Professor.

Research career started with the identification of the genetic cause of Hartnup

Disease 1961. Published the reason for the striking contrast in cancer and heart

disease types in Europe and East Africa. Provided evidence for the role of

docosahexaenoic acid (DHA) in the evolution of the brain and for the essentiality

of omega 3 in the 1970s. His laboratory was a WHO collaborating centre, 1978-86

for an international study on chemical contraceptives and human milk lipids. He

was a WHO consultant for the Joint WHO/FAO reports on the role of lipids in

human nutrition 1976, ’94 and 2010. Described the over-riding importance of

maternal health and nutrition prior to conception and lipid nutrition in relation to

neuro-development and disorders. Published over 300 peer reviewed papers and

written 3 books. Frequently invited to give Keynote lectures. Received many

international awards including the Order of the Rising Sun, for his contribution to

science and culture, from the Emperor of Japan and elected a Freeman of the City

of London in 2015.

The Talk: The Marine Driving Force of Human Encephalisation
Michael's presentation will start with a short critique of John Langdon's talk last month about bipedalism and the currently popular "Endurance Running" model of human evolution before outlining his main thesis, that the key feature of human encephalisation (our brains are 3x bigger than that of chimpanzees) cannot be explained by savannah, or other purely terrestrial, models. Michael's expertise in lipid biochemistry led him to postulate that the coastal marine chain was the only ecosystem that really could have fueled the growth of the human brain.