Discovering Darwin

In this final episode of Season 5, Sarah, Mark, and James discuss the last chapters from Lucy Cooke's book Bitch: On the female of the species. Sarah described the sex lives of barnacles and encouraged us to watch the Green Porno episode that illustrates the impressive size of a barnacle penis. Image from https://bodegahead.blogspot.com/2017/06/a-long-reach.htmlThe conversation considered why Charles Darwin did not include barnacles in his Descent of Man, and Selection in Relation to Sex. Sarah suggested it would not fit nicely in his narrative on male and female roles in sexual selection. We then discussed how clown fish, which can shift their sexual identity from male to female, challenge the notions of sexual identity. Photo: Amanda Cotton/Coral Reef Image BankMark recounted Lucy Cooke's biologically accurate retelling of Finding Nemo which results in a story that would not get a G rating.  James questions if the term Gender is only relevant to humans, since we seem consumed with identity, and in the animal world, gender is meaningless as are terms like masculine and feminine. We then speculated how a modern Charles Darwin would integrate these diverse views of sexual identity and sexual strategies into a more inclusive theory of sexual selection.

In this episode Sarah, Mark and James continue their discussion of the book Bitch by Lucy Cooke where they explore menopause in humans and non-human animals and discuss those animals that have forwent males when they reproduce. The first conversation explored how orcas are an unusual mammal in that the males do not disperse from their mother's pod, but instead they retain a close relationship with their mothers. The ultimate momma's boy. Sarah discussed the various hypothesis for why women would actually go through menopause, and why it is an evolutionary puzzle. One of the hypothesis that Sarah thought had traction was the fact that human women at birth reduce their one million oocytes to about 300,000 at birth, and the number and quality of eggs continue to decline with age. The oocytes of a human female in stasis awaiting the monthly opportunity to develop into a fertile egg.We discussed why it is the female orca that experiences menopause and not the males. We finished the podcast discussing single sex albatross pairs who successfully rear offspring every year. James discussed seeing these birds raising their single offspring in the yards of a suburban neighborhood. Humans have encroached on much of the historical nesting sites of the albatross on the Hawaiian islands but Nevertheless, she persisted. Here is a picture of a baby albatross James took on Kauai where it is manipulating its parents by maintaining the baby downy feathers on its head while the adult feathers are on the rest of the body. We finished the podcast discussing the parthenogenic Mourning geckos that have colonized many of the islands of the Pacific since they can reproduce asexually. Virgin births have been observed in many chordates except in mammals. We discussed why that may be.A Mourning Gecko James photographed when doing field work in Kauai.Opening and closing music is "May" by Jared C. Balogh.Interlude music Confessions by Sudan Archives 

 In this episode Sarah, Mark, and James continue their coverage Bitch by Lucy Cooke. We discussed systems where female aggression was common and the subjugation of other females and males was done by "alpha" females.  We were surprised to learn how murderous and violent naked mole rats and sweet little meercats could be. Photo from Akron ZooNaked mole rats are eusocial mammals where a dominant female is the sole reproducer in the colony and others help rear the young. Here is a photo of a queen rat with her newborn pubs and other females assisting in their care. Do not be fooled by the serene nature of this image, those helper females are violently coerced into their roles.Photo from https://lsc.org/news-and-social/news/our-naked-mole-rats-had-babiesagainMeercats are also a fossorial social mammal that is ruled ruthlessly by the dominant female. The play of meercats often mimics fighting, which is always a constant possibility in their tight knit clan.The second half of the discussion focused on female dominant systems that rely more on alliances and social bonding to create group coherence. Ring tailed lemurs and bonobo chimpanzees were the classic system we discussed. At the end we tried to make sense of how ecology, physiology, and culture might be influencing a social system being matriarchal or patriarchal. Sarah noted that the males in these female dominant social systems reminded her of Ken in the movie Barbie. Opening and closing music is "May" by Jared C. Balogh.Interlude music My Humps by the Black Eyed Peas   

We continue our discussion of Lucy Cooke's book entitled Bitch: On the female of the species focusing on chapters 5 & 6 which covered variation in female genitalia, the evolution of the human penis,  and maternal care. We spent some time talking about the baculum, a bone that is found in the penis of many mammals, but not in humans. Sarah described how intricately shaped the baculum of squirrels can be, as evident in the image below. From Bacula of North American Mammals by W. H. Burt, 1960Sarah also discussed a novel hypothesis presented by Jakovlic'  that proposes and explanation for the loss of human baculum through male-male aggression. James wondered why human copulation lasts so long? What is the point of all that thrusting for minutes on end?  We explored a couple of hypothesis that have been proposed to explain the exuberant level of pelvic thrusting typical in human copulation. James encouraged our listeners to look at the NSFW artwork of Jamie McCartney, a sculpture and photographer who has created a large portfolio of casts of penises and vaginas, and other secondary sexual characteristics, which clearly represent the variability in human genitalia. The second part of the podcast explored the myth of maternal care and how opposing neurological process can explain aggression towards babies or care and protection of babies. We explored how these process could help explain post-partum depression and how the modern medical process in child birth may interfere with the evolved bonding process that requires specific tactile, auditory, and olfactory cues shared between the mother and newborn. Opening and closing music is "May" by Jared C. Balogh.Interlude music was Detachable Penis from King Missile.  

 In this episode we continue our conversation based upon Chapters 3 & 4 of Lucy Cooke's book Bitch: on the female of the species. We started off the conversation doing a deep dive on the famous Bateman experiment that purported to reveal 3 principles concerning variation in male and female reproductive success and how those differences drive sexual selection. After reviewing the experiments and what they were reported to show, Sarah then discussed some more recent papers that closely re-analyzed the original 1948 experiment and how that revealed critical flaws and biases in the study which weakens the strength of its conclusion.   We were left with thinking it is more Bateman Hypothesis than Bateman's Principles. Once we established that it is not correct to characterize females as being coy and unwilling to mate more than once, we explored the reasons why females would exhibit a level of promiscuity that rivals that expected from males. We discussed the orgasm as a feature in sexual activity and how scientists have tried to characterize this physiological response in other non-human primates. Image of O face adapted from drawing in Bitch from Chevalier-Skolnikoff's research.We had a spirited conversation about the evolution of the female orgasm and how it might influence females seeking multiple mates. We ended the podcast with a discussion of sexual cannibalism. We explored the reasons why, in some species of spiders, the males are so much smaller than the adult females which facilitates her eating the male. Although killing and eating a potential mate seems maladaptive, we discussed the various reasons why it may be adaptive for the female and for the male to kill or be killed. Post mating cannibalism in a web building spider. Image from Schneider 2014 The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY Interlude musicGirls Just Want To Have Fun. Song by Cyndi LauperManeater. Song by Hall & Oats

We have returned from a long hiatus to discuss a wonderful book entitled Bitch: On the Female of the Species by Lucy Cooke. Sarah asked James and Mark to read this book that gives an updated look at Darwin's original model of sexual selection, a topic we covered extensively in Season 4. In this episode we cover the introduction and first 2 chapters of the book.In our conversation about the book, we discuss how Darwin's stereotypical, and simplistic. views of male and female roles in mating and reproduction have persisted 150 years later. As Sarah says, we are still suffering from the hangover Darwin's misogyny. Chapter one of the book does a great job challenging the simplistic notion of what "is a female?", and we explore that topic in detail. Mark was enamored with the existence of gynandromorphs (gyn=female, andro=male, morph=form), organisms that exhibit both male and female phenotypic structures. This led us to discuss the difference between sex and gender and why the simplistic view, often exposed in popular culture of late, of there being only 2 sexes, is incorrect and ignores actual biology. Image taken from https://www.eriebirdobservatory.org/ebo-blog/2021/2/21/a-second-bilateral-gynandromorph-northern-cardinal-in-northwest-pennsylvaniaWe also discuss how stereotypical gender roles influence how biologists interpret the behaviors they observed which often leads to misunderstanding and faulty interpretations. We encourage our listeners to read along with us, as we plan to discuss Chapters 3 & 4 next episode. Lucy Cooke (Photo: David Dunkerley)Here is another example of gynandromorphs, but in butterflies.Image from https://www.earth.com/news/gynandromorphs-half-male-half-female/The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY     Interlude musicBitch Song by Meredith BrooksSage Grouse calls were from Greater Sage-grouse strut display https://www.youtube.com/watch?v=m0M8pZnNlnI

In this final episode of Season 4, Mark, Sarah, and James finally critiqued Darwin's analysis of secondary sexual characteristics in humans and his clumsy attempt to apply his model of sexual selection in explaining the diversity of forms in what Darwin called "races" and we call geographically distinct phenotypes (GDPs). We found that Chapters 19 & 20 of Descent of Man distilled and concentrated Darwin's most ethnocentric and sexist observations and pseudo-scientific explanations concerning the differences between the sexes and GDPs. Image from Wilson, Miller, and Crouse (2017)Sarah made the argument that human sexual dimorphism, differences in size and body form of males versus females, is the smallest of all seen in extant primates. Sarah questioned why Darwin tried to assign those slight differences to sexual selection. James made the argument that there are two categories of traits that Darwin was discussing. James referred to the physical traits, like hair color, skin color, height, facial shape, etc. are intrinsic traits you inherit genetically. Humans also exhibit extrinsic traits, hair styles, piercings, tattoos, clothing, etc. which you inherit culturally. Mark explained the complexity of beauty and why attraction and beauty are two different issues. We explored how specific standards of beauty are locally determined and how how diverse they can be across the globe. Both James and Sarah independently concluded that Darwin's model of sexual selection was not sufficient in explaining the creation of the great diversity of human forms seen between the geographically distinct phenotypes around the world. Sarah invoked founder effects and genetic drift, non selective processes, in creating genetically distinct populations that were then acted upon by local selective pressures, both from the environment and within the social group. It is through those processes Sarah thought created the geographically distinct phenotypes, and not through sexual selection. James agreed and thought that selection at the group level, where everyone in the social group, enforced phenotypic norms on others through infanticide and cultural practices of shunning or killing undesirables created the diversity of forms seen among the GDPs.  Sarah and James' models do not require the extreme level of sexual selection and polygyny required in Darwin's model to shift the phenotype of the entire population. Also, the social cohesion model of selection can allow for rapid shifts in the phenotype as the entire social group enforces the phenotypic norms instead of just the mating male and who he selects to mate with. The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY     Interlude musicYou are so beautiful - Joe Cocker (1974)I'm too sexy - Right Said Fred (1992)     

 After a long COVID induced hiatus, we have returned to tackle the meaty middle of Charles Darwin's magnum opus The Descent of Man. It was actually most of Volume 2, three hundred and nineteen pages of anecdotes, observations, wild conjecture, and chuck'splaining his crazy system of inheritance. The dense plodding Victorian prose was diluted, a bit, by the amazing woodcut prints of beetles, fish, lizards, exotic birds whose feathers were stolen by Victorian women, and ornamented antelopes and other mammals. Human female adorned with decorative feathers stolen from birdsMark covered the fish, amphibians, and reptiles, since James forgot to assign the invertebrates, we did not discuss the myriad beetle examples Darwin discussed. However, Mark was impressed with the ways in which fish, during the breeding season, become so brightly colored. We mentioned a local fish, the male rainbow darter, which is quite striking during the spring breeding season. Mark was surprised to learn that there is no such thing as a fish and Sarah encouraged him to read Why Fish Don't Exist: A Story of Loss, Love, and the Hidden Order of Life – by Lulu MillerRainbow darter maleMark expressed his disappointment in the lack of sexual dimorphism in snakes, an animal group he has an inordinate fondness for. Although we did not discuss the invertebrates, James brought up the interesting sex determination system in slipper shell molluscs (pictured below) and how the top individual becomes the male, and all the ones below shift to be female. James tackled the immense bird section and offered a variety of hypothesis why the males of a species may look different than the females, in addition to Darwin's model of sexual selection and female choice. We also discussed the unique sex chromosome system in birds and how that is opposite of what we see in mammals and how some scientists believe it helped accelerate and magnify sexual dimorphism in birds. Fig. 47. Paradisea Papuana (T. W. Wood).Sarah covered sexual dimorphism in mammals and noted that Darwin believed most of that dimorphism was created through male-male battles for access to females and less about female choice. We had a lengthy discussion of antlers and horns and how they sometimes show up in both sexes but often is only found on the males. Sarah also discuss African lion manes and how they vary in shape and color where the darkest mane is the one most successful in fights and securing mates but there are costs with having the mane. A lion with a very dark maneWe also discussed the odd stotting behavior of some ungulates, as shown in the gif below. The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY Interlude music Fat Caps by Jason Shawhttps://freemusicarchive.org/music/Jason_Shaw/Audionautix_Tech_Urban_Dance/TU-FatCaps/Love Cats by the Cure

 In this episode we dive into Chapter 8 from Darwin's Descent of Man. James incorrectly attributed this chapter to the end of Volume I of the two volume set but it is actually the first chapter of Volume II, which makes more sense given its dramatic shift in focus and topic. Sarah tried to get us to differentiate between adaptive traits that come about from sexual selection with those that come about from natural selection.  Photo from https://rollingharbour.com/2017/02/14/bluehead-wrasse-private-life-laid-bare/We spent some time discussing the difference between sex-linked traits, like calico cat color,  and sexually selected traits like the giant antlers on the extinct Irish Elk.  James presented just a few hypothesis that have been proposed to explain female choice of traits and why those traits that females seem to prefer are often opposed by natural selection. It is hard to be a red male cardinal in the dead of winter. Sarah suggested interested listeners read The Evolution of Beauty by Richard O. Prum to learn how to differentiate the products of sexual and natural selection. We had a robust discussion about sex and gender and what Darwin knew at the time and what he should have acknowledged about the lack of binary distinction in the sexes. Mark realized he misspoke when he said that the rate of disorders of sexual development are around 10%. Data suggests that it occurs more like  (1:2500–5000 live births) whereas gender dysphoria is reported to occur around 0.002-0.014%. The bluehead wrasse is a wonderful organism that challenges the simple-minded view that your sex is determined at birth. https://www.bbc.com/news/av/uk-northern-ireland-45449128Sarah also encouraged us to watch some Green Porno to learn more details about the sex lives of non-human animals. You can see it hereThe opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY Interlude music is Alberta Hunter singing My handy man ain't handy no more from her Amtrak Blues album.

 image from:https://www.artsales.com/ARTistory/angelic_journey/index.htmlIn this bonus episode we return to our conversation with our favorite ex-monk philosopher friend Dr. Jack Furlong where he discusses whether angels, as described in scripture, could actually be moral.  We then briefly discuss the Yale baby lab where clever behavioral experiments are done on human babies to see how early they exhibit cognitive decision making. We hope to be back in the studio to record a complete episode out soon. 

 In this episode we finally confront Chapter 7 of Descent of Man,  entitled On the Races of Man. In this  chapter Darwin discusses the races of humans and outlines the scientific arguments of the time that questioned if humans are more than one species.  These arguments, of course, were based upon racist European views of the people from the lands their countries had colonized. Race is a social construct, not a biological identity, and we discussed why that is the case in this episode.  https://angelicadass.com/photography/humanae/James Wagner's daughter participated in this awesome art project and she is included in the images above.At one point we noted that Darwin reintroduced the idea of a range of varieties of organisms that can interbreed along a geographical range, but the ends of the ranges were reproductively isolated. We introduced that idea, often called a ring species, in Season 1 Episode 3, which can be found here. Sarah loves her ectoparasites and their evolution and discussed Darwin's 30 year obsession with that issue. Here is a link to a wonderful series of articles about Descent of Man and that obsession.The opening theme to Discovering Darwin is "May" by Jared C. Balogh. http://freemusicarchive.org/music/Balogh/Revitalized_Eyes/MAY Interlude music is We are Many, We are One a song from Up With People, a group of musicians who "stage song and dance performances promoting themes such as religion, racial equality, and positive thinking." Our own Mark Jackson played trumpet with Up With People before pursuing his career in psychology.

Mark, Sarah, and James discuss Chapter 6 of Charles Darwin's Descent of Man. In this chapter Darwin unequivocally declares humans evolved from ancestral primate stock and that event occurred in Africa. We discussed how prescient Darwin was in interpreting the biology and scant fossil record in determining human relationship in the evolutionary tree. (Image credit: Nick Hobgood/Wikimedia Commons)We discussed at length this problematic paragraph:The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, has often been advanced as a grave objection to the belief that man is descended from some lower form; but this objection will not appear of much weight to those who, convinced by general reasons, believe in the general principle of evolution. Breaks incessantly occur in all parts of the series, some being wide, sharp and defined, others less so in various degrees; as between the orang and its nearest allies—between the Tarsius and the other Lemuridæ—between the elephant and in a more striking manner between the Ornithorhynchus or Echidna, and other mammals. But all these breaks depend merely on the number of related forms which have become extinct. At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate and replace throughout the world the savage races. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked, will no doubt be exterminated. The break will then be rendered wider, for it will intervene between man in a more civilised state, as we may hope, than the Caucasian, and some ape as low as a baboon, instead of as at present between the negro or Australian and the gorilla.After that awkward discussion we finished with the notion that our ancestor probably looked like a sea squirt. Here is the episode that Sarah referenced on the economics of Darwin's voyage - it was called to Drawn a BillThe opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.1st interlude music was Mr. Smith - Happy Dance. https://freemusicarchive.org/music/mr-smith2nd Interlude musicIt's a long way to Amphioxus by Sam Hinton https://www.youtube.com/watch?v=B0egWbwErRQ

In this episode we enlist a different Furlong, Dr. Jack Furlong, to help us untangle morality and determine if there really is such a thing as big M morality, as Sarah calls it. <spoiler alert>  Jack, after a very in depth explanation, says "No". Jack invokes the classic Trolley thought experiment to illustrate why various historical positions on morality stumble when confronted with the scenario and asks which big M morality system should be employed when resolving the trolley dilemma. Jack also challenges the view that morality in humans is either unique or exceptional. We also discussed how morality may show up in non-human animals and Jack cleared up for James the proper term to use when referring to more than a single octopus.  We also discussed if an octopus would have morality. https://www.theguardian.com/environment/2019/may/12/octopus-farming-unethical-and-threat-to-food-chainThe opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music ENCOMIUM by Evan Schaeffer Music Studios | https://soundcloud.com/evanschaefferMusic promoted by https://www.free-stock-music.comCreative Commons Attribution 3.0 Unported Licensehttps://creativecommons.org/licenses/by/3.0/deed.en_USThe Cure - Close to You

In Chapter 4 Darwin begins to sketch out his views on how complicated human behaviors, like sacrifice, empathy for others, and group defense would evolve when selection would favor us to act otherwise.Chapter 4 is entitled Comparison of the Mental Powers of Man and the Lower Animals - continued, but the short title at the top of the page is Moral Sense, which suggests what Darwin really thinks he is discussing. although he never clearly defines morality Mark shares with us a couple of definitions of morality and notes that Darwin hints at the idea that morality is actions that we feel we ought to do, not necessarily what we want to do. Later in the chapter Darwin entangles into the concept of morality ideas of choice, doing things that are not innate, and having a sense of what others expect of us, and us wanting to avoid disapprobation from our social group.We discussed altruistic and defensive behaviors exhibited in social animals and asked if those actions were actually moral. Here is an image of a baboon facing off a leopard to protect the baboon troop, is that action moral?James proposed of the idea that there is a set of morals that are independent of religion or culture but are based upon equality and fairness that all rationale people would agree upon. Sarah referred to this as capital M morality and rejected the notion. Mark stayed silent of the idea....Chapter 5 is where Darwin outlines his view that groups selection could explain the shift for moral behaviors, those behaviors that benefit the group at the cost to the individual. Darwin noted that- When two tribes of primeval man, living in the same country, came into competition, if (other circumstances being equal) the one tribe included a great number of courageous, sympathetic and faithful members, who were always ready to warn each other of danger, to aid and defend each other, this tribe would succeed better and conquer the other. Let it be borne in mind how all-important in the never-ceasing wars of savages, fidelity and courage must be. The advantage which disciplined soldiers have over undisciplined hordes follows chiefly from the confidence which each man feels in his comrades. Obedience, as Mr. Bagehot has well shewn, is of the highest value, for any form of government is better than none. Selfish and contentious people will not cohere, and without coherence nothing can be effected. A tribe rich in the above qualities would spread and be victorious over other tribes: but in the course of time it would, judging from all past history, be in its turn overcome by some other tribe still more highly endowed. Thus the social and moral qualities would tend slowly to advance and be diffused throughout the world.We discussed the strengths and weaknesses of group selection argument and also explored the conflicted tone Darwin used in these two Chapter. In these two chapters alone, Darwin used the term "savages" thirty-two times. In the entire text, Darwin used the term "savages" 187 times! We discussed what he meant by that term and considered modern alternative.In this episode Sarah, Mark, and James discuss Chapter 4 & 5 of Darwin's The Descent of Man.  Before we got started, James noted that Mark is the campus champion of Crokinole which he plays in his campus office on this board. Mark Jackson's office Crokinole championship arenaThe opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music is Overthrow by Shaolin Dub

 In this episode we discuss Chapter 3: The Mind from Darwin's Descent of Man. We are joined by a very special guest - Dr. Ellen Furlong from Illinois Wesleyan University who studies cognition in dogs. In this chapter Darwin spends some time going through a litany of traits that he associates with intelligence. His goal is to get the reader to recognize that humans, although very intelligent, are only different in degree and not in kind when compared to other animals. The list of traits Darwin thought indicated intelligence were:CuriosityImitationAttentionMemoryImaginationReasonProgressive ImprovementTools and weapon useAbstractionSelf-consciousnessLanguageSense of BeautyComplex emotions Belief in God, superstition, etc.Darwin started off the discussion clarifying the difference between instinct and intelligence and noted some researchers proposed that instinct and intelligence are an inverse ratio to each other, the more your behaviors are dictated by instinct the less intelligence, as defined by the traits above, you exhibited. Mark discussed instinct in humans when he was a special guest of the Podcast nearly 6 years ago from when we recorded this podcast. He was a special guest in October 2015 and we recorded this episode October 2021. You can find Mark's inaugural appearance here.Ellen explained how nest building behavior is different from other behaviors we may do without thinking and why nest building is an instinct and bike riding is not.Ellen made it clear that intelligence can only be compared within a species and in comparison to other individuals within a species. It is incorrect to make cross species comparisons when it comes to intelligence, since each species is a genius for its own domain. Ellen notes people love to make claims about how smart their dogs are, but they often ignore the failings of their dogs in those comparisons. Ellen noted a short essay she wrote about how dogs do love us has been very popular as people are very interested in knowing what is going on in the minds of their pets. We ended the conversation about the classic marshmallow test which purported to measure patience and delayed gratification in young children. Children were offered a single marshmallow and told if they waited and not eat it, they would be given a second one later. It is the idea that can we resist our desire for instant gratification now for some possible bigger gratification in the future. Ellen discussed her own efforts to replicate that experiment using dogs and a variety of treats.  Unfortunately COVID has disrupted her research.The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music is "Who let the dogs out?" by the Baha Men 

  In this episode we discuss Chapter 1 of Descent of Man and are joined by a special guest - Evolutionary developmental (EvoDevo) biologist Dr. Belinda Sly. Darwin spends the chapter documenting how human bodies show the scars from evolution past. Darwin takes two approaches in convincing the reader that humans are modified from "lower forms". In one approach he discusses how humans share ailments, diseases, and parasites with other animals. The argument of homology. The second argument Darwin uses is cataloging the various rudimentary, vestigial, and nascent structures humans have and how they are present and useful in other animals.Sarah highlighted the homology argument that Darwin used - the fact that humans share diseases and parasites with other animals, showing the similarity of our bodies with other animals - by discussing the diversity of human lice - head, body, and pubic lice. After explaining the differences between each, Sarah helped us understand how they are used to identify important points in our evolutionary past, when we became hairless and when we adopted clothes. The strongest homology argument that Darwin presented was the similarity in form of vertebrate embryos and how the new technology of the time - microscopes - was increasing that dataset.  Dr. Belinda Sly discussed the different scientists of the time that were documenting embryo development - Karl Ernst von Baer and Ernst Haeckel. There is great similarity in embryo forms for various vertebrate animals, although Haeckel seems to have exaggerated those similarities in his illustrations. Belinda discussed the power of the comparison of embryos, and how they do give the best evidence of evolution via descent with modification but fall short of the old adage "ontogeny recapitulates phylogeny".The second line of argument Darwin discussed was the various rudimentary or vestigial structures we have that are of "absolutely useless faculty".  In particular he spent some time highlighting our restricted ability to use our panniculus carnosus muscles to move our skin as illustrated in this GIF of a horse twitching its skin to dislodge flies. In humans the ability is mostly restricted to our ability to move our eyebrows, but Darwin discussed some families ability to move their scalp and Sarah shared her "lamest super power ever" ability to slightly move her ears. The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.1st interlude music is Head Lice song https://www.youtube.com/watch?v=7us3ucQmrIE2nd interlude music is Black Bear Combo - Black Bear Kolo http://blackbearcombo.com/  

  https://commons.wikimedia.org/This is the first episode of Season 4 where we begin our exploration of Charles Darwin's Descent of Man, and Selection in Relation to Sex which was published in 1871. In this episode we explore how Darwin finally got around to discussing the evolution of humans, a topic he avoided in Origin of Species even though he told Alfred Wallace it was "...the highest & most interesting problem for the naturalist." In creating the book he relied on a wide array of scientists, citizen scientists, and bureaucrats in collecting the wide array of facts he uses to support his claim that humans are just another animal and we have evolved like any other organism. We discussed what the social, political, and scientific climate was like when Darwin was publishing this book and how it was received by his friends and enemies alike. https://www.darwinproject.ac.uk/henrietta-emma-darwinSarah introduced us to Henrietta Darwin, Charles's daughter who was influential in editing Descent of Man. We discussed the amazing University of Cambridge correspondence project where you can easily search the immense database of correspondences between Charles Darwin and other family members, scientists, friends, his publisher, and others, Follow this link if you wish to explore the site. Sarah reminded us of the tragic tale of the children who were on the Beagle when young Charles Darwin traveled the world. You can find that story told in detail in our first episode of Season 2 entitled Hot Coffee The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music is "Saulsalita Soul" by Mr. ruiZ

 By Photographer unidentified - MS Am 1092 (1185), Houghton Library, Harvard University, Public Domain, https://commons.wikimedia.org/w/index.php?curid=34246605In this final episode of Season 3 we actually do not talk about Darwin, but instead focus our attention to William James, a medical doctor, early psychologist, and philosopher who wrote about emotions about 20 years after Charles Darwin published The Expression of the Emotions in Man and Animals. Mark suggested we read James' views on emotion which he published first in his 1890 two volume set of his Principles of Psychology and then distilled in his single volume Psychology:Briefer Course. You can find reading editions of both books at the wonderful resource Project Gutenberg.The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music Laid by James

 modified image from Bridgeman Art LibraryMark, Sarah, and James discuss the last technical chapter of Charles Darwin's The Expression of Emotions in Man and Animals, Chapter XIII:  Self Attention, Shame, Shyness, Modesty: Blushing. Mark Jackson's graduate research was on shame and guilt and he explained to us the difference between shame, guilt, embarrassment, and humiliation (a concept Darwin did not address) and why they are actually distinctly different emotions. In our discussion Mark explains why parents and teachers should not shame their children/students, but employ guilt, the gift that keeps on giving, if a change in behavior is what you seek.Darwin recognized blushing as a very distinct human behavior. In the chapter Darwin wrote:In most cases the face, ears and neck are the sole parts which redden; but many persons, whilst blushing intensely, feel that their whole bodies grow hot and tingle; and this shows that the entire surface must be in some manner affected. Blushes are said sometimes to commence on the forehead, but more commonly on the cheeks, afterwards spreading to the ears and neck We discussed the adaptive value of the blush as an honest signal that is exhibited in all humans, regardless of their skin color. Some of the studies we discuss indicated that when people see another blushing after being involved in a transgression or a mishap, the observer is more likely to give them sympathy or see them in a more positive light than if the person has a guilty or expression of shame without the blush.  Sarah discussed James' proclivity to blushing, and her warped sense of fun in making him blush. Some papers we referencedDijk, Corine, Peter J. De Jong, and Madelon L. Peters. "The remedial value of blushing in the context of transgressions and mishaps." Emotion 9.2 (2009): 287.Feinberg, Matthew, Robb Willer, and Dacher Keltner. "Flustered and faithful: Embarrassment as a signal of prosociality." Journal of personality and social psychology 102.1 (2012): 81.Jackson, Mark A. Distinguishing shame and humiliation. Diss. University of Kentucky, 1999.The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music Too Shy by Kajagoogoo

 We discuss Chapter XII of the text The Expression of the Emotions in Man and Animals. In this chapter Darwin explores the expressions we associate with surprise, fear, terror, horror, and anxiety. The stereotypical expression of fear, as represented by the image above from the 1950's horror film franchises,  has both a physiological function and a signal function. We discuss the various arguments Darwin made about the reason your eyes are opened wide, your mouth held agape, your hands held up. In this chapter Darwin used both photographs from Duchenne and woodcuts from photographs to illustrate the unique expressions humans employ when exhibiting that emotion. Fig. 20. Terror. From a photograph by Dr. Duchenne.We discussed how these expressions often illicit aid from others. In addition to people responding to the visual signal of fear, research has indicated that we also respond to the smell of fear. James discussed a study (Chen, Katdare, & Lucas 2006) where sweat samples generated from individuals who were either neutral or experiencing fear, as induced from watching scary movies, would trigger differences in cognitive abilities in third parties who smelled the sweat and then were tested for word association. We had a robust conversation about the apparent gender differences in the expression of anxiety. One of the complexities of this issue is untangling social norms and how they alter anxiety expression from biological differences that may alter anxiety expression.    The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.Interlude music opening theme to Jaws - John WilliamsChen, Denise, Ameeta Katdare, and Nadia Lucas. "Chemosignals of fear enhance cognitive performance in humans." Chemical senses 31.5 (2006): 415-423. McLean, Carmen P., and Emily R. Anderson. "Brave men and timid women? A review of the gender differences in fear and anxiety." Clinical psychology review 29.6 (2009): 496-505.