New book explores evolution of human reproduction

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Human beings would probably be known as pilosals rather than mammals if Carl Linnaeus had not been a proponent of breast-feeding. For social and political reasons, the famed taxonomist labeled the class of animals to which humans belong with a reference to their practice of suckling their young rather than to their evolutionarily older characteristic of having hair.


This is just one of the hundreds of surprising pieces of information that readers will glean from the far-reaching and fascinating How We Do It: The Evolution and Future of Human Reproduction, a new book by Robert Martin, a member of the University's of Chicago's Committee on Evolutionary Biology and curator of biological anthropology at he Field Museum.

Readers will also learn that:

But what's the point? Good cocktail party conversation?

In fact, it was precisely such a question that prompted Martin to write this book. Years ago, when he had just finished teaching a course on primate evolution at the University of Zurich, a student asked him, "So what? What's the utility of studying this subject?"

Robert's initial reaction was to say, "Primate evolution is important in its own right, but it's also human history—our history—going far back in time."

Nevertheless, the student's question stuck with him. "I realized that my research had practical applications," Martin says, "so I wrote this book to connect primate evolution with modern human concerns and conditions."

Indeed, the book is full of pertinent facts, figures, anecdotes, and analysis about human evolution, expertly woven together to inform current issues, including birth control, enhanced reproductive techniques, miscarriage, cloning, breast feeding, the effects of toxins on human reproduction, and the dramatic drop in sperm counts—all synthesized into a comprehensive synopsis of how we got where we are today, as a species, and where we're headed.
 

Written By: Greg Borzo
continue to source article at phys.org

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  1. The real future of human reproduction has to do with filtering sperm/eggs/fetuses to avoid genetic defects, short comings, diseases,
    or with hand building a genome with Olympic athlete innards but that looks like mom and dad with a face lift.

    The wealthy then give their offspring additional benefits besides wealth, but health, the ruthlessness of Bill Gates, the intelligence of Steven Pinker, the penis of Secretariat… The rich get prettier and the poor get poorer.

    The problem is ethic attributes, gayness and will dwindle in favour of the current fads. We will be reducing our diversity (which may contain something crucial).

    • In reply to #1 by Roedy:
      The rich get prettier and the poor get poorer.

      That happens anyhow. Sometimes you see a rich bloke with an ugly wife, but she was invariably acquired before his wealth, and kept for sentimental reasons. Mostly they get ditched for younger, prettier, more intelligent, more accomplished brands. Serial polygamy allows men to have a much longer breeding life. Though they occasionally have an ugly, or old, first wife, the rich never, ever have ugly mistresses!

      That all adds up to serial families of beautiful, intelligent, successful, athletic, sexually potent progeny. Much more fun than genetic engineering, though probably even less moral.

      • Charles and Camilla? Not saying she’s ugly but many compare her unfavourably with Diana in terms of attractiveness and Charles could probably (with options limited by being in the royal goldfish bowl) have lured a prettier candidate to be his bit on the side had he been so inclined.

        (Actually I agree with your basic point – I just can’t resist a quibble)

        In reply to #3 by Kevin Murrell:

        Though they occasionally have an ugly, or old, first wife, the rich never, ever have ugly mistresses!

        • In reply to #5 by paulmcuk:

          Charles and Camilla? Not saying she’s ugly but many compare her unfavourably with Diana in terms of attractiveness and Charles could probably (with options limited by being in the royal goldfish bowl) have lured a prettier candidate to be his bit on the side had he been so inclined.

          (Actually I agr…

          But it’s what I said – kept for sentimental reasons. She was prettier when she was younger, and, according to her own testimony, a sensationally good roll.

    • In reply to #1 by Roedy:

      The real future of human reproduction has to do with filtering sperm/eggs/fetuses to avoid genetic defects, short comings, diseases, or with hand building a genome with Olympic athlete innards but that looks like mom and dad with a face lift.

      We should remember that this process already happens naturally, with competitive sperm races to fertilisation, and spontaneous abortion of weak or defomed embyos.

  2. Bear in mind that, if you can genetically engineer humans, you can also give them any genes we have on record, even if they would otherwise be rare or extinct among humans. So any diversity genetic engineering removes from us isn’t irretrievably lost, although it’d take a long time to recover from realising we shouldn’t have knocked out a specific gene.

    • In reply to #6 by wdbailey:

      I’ve not read this book yet but I suspect that the 1996 book Sperm Wars covers the subject better based solely on the comment about the comparative size of human testes

      http://www.amazon.com/Sperm-Wars-Infidelity-Conflict-Bedroom/dp/1560258489

      I read that book. It was riveting and I couldn’t put it down. If memory serves, didn’t Baker present the “upsuck theory” in that book? I’d check myself but my copy is lent out and will probably never make it back to my own shelves but if so then I should say that the idea has been tossed out. Not trashing the whole book because of that. In general I loved it.

      I think the best book to start with on this subject is The Red Queen, Sex And The Evolution of Human Nature by Matt Ridley. It gives a excellent overview of the basic concepts. In his chapter 7 of that book titled Monogamy and the Nature of Women he deals with female perspectives but for more excellent and valuable reading on female sexuality try Mother Nature, Maternal Instincts and How They Shape the Human Species by Sarah Blaffer Hrdy. I just couldn’t fully understand female Homo sapiens sexuality and reproductive strategy without that book. And final recommendation is The Case of the Female Orgasm, Bias in the Science of Evolution by Elisabeth A. Lloyd. This book, IMO is the final word on the interesting dispute over whether female orgasm is an evolutionary byproduct or an adaptation in its own right. It is on page 206 that Baker and Bellis are raked over the coals for the statistical problems involved in their uterine upsuck idea. There are some astounding conclusions that came out of that book including the very low percentage of women who experience orgasm from intercourse alone, and I must say that this is a figure that is apparently not well known to the general public and this is something that causes no small amount of anguish in both women and men. There’s no shortage of fun and useful facts in that book, such as:

      And in contrast to the median amount of time needed for a woman to have an orgasm from intercourse, women take an average of approximately 4 minutes to achieve orgasm with masturbation, the same period as for a man (Kinsey et al. 1953, p. 163)

      By the way, I wonder if we will have a book discussion section on this site. I lobbied hard for it a while back but haven’t seen mention of it since then. It’s more satisfying to discuss a book when everyone has read it already. By the time we get a number of people to read this book, which sounds like something I’d like to do, then this thread will have rolled off the front page into obscurity. The only way to discuss this book is for people to obtain it immediately, drop everything and zoom through the book and jump back on this thread in the hopes that it’s still current. Not ideal for book discussion.

      • In reply to #8 by LaurieB:

        In reply to #6 by wdbailey:

        I’ve not read this book yet but I suspect that the 1996 book Sperm Wars covers the subject better based solely on the comment about the comparative size of human testes

        http://www.amazon.com/Sperm-Wars-Infidelity-Conflict-Bedroom/dp/1560258489

        I read that book. It was…

        Well the thing that I was sort of poking fun at was that human males are either monogamous or polygamous based on comparative size of the testes…

        that’s not particularly astute but perhaps it’s not a fair representation of what is presented.

      • In reply to #8 by LaurieB:

        There are some astounding conclusions that came out of that book including the very low percentage of women who experience orgasm from intercourse alone, and I must say that this is a figure that is apparently public and this is something that causes no small amount of anguish in both women and men.

        Maybe even more astounding and also not well known to the general public, also perhaps obscured thanks to prudery, the universal taboo surrounding the topic generally and consolidated mansplaining, is the phenomenon of a type of ejaculation or expulsion of fluid on the part of the female. The existence of which, bizarrely, is not even fully accepted in medical circles much less the purpose of it understood. One might speculate that the notorious fragility of the male ego might also contribute to this phenomenon’s – rumored to be rather more spectacular than its male homologue – existence being disputed.

        Mysterious creatures indeed!

  3. In reply to #9 by wdbailey:

    I’ve not read this book yet but I suspect that the 1996 book Sperm Wars covers the subject better based solely on the comment about the comparative size of human testes

    http://www.amazon.com/Sperm-Wars-Infidelity-Conflict-Bedroom/dp/156025848

    Yes, I do remember that the topic was covered extensively in Sperm Wars and I don’t remember any confusion about it on my part after I finished the book. Are you objecting to this quote from the article above?

    The relative size of human testes indicates that we evolved to live in social groups with one-male breeding units practicing either monogamy or polygamy, usually the latter.

    Hmmm, you know when I read that I just assumed it meant – human testes relative to other primates but now that you mention it, it could also mean -human testes relative to other male humans which would give it a whole new and bizzarre meaning! Just think of crazy possibilities…every human female would keep in her pocketbook one of those testicle measuring devices (there’s no way I’ll remember the name of those weird things) and depending on the guys testicle size, then we would easily know the degree to which they were monogamous or polygamous! (also we will need one of those handy-dandy pocket graphing calculators). Speaking for all women at any point on the time/space continuum, (I have no authority to do so) for a revolutionary improvement in mating efficiency, please implement this immediately.

  4. In reply to #10 by godsbuster:

    the phenomenon of a type of ejaculation or expulsion of fluid on the part of the female. The existence of which, bizarrely, is not even fully accepted in medical circles much less the purpose of it understood.

    I just checked in the book The Case of the Female Orgasm that I mentioned above and there is only a quick reference to this in the Notes section in the back of the book. This is the material:

    There is some evidence that stimulation of this zone induces a urethral ejaculate at orgasm. The ejaculate itself may have characteristics similar to the fluid from the prostate in males (Zaviacic et al. 1984; Altshulur 1986; Zaviac et al. 1988; Darling, Davidson, and Conway-Welch 1990; Zaviacic and Whipple 1993; see the summary in Mah and Binik 2001, pp. 839-840).

    But I do agree that this phenomenon is obscure in these types of texts. I have seen mention of it in a couple of TV shows in the past couple of months. Not that this is any type of empirical evidence mind you :-) but what I did think about that was that sometimes when a sexual behavior that was previously considered to be taboo and “perverted” becomes better known to the general public through increased media exposure, then people will be less hung up about discussing it and taking it more seriously which might give us a better picture as to it’s “purpose” or evolutionary origin, etc. I am encouraged that there is more open discussion about female sexuality in books and online these days. A few weeks back I read the book What Do Women Want, Adventures in the Science of Female Desire by Daniel Bergner. This book discussed, among other things, the idea that monogamous sex is boring the hell out of women. I went to the book signing and told Bergner that I didn’t agree with some of his points in the book but I thought it took guts to say that about the bordom. Anyway, it’ll be interesting to see what the blowback on that statement will be. Dan Savage has put forth the idea that in a long term relationship, when one partner isn’t getting a certain something that he/she desires very much, then after all attempts have been made to work it out with the partner have failed, maybe it’s ok to outsource that particular behavior instead of completely trashing the whole relationship. I expect he got plenty of blowback on that one too. :-)

    • In reply to #12 by LaurieB:

      In reply to #10 by godsbuster:

      then people will be less hung up about discussing it and taking it more seriously which might give us a better picture as to it’s “purpose” or evolutionary origin, etc.

      Fueling speculation as to its possible purpose are reports from women who in natural childbirth in the comfort, privacy and familiarity of their home have experienced a sort of cataclysmic, apocalyptic, diluvian, why is there no pain? Oh… wait…. w o w w h a t i s t h i s ! ? ! parting of the heavens, orgasm does not begin to describe it, geyseresque, approaching the event horizon event which is the culmination of the about to be newborn emerging from the birth canal after having exerted considerable pressure on the surrounding erogenous tissue during contractions. Needless to say this renders obsolete and entirely laughable the epidural that the medical/pharmaceutical/industrial complex wanted to sell you included in their $10,000 hospital delivery package. Perhaps another reason why this is not being studied.

      In short, and this is pure speculation, maybe the liquid in addition to providing lubrication functions as a muscle relaxant or analgesic. Though as noted earlier the pain (to the degree there was any present at all in the first place) had already overwhelmingly been replaced with pleasure through entirely and immensely convincing means.

      Mr. Savage is a superb empiricist and in a class by himself when it comes to delivering (even more than they’re in already) pain to god(s)botherers.

      • In reply to #13 by godsbuster:

        In short, and this is pure speculation, maybe the liquid in addition to providing lubrication functions as a muscle relaxant or analgesic. Though as noted earlier the pain (to the degree there was any present at all in the first place) had already overwhelmingly been replaced with pleasure through entirely and immensely convincing means.

        Based on the lack of evidence and on my own participation in labor and delivery (three times) I am solidly skeptical about this claim. I don’t believe my body or anyone else’s could produce any quantity of fluid with enough analgesic effect to counteract the disabling and long lasting pain that is universally experienced by women in labor and delivery. Although my own experiences are anecdotal and not any sort of proof worth mentioning, I would have needed to be submerged in a vat of this analgesic fluid for six hours on that first labor and delivery for any hope of pain relief. I’d like to take this opportunity to thank the long line of my female ancestors who managed to survive childbirth due to their inheriting a commodious pelvic outlet and a cervix that was capable of a full dilation of 10cm in a reasonable amount of time and a multitude of other amazing adaptations too numerous to mention here. For a first labor, six hours is a stroke of luck, but even so, toward the end, I too was begging for drugs. My requests were denied but I now can hardly blame any other woman for doing the same thing.

        This is where I think it would be so convenient to have an all powerful God with whom I could offer a compromise. I would explain to HIM that there are certain anatomical design flaws in the female reproductive system that cause prolonged pain and suffering and an unacceptable risk of death to the mother and child. Then, as a generous compromise, I would suggest that the head size of human infants be reduced by let’s say, several cm in diameter and that the diameter of the pelvic outlet be increased by the same amount. The decreased cranial capacity of future humans and a waddling gait due to the adjustment of pelvic bones, IMO, would be an acceptable alternative to death. But my compromise will fall on deaf ears. There’s no one out there who is omnipotent enough to implement my recommendations. We are stuck with this kluge of a reproductive system and if there is anyone who knows what a severe and draconian taskmaster evolution really is, it’s a woman who realizes that she is in labor and can only hope that her anatomy functions optimally and that she will still be alive when the sun rises the next day.

  5. Hmm..how to put this….if human males had the testicular proportions of an adult male chimpanzee then men would find upright bipedal locomation to be problematic if not downright painful.

    Thus basing innate human sexual behavior on relative size of testes is rather silly

    And now I’m going to have to be on the lookout with women who carry measuring devices as well….

  6. Kevin murrell comment3

    That happens anyhow. Sometimes you see a rich bloke with an ugly wife, but she was invariably acquired before his wealth, and kept for sentimental reasons. Mostly they get ditched for younger, prettier, more intelligent, more accomplished brands.

    Really don’t understand this comment at all. Are you saying his ugly wife was thick? Or only young pretty women are intelligent and accomplished? Or implyilng rich men remain young and devastatingly handsome whilst only their wives age?

    Or are you categorising all rich men as gullible idiots who swop their wives for ones who are intent only on emptying their bank accounts whilst simultaneously sleeping with younger, hansomer, more intelligent, more accomplished males that exist in abundance?

    And you haven’t stated how good looking he was?

    Heres the strange thing, human males and often interact with human females as people. And fall in love with them as people for a multitude of reasons. And remain in love for the same reasons. Hence Charles fell in love with and remained in love with Camilla even thru his forced marriage to the more virginal and acceptable Diana, (on another thread there is mention of viriginity tests in Muslim countries, no mention made of the same things carried out by British royalty for class reasons tho). Thats how most of us evolved I’m afraid. To see beyond the superficial and fall in love that lasts a longish time.

    • In reply to #16 by PG:

      Kevin murrell comment3

      That happens anyhow. Sometimes you see a rich bloke with an ugly wife, but she was invariably acquired before his wealth, and kept for sentimental reasons. Mostly they get ditched for younger, prettier, more intelligent, more accomplished brands.

      Really don’t understand this…

      I think Kevin was being sarcastic.

  7. In reply to #16 by PG:

    Kevin murrell comment3

    That happens anyhow. Sometimes you see a rich bloke with an ugly wife, but she was invariably acquired before his wealth, and kept for sentimental reasons. Mostly they get ditched for younger, prettier, more intelligent, more accomplished brands.

    Really don’t understand this…

    I think Kevin was being sarcastic.

    One would hope so in the absence of time machines capable of wafting him here from the past.

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