Category Archives: Evolutionary Biology

Best Children’s Book on Human Evolution

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Aside from evolutionary theory itself, the teaching of Human evolution involves physiology and reproductive biology, behavioral biology, genetics, and the fossil record itself with details of a concomitant history.

And finally, there is a children’s book that addresses the latter, in amazing detail!

There are very few good (or even bad) children’s books about evolution, and far fewer about human evolution. And when a children’s book touches on human evolution, it is usually just about Neanderthals.

When We Became Humans: The Story of Our Evolution by Michael Bright with illustrations by Hannah Bailey is a very good book on human evolution. The book is over 60 pages long in large format, and my copy is cloth bound. The production quality of the book is outstanding. (That is generally the case with this publisher.)

I am am impressed with this title, and I strongly recommend it for anyone looking for a book for a kid of a certain age to read, or a younger kid to get read to.

What is that certain age? I’m thinking 10 plus or minus 2, depending on the kid. The publishers say 8-11. So somewhere around there. A 10 year old who absorbs the material in this book will do OK on an intro college human evolution midterm that focuses on the fossil and archaeological record. Or at least, the child will be able to effectively challenge the professor in a grade grubbing situation.

When We Became Humans: The Story of Our Evolution covers primate evolution, key moments in hominin history, bipedalism, early tools, brain evolution, the origin of fire (nice to see my research embodied as fact in an actual children’s book!), Homo erectus and Neanderthals, modern humans, foragers, early agriculture, holicene history, language, art, early burial, and other things such as hobbits.

There are only four places where I would take issue with the facts as presented here. The root hypothesis for the human-chimp split is left out, I would discuss early tools differently, the author embraces the scavenging hypothesis too kindly, and the great global diversity and overall craziness of the agricultural transition is glossed in favor (mostly) of the old Fertile Crescent story, which is not wrong, just limited. Given that this book presnets roughly 165 facts or perspectives, me disagreeing with this small number is rather remarkable.

The art is great, the typefaces well chosen, the layout is artful and foregrounds the aforementioned are and the facts.

You can preorder this book now; it will be out mid July.


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Time itself as a resource that drives evolution

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Many of the key revolutions, or at least, overhauls, in biological thinking have come as a result of the broad realization that a thentofore identified variable is not simply background, but central and causative.

I’m sure everyone always thought, since first recognized, that if genes are important than good genes would be good. Great, even. But it took a while for Amotz Zahavi and some others to insert good genes into Darwin’s sexual selection as the cause of sometimes wild elaboration of traits, not a female aesthetic or mere runaway selection. Continue reading Time itself as a resource that drives evolution


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An excellent study of human psychology, evolution, modes of thinking. Read this book.

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It is possible to view the human experience, and the evolution of Homo sapiens, and the development over time of human society and culture, from a number of different perspectives, all of which are, of course, wrong. That is what scholars of Homo sapiens do. They produce misleading, biased, or otherwise poor descriptions or explanations pertaining to humans and their history, one after the other, and try to make others believe them. That is really just human story telling (and story telling is clearly an important part of the human experience). This endeavor becomes scholarly when the various story tellers test their stories against each other, and against facts or observations made outside the context of the creation of the story, and thus, over time, produce an increasingly refined, still wrong, but less wrong, version.

The first chapter of The Importance of Small Decisions (Simplicity: Design, Technology, Business, Life) by by Michael J. O’Brien, R. Alexander Bentley, and William A. Brock, which discusses the evolution of scholarly thought about the origin of agriculture, provides an example of this process of evolution of understanding in the context of the growth of knowledge.

This book is an analysis of the relationship between human choices, human culture, human society, and the context in which those forces generate outcomes that may or may not have been expected. The analysis starts with one of the most important questions asked, and usually ignored, about human history. How is it that humans came up with agriculture so many times, over a short period (of a few thousand years?), more or less all at once, in regions that has zero chance of any kind of interaction? The most significant transformation in human history happened independently at that time, but not before, without any apparent single or simple cause. But there were causes. They had to do with the environment, demographics, and circumstance. They happened to humans much like similar species-species (plant-animal or animal-animal) relationships evolved in hundreds of thousands of cases across life on this life-rich planet. Individual human decisions were involved, culture was causative and transformed, and society changed and constrained, potentiated and proscribed. It was all very complicated. But when it came down to individual human decisions, they mattered in ways that you would never expect or predict because such things are utterly unpredictable.

Continue reading An excellent study of human psychology, evolution, modes of thinking. Read this book.
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People have big heads, but children have giant heads.

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A human is born with more neurons than they will have as adults. This is one of the main reasons that the size of the head of a child is not going to increase much as it grows. (Also, it is simply hard to make heads get bigger for various reasons, so it isn’t just humans that have large heads relative to body size when they are young.)

A person’s mass (weight) which roughly relates to volume goes up about 900% during growth. A person’s head circumference goes up about 35%. Big difference, even if you factor in the dimensional effect.

Try this: Find a small child. Preferably, your own, or if not, get permission. Show the child how you can touch your ear with the contralateral hand, by arching your arm over your head. Then, ask the child to try it. LOL.

This phenomenon, of head growth vs. body growth, comes up every time I teach about brain development, which I just did. And, it happens that right after doing that, I came across an interesting photograph. The photo is from a set of comparisons, putting an old family photo of one or more people when they were kids, to now, matching setting, clothing, props, body position, and facial expression.

When you do that, you see the head size thing really clearly in many photos. This one in particular shows it dramatically:

If you use the person’s right shoulder to help define her coronal plane, and visually project that onto the bricks, you can see that her head is close to three bricks tall in both photographs.

(I think the setting is not the same in both photos, by the way. Different bricks, different almost everything. But the person is the same, and that is what counts.)


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Whitey Bulger Dead, and the Trivers Willard Hypothesis

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The original version of this post was called “Whitey Bulger Caught, and the Trivers Willard Hypothesis.” A while after that, I wrote a post called “Whitey Bulger Convicted, and the Trivers Willard Hypothesis.” Today, it was announced that Whitey Bulger, Boston crime boss, is dead at 89. Thus, the new title.

Thumbnail image for 0470656662.jpgMost of you won’t know who Whitey Bulger is. He was for a while on the FBI’s ten most wanted list. He spent a lot of time overseas running from the Feds, but they eventually caught up with him, convicted him, and tossed him in jail.

Whitey was top dog in Boston’s Winter Hill gang. His brother was a Senator for the Commonwealth of Massachusetts, and served as Senate President for several years.

It is said that Whitey was an FBI informant, and that his handler, FBI Special Agent John Connolly, tipped Whitey off that he was about to be indicted on racketeering charges. No problem. Whitey had left stashes of cash in safe deposit boxes all around the world, in preparation for the day he had to go on the lam. So he took off in 1995. Special Agent Connolly spent several years on vacation in the stir.

I remember when Whitey disappeared, and ever since then, I’ve used him almost annually in lecture material describing the Trivers-Willard hypothesis. It goes like this:

Thumbnail image for 0470656662.jpgThe Trivers-Willard model (I prefer to call it a “model” rather than a “hypothesis” because it is not specific enough to really be a hypothesis … it’s a model that generates lots of hypotheses) states that selection should favor the ability to differentially bias investment in offspring by sex if the two sexes have differential variances in reproductive success, and if there is any way to predict offspring rank. That’s a bit thick, so it requires some examples and further explanation. Maybe a story about a mobster would help..

OK, so an example: Red deer (also known as Elk) give birth to one offspring (max) per year. Males compete for access to or to be chosen by females. So, only a small percentage of male red deer mate in a given year, a significant percentage may never mate at all, and a very small percentage sire many many little red deer. Male red deer have a high variance in reproductive success. If you tried to predict how many offspring a given randomly chosen male would have, knowing nothing at all, your best guess would be the average number of offspring red deer have in an average lifetime. But you would be wrong almost every time because the actual number is highly variable. Male red deer have high variance in RS.

Females, on the other hand, have a pretty standard number of offspring. There is not much competition among them, they can always find a male to mate with, etc. If you needed to guess how many offspring a particular randomly chosen female red deer would have in a life time, you could guess the average, and you would be right on or very close. Female red deer have low variance in RS.

So, male and female red deer have differential variance in RS. Males high, females low.

If a female red deer could somehow “predict” the likelihood of her offspring getting to mate, i.e., if she could tell if any offspring she had in the present year (male or female) would be average vs. high ranking, then selection should favor the evolution of a mechanism to actually give birth to the appropriate sex offspring (thus biasing investment in one sex or the other). It turns out that she can. A female red deer that is herself average or lower-quality (thin, ill, injured) is likely to give birth to an offspring that will be either low ranking or average. But if the mother-to-be red deer is high ranking, she is likely to give birth to an individual who will grow up to be high ranking.

Under these conditions, she should have a female offspring if she’s average or low ranking, but a male if she’s high ranking. And that, it turns out, is what red deer actually do.

That should be clear. But in case it isn’t, let’s take it down do real life, and bring in the gangsters.

You check the mail this afternoon, and there is a letter from a law firm you have never heard of. It says that your Great Aunt Tillie (whom you’ve also never heard of) just died, and left you with $1,000 in her will. The check is enclosed.

Thumbnail image for 0470656662.jpgThis may or may not be a recent photograph of a male red deer. Holy crap. Found money! What are you going to do with it? So you and your close advisors (your roommates, your cat, etc.) discuss it and you narrow it down to two choices. Choice A and Choice B.

Choice A is to go to your broker and buy $1000 worth of a nice, relatively safe mutual fund. The fund will buy and sell reliable blue chip stocks, thus spreading the risk over several companies, and over time you can expect to get a return of 50 bucks a years, easy.

Choice B is to buy 1000 one dollar lottery tickets. Your chances of winning are slim, but if you do, you will win 87 million dollars.

So, what do you do? The obvious sane choice is to buy the mutual fund.

But what if your cousin is Whitey Bulger? Whitey Bulger, as head of the Winter Hill Gang, is said to have owned the director of the Commonwealth Lottery agency.The connection between Whitey Bulger and the Lottery has never been proven. They don’t have a shred of evidence. He was, however, indicted for 21 counts of RICO-Murder. It is said that one of the things that tipped off authorities about this is that some of his relatives were winning the lottery a little more often than they should have. So, say your cousin is Whitey Bulger, and last time you saw him (at a family wedding) he told you … “hey, if you ever want to take a “chance” on the lottery, let me know … I can make that work for you…”

So now, you have two choices.

Choice A: Invest in a mutual fund and gain a return of 50 bucks a year (that’s dollars, not elk); and

Choice B: Buy 1000 PowerBall tickets and have a great deal of certainty of winning 87 million dollars.

What would you do?

In case it isn’t already clear. the baby male elk is a lottery ticket, the baby female elk is a mutual fund, but the female can guess pretty accurately if the lotter ticket (male offspring) will pay off. Because the elk’s cousin is Whitey Bulger. See?


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How to choose the sex of your baby.

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In order to make such a momentous decision, I insist that you learn the very interesting evolutionary biology behind it.

Start with this paragraph:

But for modern medical science, a baby’s sex would remain unknown until birth. But many mothers today know long beforehand whether a baby will be male or female. Routine ultrasound scans reveal fetal genitals a third of the way through pregnancy, and genetic tests identify sex even earlier. Yet basic questions remain. Is a baby’s sex like coin tossing, or can the male:female ratio be skewed? If sex bias occurs, does it happen through sperm sorting before fertilization or mortality differences in the womb after conception?

Then, CLICK HERE to read the rest of the story, by Robert Martin, expert on such things.


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The Origin of Life and Life on Other Planets

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The Origin of Life and Life on Other Planets

Several parallel discussions inspire me to write this post partly in the hope that you will chime in.

The chance of life elsewhere in the universe just went to near zero. Or did it?

Continue reading The Origin of Life and Life on Other Planets


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NPR: For Every Woman Who Dies In Childbirth In The U.S., 70 More Come Close

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This latest in a series of reports from NPR is out.

Over the past year, NPR and ProPublica have been investigating why American mothers die in childbirth at a far higher rate than in all other developed countries.

A mother giving birth in the U.S. is about three times as likely to die as a mother in Britain and Canada.

In the course of our reporting, another disturbing statistic emerged: For every American woman who dies from childbirth, 70 nearly die. That adds up to more than 50,000 women who suffer “severe maternal morbidity” from childbirth each year, according to the Centers for Disease Control and Prevention. A patient safety group, the Alliance for Innovation on Maternal Health, came up with an even higher figure. After conducting an in-depth study of devastating complications in hospitals in four states, it put the nationwide number at around 80,000.

I’m not going into great detail about this, but I do want to make a few related salient points. Continue reading NPR: For Every Woman Who Dies In Childbirth In The U.S., 70 More Come Close


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Yet Another South American Alien Turns Out To Be Human

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But a very interesting human. A human being six inches tall (if standing), with only 12 sets of ribs, about 7 years old at the time of death. Did I mention six inches tall? New research on the so called “Atacama humanoid” (not an alien, just a human) shows a wide range of interesting genetic differences, according to a just published paper. Continue reading Yet Another South American Alien Turns Out To Be Human


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The Early Bird Crushes The Egg

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Model I birds, the kind that lived during the Age of the Other Dinosaurs, may not have brooded their eggs. Today, birds sit on their eggs in such a way that the adult bird’s down surrounds the ovoids, and warmth from the adult can keep the eggs at a constant temperature. Depending on the bird, you may find additional intersting adaptaitons. For example, Penguins use their own feet as a nest, placing the egg there. One adult broods the egg for a long period (days, in some species) and then swaps with the other adult, with the swapping being very ritualized in some cases. Like this egg swqap between parent Adelie penguins (Tip: this video does not show the actual swap): Continue reading The Early Bird Crushes The Egg


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Strange Survivors: Book Note

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Strange Survivors: How Organisms Attack and Defend in the Game of Life by Oné R. Pagán is an excellent book with the evolutionary arms race, competition, and nature red in tooth and claw (and many other parts) as its theme. Well written and humorous, and scientifically accurate.

Mike Haubrich and I interviewed the author, and the Ikonokast Podcast of that interview IS HERE.

From the Publisher: Continue reading Strange Survivors: Book Note


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Sexual Selection Up To Date: A Taste for the Beautiful

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A Taste for the Beautiful: The Evolution of Attraction is a popular science book written by an actual expert on the field, addressing the ways in which the world of animals is shaped by sexual selection.

One of Darwin’s major contributions to the panoply of theoretical and observational work we call “evolution” was to recognize, describe, and model sexual selection. Continue reading Sexual Selection Up To Date: A Taste for the Beautiful


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Darwin Quotes, Assembled

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From Janet Browne, the author of Charles Darwin: A Biography, Vol. 1 – Voyaging and other works about Charles Dawin, The Quotable Darwin.

Quotes by Charles Darwin are not just the stuff of memes. Even the fake quotes. They can be the center of long arguments, or at least, they can significantly augment the arguments. For example, did you know that while Darwin never used the term “missing link” he did talk about missing links quite a bit, missing links are central to his thinking about evolution, and all those writers of today who claim that we must never speak of missing links are misguided? Continue reading Darwin Quotes, Assembled


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