The power of Darwin compels you to doubt him about sex differences

Evolution is true but our evolutionary explanations are always evolving and expanding in their complexity, or at least they should be encouraged to, when evidence supports it.

I've found, however, that compelling stories about human evolution, especially those penned by Darwin, are too often preferred by scientists over others or over complexity.  I think scientists are especially protective of evolutionary stories that preserve certain macho conceptions of masculinity and that are porn-adjacent. So it's no surprise that these stories dominate pop culture's understanding of human evolution.

Everyone knows all about sexual selection.  (Now before I go through it, briefly, you need to promise you'll read the rest of this blog post. I know from actual experience with readers and listeners in the classroom, that lots of folks will mistake this upfront explanation of the idea that I'm about to critique for my endorsement of this stuff. They'll read this part then tune out by the time I get around to critiquing it. Please don't fall for that.)

Okay, right. Everyone knows all about sexual selection. Males compete with other males for sex with females. Winners get sex. This ratchets up, in their descendants, whatever physical attributes got them to win that sex that sent those attributes into the future. And, as arbiters of what's sexy and what's worthy of sex, females decide which male traits get shot into the future, ratcheting up over time what they thought was so sexy in those winners that they had sex with. Didn't you know? Where have you been? Evolution is a game in which the winners get sex and the losers get nothing. It's like Survivor and The Bachelor had a baby that got in a time machine, went back to England in the 1860s, and buddied up with Darwin.

Sexual selection is the dominant evolutionary explanation for why men are taller than women. Men are tall because their tall winning ancestors won the sex. Over time this pulled men's height above the average height of women. That men are taller on average than women is taken to be legitimate evidence for this explanation.

And we're all supposed to be totally cool with that automatic explanatory power of sexual selection. After all, it's Darwin's "second great idea" and he was so forward thinking by giving agency to females!

So many of us who don't research  sexual selection, directly, but who teach human evolution courses feel like we really have no choice but to carry on like this. It's canon. And we're supposed to be grateful that females got the power of choice! See? It's not *all* about males bashing each other apart for opportunities to have sex. It's okay! And sometimes it's about males being beautiful and doing beautiful things to attract females! So get on board, people... human evolution is evolution, too! We're not special. We're just like birds and fruitflies. Humans need to embrace sexual selection as a "force" in our understanding. Get with the program.

I sure did. Sexual selection for big competitive males is what I've been teaching countless students for years and years. But, over those years it became an increasingly bizarre thing.  I stopped growing when I got my period and that's when all the boys, who didn't get periods, kept growing. My period seemed to be the evolutionary reason I'm shorter than the average man. When you think about menstruation, ovaries, puberty, never growing tall enough to touch the rim, not that you have a chip on your shoulder or anything about that, then Darwin's ideas about male competition seem, suddenly, ridiculous.

This is a great time to quote Sarah Hrdy:

“Compared with Darwin’s exquisitely detailed observations of barnacles, coral reefs and orchids—even the emotional development of  his own children—this consummate naturalist’s observations of women and other female primates were curiously cursory.”

And then in late 2016, after years of my teaching and being and increasingly doubting, Jerry Coyne got mad at PZ Myers for his understanding of evolutionary complexity and bias in evolutionary stories, specifically about sexual selection explaining  human height differences. So, I piped up and it's all documented here.

Then, I got to work, because the Coyne thing suddenly made it clear to me how powerful and influential this story is. It was suddenly very important that I do something about it.

The first thing I did was rant about it in the Washington Post, who gave it a clickbait title, which probably drove away the people I was primarily speaking to.

And then I did a lot of reading about how skeletons grow. I sent a paper about it to Evolutionary Anthropology in the summer of 2018. Four reviewers saw the first version. Two of the four disliked it greatly. The other two disliked it less, and so it miraculously got "major revisions" rather than a rejection. Some of the major blowback was against my focus on "proximate" processes (like skeletal growth and hormone effects) which are not "evolutionary" to the minds of some reviewers and many people out there. One reviewer actually wrote that "the estrogen explanation is not evolutionary" to which I can only cry out to the universe: then what is it, magical?

The two mad reviewers dropped off in the second round and three new ones were added, totalling the anonymous reviewers to seven. By this time I had found a paper by some heavyweights and in a heavyweight journal to back up my approach that eschews the "proximate" versus "evolutionary" convention, passed down from Ernst Mayr.

link to paper

Without Laland et al. to cite in revisions, I think my paper would have been rejected. That's how entrenched Mayr's convention is, to my mind. I wouldn't have been permitted to work outside of it, not yet at least. I'm grateful to the reviewers and the editor-in-chief who pushed me to improve the paper, like that and in countless other ways. It was published yesterday.

link to paper; Open access (free) link to paper

By this point, if you haven't heard me talk about this (which has been great fun where they've invited me into their lovely groups to do so), then you're wondering what the paper says. It says a lot about estrogen, ovaries, and periods. (It also says a lot about pelvic differences... so it says a lot about vaginas, uteruses, and clitorides too, which is a whole other ball of wax.) But I'm too pooped from all the activity around the Twitter thread I posted yesterday to write too much more here on the Mermaid's Tale today. So, for now, I'll link to Twitter and to where someone unrolled that thread.

HEY SEXUAL SELECTION!
You think you are the reason why men are taller than women, but if you want to remain the star of this story, then...
THE OVARY’S IN YOUR COURT.
I wrote a paper that you can’t ignore.https://t.co/oGQNu6yXcl
A (delighted) thread.

— Holly Dunsworth (@HollyDunsworth) May 2, 2020

If you hit a paywall at the journal where the paper lives, just download the pre-print for free here: https://digitalcommons.uri.edu/soc_facpubs/37/

I think my beloved former Professor Jeffrey Kurland from those glory days at Penn State would have hated this paper at first! But, if he weren't up in heaven now, we'd be yelling and yelling together, and it would be so much fun yelling together, and he'd at least entertain these ideas, and he'd think up brilliant ways to take the work further. And I so wish he were here with us now, but he will always be.

More idle thoughts in the Time of Lockdown

This blog site is generally about subjects like genetics, disease, science, and our attempts to understand the complexity of Nature.  But, obviously, those of us not involved in the science to combat the corona virus, have are other things on our minds. For some--perhaps many or even most--it is the very idea of survival, the fear that "the virus could take me down, too!"

Under these conditions, we've not been thinking about science, but about distraction, esthetics, musings on Nature and so on.  In that spirit we offer this verse.  It's about the small mountain adjacent to our new home with, that has a roughly road up to the top, where there are an observation tower and picnic tables.  It's a road we regularly walk for exercize....and for something other than the virus to think about.

Mounting Sugarloaf

In strolling up Mount Sugarloaf

One travels tors of old,
A venerable pile of rock
That in the stone reflects
A past both slow and bold

There were no human witnesses
On hand to note the course
That slowly built the hillsides up,

As layers rose and bent

With geologic force

With shaking seismic happenings

Its greatest shape was gained,
First lifting up and taking form;

But then as years wore by,

Eroding when it rained

                                         

And now can we, when walking there

And witnessing what stays,

Of taller peaks and sharper crags

That humbler have been made,

Imagine ancient days!

I'd take a walk

Taking a walk

I’d take a walk to get away

And for corona be not prey

But if it’s lurking everywhere

Then strolling can’t escape its lair

Each step may draw me close to doom

So, I’ll just hunker in my room!

More poetic thoughts for these awful times.....

These are lock-down times for us all, and for most of us they are essentially unprecedented.  We, or at least I, sit at home, gazing out the window wishing for normalcy.  Would you agree with me, that we are in a time to contemplate the meaning of things, the things that really have meaning?  And, in the absence of other ways that seems even nearly suitable, I try to write my thoughts in verse.  Whether anybody else will think that's appropriate, at least here are examples that seem apt to me.


Gravely, gravely

Gravely, gravely came the news

Of viral pestilential blues

Whence deaths and disabilities

Were nearly universal woes

The toll too great to read the roll

The land beset with sighs and cries

The toll, the toll--we scan the rolls

Of names that once were lively souls

The list grew daily as did sighs

For those who’ll ne’er again give smiles

A roll too long to be all told

Oh, land beset with sighs and cries!

Some day, some day, will names be few

Of deaths that pile, by ones and twos

To add to graves from yesterday:

Then, fertilizing fields of grass

Producing flowers and fragrant dews

Graves once beset by sighs and cries

As the Tombstones Wear Away

(From a walk in an old Massachusetts graveyard)

From tombstones in the graveyard, our history wears away;

Weath’ring very slowly, yet eroding day by day:

Of children falling ere they played, inscribed are many named;

They had brief lives, then passed away, so soon, and ne’er were famed.

Of others passing in decline are memories waning, too,

As tombstoned records of their days are slowly eaten through:

Ah! and since our Earth itself’s a slowly aging ball,

The time will come when no one’s memory exists at all.

Drink Your Clorox!

Drink your Clorox while you can,

UV your innards ‘til they tan

Since soon you will be sure to hear

The spoil-sports telling you to fear:

Advice from higher-ups to shun,

The President’s will leave you stunned!

But no! Since as you conk you're rid

Of need to fear the bad Covid

So, drink your Clorox now, before

The groceries will have no more!

This corona is not a beer, and hard to bear!

Corona Quakes

As our earth shakes

In viral trembling

Pandemic makes

Us fear assembling

Yet let’s insist

Without distorting:

We must persist

In not cavorting!

Keeping distance--

Yards spaced apart

Gives resistance:

Advice that’s smart

That bugs unseen

Could cause such terror:

A fear so keen

Of each mask wearer!

Yet this will pass

As do they all

The end at last--

A passing pall! 

But let it not

From memory fade

Lest we repeat

This grim parade!

The plague of our times.....

What can one do when hunkered down in a plague, something we've not really seen in any of our lifetimes, at least in the wealthier part of the world?  One is to try to express in some way other than dry prose or statistics, what one is thinking.  In that spirit here are a couple of verses, written in the expanse of spare time that we while away, to keep us from worrying too much in these times of plague:

Corona Masking

If all of us would wear a mask

Which, we’ve been shown’s a simple task,

Then none of us would be a loner

While all are safer from corona

A mask like that’s a snap to make

A sane precaution all should take:

With scarf, bandana, or worn-out Tee

I won’t harm you, and you not me!

A Grey Corona Day

I sit here on a grisly day, the clammy wintry kind,

When snow blows cheerfulness into a grisly pall;

A virus called ‘corona’ seems lurking all around,

And causing eerie symptoms, of any kind at all

We can’t be sure how deadly this bug might really be

In most it passes quickly, with sniffles and that’s it

But some, the ill or elderly, are made to fear they’ll see

A fever, cough, or breathing lapse, their final earthly fit

So, while they say that many won’t know they’re sick at all--

A headache it may be, or touch of wat’ry eye,

It only takes a cough to make one’s spirits fall

Since if for some it may be nothing, for others they will die!

To find uplifting thoughts is what we need to do:

To laugh, to smile, or tell a humorous tale,

Recite a verse, perhaps, or maybe even two,

And if also adding music--improvement will prevail!