Mother Nature

| 28 Comments
Dame Nature!

What is the "maternal instinct"? Does it even exist? There is a stereotype of the ideal mother as someone who expresses unconditional love, who sacrifices all for her children, and who is ferocious and unstinting in defense of her children. Women who compromise on this behavior, who express some reservations and perhaps some self-interest, may be labeled "bad mothers" or perhaps even worse, "feminists".

If self-sacrifice is the ideal maternal characteristic, though, then we should be asking our women to aspire to this biological pinnacle of mother love:

The prize for "extreme maternal care" goes to one of the various matriphagous (yes, it means mother-eating) spiders. After laying her eggs, an Australian social spider (Diaea ergandros) continues to store nutrients in a new batch of eggs—odd, oversized eggs, far too large to pass through her oviducts, and lacking genetic instructions. Since she breeds only once, what are they for?

These eggs are for eating, not laying. But to be eaten by whom? As the spiderlings mature and begin to mill about, the mother becomes strangely subdued. She starts to turn mushy—but in a liquefying rather than a sentimental way. As her tissue melts, her ravenous young literally suck her up, starting with her legs and eventually devouring the protein-rich eggs dissolving within her.

That story is from Sarah Blaffer Hrdy's Mother Nature, a book that discusses the meaning of motherhood and how it fits into biology and natural selection. I think we'd all agree that it is a little creepy, and perhaps too extreme—we should expect human mothers to love their children unconditionally, but carving off bits of flesh to make their sandwiches would probably be a bit much.

There are alternatives in the continuum of maternal commitment. Hrdy's book makes the point that motherhood is far, far more complex than any caricature of a blind maternal extinct can encompass. Being a mother is a difficult and pragmatic affair, and the lesson of biology is that Nature is solidly pro-choice...or that the answers are never simple and straightforward.

Continue reading "Mother Nature" (on Pharyngula)

28 Comments

Man … I usually consider myself pretty wordly/cynical/”Hey I’ve seen everything”, but that description of the matriphagous just gives me the heebie-jeebies …

Urrrk..

Maybe we can lobby for a button in the comments section which will hide all the comments by/related to this Wagner guy? I’m interested in what knowledgeable people say on this blog, and also the excellent Pharyngula BTW, but it’s painful and time-consuming to wade through hundreds of posts about one guy’s refusal to understand and accept evolution. Or maybe two comments sections, one for creationists, and one for other people? Or a Slashdot-type system which keeps comments in threads, and we can dedicate one thread to him? Something. Please.

Interesting comments by PZ about the matriphagous spiders and the concept of maternal self sacrifice.

Uninteresting response by Steve.

PZ Myers wrote:

What is the “maternal instinct”? Does it even exist?

The answer is yes. ——————————————-

Cell. 1996 Jul 26;86(2):297-309

A defect in nurturing in mice lacking the immediate early gene fosB.

Brown JR, Ye H, Bronson RT, Dikkes P, Greenberg ME.

Division of Neuroscience, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.

ABSTRACT Although expression of the Fos family of transcription factors is induced by environmental stimuli that trigger adaptive neuronal response, evidence that Fos family members mediate these responses is lacking. To address this issue, mice were generated with an inactivating mutation in the fosB gene. fosB mutant mice are profoundly deficient in their ability to nurture young animals but are normal with respect to other cognitive and sensory functions. The nurturing defect is likely due to the absence of FosB in the preoptic area, a region of the hypothalamus that is critical for nurturing. These observations suggest that a transcription factor controls a complex behavior by regulating a specific neuronal circuit and indicate that nurturing in mammals has a genetic component.

Steve wrote:

Maybe we can lobby for a button in the comments section which will hide all the comments by/related to this Wagner guy? I’m interested in what knowledgeable people say on this blog, and also the excellent Pharyngula BTW, but it’s painful and time-consuming to wade through hundreds of posts about one guy’s refusal to understand and accept evolution. Or maybe two comments sections, one for creationists, and one for other people? Or a Slashdot-type system which keeps comments in threads, and we can dedicate one thread to him? Something. Please.

Save yourself the trouble. I’m a guest here and I have no interest in flame wars or personal attacks. I’m only interested in scientific discussion. If the owner of this blog doesn’t want me here, just say the word and I’m gone.

Steve’s comments while understandable miss the point namely that this blog provides for a forum to discuss relevant issues to evolution and the ID controversy. Not all comments can be expected to be of equally high quality and when presented together, interested readers may want to make up their minds.

The extreme diversity of approaches to motherhood set out in this piece is interesting and challenging. I must admit that, without thinking about it much, I should have assumed that there was essentially one optimum strategy for motherhood - or at least, one per phylum per ecological niche. While all of these different strategies have an apparent rationale, it’s hard not to wonder whether in some cases these species aren’t soldiering on with a second-best strategy simply because they have specialised for it so much that evolving across to the optimum strategy involves too radical a change? Not sure how you could tell, though…

It’s very hominidist of you to criticize the reproduction strategies of matriphages. Frankly, I prefer the idea to the praying mantis’ androphage tendancies.

No, I don’t miss the point. I doubt the purpose of this blog is for arguments with creationists to blot out intelligent discussion. If the comments on an astrophysics blog were overwhelmed with anti-gravitationist arguments, they’d think about how to separate that from other things too. BTW, I never suggested anybody leave, but there are probably lots of people like me who aren’t going to want to sift through 100 comments when 90 of them concern an argument with one creationist. Having a thread system would be best for that, but I haven’t seen Movable Type blogs with those.

Steve wrote:

I never suggested anybody leave, but there are probably lots of people like me who aren’t going to want to sift through 100 comments when 90 of them concern an argument with one creationist.

You’re just lucky that I don’t charge you for this stuff! ;-)

…aren’t going to want to…

Wow! A future-in-future tense. And from a physics major. Now I’m impressed.

I have to say I am with Steve on this one. Charlie has demonstrated on virtually every thread on the site that he is ignorant of evolution, and doesn’t want to learn. It is getting so if Charlie invades a thread, I will no longer look there because it is not worth the effort. I can find the comments of ignorant creationists on the web with ease, and don’t need them here.

The problem, however, is not with creationist responces as such. It is that Charlie wants to make the same inane comments on every thread. I enjoyed Beckwith’s comments on establishment. They were intelligent, and well argued (if false in the end). Likewise I enjoy Nelson’s occasional comments, though I still wonder why he can’t provide us with a simple definition. But Charlie thinks he has something to say on every topic, either because he is ignorant, bored or inconsiderate (my vote is for all three).

Tom Curtis

Tom Curtis wrote:

But Charlie thinks he has something to say on every topic, either because he is ignorant, bored or inconsiderate…

If I’m ignorant, I’m in good company.

I find it appalling that 72% of the people who voted in the Panda poll either don’t know that Pandas are bears or couldn’t be bothered looking it up before they voted.

Maybe they were thinking of Koala bears?

Thanks for your comment on my tenses, CW. Since you earlier said you weren’t interested in personal attacks, it must be a compliment, so thanks.

I didn’t found this blog, so I’m not an expert on its purpose, (and kudos to those who did found it, it’s very good) but what I like about is that it can provide the opportunity for scientists and science-oriented people to seriously discuss evolution. But that suffers when there’s too high a concentration of people who want to discuss the off-topic question of whether evolution exists. That’s not a scientific debate. Hasn’t been for 100 years now. I want to talk about evolution with people who understand it. If astrophysicists had a similar blog, they wouldn’t want to spend all their time arguing with people who denied the theory of gravity. Solid-state physicists wouldn’t want their blog to turn into a forum for arguing with religious people who say that electrons don’t exist. Arguments with people like CW might be your cup of tea, they used to be mine, but I don’t think that’s the purpose of this blog. There are already lots of good places to do that, like Talk Origins. Evolution is an extraordinary thing, and every day new information about its effects appear, and this is really hugely interesting stuff, and is largely responsible for my switching to a different research group, and going to do grad school in biophysics. I would ask that people keep in mind the possibility of altering the structure of the comments if creationists diminish the value of the discussions.

ps, by the above, I do not mean that this isn’t the place for discussing creationists, creationist attempts to change laws, etc. I meant live arguments with creationists.

And yes, I am a physics major, and yes, I find it a little creepy that you looked that up, but whatever.

Hey, now, people. Charlie and I have a little history on talk.origins and elsewhere, and I guarantee you that I share the esteem that most of you hold of him: I think he’s an annoying dingbat. However, I think I can speak for all of the other contributors to this weblog by saying that we aren’t going to be banning or otherwise quarantining anyone for their creationist views (spam and pornography, on the other hand, aren’t going to be tolerated). I’m afraid Charlie has just as much right to speak up here as any other commenter.

Just think of it as a tedious game of whack-a-mole. Charlie provides good practice for dealing with the repetitive and obtuse. Whack him or ignore him.

Maybe we can say the maternal instinct is species specific?

PZ Myers wrote:

I’m afraid Charlie has just as much right to speak up here as any other commenter.

Thanks for the support, Paul. I’m sorry you don’t like me, but I assure you the feeling is NOT mutual. In fact, I find you rather interesting, which is why I read your blog and reply to your comments. In fact, I’m not even offended when you say that I’m an annoying dingbat! I admit I can be annoying, but I always try to be polite and friendly. Would I be out of line to tell them what the “Z” stands for? ;-)

Steve wrote:

And yes, I am a physics major, and yes, I find it a little creepy that you looked that up, but whatever.

Gee, steve, your full name and educational affiliation are right there in your e-mail address. My main interest was whether you were faculty or student. I taught physics for many years to HS seniors, so I’m interested in the subject. I hope you’ve completed your physical education requirement, because they probably won’t let you graduate if you don’t. I got out of it because I had a pilonodal cyst, which while it was very painful, it was not nearly as painful as PE would have been. (NYU if you’re wondering, class of 1968)

Basic Training took care of my PE req.

Tom said

I enjoyed Beckwith’s comments on establishment. They were intelligent, and well argued (if false in the end).

For what it’s worth, I didn’t find Francis’ arguments any more intelligible than Charlie’s but I do find Francis’ head to be more annoyingly pointy than Charlie’s.

My diagnosis is that Charlie suffers from acute innumeracy. Based on what he has written here, I believe that he simply can not appreciate the difference between numbers such as 90% and 99.9999999999%, or between hundreds of years and hundreds of millions (or billions) of years. And understanding those sorts of numbers is key. If one hasn’t a profound appreciation for how insignificant and worthless the life of each individual living creature is on a geologic time scale, one can easily get settled into a mindset that “it’s all too beautiful” and that, at some point, a miracle must have occurred.

As to why Charlie’s intelligent designers found it necessary as part of their Great Miracle to “design” such wondrous “features” as sightless eyeballs, we’ll just have to “pray” that one of Charlie’s favorite “scientists” provides us with the answer someday.

GWW wrote:

My diagnosis is that Charlie suffers from acute innumeracy.

I’m numerate enough to know that if I buy two lottery tickets I double my chances of winning and if I buy 5 tickets, I quintuple my chances of winning.

pandas are bears??!?

kinda like raccoons are, eh?

oh yes, and as one of those damn feminists, i find it interesting that most of the attempts throughout human history at defining the “maternal instinct” have been made by people who will never be mothers.

is there a maternal instinct? maybe. does it work the same way in every individual human being? probably not–we’re pretty out of touch with our instincts anymore. does it necessarily mean self-sacrifice? i doubt it. what good will a mother homo sapiens do for her children if she dies before they’re able to fend for themselves? this bizarre concept that mothers are always supposed to give their lives for their children… even evolutionarily speaking, it just doesn’t work.

Hey, you must have read Hrdy – if you click on the “continue reading” link, you’ll see that that’s pretty much the message she delivers.

I haven’t read anything by Hrdy since the 1970s when I read her book “The Woman that Never Evolved.” I recall enjoying the book until I read her graduate student reaction to the assumption of control by a new male of a macaque troop. There was only one female at the time with an infant. The mother did not make much, per Hrdy, effort to save the infant, but a sterile “aunt” did make a strong but futile attempt to save the infant from the new male. Hrdy, as I recall, thought that this was obscure. That is when I lost interest, as it is quite obvious.

The last few weeks I have been observing the reproduction of “Convergent Ladybirds” Hippodamia convergens on the willows in my front yard. These “lady bug” beetles form large aggregates over the winter, which disperse in the spring. I have noticed that they form reproduction groups as well, though smaller than the winter groups. The groups I observed seemed to have around twenty females (based in a count on near branches) and a lessor number of the smaller males. They lay egg clutches of about 10 to 20 eggs, although I saw some as few as five eggs. The eggs are placed on the undersides of leafs for the most part, though some small clutches were also on stems.

The “Ladybugs” are well known as voracious insectivores, and the larva are particularly active in this regard. What I found interesting was that the females continued to lay eggs in the close area I observed to be an “breeding zone” even though the 3rd to 4th? instars were feeding strongly on the freshly laid eggs. The later instars I watched at the same time were feeding on adult aphids, and lepidoptera larva. When the early ladybird larva began to pupate, I wathced several younger larva eat their older pupating sibs. About this time, there were no more egg clutches laid in that area of that tree, although Convergent Ladybirds continued to lay eggs in new groups on other nearby trees. I had looked very carefully for larva eating larva, but I did not observe this to occur.

This has several points of interest. The earliest Ladybird instars were not observed to eat the plentiful lepidoptera larva, favoring the eggs of their conspecifics. Later instars ate the plentiful lep’ larva. When the early Ladybird larva began to pupate, they were consumed by younger instars (including late instars), and about this time the adult females stopped laying in the area.

The “selfish” gene concept explains this, just as it did Hrdy’s macaque observations 30 years ago.

Interesting about the ladybugs. But does this strategy work only in a species where there is a relatively large number of young? I would expect that maternal infanticide would be less common in species with a higher investment in the young (like us, although not unknown, unfortunately) or maybe bald eagles?

My notion is that the lady beetles are feeding eggs to closely related larva, and quit when there are pupa. By the time there are pupa, it is a good assumption that there will be successful emergent adults. I don’t know how many eggs a female actually lays.

There is a moth species (I have not tried to key it out) that uses a scatter strategy with single eggs widely dispersed. This contrasts with the Mourning Cloak which lays about a hundred eggs together. Those I have watched this year have had less than 5% survival to pupa.

I suspect that larval diet and larval predation has more to do with insects than maternal energy investment per se. The lady beetles are able to feed their young eggs, and I think that they do this within closely related groups. Leaf eating species can’t do this and they range from solitary to grouped clutches.

I kept track of some clutches from a noctuid moth that was kind of interesting as the female died after laying ~60 eggs. The dead adult’s body was covering part of the clutch for the ~3 weeks before the eggs hatched. The larva’s first food was the egg casing. I was never able to follow these larva long enough to learn what their regular food was. One clutch I missed hatching, one dropped en mass to the ground and I lost them, and two others were 100% consumed by wasps (carried away all 1st instar larva) and beetle larva (ate the eggs).

“I find it appalling that 72% of the people who voted in the Panda poll either don’t know that Pandas are bears”

Again the court of public opinion claims authority over scientific fact.

About this Entry

This page contains a single entry by PZ Myers published on May 9, 2004 2:53 PM.

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