The camera is a DSLR with a 100mm f2.8 macro lens, an extension tube and a twin flash. The mammal crashing this invertebrate-celebrating series is me.

Of course, I couldn’t have a toy like this to play with and limit myself entirely to photographing snails. In amongst those important snail photos I have jumping spiders, hornets, geckos and really anything else that chanced across the porch I was taking photos on. One of the more striking subjects is this red-eyed fly:

And the head-on shot…

It turns out the pretty red-eyed fly is Oxysarcodexia taitensis, one of the Sarcophagidae. That family name gives you a clue to how this fly makes its living, it translates as “flesh eating” (it stems from the same root words as sarcophagus, the Greeks believed limestone ate away at corpses sealed in it). Most of the flesh-flies feed on dead animals but a few have earned a place in vertebrate nightmares, horror movies and even medical practice by depositing their maggots in on open wounds.

Relying on dead animals for food is a chancy business. Corpses are usually patchily distributed and there a plenty of other scavangers out there to compete with. This problem is especially bad for the larval stages of insects, without wings to get them to the next corpse their entire future depends on the continued existence of the flesh they are born on. The sarcophogids have developed a neat trick for making the most of corpse when they find one – they give birth to live maggots. Technically, the flesh flies are ovo-larviparous, meaning the larva develops inside an egg which is retained in the female until the larva hatches. Flesh-fly maggots can start eating as soon as they are born, maximizing their chances of getting through their lifecycle before another scavenger eats the corpse they live in.

It’s easy to get freaked out about a creature that spends it’s life eating decaying flesh but we should remember that flesh-flies play an important role in ecosystems. Sarcophigids and other scavengers turn dead flesh into living flesh. WD Hamilton, one of evolutionary biology’s most insightful and original thinkers, recognised the important role of carrion feeding insects in his burial instructions:

“I will leave a sum in my last will for my body to be carried to Brazil and to these forests. It will be laid out in a manner secure against the possums and the vultures just as we make our chickens secure; and this great Coprophanaeus beetle will bury me. They will enter, will bury, will live on my flesh; and in the shape their children and mine, I will escape. … I will be many, buzz even as motorbikes, be born, body by flying body out into the great Brazilian wilderness beneath the stars, lofted under those beautiful and un-fused elytra which we will all hold over our backs. So finally, I too will shine like a violet ground beetle under a stone”.

***

Let’s start at sciblogs where Ken Perrot has a review of Cornelia Dean’s guide for scientists Am I making myself clear? It’s particularly interesting to read that Dean urges scientists to write for newspapers in the same week that Grant Guilford publihsed some clear thinking in response to nonsense about climate science. The nonsense was in The Herald and no doubt read by thousands, the sensible reply is on some obscure piece of the University of Auckland’s website…

Dean suggests scientists shouldn’t write books unless they really can’t help themselves. Still, if you sufficiently helpless and want to go down that route there’s been plenty of advice published recently. Nature has a a special ‘web focus’ on writing science books featuring, among others, the inimitable Carl Zimmer. In a similar vein, Brian Switek, the writer behind Laelaps, is about to have his first book Written in Stone appear on the shelves. He has already documented parts of that journey on Laelaps and now he’s going to start a series of posts dedicated to the process

***

I don’t think I’ll be writing a pop-sci book anytime soon but, obviousy, I do think science blogs have a place in getting science out to the public so I don’t quite know what to make of this very odd paper on scientific blogging. The authors take a set of posts from 11 widely read science blogs and draw the following conclusions

Science blogs are a virtual water cooler for graduate students, postdoctoral associates, faculty, and researchers from a variety of disciplines and areas of inquiry. The conversations in science blogs are also of “water cooler” quality …

To become a tool for non-scientist participation, science blogs need to stabilize as a genre or as a set of subgenres where smaller conversations may facilitate more meaningful participation from members of the public. Science bloggers need to become more aware of their audience, welcome non-scientists, and focus on explanatory, interpretative, and critical modes of communication rather than on reporting and opinionating.

Which is what happens when you presume 11 blogs is a representative sample of the thousands of people who are writing about science on the net. Of course there are blogs that are pitched at other experts and other blogs that deal mainly in links but presumably that’s because that’s what the authors want to do with their blogs!

If the authors of the paper wanted to see how blogging fits in to describing scientific ideas and news to non-scientists then they might have started, not with 11 blogs plucked from google, but by selecting blogs that are aimed at a lay audience . If you want interpretation and explanation of the day’s science news there are superb writers like Carl Zimmer and Ed Yong to help you out. If you want a scientist to bring their expertise to bear on some topic then there’s a whole mess of blogs (1, 2 3, 4, 5… and another thousand or so here) that do just that (and I like to think The Atavism fills one small niche in that sprawling ecosystem). A thoughtful review of those blogs would have served a real purpose, it’s hard to see that the published paper does. One good thing came from that paper though, I now know there is a Journal of Science Communication, I trust some of the other papers will be more useful. (If you are interested The Panda’s Thumb and Blog around the Clock have more detailed reviews of the paper)

I found our star stuck in one of those deadly rhododendron shoots . I guess if I was a cold-hearted documentarian, interested only in recording the happenings of the natural world, I would have left him there to struggle. But, really, I’m just a sucker for handsomely striped elytron so I helped disentangle him from the sticky shoot.

Those impressive antennae place our specimen in the order Cerambycidae, the long horn beetles, which includes the famous huhu beetle. I can’t identify it down to species but it’s likely in the genus Coptomma (for what it’s worth, the taxonomic shorthand for ’some species in Coptomma’ is ‘Comptomma. sp’). Our Coptomma didn’t seem to have any long lasting effects from his run in with the rhododendron’s sticky trap, he wandered off my life-raft leaf and set about cleaning himself up:

Then he ran cross my camera, up my arm and lodged himself at home on my neck. All my affection for spiders and rationality with regards to the risks lasted about a tenth of a second. I didn’t actually scream but it’s fair to say my heart rate was somewhat elevated and my movements were restricted. But why? What is is about spiders that freaks us out so much? I did a bit of digging through the academic databases but psychology really isn’t my science and I couldn’t get a clear idea. Researchers in Germany* have shown (at least among German undergraduate students) spiders do have a special place in our fears – people are more likely to respond badly to photos of spiders than other arthropods, even hymenopterans which can prose a more serious threat to people than spiders. But the question of why remains. Evolutionary psychologists have suggested arachnophobia might be an adaptation but it’s hard to imagine that selective pressure applied by occasional spider bites would be sufficient to drive a specific fear of them. Perhaps lots of spiny legs, beady eyes and fearsome fangs just set off enough triggers in the brain to elicit a unique response (did I mention psychology’s not my science…).

I remember reading a more plausible (and even testable) idea about the origin of arachnophobia in one of Steven Pinker’s books that didn’t pop up in my search of the literature. I don’t have the book in front of me (and I can’t even remember which one it was, although it sounds like a Blank Slate kind of an idea) so you might want to take this with even more grains of salt than you usually would with adaptationist ideas. From memory the argument went that we may be born with a general fear of all spiders and snakes but, until recently, would have learnt the few that are actually dangerous in the area we grew up in from our families. With the good guys and the bad guys separated we could stop wasting our energies on being worried by the overwhelming majority of species which are benign. An inbuilt arachnophobia with inbuilt malleability to surroundings. In the West we aren’t exposed to many spiders of any sort in our youth so we retain the childish arachnophobia all our lives. It’s a nice story whether it’s true or not doesn’t seem to have been tested.

Oh, and if my photo of a Cambridgea didn’t put you off Te Ara has a much scarier one.

As I’ve said before there really is no such thing as the human genome. There are millions of differences between individual genomes and we are each born with about 150 new muations. In an age in which we can sequence assemble and analyse entire genomes in two years understanding the breadth of human genetic diversity is at last an achievable goal and if you want to understand human diversity then you need to look to where we came from. Trace any family tree back far enough and you will end up in Africa and, in fact, most of human history was played out entirely in that continent. Modern humans arose in Africa about 250 000 years ago and only spread out to Europe and the rest of the world in the last 60 000 years, displacing Homo erectus in the process. The migrants that founded the modern European, Asian and American populations would have carried with them only fraction of humanity’s genetic diversity when they left Africa but untill recently genomics has focused on those populations. Until last week the two African genome sequences available to researchers were both from Yoruban volunteers to the hapmap project. Although those sequences are very useful they represent only one tip in the deeply branching tree of humanity

Summary of human genetic diversity redrawn from Campbell and Tishkoff (2008) doi:10.1146/annurev.genom.9.081307.164258 . Numbers in brackets are the number of complete genome sequences from each region available before last week.

To broaden our understanding of African genomes Schuster et al looked to the South of the continent and at two people in particular. !Gubi is a Khoisan (or bushman), a member of a one of the earliest diverging groups within the humanity while Desmond Tutu hails for various Bantu peoples. The results taken from theses genomes along with lower density sequencing and genotyping of other Bantu and Khoisan volunteers reinforces just how much genetic diversity exists within Afirca. By using a method called principle component analysis to reduce a the correlations among millions of single base pair differences (single nucleotide polymorphisms or SNPs) to a smaller set of uncorrelated vectors you can see patterns in the genetic diversity of groups. Applying this method to West African (Bantu and Yoruba), Khoisan and European populations reveals the comparative genetic homogeneity within Europeans and that the difference between the two African groups is comparable to that between either of them an Europeans.

Schuster SC, Miller W, Ratan A, Tomsho LP, Giardine B, Kasson LR, Harris RS, Petersen DC, Zhao F, Qi J, Alkan C, Kidd JM, Sun Y, Drautz DI, Bouffard P, Muzny DM, Reid JG, Nazareth LV, Wang Q, Burhans R, Riemer C, Wittekindt NE, Moorjani P, Tindall EA, Danko CG, Teo WS, Buboltz AM, Zhang Z, Ma Q, Oosthuysen A, Steenkamp AW, Oostuisen H, Venter P, Gajewski J, Zhang Y, Pugh BF, Makova KD, Nekrutenko A, Mardis ER, Patterson N, Pringle TH, Chiaromonte F, Mullikin JC, Eichler EE, Hardison RC, Gibbs RA, Harkins TT, & Hayes VM (2010). Complete Khoisan and Bantu genomes from southern Africa. Nature, 463 (7283), 943-7 PMID: 20164927

While I was in Masterton for christmas my girlfriend went to Vanuatu (no, you’re right, that doesn’t quite seem fair…) with a waterproof camera so I’ve stolen a few of her photos of coral to illustrate todays sunday spinelessness.

It’s easy to see why early naturalist thought corals were plants but what you are looking at in those photos is not a single organism, rather it’s a colony of tiny genetically identical animals. Corals are members of the phylum Cnidaria (the ‘c’ is silent) which includes corals, anemones and a diverse bunch of animals we call jellyfish. Such a diverse collection of animals are united under the name Cnidaria because they all employ the impressive nematocyst, a barbed harpoon like cell, to catch and deliver toxin to their prey. Cnidarians have two distinct life stages – a swimming “medusa” (adult jellyfish being the classic example) and a sessile polyp (like the sea anemones familiar to rock pool fossickers the world over). Individual coral colonies (termed “heads”) are made entirely of polyps which reproduce asexually depositing a calcium carbonate base as they grow – the exact pattern in which polyps bud from their parents determines the shape a coral head takes.

Many tropical corals supplement their diets by forging a symbiotic relationship with swimming algae (arguably plants that move…) called zooxanthella, the algae get carbon dioxide from the coral’s respiration while the coral gets energy from the algae. This relationship is of huge importance in the tropics because it allows corals to grow in those region’s warm, nutrient poor waters. Without coral reefs, made from thousands of years of calcification from corals, tropical waters would be nowhere near as biodiverse as they are now and people whose love of animals only goes as far as that peculiar phylum Chordata should care about that:

As always, you can click on any of those photos to see higher-resolution versions.

I’ve said before that the bugs in my parents’ back yard seemed especially hungry over the Christmas break. Above you see more evidence to this fact. In the lower half of the photo is a robber fly and above is its meal, a blowfly of some sort. I’ve never seen live robber flies in Dunedin (though there is a dead one here) but the species captured above seems to be reasonably common in the Wairarapa. The first time I spotted one of them I struggled as to where to place it among the insects. The robber flies have long slender bodies and large rounded eyes which misled me into thinking that first sighting might be a small dragonfly. The real taxonomic position of the robber flies is spelt out in bright yellow in the next photo.

That bright yellow structur under the main wing is a haltere. Most insects have two sets of wings and we can tell quite a lot about where a given species fits in the insect scheme based on how it uses those two. Dragonflies and damselflies use both for flying, in beetles the forewings are “sclerotised” into a rigid case that protects the flight wings and the “true flies” ( order Diptera) have turned thier hind-wings into halteres – greatly reduced wings which act as gyroscopes stabilising the flies’ flight and allowing them to perform aerobatic tricks. The robber flies from the extremely widespread and speciose family dipteran family Asilidae which includes a staggering 7 000 described species, meaning there are rather more robber fly species in the world than there are mammalian ones.

The features that led me to mistake that first robber fly that I saw for a dragonfly are likely the result of convergent evolution – dragonflies and robber flies are both predators that specialize in taking other insects on the wing. The robber flies differ from odonates in having piercing mouth-parts which they use to inject first a neurotoxin then digestive enzymes into their prey. The blowfly in the photos in this post is paralysed and its tissues are in the process of being liquified and sucked through the robber flies mouth parts. But ever before the neurotoxin entered the blowfly’s body it was done for, the robber fly’s strong “raptorial” legs are covered in sharp spikes and end in claws that offer little hope for escape once a catch is made.

Happy Darwin Day everyone! Today would have been Charles Darwin’s 201st birthday so around the world geeks are celebrating, churches are standing up to creationism and at least a few biologists are trying to eat their way through the tree of life. With Darwin Day falling so close to Valentines Day I thought it might be fun to forget about Darwin’s science just for a few minutes and look at his attitude to love and marriage.

No one has ever accused Darwin about making a rush to judgement about any topic. Just as he spent years poring over the minutest detail of barnacle anatomy before he published The Origin he gave the topic of marriage careful consideration before singing on. In fact, preserved in his notebooks we have a record of the deliberations he undertook. Sometime in 1838 Darwin turned to a new page in his notes and drew a line down the middle, he added the headings “Marry” and “Not Marry” to either side of the line an proceeded to list the pros and cons of either decision. You can see the notebook here but below (presented without comment) is a transcript :

On the “marry” side of the page Darwin makes his conclusion:

Giant Microbe’s plush Tardigrade

• Ted MacRae at Beetles in the Bush hosted the latest edition of the Circus of the Spineless which includes posts on noisy ants, maggot therapy, the place of amphipods in pop culture and no fewer than two samurai related stories.
• Weird Bug Lady (check out her Etsy shop, it’s amazing…) now sells a stuffed toy in the shape of a flatworm. Yes, plush planarians!
• Sticking with the plush theme (as phrase I never thought I’d write…) the people behind the wonderful Giant Microbes have stretched their reach into Metazoa, the latest example a plush water bear (Tardigrade)! I note they are not yet available in the Australian/ New Zealand version of their store, but how can animal this cool fail to become a top seller?
• There’s yet more invertebrate craft at I Love Insects where Erika finds oragami insects
• Finally, Mike at Arthropoda has more evidence of the coming insect revolution – bees have learned how to recognise our faces. I for one refuse to make the obvious joke.

Weird Bug Lady’s plush planarians