The logic of Siberia

Why exactly am I going to Siberia? I explained in a previous post that Eurasia holds a diversity of Pellenes that’s important for me to study, for comparison with North America’s Habronattus jumping spiders. But of all the places in Eurasia, why Siberia?

First, work by Russian colleagues has made the Siberian fauna known and accessible. Dmitri Logunov (now at the Manchester Museum) did extensive field work in the same region around 1990. He, Yuri Marusik, and other colleagues published several important papers on Pellenes in the central Asian region from Siberia to Iran. This gives us a solid idea of Siberia’s Pellenes species, and of precise localities we could visit. Galina Azarkina, working at the SZMN-IEIE-SB-RAS in Novosibirsk, knows the region well, though she’s focused primarily on a different group of jumping spiders, the aelurillines.

Second, southern Siberia has just the right combination of species to give us key information. It has all of the basic Pellenes diversity we might find elsewhere in Eurasia, but it is also the only place to find a special target, Pellenes logunovi. As you might guess, this species was named in honour of Dmitri, by Yuri and colleagues.

Here’s the reason that P. logunovi is so special: Among Pellenes and related genera, two groups are restricted to the Americas: the spectacular Habronattus, and a distinctive group of several Pellenes species that includes the familiar Canadian P. peninsularis. The peninsularis group and Habronattus appear very closely related, and indeed recent evidence hints that the peninsularis group might be within Habronattus. This would discombobulate our view of Habronattus evolution, and so we want to confirm or refute it. P. logunovi is unusual among Eurasian Pellenes in appearing to be very similar to the peninsularis group. If it is the closest Eurasian species to the peninsularis group and Habronattus, it could help resolve whether Habronattus has the peninsularis group within it.

Original description of Pellenes logunovi by Marusik, Hippa, and Koponen, 1996

Now I’ll go (even more) technical, for the salticid geeks (the rest of you can cover your eyes). The Harmochirina fall into two groups, the harmochirines sensu stricto (Harmochirus, Bianor, Sibianor, etc.) and the pellenines (Pellenes, Neaetha, Havaika, Habronattus, and a few others). Some unpublished (and incomplete) molecular data hint to the following:

  • Several subgenera of Pellenes (Pellenes, Pelpaucus, Pellap) form a monophyletic group, the true Pellenes.
  • The American Pellenattus are closer to Habronattus than to Pellenes, which would likely lead to Pellenattus being to move out of Pellenes as its own genus.
  • Havaika is the sister to Pellenattus plus Habronattus.
  • The African Pellenes with a filamentous or absent tegular apophysis are even more distant from the true Pellenes.

The Siberian specimens will not only help to test these hypotheses, but also help place other subgroups of Pellenes (Pelmultus, Pelmirus). This will leave only a few pieces of the puzzle to get, most importantly Neaetha and similar genera with a very long third leg.


Reliving my youth in a parallel universe

One of the most vividly colourful memories I carry is of two jumping spiders: a male and a female Habronattus viridipes, mating, on the leaf of a milkweed. I was 14 years old, along an abandoned road outside of Dwight, Ontario, and I was entranced. The male was stunning: yellow-green front legs with a delicate fringe of white hairs, and a third leg whose knee was enlarged into a triangular yellowish flag. I don’t think I’d ever seen spiders mating before. This, and the pink-bummed Habronattus decorus I had seen the year before, were my introductions to Habronattus, a diverse and wondrous group typically found on rocks, leaves and sticks on ground well-lit by the sun. They became a fascination of my youth. I spent so many hours scanning sunny ground for Habronattus that I can still feel the sun on my back from decades ago.

Here are drawings I did of H. viridipes several years later, with close ups of the first pair of legs (green) and the third (with the triangle).

Habronattus viridipes male, drawn in 1978.

A few metres from the H. viridipes at Dwight we (my brother David and I) found another species of jumping spider, Pellenes peninsularis. This species lives on the rock outcrops of the Canadian shield, modest colours matching the rock’s grey. Here’s a drawing of the male:

Pellenes peninsularis male, drawn ca. 1978.

Pellenes peninsularis brings a different set of emotions. While H. viridipes represented fantasy creatures, P. peninsularis represented family: humble, secure, predictable. David and I got to know it well, in part because the rock outcrops at Dwight were across the highway from where our father would go to catch minnows for fishing bass.

Despite the contrast in their appearance, Pellenes peninsularis and Habronattus viridipes are pretty closely related on the jumping spider evolutionary tree. Indeed, it seems that the several dozen species of Pellenes collectively form the sister group (or sister groups) to the 100 species of Habronattus.

Since those early days, I’ve done a lot of research on Habronattus, but very little on Pellenes. It’s time to go back to Pellenes. I’m now working with Marshal Hedin and Damian Elias to look in more detail at the remarkable diversification of Habronattus. To fully understand it, we need to make comparisons with their close relatives, i.e. Pellenes. While there are a few Pellenes in the Americas, most of their diversity is in Eurasia and Africa. This is one of the contrasts between North America and Eurasia: the former has many Habronattus species, and few Pellenes, while the latter has many Pellenes species, and no Habronattus.

And so, in going to Siberia, I will be looking in the same way as I did as a teenager — peering at sun-soaked ground on mountain sides, prairies, and forest edges, watching for tiny sunbathers on rocks or hoppers on sticks. It will be like reliving my youth, but in a parallel universe populated by a diversity of Pellenes rather than Habronattus.

Westward to Siberia

From western North America, where I live, to Siberia, where I will be in one week, is only a short hop across the Bering Strait. I’ve never been to Russia. In my imagination, the landscape of Siberia is very much like that of British Columbia: hills, conifer forests, bears, wolves, deer. While the two areas share many species (or very closely related species), there are some notable differences in their faunas of the animals I study: jumping spiders. I’m going to Siberia to see jumping spider species I’ve never seen before.

I’ll arrive to Novosibirsk, where I’ll meet up with Dr. Galina Azarkina of the Siberian Zoological Museum, of the Siberian Branch of the Russian Academy of Sciences, with whom I’ve planned this expedition. To be honest, she has done considerably more planning than I have, organizing much of the logistics. We will first do, as a warm up, a few days of field work near the Kazakh border (2 in the map). Then, she, I, and a few of her colleagues will travel south and southeast from Novosibirsk (1) to the Altai (3) and Tuva (4), mountainous areas along the Mongolian border. Her primary target will be aelurilline jumping spiders; mine will be Pellenes.

Novosibirsk (1), and the places we’ll do field work.

I’m excited about this trip. The idea of Siberian field work occurred to me only a few months ago, and yet the roots of my excitement go back to my teenage years. I’ll explain that in a subsequent post.

I am already mostly packed. Ready are hand lenses, beating sheets, camera, pens, field notebooks, etc., etc., etc. — so many things. The “to do” list is still long, but my equipment and my brain are gradually getting organized. Westward ho!

Citation Vacuums

In science, there’s a simple currency earned by important publications: citations by subsequent papers. Each citation gives credit, a small nod of recognition, a karma point, a feather in the cap. We are proud when our publications garner many citations. Citation count, however, is not a great metric of true quality or impact: all that glitters is not gold; all that is gold does not glitter. Counting citations sometimes credits authors with a greater part in advancing the field than they deserve, and fails to credit those who do.

I remember many years ago hearing David Swofford, the author of the widely-used PAUP program for analyzing evolutionary trees, grumbling about a paper just published. His complaint was that the paper’s “novel” concept wasn’t particularly novel — it was so obviously implicit in the literature’s ideas that none among the most theoretically astute biologists thought it was worth publishing in a standalone paper. And yet, the paper was published, and received attention precisely because no other paper had previously said that useful (though obvious) idea so directly.

Such gap in the literature is a “citation vacuum“, a region of “idea space” that is well within the current paradigm, but unoccupied by a citable paper. Over the years I’ve seen several vacuums exploited to the career benefit of their discoverers. We scientists like to cite compact, precise, and strong statements of an idea, and if none exists, then there is a vacuum in the literature waiting to be filled. It doesn’t matter if the idea is already understood by many, or if the idea is in fact already in the literature but in a long-forgotten paper or buried on page 9 of a software manual. It only matters that there is no obvious paper to cite, and if you write one, cha-ching, the citations come rolling in.

I’m reluctant to name names. Most authors who’ve written vacuum-filling papers probably don’t think of them as such, instead believing them highly novel, and I wouldn’t want to disturb their glory. I will mention one name, however — my own. My best cited paper is my 1997 paper “Gene Trees in Species Trees”. When I wrote it, I didn’t think of it cynically as a vacuum-filler, but in many ways, that’s what it was. It was a condensation of the Zeitgeist, gathering together and organizing ideas that probably were already, in large part, in the heads of the leaders of the field. It’s become a magnet for citations because it’s accessible and provides a compact citation for the field’s perspective. It’s a pedagogically useful paper, but I expect that it brought the median understanding in the field forward more than it informed those at the cutting edge.

So, go find a vacuum, publish, and profit*.

*To be clear: I’m not advocating that you withhold credit to your predecessors. Please, when filling a vacuum, look for and cite the papers that set up (or perhaps even mention) your idea. Treat your paper as a new attempt to synthesize and explain ideas already in the conversation of the field. Take credit for the clarity and thoroughness of your exposition, because those may be new, and will add value to the field.

Remembering Fred Wanless

Back in the old days (i.e. pre-web) it was hard to connect with others with common interests, at least when your interests were uncommon. By the time I was a graduate student, I’d been studying jumping spiders (salticids) for a decade, but had met precious few experts on my favourite spiders. Conferences were a rare chance to chat real-time with your far-away role models and comrades, and maybe find someone with whom you could speak at the speed of your excitement.

As a 28 year old, in 1986, I flew to Spain for my first International Congress of Arachnology (and my first visit to Europe), where I met Fred Wanless, an arachnologist at the British Museum of Natural History (now known pretentiously as The Natural History Museum). His publications on jumping spider systematics combined two strengths that were unique at the time: they examined salticid diversity broadly across phylogeny and geography, and they used cladistic logic to discuss evidence for jumping spider phylogeny. My recollection was that we met at a bar in Jaca; he was humble, uncomplicated, sincere. Talking to him was amazing — “Do you think Lapsias could be a spartaeine?” “Do you think an articulated embolus is an important character?” — and on and on. I left the evening feeling as if I had just flown through the forests of Endor on a speeder bike.

Fred died last month. We arachnologists hadn’t heard much from him for many years, because he had been forced in 1990 to stop studying spiders, told to study instead the more “relevant” nematodes. His departure from salticidology deprived us of a colleague and years of important publications (though no doubt the nematologists appreciated him). But his 1980s publications remain a cornerstone of our literature for the knowledge that they gained, and also for the model they provided: well illustrated, well argued, well organized. When I wrote a recent paper reviewing the phylogeny and classification of all jumping spiders, his papers were the first I went to, to pour over their data and interpretations.

I phoned Fred about 12 years ago to ask a question about a notable specimen I thought he might remember. His thoughts were far from jumping spiders, having drifted first to worms then to retirement projects. I told him how important his papers had become to us, and he was surprised — still humble and uncomplicated. We were lucky to have had him in our literature, and in our community.

Farewell to Mexico and #Mexigonus2017

It’s been almost three weeks since I got back from our Mexico jumping spider expedition, and I’ll give one last post to wrap up. The trip was a full of wonderful spiders and people and places. I have already thanked some of those who helped, but I’ll repeat and add others, who helped so much: For logistics, thank you Tila, Griselda, Ricardo, Gerardo, Arturo, Jorge, Juan Pedro, José Luis, Fernando, Alex, and Janette. For sharing your salticid expertise and experience, thank you Uriel, Łukasz, Dariana, Valentina and Ellen.

I should have known the trip was going to be a success before we hit the road. At the UNAM university bookstore, as we were stocking up at the start of the trip, there was this little souvenir puma — the mascot of UNAM — labelled as a biologist, with a spider on one arm and a beetle on the other. What better omen?

UNAM Puma biologist with spider and beetle

No, I didn’t buy the souvenir. Why, I don’t know. I have an aversion to (almost all) knick knacks.

Compact spider photo setup

The photos of beautiful spiders in my posts about our #Mexigonus2017 expedition were taken with a new camera, the first I’ve had in many years. For the previous 12 years I’d taken spider photos, tens of thousands of them, with a comical ancient Pentax Optio with a hand lens glued to it. Even though it’s old and low resolution (3 megapixel), it worked for me. In order to have a hand free for wrangling the spider, I need to be able to hold the camera in one hand and manipulate it easily. I also need to take photos of dozens of specimens each evening. Standard DSLRs are too awkward and heavy, so much so that I wouldn’t be able to take photos of all the species I want to photo, were I to use a big DSLR. I’d rather have low resolution photos than none at all, and for that reason I stuck with my tiny camera for many years.

A friend’s small mirrorless Olympus impressed me, and convinced me it was time to change, and I’m so glad I did. My new camera is an EM10-Mark II, with basic 60 mm macro lens and the standard TTL flash, which I mounted with polymer clay and zip ties as shown here. It’s a compact package I can manage mostly with one hand. It took me a while to figure out the settings (manual focus, etc.), but I’m very pleased with the results. The photos aren’t aesthetically as good as those of the current generation of good salticid photographers (I don’t use diffusers, etc.), and I could improve the arrangement to reduce shadows, but the photographs serve my purposes well. On one photo of a male that was hanging upside down, I could see the shape of the embolus of his genitalia. That’s good enough resolution for me!

Olympus EM10 — Mark II with Macro and flash, for taking spider photos.

Racing Stripes

People who know jumping spiders know that adult males of many species look different than females. Females are usually modestly coloured, but males may have bright colours they show to the females in elaborate dances. Some commonly-seen differences, however, don’t seem to relate to courtship. In many species, the males have distinctive black and white stripes, but the stripes are on their backs, which the females don’t see during the male’s courtship. Why do the males have stripes?

One of the most handsomely striped species I’ve ever seen is an undescribed Mexigonus from eastern Mexico. We caught it during our #Mexigonus2017 expedition at Sierra Gorda national park. Uriel calls this species “tuxedo” for the fancy suit the males wear. Here it is; on the left is the male, on the right the female.

Mexigonus “tuxedo”.

A similar male-female difference in stripes is seen in many other genera of jumping spiders, including some familiar in Canada such as Pelegrina, Eris, and Habronattus.

My best guess for the stripier pattern of males is that they move more than females. We have data from a few species of jumping spiders to indicate that males wander more, traversing a lot of territory in a day (looking for females?), while the females are relatively sedentary. An idea that’s been around for a while (e.g., look up Jackson, Ingram & Campbell 1976) is that what is good camouflage for an animal depends on how much it moves. If an animal sits still a lot, then it’s more cryptic if it’s mottled or spotted. If, on the other hand, an animal spends a lot of time moving forward, then longitudinal stripes can provide a disruptive visual effect that makes it harder for predators to see the moving animal. Hence, mobile males have stripes, homebody females not.

The Rainbow of Mexigonus

#Mexigonus2017 is over, and I’m back in Canada. I’m left with many memories of Mexico, strengthened friendships, great samples of new jumping spider species, and good data. As the first of a few retrospective posts here, I present The Rainbow of Mexigonus:

The Rainbow of Mexigonus

We saw the whole visible spectrum among the colours of Mexigonus. The red was intense; the orange was common; the green was delicate; the blue was stunning; the purple was unexpected. You’ll notice I didn’t mention yellow. For some reason, strong yellow is not obvious in Mexigonus adornments (except as a momentary flash in the metallic iridescence of the “quetzal” Mexigonus).

This is what the whole spiders look like, in the same sequence as the rainbow. The caption says who they are. You’ll notice that the multicoloured “quetzal” gets three appearances!

The cast of colours:

“quetzal” from El Triunfo “red moon” from Chicahuaxtla
“orange ghost” from San Jose del Pacifico “orange yellow” from Montebello
“big moss” from El Triunfo, female “yellow face” from San Fernando
“green ghost” from Humo Chico “quetzal” from El Triunfo
“blue legs” from Puerto Antonio “quetzal” from El Triunfo
“purple tomato” from Lachatao “purple tomato” from Lachatao

The second one down on the left side is worth mentioning — it’s an orange ghost! You may remember the green ghost from Humo Chico north of Ixtlan. When we headed south to the Sierra Madre del Sur and collected the “bell bottom pants“, we also found what we thought was the same green ghost species. But closer inspection showed it to be a different species — even fuzzier, without the white moustache, and with legs orange instead of green. Here is a better picture of him:

“Orange ghost” Mexigonus

Mexigonus is just so diverse, and almost all undiscovered.

The Weavings of Chicahuaxtla

In my first post about our #Mexigonus2017 expedition, I showed a photo of a brilliant red Mexigonus that was one of the inspirations of the study. We had found it in 1998, less than a kilometre northeast of San Andrés Chicahuaxtla, in Oaxaca. After our fulfilling time in Chiapas, we managed to arrange a visit to the area of Chicahuaxtla on the last day of the Oaxaca-Chiapas expedition, as we were driving back to Mexico City. I was filled with anticipation. I so much wanted to see the beautiful red “tomato” species again.

Early last Friday morning, we drove to Chicahuaxtla, where we met Amador Tello Rojas and Heladio Fernández Martinez. We weren’t able to go back to the exact site at which we’d found the red “tomato” beast in 1998, but Amador graciously allowed us to go to his family’s land, which was about 800 metres northwest of the 1998 site. The habitat was similar, oaks and pines in a fairly dry landscape.

We started to look on the ground and bushes beneath the oaks, and soon found a couple of small juvenile spiders that we thought were the red beast. But, we needed an adult male to be sure. After a long, frustrating search, a male finally fell onto my sheet. I was so excited — finally I’d see the red beast again! But, something was wrong. It should have had stout dark front legs; the one on my sheet had long delicate front legs with a little “feather” at the end. I got it in the vial, looked at it up close, and realized I had a brilliantly red spider, but different from the 1998 one. Here he is:

Mexigonus male from Chicahuaxtla

He’d certainly turn heads if he walked into a room.

Finding a new form so close to the red “tomato” beast confused me. It occupied what seemed to be the same microhabitat as the 1998 species, and it lived only 800 metres away. Do the two forms make contact between the two sites? They look closely related — do they hybridize? To add even more complexity, Jose Luis Castelo, a colleague who has done research on Mexigonus, noticed that our 1998 collection from Chicahuaxtla included a third fancy species, one that looked like our purple tomato. Three exquisite species of Mexigonus within one kilometre?

Are Chicahuaxtla’s mountains full of many beautiful Mexigonus, each occupying a small territory? Could it be that decorated Mexigonus exist as a pattern of many forms and colours spread across the landscape, evolved slowly over many generations, like the beautiful woven huipiles for which Chicahuaxtla is known?

In the end, we didn’t collect at the 1998 site, and so my desire to see the “tomato” species again remains unfulfilled. But, instead, we found a new and beautiful form. What we thought was a simple search has turned into a lot of questions about the diversity of ornamented Mexigonus in this mountain range.