Norman Platnick 1951-2020

Norman Ira Platnick, by many measures the greatest arachnologist of the past century, entered the field young and with impact. This past week he left it far too early, to our heartbreak, through his unexpected death at the age of 68. He contributed to spider systematics in so many ways that it’s simply not possible to think of the field without encountering his deep influence.

In each of three broad areas — empirical spider systematics, biodiversity informatics, and systematics theory — he contributed so much that were it his sole effort, his life would now be celebrated for it. He got his hands dirty with nature, as a spider taxonomist, surpassed only by Eugène Simon in describing spider species new to science: more than 2000 species discovered. He was the careful librarian and infrastructure-builder, pulling together and organizing the literature through the World Spider Catalog, a key resource in informatics that we use day after day. He was the obsidian-sharp thinker, clarifying the logic of biological systematics, helping to lay the foundation of how we think about the structure of biodiversity. In each of these areas he was a builder and a leader, and though his self-confidence was fierce, his mission was not his own glory: he served the spiders, and the arachnologists, and those who think clearly. I never asked him, but I suspect he might have said that he served the truth.

His work affects many of us every day that we work on spiders. On such a lucky day I go online to the World Spider Catalog to find details of the literature on spider species. It’s infrastructure central to my life, like the intersection near my house whose shops sustain me. I’m sure it’s the same for other arachnologists. The catalog allows us to work fluidly, quickly, focusing on the spiders rather than struggling to trace literature. Now maintained and beautifully enhanced by Kropf, Nentwig, Gloor and their team, this amazing resource would likely not exist in digital form without Platnick’s efforts. He began the catalog in 2000 as a digital translation and update to Brignoli’s catalog, whose catalog in turn was an update to Roewer’s. By digitizing it, Norm gave it new life, making its continued maintenance feasible. Norm’s attention to correctness and detail is well known, and thus the catalog became a highly trusted reference. A small sign of its perfection: In about 2013, I wrote a script to process Norm’s HTML code, as I wanted to get lists of species and genera in a different form. Even though he wrote the HTML code by hand with a basic text editor (to my knowledge), it was so regularly formed that my script had no trouble at all parsing the file, error-free.

His work on spider species will continue to affect us for centuries. Each of his 2000 new species discovered is a permanent contribution to our knowledge of what is in this world. Through his descriptions the basic features of these species are known, but more importantly the species are now doors open to us: we know to find more and to study their bodies, lives, and interactions. They, and Norm with them, will be remembered. However much Norm may have seemed dedicated to abstract thought (e.g., the sections “Form”, “Time”, and “Space” of Nelson & Platnick 1981), he was deeply bound to concrete discoveries like those of novel species. Indeed, his strong opinions in theoretical realms may have arisen precisely out of this focus on the concrete.

Norm’s impact on systematic theory is harder for me to gauge, because there was such a diversity of voices during the years of his greatest influence. (Also, I belong to a different subspecies of cladist, and I see my school of thought descending only partly from his.) Norm’s prodigious mind, which brought him to undergraduate studies while not yet a teenager, and a Harvard PhD at 21, entered the 1970s wars in systematics with enthusiasm. His opponents may have seen his approach as more philosophical than biological, but the conceptual cobwebs in the attic of systematics had grown rather dense by the late 1970s, and it was high time to give the field a thorough cleaning. He was one of the more prominent members of a group stripping the attic to its bare wood.

The paper of his that had the most impact on me is his 1977 paper “Cladograms, phylogenetic trees, and hypothesis testing”. It provided a critical load-bearing element in my thinking about phylogenetics. In it he argues that a line on a phylogenetic tree diagram shouldn’t be taken as representing a literal lineage descending through time, but merely as a claim of a group united by recency of common ancestry, because the latter is often all we can hope to distinguish with data from visible traits. This paper stands inside me like a conscience, cautioning me about the limits of knowledge. I still tell its core lesson when I teach about integrating fossils into phylogenetics.

Norm’s theoretical writings were terse, with the directness of someone sure of his ideas and their correctness. I did not talk to him enough to know his mind well, but it seemed that he rendered judgments in stark contrasts of true and false, evidence and non-evidence, preferring the black and white logic of the tangible, the visible, the concrete character, the synapomorphy. He did not see evidence within the machinations of cloudy grey probabilistic models and statistical methods. The field of phylogenetics has largely come to embrace those clouds, and is willing to take risks Norm was not, seeing a tree diagram’s lines as descending lineages. The arc lamp of Norm’s logical scrutiny, however, still throws into sharp relief the costs we must pay in assumed generalizations.

Some of his contributions are not easily traceable, like the largest tree in the forest whose hidden roots bind and support the soil far beyond its crown. Norm gave us leadership in the way it matters most: a leadership of values. He had an uncompromising dedication to, and respect for, basic discovery, the organism, evidence, logic, and those who shared his passion. Through his research, his leadership of societies, his mentoring of early career arachnologists, he affirmed these values, even while a different suite of values, which need not have competed but which did, was sweeping the field. His theoretical inclinations may have been seen as a denial of advances in molecular and statistical methods, and to a certain extent they were, but it is more productive to see them for something else they also were: an affirmation of the value of the simple, permanent, and central discovery of what is: the organisms of this earth and their visible traits. The proclamation and exemplification of this value, through which he humbly put the organisms ahead of himself and theory, was perhaps his greatest contribution.

(For a fuller account of his life and work, see the In Memoriam posted on the AMNH website)

Edit: Updated the link to the In Memoriam on the AMNH website.

To the early career scientists affected by #PruittData

I have been both heartbroken and heartened following the news of irregularities in Jonathan Pruitt’s data in published papers on animal behaviour. Heartbroken, thinking of the students and other young scientists whose publication records will be diminished by retractions, of those whose trust in science has faltered. Heartened by the courage of the co-authors to step forward (Kate Laskowski and Ambika Kamath led the first public announcements), and by the compassion and efforts of those like Daniel Bolnick to replace clouds of suspicion with clear-headed assessments. I have been reminded that the scientific community is indeed a community.

To those injured by this collapse of trust: You are a member of a community, and this community is rallying to heal, and to support you. Your honest and sincere efforts to understand nature are appreciated; they are contributions regardless of the fate of the papers. You should not blame yourself for not having noticed the flaws in data handed to you by a respected scientist. We, the community, have a responsibility to support you as you recover your path.

I left my first scientific conference — 1977 American Arachnology — feeling as if I had just joined a family. I felt welcome, but that wasn’t what struck me. Rather, I could see the genuine happiness when old colleagues met, the pride of supervisors and their students, the excitement of new connections and ideas. Sharing was everywhere. Sharing remembered, sharing in action, sharing planned. In subsequent arachnological conferences, I wondered if arachnology is special because we are united by our quirkiness, studying creatures few people appreciate. But I’ve grown to see that many scientific communities are like this, networks of trust and cooperation.

Yes, Arachnology has its problems, just like any family, but I have been amazed, for all the decades of my career, at the quality of the people. Intelligent, sincere, cooperative, dedicated, responsible, compassionate, and honest. And, generation by generation, the newest members of the family are welcomed, nurtured, and grow into world-class scientists. They contribute even earlier in this generation, as they learn and lead through social media. Indeed, much of the healing process happening now is being led with thoughtful commitment by early-career scientists.

I’m grateful to be part of this community. I’m also grateful that arachnids have scientists such as you to study them and celebrate them.

The dark age of spider collecting

I fear that the 2000s and 2010s will be looked back on as the dark age of spider collecting for taxonomy and systematics. Traditionally, researchers discovering and archiving specimens of spiders have used 70% to 80% ethanol for preservation, as it’s strong enough to ensure no decay, but has enough water that the bodies retain some flexibility. If higher concentration ethanol is used (95% to 100%) the bodies become brittle, and are likely to break when examined. Also, they tend to be distorted, as their legs can collapse as their water is drawn out quickly. For morphological study, it’s pretty clear that 70-80% ethanol is better for spiders.

But for molecular studies, the 20% to 30% water has been a real problem, because it degrades the DNA. For this reason many spider researchers (including myself) have collected most of their material over the last two decades in 95%. Good for DNA, not so great for morphology, though marginally acceptable.

An example of the perils of 95% ethanol: In 2007 I was collecting in Gabon, and had many beautiful specimens from Monts de Cristal preserved in 95% ethanol. Our next site was a harrowing 50+km drive down a rain-gullied dirt road. We held on for our dear lives (literally) as we were tossed around in the back of the pickup truck bouncing down the road at 40 to 80 km/hr. The little pickled spiders in their vials had nothing to hold on to, and when we arrived I found that they were floating in a soup of their own setae (hairs). Many of the spiders were bald because the 95% ethanol robbed the bases of their setae of flexibility, and being brittle, they just snapped off.

Such are the costs of doing molecular phylogenetics, and 95% ethanol preservation seemed worth the cost to be able to gather this vital source of phylogenetic information.

But, with molecular methods improving, we will soon come to the point where a specimen in 80% ethanol can yield good enough DNA data easily enough that the tradeoff no longer favours 95%. We will go back to preserving in 80% ethanol.

And so, I imagine this conversation in 2050:

Student: I’d like to study thiratoscirtine jumping spiders. Where should I start?

Professor: Best to start studying Mbuta’s material from the 2030s. There’s also some good material in Tervuren from the 1990s.

Student: But why not start with the large amount of Gabonese material collected by Maddison in the 2000s?

Professor: Work on that last. It’s not in good condition. It was preserved in 95% ethanol.

Student: 95% ethanol!!!! How awful! Why?

Professor: Sigh. Let me tell you a story about how gene sequencing used to be done….

Portraits of Singapore

Some day, when I can play the violin and have the tangle of cables behind my desk dusted and organized, I’ll learn how to paint in oils, and I’ll do formal posed portraits of jumping spiders in book-filled studies or luxurious garden backdrops. In the meantime here is the unusually proportioned Cocalus, from Singapore.

Cocalus female. Note the long palps, the low position of the lateral eyes, and the big posterior median eyes. She’s a spartaeine.

And here are, respectively (from top left, across and down), the alien Viciria, the grumpy Pancorius, the direct Parabathippus, the fabulous Chrysilla, the spooky Portia, and the self-assured Hyllus.

Portraits of Singaporean jumping spiders

Singaporean gold

The jumping spider tribe Chrysillini takes its name from the genus Chrysilla, whose name means, more or less, the little golden one. Gold promises brilliance, and Chrysilla is more than brilliant gold — it’s a jewel of many colours. Here is a stunning male we got on Pulau Ubin in Singapore:

Chrysilla male from Singapore

The chrysillines are quite common across Eurasia and Africa, and are a target of our collecting in Singapore. We found many species of chrysillines, including species of Siler, Cosmophasis, Menemerus, Epocilla, Pseudicius (s. lat.), Phintella, and Phintelloides. Here are gloriously shiny males of the latter two genera

Males of Phintella and Phintelloides

Common in some places in Singapore are charming little chrysillines that I think belong to Helicius. Here are females of two different species that we think are closely related, because there respective males are quite similar.

Females of two species that I think are Helicius

As with the Plexippina, the Chrysillini include only a few species in the Americas, and so it’s a branch of the family I can’t find in my backyard.

Formalities of the Plexippina

A bit of formality: The traditional taxonomic classification has families, genera, and species. Sometimes, a family is divided into subfamilies, and the subfamilies into tribes. Within the jumping spider tribe Plexippini, there are even subtribes, one of which is the Plexippina. This species-rich group is ubiquitous in Eurasia and Africa.

The Plexippina deserve a bit of formality, as the males of one of the most familiar species, Plexippus paykulli, wears a sharp tuxedo of black and white. In Singapore we found plenty of other species of plexippines, most with more relaxed — or outrageous — attire. Among the most outrageous is the very large jelly-green Artabrus:

Adult male Artabrus, a large green member of the Plexippini.

I had never seen a living Artabrus before, and I was thrilled. Contrasting against its greenness were two orange-and-black species of Pancorius:

Two orange-and-black Pancorius species

A big and a little Evarcha from Pulau Ubin were of special interest for the colour vision study, as we suspect some African Evarcha can distinguish red:

Two species of Evarcha, to the same scale, both males.

In the Americas we have only two native species of Plexippini, both Evarcha, and so it’s quite a treat to see so much plexippine diversity. Here are a few of the other plexippines we found in Singapore.

A sampling of plexippines from Singapore

A Wall of Neon Lites: Update to “Apologies to a Spider”

A couple of weeks ago I blogged about my dismay in losing a special specimen, a tiny tiny striped jumping spider that escaped in my hotel room. I regretted losing the chance to make the species better known. Well, we have an update.

A few days before leaving Singapore, we went back to the same area to look for more. After several frustrating hours, I found another specimen of the tiny striped thing. Not just one, but three, in the same shake of some ferns. Over the next few hours, we homed in on the habitat, and could predictably find more. This is one on my beating sheet:

My finger pointing to an adult male Neon sumatranus on my beating sheet.

Here’s where they live. In the forest are occasional small sunny clearings, possibly where a tree has fallen, and these clearings are choked with ferns. The ferns rise upward along the trees facing the clearing, forming walls of lush fern-ness. Underneath, in the tangle of stems at the base of these rising ferns, is moist leaf litter suspended just above the ground. The tiny striped spiders seem abundant in that leaf litter, and at least in the morning, up among the green ferns themselves.

Where Neon sumatranus lives

Kiran and I found several males and several females, and we knew we had everything that we needed to characterize them. As soon as we got back to the lab, I looked at a male under the microscope to figure out what it was, and got a surprise: we don’t need to do the basic characterization, because it’s already been done. It’s a known species.


Not only is the species known, but it’s closely related to a species I grew up with in Canada, Neon nelli. The tiny striped thing is Neon sumatranus, described by Dmitri Logunov in 1998, from Sumatra and Borneo. How could I not have recognized it as a Neon? Well, all of the Neon species I’d seen in the past are “bigger” (i.e. 2.5 mm instead of 1.5 mm), and with characteristic black and brown colours. Neon sumatranus is quite unusual among Neon for its super small size and its stripes.

The other thing that kept Neon from my mind is that I think of them as temperate zone creatures, being best described from Europe, northern Asia, and North America. This is not the correct way to think about them, however, as phylogenetic evidence and unpublished explorations suggest that Neon is actually an Australian group that has dispersed around the globe. So, finding it in southeast Asia shouldn’t have been a surprise to me.

I’m not disappointed that it is a known species, and that I was needlessly upset at losing the first male specimen. That upset provoked me to introspect, which was useful. And while it was known, it was barely known, as is the case for most of the world’s species. Now, we can learn more about it. And, they are *so cute*. Here’s a video of a male. Remember he’s 1.4 mm long.

As one of the smallest jumping spiders, it challenges us to explain how it can pack the sophisticated visual system of salticids into such a small head. Vision biologists want to know the answers to such questions. Now that we know how to find Neon sumatranus predictably in the ferns of Singapore, we have a chance to study their tiny tiny eyes.

In the Neighbourhood of Nannenines

We’re all used to biodiversity being localized — kangaroos in Australia, tigers in Asia — but the degree of localization varies from group to group. A broader group of species may be distributed across the world (e.g. bats), even though individually each of its distinct species might have a limited range. In the case of jumping spiders, some broader groups are quite restricted. Nannenines, for instance, are only in southeast Asia, the thiratoscirtines only in Africa.

Singapore, and southeast Asia in general, is the land of nannenines. That mouthful of Ns refers to a group of species of little jumping spiders most of whom hop on the leaf litter of forests. They hold a special place in my heart, for I met them on my memorable first trip to Asia in 2005. Back in Singapore 14 years later, I was pleased to see some familiar faces. Here are two, Idastrandia and Nannenus, shown at the same scale.

Males of Idastrandia orientalis (left) and Nannenus syrphus (right), to same scale. 

From my previous sampling, there remained some puzzles. For example, in 2005 I’d found two types of male Nannenus and two types of females, but I couldn’t figure out which male matched with which female. (I could have seen which males mated with which females, but that type of behavioural experiment requires more specimens and time than I had.) Now I think I’ve figured it out by getting paired types in the same patches of leaf litter. This seems to be the pairing.

Nannenus species A (left) and B (right), with males on top and females on bottom. Yes, they look a lot alike.

Nannenines are very poorly known; there are many species that I’ve collected, but only a few have been described scientifically. Perhaps they haven’t been as well collected as other salticids because they are hidden in the dark forests.

I suspect their preference for dark humid places is also the reason they are localized to southeast Asia. For their ancestors, finding a moist and shaded path between southeast Asia and the African rainforests, for instance, was rather difficult, with habitats inhospitable to them — deserts and savannahs — intervening. Reciprocally, the thiratoscirtines of Africa are mostly isolated to the shaded rainforests, and are not known from Asia. In contrast, groups of jumping spiders that live in open sunny habitats, like the chrysillines and plexippines, are widespread across Africa, Europe, and all corners of Asia. If you want to find the unique salticids of an area, go to the humid darkness.

Convergence on Colour

I’d mentioned in a post earlier today that there was a second motivation for me to come to Singapore beyond basic biodiversity discovery. We are here to survey spiders for their colour vision, working with Li Daiqin of the National University of Singapore. I’ve visited Daiqin before, in 2005, when we worked together sampling jumping spiders. Here he is, 14 years ago, arranging our field work as we travelled by boat to Palau Ubin.

Li Daiqin in 2005, going to Palau Ubin for field work.

Daiqin is a well known spider biologist studying their behaviour, physiology, and ecology. In other words, how they function as organisms. Normally, these aren’t topics I work on, but we can understand evolution more completely by studying function (Daiqin’s expertise) in multiple species and mapping it on the evolutionary tree (my expertise). Thus my second motivation in coming to Singapore is to help study the evolution of how jumping spiders work, using diverse representatives from the Singaporean fauna.

In the last paragraph I shouldn’t have used the singular pronoun “I”, because really I am just part of a large team that is coming to Singapore this month to study jumping spiders’ ability to see colours. The team, led by Nate Morehouse of the University of Cincinnati, chose Singapore as a perfect blend of accessible diversity and world-class science. I’ve explained in a previous post why spider colour vision so interesting that we have formed an international collaboration to study it.

The five spider biologists converging on Singapore are Nate Morehouse from the University of Cincinnati and David Outomuro and Jenny Sung from his lab, and myself from the University of British Columbia and Kiran Marathe from my lab — representing in total five different countries (USA, Spain, China, Canada, and India).

And so, for the next two weeks we’ll be in the forests, mangroves, swamps and beaches of Singapore to look for diverse jumping spiders to study for their colour vision. We also look forward to the hawkers’ markets, the beautiful cityscape, and the friendly people of Singapore.

Red in a spider’s eyes

You probably never imagined the world through a spider’s eyes, but if you did, chances are you’d wonder how they consolidate the signals from eight different eyes. In that, however, they may not be as different from you as you might expect, because after all, we humans have to blend signals from parts of our eye that see differently: the peripheral vision that is better at low resolution motion detection, and our central vision that is better at high resolution colour images. Different animals have visual systems that differ in details, and yet perhaps their evolution responds to consistent selective pressures, or is constrained to find consistent solutions. And so, comparative biologists study many species to see if we can find the rules of visual evolution.

To better understand how vision evolves, a group of biologists led by Nate Morehouse of the University of Cincinnati have turned to jumping spiders (“salticids”), and in particular how they see colour. Jumping spiders have exquisite eyesight — as you can tell by watching a jumping spider watch the world — and yet it was an open question as to how well they could see colour. Studies suggested that some (most?) jumping spiders are as colour-blind as a dog, unable to distinguish red from green.

However, some species of jumping spider gave us a strong hint that they can see and distinguish red: their males have fancy plumes and scales and spurs full of colour, including red. These include the now-famous peacock spiders of Australia (Maratus) and the paradise spiders of North America (Habronattus). Here’s the wonderful Habronattus americanus.

Male Habronattus americanus

That the males display these ornaments to the females during courtship suggests that these females can likely distinguish red.

After Daniel Zurek, Morehouse and colleagues discovered a ruby-red filter in the eyes of Habronattus that gave them the ability to distinguish red, Nate pulled together an international team to see whether and how other jumping spiders could see red, including Megan Porter (University of Hawaii), Lisa Taylor (University of Florida), and myself.

What motivates us is this simple observation: There are only a few lineages of salticids with red male courtship ornaments, and those are scattered in isolated pockets on the evolutionary tree. Most groups of jumping spiders do not obviously (to our eyes!) use red in their male courtship ornaments, and so we might surmise they lack the ability to distinguish red. The scattered distribution of red ornaments hints that the ability to see red has evolved several times independently.

Independent evolution of a similar trait is magic to an evolutionary biologist, because it offers the possibility of discovering the rules of evolution: Under what circumstances does red-distinguishing vision evolve, typically? What are the consequences of evolving this ability?

Salticids give us a special opportunity to answer these questions. Our preliminary assessment is that red-distinguishing vision has evolved multiple times independently in jumping spiders, perhaps more than a half dozen times. That’s a remarkably large number for a group of terrestrial animals that has diversified in only the last 60 million years. And so, our team will survey across the evolutionary tree of jumping spiders to find out what colours their retinae are sensitive to, what light environments they live in, and how it affects their lives.