Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
One of the striking observations about life on oceanic islands—those islands, like Hawaii and the Galapagos, that arose, bereft of life, from volcanic activity below the sea—is the prevalence of native birds, insects, and plants, and the paucity of native reptiles, mammals, and amphibians. (Continental islands, like Great Britain, that were once connected to larger land masses, don’t show this pattern.)
Darwin was the first to make this observation and show that it supported his theory of evolution. Plants, insects, and birds can more easily get to islands, where they evolve in relative isolation into new species, while mammals, reptiles, and amphibians can’t easily cross large expanses of seawater to colonize distant islands. His view could be summed up as biogeographic patterns = dispersal + evolution.
One of the ways that plants get to islands (besides via their seeds floating in seawater) is through bird movement: birds eat fruit and seeds, fly to an island, and the seeds germinate from the bird’s post-migration poop. In fact, I think a lot more plants have arrived on islands this way than by seed flotation, but don’t quote me on that.
But more than plants can get to islands in bird poop. A new short paper in Ecology by S. Kenji et al. (reference below, free pdf here) shows that stick insects (phasmids) produce hard-shelled eggs that can remain viable and hatch after they pass through a bird’s digestive tract. Moreover, since the eggs don’t require fertilization (they’re from “parthenogenesis”), they don’t have to be fertilized right before being laid, as most insect eggs are. They can simply be nommed by the birds right after being laid, or ingested by gobbling a pregnant female.
The eggs of many stick insects are sculptured like seeds and, more important, have a hard layer of calcium oxalate on the outside that is dissolved only by acidic environments like bird stomachs (this layer appears unique to phasmids). You can see some of these tough eggs in part “B” of the figure below, taken from the paper.
The authors fed eggs of three species of phasmids, mixed with an artificial diet, to Japanese brown-eared bulbuls (Hypsipetes amaurotis), which they claim is one of the main predators of stick insects. They then collected fecal pellets of from the birds when they were pooped out within three hours, and measured hatchability of the eggs. Those hatchabilities were 5%, 8.3% and 8.9% (sample sizes between 40 and 60 eggs per species).
The figure below shows bulbuls eating a phasmid, the eggs, and a nymph of one phasmid species:
(From paper): FIG. 1. (A) The parental brown-eared bulbul Hypsipetes amaurotis feeding the stick insect Ramulus irregulariterdentatus to its chicks. (B) Intact Ramulus irregulariterdentatus eggs defecated by the brown-eared bulbul Hypsipetes amaurotis. Bar = 2 mm. (C) First instar nymph of R. regulariterdentatus hatched from the egg defecated by H. amaurotis.
One obvious conclusion is that, given that bulbuls can fly about 40-60 km/hour, they could disperse phasmid eggs over a hundred kilometers (eggs are produced at about the time the Japanese brown eared bulbuls migrate). The authors fed eggs excised from adult phasmids to the birds, which suggests further that the birds could ingest a bunch of eggs at once simply by eating a pregnant female (they didn’t do this test).
The next questions are these:
1.) Did the eggs evolve that hard coat to facilitate dispersal? There are advantage to dispersing your offspring widely, especially if local predation is high or environments uncertain, and many species of animals have evolved elaborate dispersal mechanisms. (Fruits with seeds inside are one of these!). This is possible, but the authors prefer the idea that the tough eggs evolved to reduce parasitism by wasps. But of course the coat could have evolved for several “reasons” (and by that I mean there could have been more than one reproductive advantage to toughening up your eggs).
2.) Have phasmids actually dispersed this way? We don’t know, as the biogeographic studies haven’t been done. As the authors note, this should show up as evidence for wider dispersal of parthenogenetic phasmids than of their sexually-reproducing relatives:
If avian dispersal is important to stick insects, the phylogeographical patterns should reflect occasional long‐distance dispersal events (e.g., Miura et al. 2012). In addition, the patterns of spatial genetic structure will differ among stick insects with parthenogenetic reproductive capability (and hence potential avian dispersal) and non‐parthenogenetic stick insects. The phylogeographical patterns in these stick insects thus deserves further studies.
Further, stick insects themselves should in general show dispersal different from non-stick insects (I don’t mean Teflon ones!), since some of the former have the ability to get their eggs dispersed hundreds of kilometers. But all this awaits further study, as there was no reason to investigate those patterns before this new paper appeared.
It used to be standard practice for final year science students to do a lab-based research project. At the University of Manchester we have broadened the choice of final-year projects so that biology students can also choose to do a Science Media Project. This involves creating a portfolio of writing and other work around a scientific topic. Last year we featured films made by two of my students, and the comments from readers were invaluable.
I’d like to for you help again, by watching this 20-minute video by my student, Kirsty Wells, on the topic of ‘rewilding’. As she explains:
I have produced a short documentary exploring the possibility of wolves being reintroduced into the Scottish Highlands. Having extensively reviewed the literature surrounding the impacts of re-established wolf populations in other parts of the world (Western Europe and Yellowstone National Park), I decided to investigate how these impacts may apply in the context of Scotland. I ventured up North to meet with a few people to discuss what wolf reintroduction would mean to them, and what it could mean for the people of Scotland and Britain more broadly.
Please have a look at her video, and then fill out the quick questionnaire – no personal data are collected! Your comments below would also be greatly appreciated.
Here’s my answer: a worker honeybee was visiting a white flower to get nectar. She was attacked by a white crab spider who was remarkably camouflaged (probably chemically, as well as visually). The crab spider had another, brown, crab spider sitting on it.
Now for the bit you may have missed – no sooner had the deed been done than a kleptoparasitic fly turned up and landed on the poor bee’s abdomen (you can just make out its red eyes), hoping to slurp up some juices from the corpse. So we have two kingdoms (plants, animals), two classes in the arthropod phylum (chelicerates and insects), two orders of insect (Hymenoptera and Diptera) and two members of the chelicerate family Thomisidae (probably both in the same genus, Thomisus). If you want to know more about crab spiders, I highly recommend Douglass H. Morse’s 2007 book “Predator Upon A Flower”.
This photo by R Fontaine (aka @Tenfon2 on Tw*tter) contains a complex set of interactions, involving two kingdoms and two classes, with two orders within one of those classes, and two genera or perhaps species within the other. Your task is to describe them. You don’t need to use fancy latin names, but there will be extra marks for those who do. My answer will be posted at noon Chicago time.
I’ve had my worries about the American Association for the Advancement of Science (AAAS), especially its cozying up to religion. They’ve collaborated with Templeton in funding an accommodationist program, the Dialogue on Science, Ethics, and Religion (DoSer), and have engaged in other religion-coddling activities unseemly for a secular science organization (see, for instance, here, here, here, and here). I’m not sure why that is, unless somehow the AAAS wants to court popularity by making nice with faith.
But when I saw a new “editorial” in the AAAS’s journal Science, I was gobsmacked. The piece, “Pursuit of integral ecology,” is clearly labeled as an “Editorial” (which means its message has the approval of Science), and was written by Monsignor Marcelo Sánches Sorondo, Chancellor of the Pontifical Academies of Science and of Social Science, and Veerabhandran Ramanathan, a climate scientist at UC San Diego and a council member of the Pontifical Academy of Sciences.
The editorial, part of a special Science Issue on “Urban Planet,” is basically a paean to the Pope’s views on environmentalism, and really says nothing more than this: “We like the Pope’s views that pollution, environmental degradation, and so on, impacts people differently, with the poor suffering the brunt of the damage.” Fine, but that’s been said over and over again. There’s nothing remarkable or new in the piece. But there’s also a notable inclusion and a notable omission.
The inclusion (my emphasis):
The Paris agreement was signed by 195 nations to limit global warming to well below a 2°C increase. These global acknowledgements of systemic ecological and social problems have opened a window of opportunity to focus on how problems of poverty, human well-being, and the protection of creation are interlinked. The real innovation is this new synergy between science, policy, and religion.
What the hell is the notion of “creation” doing in a science journal? It’s this kind of wording that got the Los Angeles County Museum of Natural History in trouble for referring to its Nature Lab exhibit (funded by a donor) as helping celebrate “God’s creatures.” On the curators’ insistence, that sign was quickly taken down. Why does Science, then, allow mention of “creation,” a clearly religious concept, in an “editorial”?
And the notable omission: there is not a single word in the Science editorialabout population growth as a cause of environmental damage, nor about population control. No surprise, given who wrote it! The Catholic Church has of course refused to connect population growth with environmental damage—perhaps the most important nexus between society and ecology—because the Church wants its warren to breed like rabbits. And no condoms or pills! Instead, the piece simply praises Pope Francis as being prescient:
Indeed, 1 year ago, Pope Francis emphasized, in the encyclical Laudato Si, that complex crises have both social and environmental dimensions. The bond between humans and the natural world means that we live in an “integral ecology,” and as such, an integrated approach to environmental and social justice is required.
Where is the social dimension of birth control?
Others have noticed the AAAS’s reluctance to even discuss birth control. In a piece called “AAAS wields the censor’s hammer on U.S. population issues,” Stuart Hurlbert, emeritus professor of biology at San Diego State, writes a “J’accuse” piece on the AAASs apparent accommodationism:
Over the last four years three different population-focused NGOs have tried to have exhibitor booths at AAAS meetings. All have been turned down. The 2011 battles by Californians for Population Stabilization and Population Institute Canada to have booths at the 2012 AAAS meeting in Vancouver have been recounted elsewhere (1), as has AAAS’s exclusion of substantive discussion of U.S. population growth and policies from its flagship journal, Science.
Most scientists scream bloody murder when others suppress knowledge. But a few are in fact happy to censor when it suits their own ideological predispositions.
The positive consequence of those earlier battles was the formation of a new national NGO, Scientists and Environmentalists for Population Stabilization (SEPS). SEPS now educates people not only on population issues but on the problem of censorship by scientists of other scientists as well.
SEPS applied for a booth at the 2014 AAAS meeting in Chicago and was rejected. So when it applied for one at the 2016 AAAS meeting in Washington, D.C., it listed in its application the 19 scientific societies that since 2012 have warmly welcomed SEPS exhibitor booths at their meetings. No society other than AAAS has ever rejected a booth application from SEPS.
The 2016 application also listed 40 current or former presidents of scientific societies who were endorsing SEPS’ application. These included several distinguished past and present members of my own San Diego scientific community such as: Michael Soulé, former UCSD professor and founding president of the Society for Conservation Biology and the Wildlife Network; Margaret Leinen, director of the Scripps Institute of Oceanography and current president of the American Geophysical Union; John Rieger, former SDSU grad student and founding president of the Society for Ecological Restoration; Peter Jumars, former SIO grad student and past president of the American Society for Limnology and Oceanography; Edith Allen, former SDSU professor and past president of the Soil Ecology Society, and Dennis Murphy, former SDSU grad student and past president of the Society for Conservation Biology.
But no luck. The narrow-mindedness of AAAS staff once again trumped the judgment of large numbers of top scientists both in and out of SEPS, including the meeting organizers of 19 other societies.
Pretexts offered by AAAS for application rejections have been diverse, disingenuous and puzzling.
For the 2016 meeting, AAAS CEO Rush Holt claimed that rejection of SEPS’ application was “based on the mission, focus and actions of your organization.”
So let’s see what is causing all this fear and trembling at AAAS.
SEPS mission statement as given on its website is this: Our mission is to improve understanding within the U.S. scientific, educational and environmental communities of the fact of overpopulation and its social, economic and environmental consequences at both national and global levels. We advocate for U.S. population stabilization followed by its gradual reduction to a sustainable level by humane, non-coercive means.
Hurlbert ends this way:
Such discussions seem destined to never be had in an AAAS exhibition hall.
The problem here is far bigger than rejection by AAAS of booth applications from a few NGOs. The AAAS staff and board of directors seem to have decided, surreptitiously, to exclude substantive discussion of U.S. population issues from all AAAS venues. An independent board of inquiry is needed. This behavior by AAAS has already been discussed by the board of the Council of Scientific Society Presidents. Perhaps they will bite the bullet and take up the task.
For some reason the AAAS, like the Pope and the Pontificating Academy of Partial Sciences, doesn’t want to bring up population control as an important social issue affecting the environment. I get why the Catholics don’t do that, but why a respected scientific organization? How do they benefit from censoring discussion of population growth?
JAC: Melissa Chen is a doctoral candidate in genetics at MIT, and, like me, a moderator of the Global Secular Humanist Movement Facebook site. She recently went on a cool NASA-sponsored trip from Wood’s Hole, and when she volunteered to write about her adventures here, I of course said, “Sure.” Here they are. (By the way, Melissa’s alter ego is “Space Girl,” which she assumes, as you see below, by putting on a fake NASA helmet.)
The Adventures of Space Girl: What’s in a NAAMES?
by Melissa Chen
With Prof. Craig Carlson and Jason, both researchers on the NAAMES mission, about to embark on a 26-day journey to sea
Space Girl was invited by NASA for a “social” which was essentially a press junket for social media “influencers” to aid the agency in disseminating information and publicizing its research. In particular, this was an insider’s look into NAAMES (North Atlantic Aerosols and Marine Ecosystems Study), a 5-year study to understand processes that govern ocean ecosystems and their influence on atmospheric aerosols—which in turn affect clouds and Earth’s climate.
NASA’s scientific portfolio is usually dominated by the “sexy” space sciences which involves research about other planets, asteroids, galaxies and the fundamental nature of our universe. It conjures up enthralling images of space exploration, rocket launches and spacefaring missions that captivate the public mindset and stoke the flames of science-fiction fantasies. But what about our own planet, the pale blue dot that we call home? Probing outer space for an extraterrestrial sanctuary for our species seems prudent, but why not spend some resources to save the one we live on now? To do so, we’ll have to understand the problems that plague Earth first.
I arrived early at the NASA Social hosted at Woods Hole Oceanographic Institute. Check out all the NASA swag laid out for bloggers and guests!
This is exactly what NAAMES, the first earth-suborbital mission focused on studying the coupled ocean ecosystem and atmosphere, intends to do. Fortunately for us, NASA has an Earth Sciences division that is funded to the tune of USD$2 billion. Dr. Paula Bontempi spoke to us about this terrestrial niche, one that gets scant attention compared to the titillating and awe-inspiring space sciences. Further exacerbating this is the fact that the research they do, particularly in areas like ocean sciences and biogeochemistry, have been caught up in the culture wars of our time. There’s no question that the earth sciences tend to be held to a much higher and more rigorous standard due to the stubborn pervasiveness of climate-change denialism among some factions of the American public. Funding is scarce and press coverage virtually non-existent.
“Which is why Space Girl was here to save the day,” I mused to myself as I sat in the conference room on a warm spring morning at Woods Hole Oceanographic Institute.
Dance of the phytoplankton
The NAAMES mission is not only multi-disciplinary but also multi-modal, using ships, aircraft and satellites simultaneously. A C-130 Hercules airborne laboratory that deploys from St. Johns, Newfoundland will rendezvous with the R/V (research vessel) Atlantis which departs from Woods Hole, MA, along a route in the North Atlantic that takes it to the tip of Greenland.
One of the major biological events of the year is the phytoplankton bloom that takes place in the North Atlantic ocean. Below, you’ll notice the mesmerizing swirls of green biomass, reminiscent of a dreamy Van Gogh painting; they form the basis for the entire marine food chain. Satellites pick up the climax of blooms from April-May and were previously attributed to the same seasonal processes that cause terrestrial plants to flower in spring – namely, the gradually warming temperatures and increasing sunlight.
Under this hypothesis however, warmer oceans should produce larger phytoplankton blooms, which means more carbon-rich fuel for zooplankton and the other marine creatures that depend on them. That goes against what we observe, however.
According to Mike Behrenfeld from OSU (pictured below), a researcher in the NAAMES study, phytoplankton actually bloom when conditions are “worse” for growth, i.e., during the dead cold and stormy swells of winter in the North Atlantic. It follows that global warming would produce smaller and smaller blooms, reducing photosynthesis and drastically limiting the ocean’s food supply and the foundation for the entire ocean ecosystem.
How biology influences cloud science
Another way these phytoplankton blooms affect global climate is by affecting aerosols and hence cloud formation. Clouds are made up of many tiny droplets of water condense from water vapor onto microscopic particles floating in the Earth’s atmosphere. Plankton essentially help to provide clouds with these nuclei to form around by “aerosolizing” to form airborne particles. It’s akin to how crystallization of a supersaturated liquid requires a “seed.”
The more dissolved organic material in the ocean, the more particles get aerosolized in the atmosphere, which encourages cloud formation. Warming of the oceans could lead to decreased phytoplankton blooms, which, in turn, would decrease aerosols in the marine layer, thereby decreasing cloud formation. This further accelerates warming, resulting in a positive-feedback loop!
One of the NAAMES scientists showed us a neat demo which illustrates this point: holding a piping hot cup of tea on a particularly crisp cold day with minimal pollution (virtually no airborne particles), no ghostly streams of steam were detected emanating from his mug. When he blew onto the beverage surface or tried perturbing it with a lighter, hazy white ribbons of steam immediately formed.
In addition, large phytoplankton blooms are what causes the oceans to act as carbon sinks, since via photosynthesis, these micro plant cells convert CO2 to sugar that form the basis for all marine life.
R/V Atlantis: a floating laboratory
After the briefing, the participants were led on a tour of the R/V Atlantis, which was poised to embark on a 26-day mission the following day. This is no cruise – it’s a utilitarian research vessel that functions as a floating science laboratory, carrying 33 scientists and 26 crew.
There wasn’t an idle soul on board – everyone was industriously bustling about, tending to their respective duties or calibrating scientific instruments. We walked through the main lab space where we got a sense of what each group was studying, from the genomic sampling of the phytoplankton to the biogeochemistry of the oceans. It was clear to me that the only way to successfully carry out research on a ship that will, at times, be rocking quite violently, is to be fastidious and neurotic about securing everything with cable ties and rope.
Out on the deck, we had to be very careful as we moved around, for the floor of a research vessel is a booby trap for those who, like me, have two left feet. Rows of plastic incubators were being set up to see how phytoplankton respond to various conditions like osmotic shock or varying degrees of sunlight.
Biologists setting up a series of incubating tanks to learn more about the variables that affect phytoplankton growth. Check out that scientist’s (right) T-shirt!
Toward the bow of Atlantis, several modular ship containers (below) are perched side by side, each masquerading as mobile science laboratories. Inside, instruments like mass spectrometers and flow cytometers haphazardly corralled together from spare parts were whirring noisily as researchers were doing their final preparations.
The NAAMES study involves some really unique and expensive instruments to take measurements. The CTD “rosette” (left) is basically a glorified sample collection device with multiple cylinders. When it is carefully hauled back on deck, the scientists gather around it with their containers in a ritual that is known on board as “milking the cow.” Then there are the “floaters,” (right) which is a little bit of a misnomer because they actually sink quickly and slowly rise as they collect data about the water column and transmit the information back to the ship. Each of these costs USD$30,000 and are for single use only!
Off the ship, we saw the deep-sea sub named Alvin, who works with the R/V Atlantis for scientific research and exploration. He was in the dry dock because his ability to operate under immense pressures and total darkness was not needed for the NAAMES mission. Of his 4,400 dives, the most famous was probably the exploration of the wreckage of RMS #Titanic led by Dr. Robert Ballard in 1986.
Despite such an esteemed track record and illustrious career, Alvin is of course, still subject to what the internet does best – poking fun at things. Fittingly, he has been christened “Subby McSubface” (below) by an eager engineer wielding a label-maker.
Like the ocean ecosystem that the NAAMES researchers were studying, the entire ship and its inhabitants are a kind of ecosystem as well, each part of a teeming organism whose lifeblood is the desire to learn and discover. It was all quite beautiful, like a symphony in perfect harmony or a stage of dancers in exquisite synchronicity.
Theirs is a devotion to science on a level that I have never known despite having worked in wet labs in academia for many years: crammed sleeping quarters, narrow and dim hallways, and huge logistical challenges plaguing the most basic everyday routines. Scenes from disaster movies such as “The Perfect Storm” are not just fiction to those on board – the maniacal stirrings of the North Atlantic occasionally toss people and things around. Motion sickness notwithstanding, the crew has to also “do science” under these conditions! Because of the variable working (and funding) conditions, many of the NAAMES scientists have mastered the art of “MacGyvering,” one even repurposing an engine from a Dodge truck to power sea water ionization.
One of the NAAMES scientists was specifically looking out for Space Girl and wanted this photo. I told her that SHE was the real “celebrity” here!
The day ended with lunch at Captain Kidd’s next to WHOI where we were all still riding on the kind of high you can only get from being inspired by science. All this data from NAAMES will not only tell us so much about what processes trigger the yearly pattern of phytoplankton blooms, but also connect the dots between the blooms, aerosols and clouds. This information will in turn, help us to refine our climate models so that we can make better predictions on how marine ecosystems will be affected by climate change.
Thank you to NASA for inviting me. I met some amazing people like mega space dork Jason Major who’s a social media rockstar and blogs at lightsinthedark.com; Michael Finneran from NASA Langley Research Center; Nichole Estaphan, reporter from WCVB and a journalist who embedded with the NAAMES mission during its November mission. She wrote about her experience as a science journalist who spent her free days roughing it out on the rough sees on the Atlantis instead of kicking it back on vacation in the Carribean at journalistatsea.com. Why? To tell the stories of the men and women who put it all the line for the sake of knowledge and discovery.
My Okinawa correspondent sends a happier picture than last time, this one of a living longhorn beetle, a member of the family Cerambycidae. Note the very long antennae, and the impressive tarsi. Cerambycids are often brightly or contrastingly colored.
An Okinawan longhorn beetle, 30.iii.2016.
Normally I’d have no idea what particular genus or species an Okinawan insect would be– I was happy I recognized the order and family!– but this seems to be an Asian longhorned beetle, Anoplophora glabripennis, which has become an invasive species in the US, Canada, Trinidad, and several European countries. The larvae feed on the sapwood of maples, elms, and other trees. If a reader more knowledgeable about Okinawan or East Asian insects has an opinion, please weigh in.
