Friday Harbor Laboratories
Revised: 12-20-2012

Blinks - NSF REU - BEACON Internship Program

Research Experiences for Undergraduates

Integrative Biology and Ecology of Marine Organisms

Application deadline: March 1, 2013 (Now closed. 350 applications received)

Program dates: June 18 to August 10, 2013

Program Description

Friday Harbor Laboratories' Blinks - NSF REU - BEACON Summer Internship Program seeks to link undergraduate students with scientist-mentors as collaborators in marine science research projects. The program takes advantage of the pristine environment, remarkable biodiversity, and the scientific and technical resources at University of Washington's marine science research facility. We have combined the NSF REU program with the Blinks Research Fellowship program, which targets groups who are historically underrepresented in the marine sciences, with the NSF-funded BEACON Program. With additional support from the United Negro College Fund, the Andrew W. Mellon Foundation, the American Society for Cell Biology, the Federation of American Societies for Experimental Biology, and the Anne Hof Blinks Memorial Fellowship, the Blinks-REU Program offers a full immersion research experience for motivated undergraduates, post-baccalaureates and graduate students. In keeping with the University of Washington's policy of encouraging diversity in its student body including underrepresented groups, the program seeks 10-15 students of diverse backgrounds and interests to participate in a eight to twelve week summer research project in the marine sciences. By linking fellows with marine scientists in a 1:1 research experience, fellows learn both the process and the substance of scientific research. As the research progresses, fellows will be encouraged to become semi-independent collaborators. The experience will expose fellows to the life and work of a marine science research laboratory. The program will incorporate workshops, seminars and training sessions in addition to hands-on research.

The mentors and projects vary from year to year according to the developing research interests of faculty and students. Research projects are designed by the scientists to be achievable projects which dovetail with their research plans. Project descriptions are posted below. Fellows will work semi-independently for approximately 40 hours per week.

For summer 2013, the BEACON Program will fund up to four students, bringing the Blinks-REU-BEACON cohort up to 15 or 16 students.

As participants in the FHL community, students will participate actively in FHL community activities, e.g. attend the weekly seminars, eat in the Dining Hall and live in the student dormitory. Early in the summer session, there will be a meeting of student participants with graduate students and mentors to share perspectives on graduate programs and participation in academic life, with a brief description of ongoing projects, and a question/answer session. At the end of their internship, fellows will present their research in a short powerpoint talk. Fellows will also write a scientific paper describing their work, and revise it based upon feedback from the mentor.

The Setting

Friday Harbor Labs is University of Washington's marine science field research station. Located north of Puget Sound in the San Juan Islands, FHL takes advantage of a remarkable diversity of marine habitats and organisms. FHL hosts 10-12 courses per year and approximately 100 independent researchers during the year. The 484 acre campus is the site for thirteen lab buildings, a dining hall, 3 dorms and other housing units.

Research at FHL emphasizes marine invertebrate zoology, phycology, fisheries science, conservation biology, cell and molecular biology, biomedical sciences, oceanography and other scientific disciplines. Investigators and students use diversified field resources as well as modern analytical technologies such as a nucleotide sequencer, scanning laser confocal microscopes, scintillation counter, centrifuges, HPLC, TEM, SEM and other equipment. Friday Harbor Labs is equipped with a 58' research vessel, numerous smaller boats, cold rooms, and an extensive seawater system serving numerous lab buildings. The facility includes a computer lab, networked research labs, wi-fi connectivity, a well equipped stockroom, a 17,000 volume library, and SCUBA facilities.

Financial Support

Participants will be provided with financial support to meet costs of room, board, round trip travel and a monthly stipend of $1000.

Eligibility

The NSF REU Site grant supports U.S. citizens or permanent residents during their undergraduate careers. The Blinks Endowment supports students who bring diversity to the FHL student body in any phase of their undergraduate or graduate career.

To Apply (applications are no longer accepted. 350+ received)

1. Fill out the FHL >REU Application form to apply for participation in a specific research project. In the ethnicity field, please be sure to indicate if you're from an underrepresented group.

2. Apply to work with a specific mentor by writing a one-page application statement which describes your background, your interest in this project, and how this specific project will help you achieve your career goals. Please submit up to three application statements, one for each project to which you'd like to apply, and send them to fhlinapp@uw.edu. The statements should be sent as separate files in .doc, .docx or .pdf format.

3. Request unofficial copies of your transcript to be sent to fhlinapp@uw.edu. Transcripts can be either official or unofficial, and either electronic or on paper. Electronic transcripts are preferred. If your school prepares only paper transcripts, please send them to Scott Schwinge at the address below.

4. Request two letters of recommendation from faculty members who are familiar with your work. Letters should be emailed from faculty directly to fhlinapp@uw.edu.

Questions may be directed to:

Scott Schwinge
schwinge@uw.edu
Administrator Friday Harbor Laboratories
620 University Road
Friday Harbor, WA. 98250
phone: 206-616-0708
FAX: 206-543-1273

Students who are selected will be notified in late March.

FAQs about FHL

REU Project Descriptions for 2013

Effects of low tide conditions on consumer-prey interactions.

Dr. Jennifer Burnaford
Cal State Fullerton
jburnaford@exchange.fullerton.edu

Dr. Scottie Henderson
Cerritos College
scottiehenderson@cerritos.edu


The intertidal zone is covered by water during high tide and exposed to terrestrial conditions at low tide. Intertidal organisms are exposed to different potential threats during these two periods. In the San Juan Islands in the summertime, low tides occur during the middle of the day; and exposure to sun and wind can cause intertidal organisms to experience dramatic temperature fluctuations and lose substantial amounts of water. Our question is: how does exposure to low tide conditions affect the interactions between consumers and their prey items?

We are primarily interested in two questions:

1. How do environmental conditions (e.g. temperature and light intensity) affect the microhabitat choices of consumers as the tide drops?

Most intertidal invertebrate consumers move and locate their food items during high tide; but feeding rates are slow, and consuming a single food item can take several hours. Since the consumers do not move when they are exposed to air at low tide, and low tide conditions can be stressful, their movements as the tides drop can have physiological consequences. If consuming a prey item requires a consumer to become exposed to potentially stressful low tide conditions, what choices will the consumer make? Under what circumstances will the consumer choose to consume the food, and under what circumstances will the consumer instead choose to avoid abiotic stresses?

2. How do environmental conditions during low tide affect the feeding rate of consumers during high tide?

If a consumer is exposed to stressful low tide conditions, how does this affect the rate of feeding when the tide comes back in? Are feeding rates high to 'make up for' high metabolic costs of low tide exposure? Or are feeding rates low due to lingering effects of the stressful conditions?

These questions could be addressed using sea star predators (Pisaster ochraceus and Leptasterias hexactis) and their animal prey items (e.g. limpets, snails, mussels) or molluscan herbivores (limpets in the genus Lottia and the chiton Katharina tunicata) and their algal prey items. Student projects will include both laboratory work and field studies to address the effects of low tide exposure on the spatial and temporal foraging patterns of common intertidal consumers.

Each fellow on this project will be assigned to a single primary advisor. The entire team (both advisors and up to 2 students) will participate in field sampling on beaches around the San Juan Islands. Each individual fellow will conduct laboratory and field experiments to investigate a question that they find most interesting with regard to the effect of low tide exposure on consumer / prey interactions. Good physical health and a love of field work are essential for participation in this project. This project would be appropriate for students generally interested in the ecology of species interactions and also for students specifically interested in understanding the potential community-level effects of global climate change.


The effect of food patches on the behavior of seastar larvae in haloclines.

Dr. Sophie George
Georgia Southern University
georges@georgiasouthern.edu

A regular occurring event in the coastal waters of the Pacific Northwest is a decrease in salinity to less than 15‰ in some areas, as a result of increased precipitation and ice melts. Studies by George and Walker (2007) and Pia, Johnson, and George (in preparation) indicate that Dendraster excentricus (right top picture) and Pisaster ochraceus larvae (bottom left) can develop to metamorphosis at 22‰ and 20‰ salinity (bottom right, juvenile P. ochraceus). However, larvae exposed to 20‰ for 14 days were shorter, wider, had smaller stomachs, developed slowly and produced smaller juveniles than those exposed for 7 days. This is rather intriguing given that echinoderms cannot regulate the osmolarity and ion content of their internal fluids. These studies also indicate that the timing, magnitude and duration of ice melts and rainfall in the Pacific Northwest could alter larval morphology, larval feeding and swimming efficiency, and ultimately the quality of new P. ochraceus recruits into the intertidal zone in the Puget Sound. During the summer of 2013, research will continue looking at larval behavior of P. ochraceus in haloclines with different food patches. This project will illuminate the complex interactions between nutrition, salinity, and growth rates of an asteroid with bipinnaria and brachiolaria larval forms.

Knowledge on larval behavior in haloclines would enhance our understanding of how echinoderm larvae will respond to a decrease in ocean salinity as a result of climate change. The participating student would be directly involved in preparing algal cultures; rearing larvae to metamorphic competency, preparing and observing larvae in haloclines, photographing echinoderm larvae etc. Past students have presented their research at regional (GAS) and international meetings (SICB), and are coauthors on 3 recent articles from research at FHL with two in preparation.

George, Sophie B. & Walker, Devoc. 2007 Short-term fluctuation in salinity promotes rapid development and metamorphosis of Dendraster excentricus larvae Journal of experimental marine Biology and Ecology. 348:113-130.

George, Sophie B., Fox, Colleen & Wakeham, Stuart 2008. Fatty acid composition of larvae of the sand dollar Dendraster excentricus (Echinodermata) might reflect FA composition of the diets Aquaculture 285: 167-173.

Tanya Pia, Tiffany Johnson, and George, Sophie 2012. Single and multiple fluctuations in salinity affect growth, development and metamorphosis of the sea star Pisaster ochraceus. Journal of plankton research 34:590-601.

Sam Bashevkin, Daniel Lee, Paul Driver and Sophie George. Vertical distribution of brachiolariae larvae in haloclines is influenced by prior exposure to low salinity. In prep. (past Blinks-REU scholars or grad students in bold).

 

Sexual selection on the seashore: mating systems of marine arthropods.

Dr. Vik Iyengar
Biology Department, Villanova University
vikram.iyengar@villanova.edu

Arthropods are the most abundant and diverse group in the animal kingdom – they occupy nearly every ecological niche in marine, freshwater and terrestrial habitats.  Their extraordinary evolutionary success can be partly attributed to the remarkable diversity of mating systems found in arthropods.  This summer, we will investigate the mating system and reproductive strategies of intertidal arthropods.  The California Beach Flea (Megalorchestia californiana), which reach over 1” in size, is an amphipod commonly found on the beaches of the Olympic Peninsula.   Adults spend a good portion of the night scavenging washed up animals or eating seaweed, and females spend most of the daytime in burrows that are guarded by males.  Competition over females can lead to territorial fights between males looking to control access to the group of females (harem) found inside the burrow using weaponry.  Victorious males get the reward of mating with the females, who brood their eggs in an internal pouch and release fully active juveniles.  We may also study Idotea wosnesenskii, an isopod found locally that also exhibits mate-guarding of females.

We will be making field observations and working together to design and implement appropriate laboratory experiments to determine the reproductive strategies of both sexes.  Students involved in this project will investigate these arthropod mating systems by attempting to answer some of the following questions:

(1) What are the local abundance and distribution of males and females, and how might those factors affect the strength of sexual selection? Basic population parameters such as density, sex ratio, and body size may have profound effects on the nature of inter- and intrasexual interactions. Density and sex ratio information will provide information regarding the frequency of encounters, which may impact the level of aggression and, in turn, the selection for male weaponry to defend a limited resource. Skewed sex ratios and clumped spatial distributions often lead to polygyny in mating systems across taxa, and these population parameters have been shown to affect reproductive behavior in amphipods. The mean and variance in body size in males and females may also provide insight into the degree to which sexual selection is acting; since females are usually larger than males in arthropods, sexual dimorphisms in the opposite direction (as seen in M. californiana) are particularly noteworthy. 

(2) What are the natural levels of aggression, and what factors determine burrow fidelity? I wish to determine whether males and females switch burrows, and whether their degree of burrow fidelity is determined by mate quality or resource value. These may differ between the sexes, as a male’s burrow fidelity may depend on his harem size and the density of rivals whereas a female’s burrow fidelity may be determined by the quality of her mate relative to other potential suitors in the population. There is also the possibility that males may defend multiple burrows as a means of expanding their harem size, a strategy seen in fiddler crabs. 

(3) Do males modulate intrasexual aggression based on their own size, their opponent’s relative size, residency status or prior fighting experience? Larger M. californiana males are usually more successful in securing females, and male body mass correlates with the length and redness of the antennae, two parameters potentially responsible for reproductive success.  Antennal length appears to be an important component of fighting ability, as larger males often use their long antennae to pry smaller male occupants out of a burrow.  Contests to secure valuable resources are often settled based on asymmetries in fighting ability, and we plan to test alternative explanations related to winning disputes. 


Testing aquatic adhesion systems in tube worms.

Metamorphic larva.

Dr. Rachel Merz
Swarthmore College
rmerz1@swarthmore.edu

Examining how organisms move through water has long been studied both to understand the lives and evolution of swimming organisms and to evaluate the mechanisms they use, in some cases for potential application to human needs. What is much less well known is how aquatic organisms hang on to wet surfaces - knowing how organisms meet this mechanical challenge is important for the same reasons – to understand how the animals work and to look for possible applications for other uses.

Building on my previous research on the architecture of worm tubes and polychaete morphology, the task this summer will be to quantify the frictional interaction between the bodies of tube-dwelling worms and tube walls – where those tube walls are both natural and artificially constructed to vary texture. We already have good data on the morphology and ability of these worms to adhere to the insides of their natural tubes, what we want to do this summer is to compare the behavior and ability of worms in their natural tubes and artificial tubes made with different surface qualities. Accomplishing this goal will likely require careful observation of the worms in order to design good experiments and construct experimental apparatus. It will also involve video analysis and use of scanning electron microscopy.


Neuroethology: How brains control behavior. A study of the orange brain of a toxic sea slug.

Tritonia nudibranch.

Dr. Jim Murray
Cal State University, East Bay
tritoniadiomedea@mac.com

This internship will focus on learning techniques in neuroethological research such as behavioral recording and analysis, recording electrical signals from brain and nerve, cell injection, and confocal fluorescent microscopy of neural structures. Research will focus on the nudibranch sea slug Tritonia diomedea because it is most amenable to neuroethological analysis, but will also extend to related species of opisthobranch as part of the comparative approach.

The Tritonia sea slug has served as a model system in neuroethology, i.e. relating the activities of multiple nerve cells to behavior in a natural context. In particular, we will investigate the neural basis of navigation using Tritonia to tidal flow, odors of food, mates, and predators, as well as the geomagnetic field. Because the nervous system is easily accessible and composed of relatively large cells, we will identify brain cells that are involved in sensing stimuli, and effecting crawling and turning.

One of the major advantages of teaching with the Tritonia model is that its large, orange neurons make learning to record from the central nervous system relatively easier compared to other species. The intern will also learn how to track animal movement using cameras, how to analyze video of body movement on a computer, and how to correlate movement with neural activity. This sea slug specializes in eating coral prey that are toxic to most other animals, so we are also investigating its chemical ecology and how it protects itself from toxins.

http://impulse.appstate.edu/articles/2012/structure-and-function-pedal-neurons-controlling-muscle-contractions-tritonia-diomedea

Chemical signaling in a plant-herbivore interaction.

Dr. Dianna Padilla
Stony Brook University
padilla@life.bio.sunysb.edu

The use of external chemical signals is an important mechanism by which organisms obtain information about both their biotic and abiotic environments.  In aquatic systems, chemical signals can be used to navigate, home, locate food, identify suitable habitats for settlement, and trigger larval metamorphosis.  Chemical signals are also involved in many aspects of mediating interactions between consumers and prey, including plants and herbivores, and the ability to detect and use chemical signals can provide benefits to both consumers and their prey.  Often defensive (protective) and offensive (those that enhance consumption) traits can be altered over short time periods (within the lifetime of an individual, thus are phenotypically plastic) in response to the local environment.  Chemical signals are increasingly being recognized as the cues that trigger these phenotypically plastic responses.

We will focus on the chemically-triggered induction of an herbivore offense -- phenotypically plastic changes to the feeding morphology in snails within the genus Lacuna.  Snails in the genus Lacuna are generalist herbivores that live on and consume a wide range of macroalgae, and also live on eelgrass, where they consume ephiphytic microalgae.  For gastropod grazers, the radula (a long chitinous ribbon with repeated rows of teeth) is the primary tool for feeding.  Lacuna generate one of two distinctly different radular tooth morphologies in response to different food types.  Pointed teeth are produced when animals consume any macroalga (independent of type), and blunt-shaped teeth are produced in response to consuming epiphytes found on eelgrass.  New teeth are constantly produced at the distal end of the radular ribbon while old teeth are shed anteriorly (Padilla et al. 1996) throughout the life of the snail.  Tooth morphology cannot be changed once a tooth is fabricated, and it takes over three weeks for a newly produced tooth to be used to graze.  This results in a long lag time between induction and having a functional morphology, which can limit the adaptive value of a plasticity.  Mismatches between Lacuna tooth morphologies and food type can result in lower consumption rates. 

We are working with a chemical ecologist at Shannon Point Marine Center (Dr. Kathy VanAlstyne) to determine the nature and identity of chemical signals that trigger this phenotypic plasticity and the controls of feeding in two species of Lacuna that are common in the waters around Friday Harbor.

Through a variety of experiments with larvae, juveniles and adults, we will explore the following questions:

1. Does Lacuna has a default radular morphology?
Preliminary studies suggest that pointed-shaped teeth are the default morphology, that morphology produced in the absence of chemical signals.  To test this we will rear larvae from each of the two species in the absence of and presence of potential chemical cues and explore the tooth morphologies produced.

2. What are the consequences of having tooth shape missmatched to diet?
To test this question we will look at feeding rates of snails with pointed or blunt-shaped teeth when feeding on marcroalgal food (kelp or Ulva) and on epiphytes on eelgrass.  Quantifying differences in feeding effectiveness under different conditions will help us determine the costs of morphologies missmatched to their enviornment, and thus the potential benefits of phenotypic plasticity.

3. What are the chemical inducers of this phenotypic plasticity?
We will be testing whether different types of chemicals (proteins, polar and non-polar comounds) are the triggers of radular plasticity in Lacuna.  We will be working with Dr. VanAlstyne to isolate different types of chemicals from diatoms (the suspected cues) and test whether different types of extracts induce different morphologies in this snail.

4. Do close relatives of Lacuna show a similar plasticity in radular morphology when given different foods to eat? Lacuna is a close relative of snails in the genus Littorina.  Experiments will be used to test whether littorinid snails also have the ability to change their radular morphology in response to different diets.

Student projects will include both laboratory and field studies.  Projects will provide the opportunity to learn field sampling methods, diet determination in field collected animals, larval rearing, feeding and morphology experiments, microscopy, including Scanning Electron Microscopy and/or chemistry.

Each fellow on this project will choose a specific experiment/question to focus on.  All team members will participate in field sampling on shores around San Juan Island.  This project is most appropriate for students interested in the ecology and evolution of species interactions, phenotypic plasticity, chemical ecology and plant-herbivore interactions.

Morphospace, the final frontier: exploring shape and mechanics of vertebral and joint shape.

Dr. Marianne Porter
Friday Harbor Laboratories
University of Washington
meporter@vasser.edu

Variation in vertebral morphology occurs within and among species. Previous research on morphology and joint mechanics lacks a comparative context. Our goal is to explore vertebrate morphospace and the associated joint mechanics, using physical models, to gain insights into vertebrate evolution in terms of diversity and water to land transitions. Preliminary data show land and aquatic mammal models generate statistically similar bending moments, also fish models were similar to each other.

However, fish models produced bending moments that were significantly different from mammal models. The trends within these findings raise questions about the effects of concavity angle and intervertebral length affect stiffness, stress, moment, and overall bending performance with biomechanic and evolutionary implications. We will build physical models of vertebrae from representative groups including fishes, amphibians, reptiles (including Testudines, Squamata, and Crocodilia), and mammals (including terrestrial and aquatic). Physical models of motion segments (vertebrae – joint – vertebrae) will be made of a homogeneous material to ensure that differences in mechanics are related to vertebrate shape rather than composition. In addition to shape, joint material and joint length will vary. Motion segments will be tested in bending on Materials Testing System. A moment arm will be attached to the motion segment to ensure we are measuring bending mechanics rather than shear.

Neuroethology of acoustic communication in the plainfin midshipman fish.

Dr. Joe Sisneros
University of Washington
sisneros@uw.edu


In general, our lab is interested in the behavior and neural mechanisms involved in social acoustic communication. We use fish as model systems to investigate the adaptive plasticity of the auditory system for acoustic communication. Our research program is composed of three foci that reflect our general interests in understanding the proximate mechanisms of social and reproductive-related behaviors, and how sensory systems contribute to their expression.

 

The primary focus of our lab is the investigation of seasonal reproductive-state and steroid-dependent plasticity of the adult auditory system in the plainfin midshipman fish (Porichthys notatus). A second focus is the examination of ontogenetic changes in the response properties and function of the fish auditory system, and a third focus is the investigation of the brain activation patterns and neurochemistry that underlies motivational changes in auditory-driven social behavior.


We use a combination of experimental approaches that include neurophysiology, neuroendocrinology and behavioral studies to determine how the vertebrate auditory system functions in natural ecological settings, how the brain processes species-specific communication signals, and the adaptive sensory mechanisms that are used by animals for the detection and localization of acoustic communication signals.

 

 



BEACON Program internships.

Dr. Billie Swalla
University of Washington
bjswalla@uw.edu

The BEACON Program will fund up to four students. They will work under the supervision of Dr. Billie Swalla.



Sticky Fishes

Dr. Adam Summers
Friday Harbor Laboratories
University of Washington
fishguy@uw.edu

Several marine fishes have suction cups they use to attach to a substrate. We would like to know the effect of fouling on suction cup performance and also the effect of surface roughness. The student will learn force measurement, surface replication, profilometry, and scanning electron microscopy.

Metamorphic larva.

Feedback between form and function in colonial animals

Dr. Michaelangelo von Dassow
Duke University Marine Lab
mvondass@gmail.com

Many important biological systems use local feedback between mechanical cues and development to control the structure of the system. The human circulatory system is one well-known example. Colonies of the bryozoan Membranipora form a two-dimensional analogue to a circulatory system. The development of this system involves feedback rules similar to the feedback rules found in other biological fluid transport systems, including human blood circulation: faster fluid flow induces the formation of larger conduits (von Dassow, 2006).

The long term goal of this project is to develop Membranipora colonies as a new model system for studying how feedback between physiological function and development affects organisms. Membranipora colonies have a very different structure, function, and mode of development than most other biological fluid transport systems, yet they share similar physics and similar feedback rules. Therefore they provide a unique perspective on how these feedback rules contribute to the development and performance of fluid transport systems in general. This summer I hope to test two possible mechanisms that may stabilize the structure of this system. One is that the subunits of the system may lose their responsiveness to flow as they age; the second is that they may respond to flow reduction less quickly than to flow increases.

The student will gain experience with designing and conducting experiments in organismal biomechanics while working with a fascinating and beautiful organism. The student will also gain experience with data analysis, scientific writing, and presentation. The student will be encouraged to take the project in new directions that suit the student's interests.

Photo: M. von Dassow. Bryozoan colonies (Membranipora). Top: plan view (~3 cm wide); Bottom: cross section (colored streaks show flow).

von Dassow, M., 2006. Function-dependent development in a colonial animal. Biological Bulletin 211, 76-82.

Metamorphic larva.

Biomechanics and development: an environmental perspective

Dr. Michaelangelo von Dassow
Duke University Marine Lab
mvondass@gmail.com

Does embryo biomechanics influence how environmental variation affects development? By studying this, we can gain a better understanding of how organisms withstand the normal environmental variation that they have evolved to cope with, and how mechanical processes contribute to developmental defects (von Dassow and Davidson, 2011).

The changes in embryo shape that convert a single celled egg into a complex animal are driven by mechanical forces. Echinoderm embryos (e.g. sea urchins, starfish, and brittle stars) provide beautiful and tractable systems for investigating how environmental factors influence this biomechanical process. Early in development, echinoderm embryos form a simple hollow ball, the blastula.

Environmental factors could affect this process in several ways. For example reduced salinity could swell cells or change extracellular matrix properties. One goal for this summer is to test whether salinity variation affects the viscoelasticity of the blastula. The student will gain experience with embryological techniques (e.g. rearing embryos and light microscopy) and developmental biomechanics, while learning to integrate cellular and developmental biophysics with larger organismal and ecological scale processes. The student will contribute to all aspects of the project including experimental design, conducting experiments, data analysis, writing, and data presentation.

Photo: M. von Dassow. Blastula formation in a sand dollar embryo (Dendraster excentricus).

von Dassow, M., Davidson, L.A., 2011. Physics and the canalization of morphogenesis: a grand challenge in organismal biology. Physical biology 8, 045002, PMCID: 3200556, DOI: 10.1088/1478-3975/8/4/045002.