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May 2009 Archives

COLD SPRING HARBOR, NEW YORK—Going from one cell to many all in one organism was no easy feat. Multicellularity required molecular machinery that made it possible for cells to stick and work together. They needed to be able to talk to one another and to recognize and deter intruder cells.

But the last unicellular ancestor of animals was ready to make that leap. And even the most ancient multicellular animals were equipped with a skeleton crew of the genes that made the diversity of animal forms seen today possible. That was the news from the Cold Spring Harbor Symposium “Evolution: The Molecular Landscape,” held from 27 May to 1 June. Two teams have reached down to the base of the animal tree of life to learn how this key evolutionary transition occurred.

Nicole King of the University of California, Berkeley, and her colleagues use choanoflagellates as stand-ins for the last unicellular ancestor of animals. These single-celled creatures ColonyClose look and function a lot like cells called choanocytes in sponges. A flagellum sticks out of one end, whipping up water currents to circulate bacteria back toward a "collar" that slurps up the microbes. Some of the 150 species form colonies (left), approximating multicellular life.

A choanoflagellate genome, published last year, revealed genes for proteins that animals use for cell adhesion and signaling, and King has been looking into what those genes do in single-celled organisms. From those studies, she says, "we can learn some basic mechanisms of what was in place in the common ancestor."

One surprise in the genome were two dozen genes for cadherins, proteins that are critical for holding cells together in all animals. If cadherin genes are disabled during development, the embryo falls apart. Such genes had never been found outside a multicellular animal before. "We think [cadherins] are distinguishing different prey," King reported at the meeting. She and her colleagues have been examining these cadherin genes one by one. They have determined that some cadherin genes are active in the collar. They also find the amount of a particular cadherin protein depends on what bacteria are present in the surrounding water. For example, three cadherins are upregulated in the presence of flavobacter microbes but not when enterobacter bacteria are present, whereas the concentrations of other cadherins are unaffected.

King suspects that cadherin senses and binds to the bacteria, as some pathogenic microbes dock at cadherins to invade human cells. "[Choanoflagellates] have systems in place that allowed cell-cell recognition. [We] can see how one could evolve into a multicellular organism by using [these proteins] in a different way," says Bruce Stillman, president of Cold Spring Harbor Laboratory in New York.

Choanoflagellates were a prelude to sponges, which evolved 600 million years ago and as such are the oldest extant animals. Sponges split off from the animal tree of life early on and maintainadult4ed their simple body plan—sans muscles and a nervous system—while the eumetazoans evolved wings, fins, feet, heads, and tails to create the myriad of shapes and sizes seen in the animal kingdom today. By looking at the newly sequenced genome of one sponge, Amphimedon queenslandica (left), and choanoflagellates, "we can appreciate how multicellular organisms came about," says Stillman.

The protoanimal genome was quite busy during the more than 100 million years between choanoflagellates and the evolution of sponges. Bernard Degnan of the University of Queensland, Brisbane, Australia, and his colleagues have looked for what's common to all the animal genomes, concluding that they share about 5000 ancestral gene families, 1300 of which must have evolved during that time because they have no representatives in the choanoflagellates yet are found in sponges. For example, most of the genes needed to make the epithelium, which separates an organism from the outside world, appeared first in the sponge. In other gene families, in which choanoflagellates have a single gene, the families have expanded in sponges and sometimes exploded in more complex animals.

The sponges have precursors to some of the key development genes. One called hedgling codes for a protein that's like the signaling molecule called hedgehog, but it's locked to the cell membrane and cannot travel from cell to cell as does hedgehog. Hedgling "is still probably a signaling molecule but plays a different role," Degnan reported.

What sponges seem to lack is complex regulation of all these genes. In other animals, genes are often used in multiple contexts, but this is not the case for the sponge, says Degnan. Its genome is compact, with little room for regulatory DNA in between genes. This regulatory simplicity, he adds, "may be the key to why the [sponge] body plan has not changed" for 600 million years.

—Elizabeth Pennisi

Credits: Choanoflagellate Colony, Mark Dayel; Sea Sponge, Gemma Richards

LONG ISLAND, NEW YORK—After an evening that touched on Darwin and the evolution of fish, ants, and humans, the "Evolution: The Molecular Landscape" symposium at Cold Spring Harbor Laboratory was true to its title and headed into the RNA world first thing the next morning. Or rather, the ribonucleoprotein world. Ribonucleoproteins (RNPs) are complexes of RNA and proteins. Many researchers are convinced that the first life depended on RNA and that proteins came later. Those proteins eventually squeezed out RNA from most of its roles carrying out the molecular processes needed for survival. But proteins—or at least simple peptides—were likely in the mix from the very beginning, said Thomas Cech of the University of Colorado, Boulder. He added that "it was never an RNA world." Moreover, it's not just a protein world today. There is increasing appreciation for the amount of RNA transcribed from the genome that doesn't code for proteins. Thus, in partnership with proteins, RNA continues to figure largely in cellular function. A look at RNPs shows that there is a give-and-take between the two partners in the roles they play in the complex.

The discovery of the first ribozymes—RNA enzymes—in 1982 had provided a way out of the chicken-and-egg problem of which came first, proteins or nucleic acids, such as RNA, because today both types of molecules are critical to life. Life started with RNA, then proteins and DNA came along later and outdid RNA as arbiters of biological reactions and information carriers, respectively. Ribozymes evolved into RNPs, which gradually lost their RNA components to produce modern protein enzymes (see diagram). riboBut "we don't see RNA disappearing," Cech said. Instead, it's proved surprisingly versatile.

Cech argues that the same abiotic conditions that favored the formation of nucleic acids likely also favored small peptides. On its own, RNA is so-so as a catalyst, but in RNPs, it continues to play a vital role. The same synergy likely existed in those earliest days, he says.

Take the ribosome. "They are the Trojan horses that came out of the RNA world," said Venki Ramakrishnan of the Medical Research Council Laboratory of Molecular Biology in Cambridge, United Kingdom. Every molecule in the cell is made by the ribosome or by a protein produced by the ribosome. Over the past decade, he and others have worked out that the RNA subunits are at the core, controlling the assembly of amino acids into specific proteins. Its protein partners help hold two RNA subunits in a semirigid structure that shifts back and forth to pull in amino acids and push out the emerging protein chain.

The rigidity of the ribosome is a sharp contrast to telomerase, which was found to be an RNP in 1987. Telomerase typically consists of one RNA and several protein subunits, including a reverse transcriptase protein called TERT that extends the ends of replicated chromosomes to keep them from getting shorter each time they are copied. The RNA specifies the bases that TERT adds. But Cech's group has found that RNA also acts as a flexible scaffold that recruits other proteins, such as a DNA repair protein called Ku. When they alter the RNA so that it doesn't bind Ku, telomerase doesn't work as well. When they add an extra binding site on the RNA for Ku, then chromosomes grow extra-long, he said. The RNA's arms are flexible and swing into different positions. Yet in the lab, Cech's crew has shortened these arms without affecting the RNP's function. "It's a dynamic system where proteins can switch in and out," says Cech.

Both the ribosome and the telomerase show signs that the protein-RNA partnership is dynamic over evolutionary time as well. Cech and his colleagues have discovered that there is a part of the telomerase RNA that helps speed telomerase activity. "He's finding new functionality in the RNA," says Susan Lindquist of the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts. "A new region has come in and contributes to catalysis."

In the ribosome's case, proteins are lending the helping hand. Ramakrishnan reported the discovery of an arm of one of the ribosomal proteins that extends deep into the RNA where transfer RNAs bind and deliver amino acids. Now instead of depending on RNA alone, "protein tentacles are assisting the process," says Ramakrishnan. In mitochondrial ribosomes, proteins have taken on an ever-larger role. The ratio of RNA to protein in the cell's ribosomes is 2 to 1; but in mitochondrial ribosomes, the ratio is roughly 1 to 2. This ribosome looks about the same, but most RNAs have been replaced by protein, leaving just a small RNA core.

These examples show that RNPs "are not decaying," says Lindquist. "They are continuing to evolve."

—Elizabeth Pennisi

Illustration credit: Harold White, University of Delaware

After receiving the red-carpet treatment in New York City and London (Science, 29 May, p. 1124), the fossil primate known as Ida returned home to Oslo this week, where she will appear at the University of Oslo Natural History Museum starting 5 June. Meanwhile, life-size casts of Ida are already on display at the American Museum of Natural History in New York City and the Natural History Museum in London—and others will soon appear at museums in Germany, not far from the Messel pit where the 47-million-year-old fossil was found, according to paleontologist Jørn Hurum of the Oslo museum.

The fossil of an ancient adapid primate formally named Darwinius masillae was unveiled by Mayor Michael Bloomberg in New York City on 19 May. In one remarkable week, Ida was the subject of a media blitz worthy of the winner of American Idol. First, she starred on 25 May in The Link, a documentary film shown by The History Channel in the United States. The next night, Ida appeared in London with the filmmaker Richard Attenborough, who narrated the version of the film shown on BBC One in England on 26 May. By the end of the week, she was the first fossil to be featured on Google’s home page and the subject of a companion book to the documentary and a Web site.

But one group was conspicuously absent in the toasts to Ida’s success: the scientists who are the world’s experts in primate evolution. Even though they were impressed by how complete and well-preserved the fossil primate was, many were troubled by the branding of Ida as a “missing link” to humans (ScienceNOW, 19 May). Most complained that Ida was the ancestor of lemurs, not humans, and that the hype was not justified by the analysis provided in the scientific paper published last week in the online journal PLoS ONE. The uncovering of Ida’s true identity, however, failed to rain on her parade: At least 2 million viewers tuned in at 9:00 p.m. EDT on 25 May to watch Ida on The History Channel, according to Nielsen Fast Cable ratings. That is up 67% compared with The History Channel’s prime-time average.

—Ann Gibbons

Symp2009_mockup.jpg LONG ISLAND, NEW YORK—Leave it to Cold Spring Harbor Laboratory (CSHL) to put molecules center stage at Darwin’s birthday party. Home to Nobel laureates such as DNA discoverer James Watson and corn geneticist Barbara McClintock, the lab plays host this week to 390 researchers for "Evolution: The Molecular Landscape" (27 May to 1 June). The theme stands in sharp contrast to when the lab last toasted Darwin, in 1959. Then "what was absent was any reference to molecules," says CSHL meeting organizer Jan Witkowski.

One of dozens of Darwin conferences taking place around the world to celebrate the 200th anniversary of Charles Darwin's birth, this event is billed as more of a scientific meeting than a celebratory one, billing 75 talks and 200 posters. The meeting is the lab's 74th annual symposium—originally a monthlong mix of research and presentation and now an annual 5-day themed meeting. It usually takes a year to plan, says CSHL meeting organizer David Stewart. But this time, he and Witkowski started 6 months early, anticipating that many meetings would be vying to book evolutionary biology's biggest names. They succeeded: The program reads likes a "Who's Who" in biology—with luminaries such as Edward O. Wilson and Thomas Cech on the program.

The opening session reflected more than just molecules and gave a flavor of the diversity of topics yet to come. First up was a close look at Darwin himself. Darwin scholar Janet Browne of Harvard University emphasized Darwin as an experimentalist who tapped into a far-reaching network of friends and relatives as collaborators. "He turned his house and garden into a domestic version of a modern research lab … in an age when laboratories were hardly in existence," Browne said. Darwin relied on simple tools. For example, a chemical balance from his youth and tin plant markers sufficed for his studies of what and how carnivorous plants ate. And he used household chemicals—wine, beer, ammonia, urine, nicotine—in those experiments.

Yet Darwin was also an early scientific celebrity. During his day, fans could buy portraits and paintings of their favorite naturalist. Songs, children's books, even Wedgwood china and a "gargling oil" had Darwin themes. Cartoonists depicted him as part human, part ape. And his theories overshadowed his research. His book On the Origin of Species "clouded everybody's view of what he was up to," says Browne. Darwin nonetheless cultivated collaborations across the globe—some 14,000 letters still exist—and solicited from these colleagues their own thoughts and observations about problems he was pursuing. "Letters were a major vehicle of scientific communication," said Browne.

—Elizabeth Pennisi

Photo credit: CSHL 74th Symposium and Daniel Smith

sea lamprey (Wikipedia)

The sea lamprey draws attention mainly for its alienlike appearance, particularly its oval mouth ringed with rows of sharp teeth that allow the parasitic creature to latch onto a fish host. These eel-like creatures are often called “living fossils” because they are thought to have changed little since they arose 450 million to 500 million years ago, as part of a branch of jawless creatures that split off early from the rest of the vertebrate tree. Lampreys and hagfish are the only survivors of that jawless branch, and accumulating evidence indicates that the animals have developed an immune system far different from that of other vertebrates, including people. Today, in Nature, a team led by Max Cooper of Emory University in Atlanta, Georgia, unveils the latest chapter in this emerging evolutionary tale, providing data indicating that the sea lamprey has its own versions of B and T cells, the two cell types central to the so-called adaptive immune response found in people. Whether those lamprey cells are related to our T and B cells, or are an independent invention, remains unclear, but that hasn’t dampened the fascination of immunologists. “I don’t think there’s any question now that there’s a separate adaptive immune system in the lampreys,” says Chris Amemiya of the Benaroya Research Institute at Virginia Mason in Seattle, Washington.

This month’s Origins essay tackled the evolution of the immune system, but it took a decidedly parochial view of the topic, focusing primarily on the microbial defenses wielded by people and other jawed vertebrates. The essay didn’t describe the lamprey story, which first gained prominence several years ago.

snmicrobes.jpgFour billion years ago, asteroids and comets rained down on our planet with such ferocity that scientists have labeled the era the "Hadean"—literally, hell on Earth. Yet despite these infernal conditions, early life could have survived—and may even have thrived in the warm, wet spots left in the crust by impacters—according to a new study.

Earth was born into violence. Shortly after its formation 4.6 billion years ago, a Mars-size body slammed into it, throwing off enough debris to create our moon. As Earth was cooling from this event, debris from the solar system's own formation was shelling it on a regular basis. This hell storm eventually waned, but about 3.9 billion years ago it briefly surged again, a period geologists refer to as the late heavy bombardment.

The bombardment could have spelled the end for any nascent life on Earth. In fact, early calculations suggested that some of the largest impacters, ranging up to several hundred kilometers in diameter, could have vaporized the oceans and sterilized the planet down to a kilometer or so beneath the surface. But in recent years, analyses of chemical and isotopic records preserved in tiny rock crystals have shown that conditions as early as a couple of hundred million years after the moon's formation were relatively mild and possibly conducive to life.

The new simulations back this up. Geoscientists Oleg Abramov and Stephen Mojzsis of the University of Colorado, Boulder, calculated what happens to the heat from large impacters, which vaporize themselves and melt the crust where they hit. In the simulations, these impacts don't generate as much sustained heat as initially thought. Even during the late heavy bombardment, enough water could have percolated through the newly heated crust to quickly cool it, the researchers report tomorrow in Nature. They also assume, from studies of modern deep subsurface microbes, that life could have thrived in the rock down to a depth of 4 kilometers, putting it out of the reach of impact heating.

But Abramov and Mojzsis don't stop there. Not only would life have survived the late heavy bombardment, they say, but it could have arisen as early as 4.3 billion years ago—hundreds of millions of years earlier than the geologic record suggests. That may explain why the earliest ancestor of modern life is believed to be a heat-loving organism: Such a life form may have relied on the hot springs created by impacts long before the late heavy bombardment, the duo says.

"I think we're in basic agreement on" the habitability of the Hadean, says geophysicist Norman Sleep of Stanford University in Stanford, California, who has done similar calculations. But he still thinks that the largest impacter could have devastated most life on Earth and that it may have wiped out all but the heat-loving organisms.

—Richard A. Kerr

Now a Ph.D. student in evolutionary biology, Nicholas J. Matzke was a public information officer at the National Center for Science Education (NCSE) back in 2005. As such, he played a key role in NCSE’s participation in the Kitzmiller v. Dover Area School District trial that pitted intelligent design (ID) proponents against supporters of evolution. In particular, Matzke was central to the trial’s focus on the evolution of the immune system and the cross-examination of ID proponent Michael Behe. He recalls that episode, described in this month’s Origins essay looking at the evolution of the immune system, in an e-mail interview (edited for clarity) with Science's John Travis.

Q: Was it obvious to make the origin of the immune system a focal point of the case? I read that previous online debates with ID proponents led to the choice.

N.M.: Yeah, partially. The fuller story is that for several years, 2001-2004 or so, a number of us "Internet creationism fighters," of which I was one (as a hobby, before I worked at NCSE), would get on various UBB bulletin boards and newsgroups (and blogs starting in about 2004) and debate the ID guys. We were the people associated with,, etc. (Later, this group became the Panda's Thumb bloggers.) Anyway, these debates were long and covered just about every topic in more detail than almost anyone could want. After doing this for years, we got a sense of not just where and how the IDists were wrong (since they are wrong on just about everything), but areas where they are spectacularly, obviously, blatantly, embarrassingly wrong. E.g., Behe's irreducible complexity (IC) argument is the favorite ID argument. And it is true that in 1996, some of the biochemical systems Behe used as examples had not received much attention in terms of their evolution. However, the immune system had received lots of attention even in 1996, and much more by 2005, primarily because (1) it is medically crucial, so there are many more researchers/funding/studies on it, and (2) much of immunology going back to the beginning has relied on comparative studies in animals, so there has been an explicit evolutionary context for 100 years in that field.

The amount of work is relevant because the IC argument always goes like this: 1. ID guy: Natural selection can't explain an IC structure because all of the parts would have to come together at once. 2. Evo guy: Here are some systems with only some of the parts but they still have some function, so your argument doesn't work. 3. ID guy: That doesn't explain how these systems arose, we need to see peer-reviewed publications giving detailed, testable explanations. 4. Evo guy: Here is a peer-reviewed publication on the topic. 5. ID guy: It's not detailed enough, I need to see every single mutation and selection event detailed or I will still say that ID was responsible, not evolution.

At this point, the ID guys have (a) given up on their original IC argument and (b) demanded an impossible, ridiculous amount of detail for the evolutionary explanation, while providing no details or tests of their own explanation. It looks ridiculous from the outside, but ID guys, including Behe, made these moves so regularly that it was pretty predictable.

So, in 2002 this began to become obvious when Matt Inlay wrote it up in an essay for ("Evolving Immunity"). We then jumped Dembski with it in 2002 or 2003 on his own Internet forum at and observed the above progression. Then we posted a bunch of references to articles on the topic and challenged Dembski to provide as much detail for the ID explanation. Here was Dembski's response:

"ID is not a mechanistic theory, and it's not ID's task to match your pathetic level of detail in telling mechanistic stories."

A similar episode happened with Behe in 2005.

In spring 2005, Eric Rothschild began preparing for Behe's deposition in the Kitzmiller case, which was happening in May. I gave him all this background and said if we wanted to pick one system to challenge Behe on, it should be the immune system. We poked him a bit on it at the deposition and got the expected replies.

So then, before the trial, I assembled the stack of books (from the UC Berkeley biosciences library) and articles on the evolution of the immune system and made a big exhibit for Eric to use. Eric asked the questions and got the expected replies, so when Behe started making noises about how the science "wasn't detailed enough," Eric started piling books and articles on the stand, and asking Behe if it was good enough for him. The rest is history...

Q.: You have called the Behe cross-examination on immune origins a "turning point" in the trial. Why do you say that?

N.M.: Well, it was kind of the ultimate Behe defeat amongst a long string of defeats during the Behe cross. I think Eric's whole cross was a "turning point" in that Behe's direct testimony was the one big chance the defense had to come back after the plaintiffs had been beating on ID for 3 weeks during the plaintiffs' case.

It was kind of a turning point for the whole ID argument over the last decade or two because it really exposed for all to see that ID was mostly boasting and dissembling, compared to the substance (physical substance, in the case of the immune system exhibit!) of the evolutionary science.

It was very gratifying to have my very obscure hobby turn into a key skill in an internationally recognized court case. It was kind of like the movie Galaxy Quest, where the Trekkie nerd gets told that the spaceship and aliens from the Star Trek-esque TV show are all real, and his nerdy knowledge saves the day.

In our initial Origins essay looking at the origin of life on Earth, Carl Zimmer discussed research on how the key genetic molecule RNA may have arisen from an abiotic broth. Part of the discussion centered on the RNA work of John Sutherland of the University of Manchester in the U.K., some of which is being published today in Nature. Here's the relevant excerpt from our essay:

Step 1: Make RNA
An RNA molecule is a chain of linked nucleotides. Each nucleotide in turn consists of three parts: a base (which functions as a "letter" in a gene's recipe), a sugar molecule, and a cluster of phosphorus and oxygen atoms, which link one sugar to the next. For years, researchers have tried in vain to synthesize RNA by producing sugars and bases, joining them together, and then adding phosphates. "It just doesn't work," says Sutherland.

This failure has led scientists to consider two other hypotheses about how RNA came to be. Cleaves and others think RNA-based life may have evolved from organisms that used a different genetic material—one no longer found in nature. Chemists have been able to use other compounds to build backbones for nucleotides (Science, 17 November 2000, p. 1306). They're now investigating whether these humanmade genetic molecules, called PNA and TNA, could have emerged on their own on the early Earth more easily than RNA. According to this hypothesis, RNA evolved later and replaced the earlier molecule.

But it could also be that RNA wasn't put together the way scientists have thought. "If you want to get from Boston to New York, there is an obvious way to go. But if you can't get there that way, there are other ways you could go," says Sutherland. He and his colleagues have been trying to build RNA from simple organic compounds, such as formaldehyde, that existed on Earth before life began. They find they make better progress toward producing RNA if they combine the components of sugars and the components of bases together instead of separately making complete sugars and bases first. Over the past few years, they have documented almost an entire route from prebiotic molecules to RNA and are preparing to publish even more details of their success. Discovering these new reactions makes Sutherland suspect it wouldn't have been that hard for RNA to emerge directly from an organic soup. "We've got the molecules in our sights," he says.

Sutherland can't say for sure where these reactions took place on the early Earth, but he notes that they work well at the temperatures and pH levels found in ponds. If those ponds dried up temporarily, they would concentrate the nucleotides, making conditions for life even more favorable.

Were these Darwin's warm little ponds? "It might just be that he wasn't too far off," says Sutherland.

Today's New York Times has one of the many newspaper articles discussing the study, and it includes a nice graphic that helps explain the new advance.

—John Travis

April's Origins essay in Science is devoted to the evolution of flowering plants and so, too, is a meeting yesterday and today at the Royal Society in London. The finale of the meeting will be an evening public lecture on 12 May, Web cast live and then available archived, by Sir Peter Crane, a former director of the Royal Botanic Gardens at Kew who is now at the University of Chicago in Illinois.

Credit: Wikipedia

Although many historic ships are preserved in museums or at docks, the Beagle, the vessel employed for Charles Darwin’s voyage to the Galápagos Islands and around the globe, has apparently lain in a muddy grave in the east of England for the past 130 years. At a public lecture last week in London at the Royal Society, Robert Prescott, who uncovered the first clues to the Beagle’s whereabouts in 2004, detailed his team’s hunt for the ship. The marine archaeologist believes he has found his prize, although his team is seeking more confirmation and eventually hopes to excavate the ship’s remains.

Prescott and his colleagues determined that after three long-distance voyages, the well-traveled Beagle was relocated to a backwater town in coastal Essex in 1845. Stationed along the River Roach in a village called Paglesham, it was used to guard coastal creeks and waterways against smuggling after the Napoleonic Wars. The ship was finally decommissioned in 1870, as smuggling slowed in response to the expanding Victorian economy, and was dismantled over time. Prescott’s team then studied historic maps of the river area and performed geophysical surveys using magnetometry and ground-penetrating radar to identify the ship’s final resting place—a site now 7 meters below ground.

A quick look at the site, which is now engulfed by muddy marshes, would betray little trace of a buried ship. However, at low tides, water can be seen swilling into an indentation just a few centimeters deep in the mud. “The water fills the dips and eddies [providing] a ghostly shadow of the Beagle,” says Prescott, who is based at the University of St Andrews in the United Kingdom. (The pictures below shows the suspected site of the Beagle at various tide levels.)

Final resting spot? (Credit: Prescott)

It’s likely that the ship was broken up on site, he says, as those dismantling it gathered useful materials they could sell. Once the remaining vessel began to sink and flood, they would have abandoned it: “It would be a dead weight and slowly get buried.” However, this last chunk of ship is entombed in poorly oxygenated mud, which is good for preservation, notes Prescott.

Hoping to confirm that the remains are those of the Beagle, the team has recently been drilling into the mud to extract tiny segments of the remaining timber. These fragments are home to tiny micro-organisms called diatoms, which could be used to trace the ship’s journeys around the globe. The “pot of gold” would be to find diatoms normally found in the Pacific Ocean, from Darwin’s charting of the South American waters, says Prescott, but none have been seen yet.

The team is calculating the resources required for an excavation, but with the money needed likely to reach a six-figure total, it may be some time before it’s possible. “At some point, we might make a delve into the depths of the marsh,” says Prescott. Until then, arguably the most famous ship in science may lie quietly in the mud.

—Claire Thomas

Credits (Top to Bottom): Wikipedia; Robert Prescott