FEBRUARY 12, 2009 News in brief Marine biology news briefs, done in co- ordination with the Marine Biology Web Page https:// you.stonybrook.edu/ MBNEWS marinebio

Photo by Jeffrey Levinton CHARLES DARWIN: THE GREATEST MARINE BIOLOGIST

Charles Darwin was born 200 biologist? Even the greatest marine years ago, on February 12, 1809. He biologist of all time! spent his childhood mostly landlocked Let’s not forget the most momen- in the Welsh borderland, collecting tous experience of his young life. On beetles, hunting, and being the equiva- December 27, 1831 he set out on the lent of a 19th century intern (in modern H.M.S. Beagle, which circumnavigated parlance) with Adam Sedgwick, one of the globe in 5 years and gave Darwin the great geologists of the 19th cen- the opportunity to see the world tury. He spent most of his later life, through his brilliant intellectual lens. again, landlocked in the small village of More important, he not only carefully Downe, just a few minutes along the observed nature, he reasoned. It is this road from the local pub and church, combination of observation and rea- neither of which he frequented. In fact, soning that places him, in my view, on Great Wave Off Kanagawa he mostly occupied his lovely house, the pedestal of greatest marine biolo- This famous image is the great tended his garden, and paced the gist. wave, as captured by the Japanese artist Hokusai. The work is famous “Sand Walk” again and again. So how Consider the way great science for its beauty and reality. can he be called a visionary marine works. The way it really works. A sci-

[1] entist gets a feeling, a notion, that signed to explain, or attempt an expla- have the reasonable premises: rapid something might be true about the nation, of a paradox concerning coral growth, large extent, and the require- natural world. Call it intuition, but it is reefs. ment for growth only in shallow waters. This led to Darwin’s obvious conclu- sion, which he published in his first major scientific work: “On the Struc- ture and Distribution of Coral Reefs” published in 1842. The very important conclusion was that the bedrock beneath coral reefs must be sinking, while the reef was growing upward! How else could these reefs be growing upward indefinitely at a rapid rate? Over large amounts of The H.M.S. Beagle, credit The Beagle Project geological time, this sinking of the bed- often a best conclusion based upon a Keep in mind that this level of rather integrated thought process. The thinking simply did not exist in marine feeling evolves into a statement, but biology at this time. Darwin articulated the scientist realizes that it may not be the first sophisticated overarching sci- all that convincing to others. So he entific hypothesis about coral reefs, must make a case to support the and global geology, based on logic and statement, but the sum total of his past prediction, in the history of marine bi- experience has already made a con- ology! If that is not greatness, I don’t vincing case to himself. Then he must know what is. articulate the premises of the state- Darwin knew that corals on reefs ment: are they logical? Are they con- grew in well-lit shallow waters and sistent with what we know of the grew fairly rapidly. If that was so, they world? Finally, he must show to himself must be growing upward. But why do that the consequences of the state- we see such enormous coral reef Pearl and Hermes Atoll, NW Ha- waiian Islands (credit NOAA) ment flow from the premises. Such a tracts? By Darwin’s time, navigators complete statement, with consistent already knew that coral reefs were of- rock beneath would be balanced by premises and a logical prediction is ten enormous, and were often patently upward growth of the reef itself. Sud- known as a hypothesis. dangerous navigation hazards. Explor- denly, the worldwide extent of coral Keep in mind that the grandest of ers like Captain Cook immediately un- reefs in the tropics gave us a new no- hypotheses, relativity, gravity and derstood how extensive coral reefs tion of earth history: a continuous sink- many others, all had this sort of devel- were. Many a sea captain foundered ing of the earth balanced by an upward opment. Einstein conceived of relativity on them, including the famous captain growth of corals, which kept them al- with no mathematics at first. Isaac of the Essex, the only ship known to be ways near the surface. Newton thought of gravity while watch- attacked by a whale. What bad luck to ing apples fall from a tree. No matter survive such an episode, only to get how these inspirations happened, you command of another ship and be can see how “informed intuition” leads dashed on the coral of a western Pa- great minds to make such statements cific island. that are later formalized. But I digress. Darwin knew these And that precisely is why Darwin coral reefs were large and grew in towers as a marine biologist. His first shallow waters. But how could such great scientific publication was de- large coral tracts develop? Well we

[2] An important detail involved set of 150 m worldwide and as the ice re- Darwin’s idea was grand but not different reef types that Darwin inter- treated (as it has done over the past completely correct. But it reveals an preted as phases of sinking. He saw few thousand years), the melting ice important truth about science: mistakes small fringing reefs as the first phase, has caused a rise of sea level. Coral often are just as important in our un- large coastal reefs, like the Great Bar- reefs must erode when sea level de- derstanding of the world as successes. rier Reef, as a second phase, and clines and many have grown upward If you doubt Darwin’s greatness, open sea island rings, or atolls, as the when sea level rose and still are alive here is one last thing to ponder. Darwin final phase1. today. So Darwin missed much. formed his theory of coral reefs before This was a truly visionary scientific But there is one major class of he ever saw one! As he wrote: “No hypothesis. It was global in scope and reefs where Darwin got it exactly right other work of mine was begun in so built a grand idea from the activities of and these are known as atolls. Atolls deductive a spirit as this, for the whole tiny coral polyps, adding infinitesimally are ring-shaped groups of islands with theory was thought out on the west small amounts of carbonate skeleton fringing coral reefs (e.g., Enewetak coast of South America, before I had each year to grow upward. Most impor- atoll in the Marshall Islands of the cen- seen a true coral-reef.2” tantly, Darwin made a clear prediction. tral Pacific). These reefs sit atop an Darwin was not only a great and You should be able to drill down into a extinct volcano which has subsided for pioneering marine environmental sci- coral reef, particularly an atoll, and go millions of years. As the sea floor entist and ecologist, he also was a ma- through large amounts of coral, before moves laterally, in a phenomenon jor pioneer in describing the ocean’s encountering another type of geologi- known as sea floor spreading, the vol- biodiversity. While on the Beagle, he cal bedrock beneath. Darwin was now cano moves into a region of geologi- collected thousands and thousands of moving out on thin ice, but he even cally cooler conditions and the crust marine specimens, many of which made a prediction: a reef of 5000 feet subsides and the volcano sinks. Coral were distributed to various experts in thickness would be found and bedrock grows on the fringe of the volcanic rock the appropriate specialties when Dar- would be found beneath it. above the surface at first, but as the win returned to England and moved to volcano sinks, the coral reef grows London to work on his collections. But upward, leaving a very tall cylinder of he kept for himself the great task of coral rock on top of the sunken vol- describing and classifying the world’s cano. The geophyscist J. Tuzo Wilson barnacles. In the 1850s he published realized that plate tectonics might be four volumes on the world’s barnacles Figure from Darwin’s original behind such sinking, but also occa- and attempted to classify them by volume on coral reefs, showing his idea of the evolution of sional uplifts of oceanic volcanos. means of their morphology. It had not reefs from fringing, to barrier, Drowned reefs atop sunken volcanoes been very long since barnacles were to atolls. are common throughout the Pacific realized to be crustacea, relatives of How successful was this hypothe- Ocean. shrimp and lobsters, and not mollusks, sis? Well, only partially. Investigations The truth of Darwin’s sinking hy- or relatives of snails and clams. Darwin over the past hundred years or so pothesis was tested once and for all by carefully described all of the species demonstrated that many coral reefs Harry Ladd and colleagues in the he collected but also got more from were not subsiding steadily, and it is 1950s. They drilled into Enewetak atoll other collections brought to England, not true that fringing reefs, coastal and found that they had to drill some including the giant barnacle Balanus reefs, and atolls are sequential phases. 4000 feet before encountering volcanic nubilus, brought back from Captain Darwin also failed to take into account rock, over 40 million years old. This George Vancouver’s expedition to the the advances and retreats of glacial ice result was amazingly similar to Dar- Pacific northwest in the late 1700s. He over the continents. As the ice ad- win’s prediction. also used fossil barnacles from his own vanced, sea level lowered as much as and other collections. His grouping of

1 See Rosen, B. 1982, “Darwin, coral reefs, and global geology” in BioScience, v. 32(6), p. 519 for a more detailed discussion of this theory.

2 See the Life and Letters of Charles Darwin, 1888, v. i, p. 70.

[3] barnacles into major groups of species to explain the process. But do not for- (stalked versus unstalked barnacles) get, Darwin also set the table for ma- and then smaller groupings was based rine biology and natural history for on a careful analysis of a variety of decades and centuries to come. His characters. To study the barnacles, genius ranged far beyond the beak of Darwin purchased a fine compound the finch. microscope. The amazing thing is that his taxonomy was brilliant and has Happy Birthday, Mr. Darwin!! largely stood the test of time. The thinking and publication of these books Jeffrey Levinton is Distinguished predated his masterpiece, The Origin Professor of Ecology and Evolution at of Species, by a number of years, but Stony Brook University. He is a marine we now know that he was thinking and ecologist and author of the textbook writing about evolution and natural se- Marine Biology: Function, Biodiversity, lection in his famous notebooks years Ecology, 3rd ed., published by Oxford before this. The words barnacles and University Press in 2009. cirripedes appear 28 times in The Ori- gin. So we cannot escape the conclu- Want to contact us: Please email sion that Darwin likely used evolution- JEFFREY.LEVINTON@STONYBRO ary thinking in the construction of his OK.EDU taxonomy of barnacles, and he learned much from them, including the evolu- tionary loss of characters. Darwin no- ticed that parasitic barnacles lacked a number of characters found in free- living species, and believed that the evolution of the parasitic condition in- volved the loss of characteristics (e.g., an external shell) that added unneces- sarily to the cost of living of a parasitic form.So Darwin was not only a great ecological marine biologist, he also essentially invented the field of evolu- tionary marine biology. It might be wrong to give Darwin credit for every- thing, but his grand style of thinking permeated his forays into marine biol- ogy, and these achievements firmly Charles Darwin, The Greatest establish his firm grip on the title of Marine Biologist Grand Master of Marine Biology. Today we celebrate Darwin for his genius, his invention of the theory of natural selection. His “one long argu- ment” convinced the educated world that evolution was the only rational explanation for the diversity of life and he greatly advanced science by show- ing that there are good notions of how

[4]