Thursday, May 26, 2011
"A precise answer to such a question is impossible and an adequate one demands a longer time than can usually be afforded. The consequences of inadequate explanation often proved to be unsatisfactory. The visitor becomes skeptical and instead of taking interest in the subject, he seems to be confirmed in his doubts.
In this leaflet is given a condensed, general statement of methods of determining the age of ancient life...It is intended for those who are interested in the age of past life and yet do not intend an exhaustive study of the subject..."
The author begins by discussing previous methods of determining age, including the rate of land erosion and the rate of salt derivation. These methods, however, are flawed. The rate of sedimentation varies according to the "character of the sediments deposited," whether the river terminates in the sea, thus depositing sediment in the ocean, and severe weather conditions that may affect shallow water sediments. Similar uncertainties exist when using the rate of salt derivation, including an uncertainty about how much salt from shorelines or ocean beds was dissolved into the oceans in the past, or how much salt has been taken from the oceans into rock salt beds on the earth.
Using methods such as trying to determine the earth's age by considering "the rate of life transformation in successive periods" is challenged by certain species, such as the brachiopods, which have resisted evolutionary change since as long as we have record of them. Similarly, the evolution of other species is extremely accelerated, such as the evolution of fish to amphibians to reptiles to birds to mammals. If we rely on dating methods that take into account how species have changed over time, but know that these changes are directly influenced by shifting environmental factors and not all species encounter changes that require an evolutionary response while others encounter conditions that require a much more rapid response, we quickly learn that this method of calculating age is also unreliable.
The ability to calculate the number of radioactive changes in certain chemicals, however, has changed the game. The star player in the game is uranium, which undergoes a transformation over time, ultimately breaking down into the metal lead and the gas helium. This transformation is unaltered by any external process. Therefore, "Since the rate of transformation is known, data for calculating the age of the mineral and with it the rock formation of which it is a part, can be obtained by measuring the quantity of helium and lead in the rock and comparing it with the quantity of uranium in the same volume of material." While this method may be somewhat flawed, as helium, being a gas, may partially leak out of its rock home over time, "estimates based on the lead ratios of radio-active minerals offer results consistent among themselves." With these known factors, 8,000* million years are required for the formation of one gram of lead from uranium.
As a result of these studies, "the earliest life of which we have fossil records is about 1,500,000,000 years old. From this, it could be safely concluded that the inception of life on earth must have taken place much earlier." Referring to the geological time chart included with the text (and pictured in this post), the author writes, "As we climb higher in the geological column, life becomes more and more complex and specialized. From the one-celled life of the Archeozoic it passes through the invertebrates - fishes - amphibians - reptiles - birds and mammals to man of the Recent time."
We hope you've enjoyed this quick crash course on dating fossils, courtesy of our book of the week, How Old are Fossils (1927), by Sharat Kumar Roy (contributed by the Field Museum). Now go out and find your own fossils and think about the magnitude of time they represent.
Wednesday, May 25, 2011
The John Thackray medal "recognizes significant achievements in the history or bibliography of natural history." According to the website for The Society for the History of Natural History, which awards this medal, "significant achievements" specifically include "making available ... collections and/or information in new and novel ways." While the 34 million + pages of literature that BHL has now made available for open access use, in addition to several of our special features, such as species name finding, the ability to generate your own custom PDF, and the opportunity to nominate titles for scanning, is a great start, this award serves as an encouragement to all of us at BHL to continue pushing the envelope and developing new ways to provide meaningful information and services to our users.
When asked to comment about the significance of this award for BHL, Mr. Higley responded,
"John Thackray was a past President of The Society for the History of Natural History (SHNH) and also the Archivist at the Natural History Museum, London (NHM) for several decades. It is particularly fitting that the BHL should be recognized by this award, since John and his colleagues in the SHNH made avid use of the historic collections at the NHM. It is now possible for their successors to look at or obtain copies of these rare early texts directly from the BHL, which is a truly global resource for historians as well as current scientists."
We send a special thanks to The Society for the History of Natural History for honoring us with this award. We plan to continue to provide rare, important, and relevant biodiversity information to our users, and promise to continue developing novel ways for our users to interact with and use this content.
For more information on the John Thackray Medal, see our previous blog post regarding the award and visit The Society for the History of Natural History website to see their official announcement of the award.
Tuesday, May 24, 2011
Thursday, May 19, 2011
Monday, May 16, 2011
The paper and subsequent commentary has accelerated nascent efforts at macroscopic, algorithmic questioning of large historical textual data sets. Can similar methods be applied fruitfully to the BHL corpus?
Already, Rod Page, bioinformatician and developer of BioStor, has demonstrated suggestive evidence in the affirmative by tracking a small sample of species names for the same organism in BHL texts through time and plotting the number of citations. The graph may be a visual representation of scientific debate and usage. Many other uses are possible, including:
- Co-occurrence of place names with species
- Frequency of co-occurrence of species names esp. with key words such as host, prey, predator, symbiont etc.
- Tracking trends in zoological and botanical research by tracking methodological terminology through time.
- Identification of taxonomically significant “events” in the literature based on textual cues.
Much of the follow-on activity to the Science paper is occurring in the “Digging into the Data” program. Thus, on May 9, the BHL made its data available for researchers in the Digging into the Data program.
BHL Director, Tom Garnett, will be attending the conference, “Digging into the Data” in June where speakers, including the authors of the Science article, will address issues of and opportunities in data mining of large textual corpora. With suitable partners, it is possible that we can seek NSF or Google funding for the unique use case our increasing text corpus presents. The framework for a proposal would be a team of biologists and a team of computer scientists posing research questions for the BHL corpus that would be amenable to algorithmic investigation. Even if funding is not forthcoming, if third party researchers use the BHL corpus to produce scientifically or historically salient results, it will enhance the value and use of the BHL, which can lead to further collaborations.
Thursday, May 12, 2011
Tuesday, May 10, 2011
Q: What is your title, institutional affiliation, and area of interest?
A: I am a postdoc at the Biodiversity Synthesis Center (BioSynC) based at the Field Museum of Natural History in Chicago, IL, USA. I am a revisionary systematist conducting phylogenetic, taxonomic, and biodiversity studies on a group of flies named Apioceridae (flower-loving flies), Asilidae (robber flies), and Mydidae (mydas flies).
Q: How long have you been in your field of study?
A: I started serious work and began writing publications on these flies in 1999 while studying biology.
Q: When did you first discover BHL?
A: As I am working for BioSynC, which is part of the Encyclopedia of Life with which the BHL is closely associated, I have been hearing about BHL from the early beginnings and started using the resources in the beginning of 2008.
Q: What is your opinion of BHL and how has it impacted your research?
A: The BHL is an outstanding source for biodiversity information particularly from older books/journals that are otherwise found in only a few libraries.
As a taxonomist who has to deal with numerous historical publications to decipher the identity of species and type specimens, my research relies heavily on old publications. Before 2008, I would copy or scan publications myself in order to have them available in my office for my research on flies. But when I visited another natural history museum to study specimens, I didn't have access to these copies as I couldn't bring my entire file cabinet with me. The high-quality scans produced by BHL in PDF format allow me now to have the vast majority of papers/books on my flies with me on my laptop and therefore I can always check a certain publication when traveling to other museums and being away from my desk.
In addition to my own research interest, I have encouraged smaller institutions like natural history museums or scientific societies who publish their own journals to consider digitization of their journal(s) by the BHL. Often these smaller institutions or societies don't have the infrastructure to digitize or host electronic copies of their journals. So far I have initiated contact between journals from Argentina, Brazil, Bulgaria, Chile, Germany, Italy, and South Africa that are now available through the BHL portal. All of these journals waived the copyright so that the BHL can provide access from the first volume to a particular volume within the last 5 or 10 years, allowing the institutions/societies to keep access of the most recent volumes restricted to subscribers only. It would be nice if more institutions/societies follow this model to provide electronic access to biodiversity information published in their journal(s).
Q: How often do you use BHL?
A: I use the BHL weekly I would say.
Q: How do you usually use BHL (read titles online/download whole PDFs/Select Pages to Download/etc.)
A: I am employing two strategies when I use the BHL. For large books or very long papers I will download the entire volume, delete those pages/papers I am not interested in, and store it as a PDF on my hard-drive. For regular-sized taxonomic papers, I prefer to access the material with the "Select Pages to Download" option and to provide the bibliographic data on the following screens. This has two advantages: one is that I "only" get the pages I am really interested in, but the second, and much more important one, is that a PDF that now has associated bibliographic data is deposited in the BHL CiteBank, which allows other users to easily find this particular paper by searching for the title, for example. Furthemore, when I download the generated PDF I obtain a permanent link to this particular article on the BHL CiteBank, which I can now incorporate into my bibliographic manager as well as e-mail to colleagues instead of attaching large PDFs to e-mails directly. Itemizing the journal publications on BHL is a great service that researchers who have a bibliography covering a particular topic can provide to the scientific community at large.
Q: What are your favorite features/services on BHL?
A: I think the most amazing feature is the ability to search for genus or species names directly in BHL. The OCR-text recognition coupled with the identification of binomial names increases the value of the generated PDFs. Sure, any PDF with prior OCR-text recognition can be search directly, but that BHL instantly shows the scientific names on a particular page of a digitized document ("Names on this Page" in the lower left window) is just great.
Q: If you could change one thing about BHL, what would it be, or what developmental aspect would you like the BHL team to focus on next?
A: I have encountered inconsistencies in several instances where part of a journal is digitized by different BHL partner libraries. For example, if you search for "Stettiner" to find the Stettiner Entomologische Zeitung you get two search results, one item digitized by Ernst Mayr Library at Harvard University from 1840-1911 and one item digitized by the Smithsonian Institution Libraries from 1912-1923. Unfortunately, the title is slightly different in both items and a user need to look at both links to find the correct item of her/his interest. Also, the volumes are inconsistently numbered/itemized, which makes it sometimes difficult to find a particular volume in old journals.
Thank you, Torsten, for your detailed account of your use of the BHL, and the work you do on our behalf to help us establish contacts that result in permission to scan in-copyright material for our collection. Furthermore, thank you for your honestly in helping point out ways in which we can make our content more user-friendly, as by merging titles and standardizing itemization in BHL.
The particular title you refer to actually represents a data presentation model that we follow in BHL, which is maintaining separate pages for title changes of the same serial. So, the 1840-1911 entry in BHL is the first title change in this serial, while the 1912- entry is the succeeding title. These two titles are linked to each other via the "Related Titles" links on the left hand side of the bibliographic page.
However, while these two titles may not need to be merged, there are many instances in BHL where title merging does need to occur. This is, unfortunately, a manual process for BHL staff, and we need help identifying those titles and items that need this attention. Please do not hesitate to submit feedback on our website to let us know about titles and items that need our attention. We are a constantly growing and improving project, and we rely on the feedback of our users to make that happen!
Stay tuned for our next blog post, which will appear later this week, in which we highlight one of Torsten's favorite books in BHL as our book of the week! And if you'd like to be featured on our blog, please don't hesitate to send us feedback, leave us a message on our Facebook page, or send us a tweet to @BioDivLibrary!
Monday, May 9, 2011
At the time of the launch, there were just over a million pages of taxonomic literature available on the site. Today, there are now just short of 34 million pages.
Though this could be a moment to look back at the numerous accomplishments of BHL during the past four years, the trajectory of BHL compels us to look ahead. In addition to the increase in available text, the globablization of BHL has been remarkable and promises to provide new grounds for more growth. The way that the idea of the BHL has taken hold around the world. BHL nodes have been established in Europe (BHL Europe), Australia (BHL Australia), South America (BHL SciELO), China (BHL China), and work is underway to establish a node with the Bibliotheca Alexandrina (Egypt).
Also boding well for the future is the way in which BHL has become a working tool in the day to day work of taxonomists around the world. BHL data, used through the BHL website, but also increasingly through APIs and machine-to-machine communication is providing researchers and others with immediate access to hard to locate historic literature.
And what are our next steps? Many. We happily face new tasks upfront: synchronize data across our global partner nodes. And moving beyond just the large amounts of data generated by our scanning projects, our next steps will be to attempt to syncronize and share our code to keep our data up-to-date on a redundant worldwide network. Having these systems in place will facilitate bringing on new partners and allow for better integration of functionality and interfaces. If you'd like to comment on the next wave of BHL development & functionality, join us 14-15 November in Chicago, USA, for Life & Literature, a 2 day workshop that will convene librarians, biologists, computer scientists, publishers, students, and other stakeholders to set the agenda for biodiversity literature digitizing and its networked environment for the next four to five years.
This is exciting, it proves we are fullfiling our users needs and even promoting new demands for information.
|BHL Global Partners|