A Blog Around The Clock

One of the latest additions (just two days ago, I think) to the Directory of Open Access Journals is a journal that will be of interest to some of my readers – The Open Sleep Journal. The first volume has been published and contains several interesting articles. One that drew my attention is The Phylogeny of Sleep Database: A New Resource for Sleep Scientists (PDF download) by Patrick McNamara, Isabella Capellini, Erica Harris, Charles L. Nunn, Robert A. Barton and Brian Preston. It describes how they built a database that contains information about sleep patterns in 127 mammalian species. The Database itself can be found here and one can search it by species, by what was measured, by physiological or environmental conditions in which sleep was measured, etc. It has links to research on everything from platypus and echidna, through humans and kangaroos, to elephants, giraffes and sloths.

Since one of the stated projects that will come out of the database is a publication of a book on the Evolution of Sleep, I looked around to see if they are interested in anything else apart from mammals. Looking at the Projects page, I see they intend to add birds to the database later on. But that is not enough. Sleep did not suddenly appear full-blown in mammals and separately in birds. There is a long history of sleep research in reptiles, amphibians and fish, as well as – more recently – in insects like cockroaches, honeybees and Drosophila. In order to study the origin, evolution and adaptive function of sleep we have to look at its precursors among the invertebrates, not just focus on mammals and birds.


  1. #1 Isabella Capellini
    February 26, 2009


    yes you’re very right, sleep is not a feature of just mammals and birds and we scientists should also study other animals. The Phylogeny of Sleep database is the first step to summarize and share lots of data that have been collected in the last 50 years on sleep. The bias towards mammals and birds in the database reflect the fact that almost all studies focused on these taxonomic groups. We used the database for a large comparative study which resulted in a series of papers you can find in the project website.

    We encourage everyone to use the Phylogeny of Sleep database for other studies, and also to upload new data to be shared with the scientific community. We will add other animal groups once more data become available (or perhaps even earlier… as usual the funding element is a limiting factor!)

    Isabella Capellini