Over the past 50 years, songbirds have become a valuable model organism for scientists studying vocal communication from its behavioral, hormonal, neuronal, and genetic perspectives. Many advances in our understanding of vocal learning result from research using the zebra finch, a close-ended vocal learner. We review some of the manipulations used in zebra finch research, such as isolate housin...

The song of the adult male zebra finch is strikingly stereotyped. Efforts to understand motor output, pattern generation, and learning have taken advantage of this consistency by investigating the bird's ability to modify specific parts of song under external cues, and by examining timing relationships between neural activity and vocal output. Such experiments require that precise moments durin...

Understanding the mechanisms underlying speciation remains a challenge in evolutionary biology. The adaptive radiation of Darwin's finches is a prime example of species formation, and their study has revealed many important insights into evolutionary processes. Here, we report striking differences in mating signals (songs), morphology and genetics between the two remnant populations of Darwin's...

Also, a process {Yt : t ≥ 0} is said to have independent increments if, for all t0 < t1 < . . . < tn, the n random variables Yt1 − Yt0 , Yt2 − Yt1 , ..., Ytn − Ytn−1 are independent. This condition implies that {Yt : t ≥ 0} is Markovian, but not conversely. The increments are further said to be stationary if, for any t > s and h > 0, the distribution of Yt+h− Ys+h is the same as the distributio...

Serious sepsis is a major medical problem. Studies from the USA and Europe attest to its importance and possibly increasing incidence. Annually, an estimated 400,000– 600,000 persons develop sepsis in the USA and, of these, approximately 35% die. Although surgery, transplantation, cytotoxic chemotherapy, immunomodulation and other advances in the management of disease increase longevity, these ...

Cutaneous pigmentation is a well-recognized feature of idiopathic haemochromatosis and, in various series, has been recorded in up to 8o per cent. of patients (Finch and Finch, I955). In the world literature there are occasional reports of pigmentation in the gums (Saundby, I890), buccal mucous membranes (Richardiere, I895), lips (Parker, I903), and tongue (Hess and Zurhelle, I905), and Maddox ...