Sapogenin levels in Narthecium ossifragum plants and Ovis aries lamb faeces during two alveld outbreaks in Møre og Romsdal, Norway, 2001.

The proposal that saponins produced by the lily bog asphodel (Narthecium ossifragum) may be the direct cause of the hepatogenous photosensitization disease alveld seen in Norwegian lambs was investigated by comparing sapogenin levels in two control and two toxic pastures, and in faeces from lambs grazing the four pastures in the Halsa and Surnadal municipalities, Møre og Romsdal county, Norway. Generally similar levels of sapogenins, determined after hydrolysis of parent plant saponins, were found in Narthecium leaves collected in June/July 2001 from the two alveld outbreak areas and two nearby control areas. Differences in the median sapogenin levels determined for leaf samples in outbreak and control areas were not statistically significant. The total level of free and conjugated sapogenins in faeces recovered from the rectums of lambs grazing the outbreak and control pastures areas varied greatly. The results obtained do not support the hypothesis that a dose-response relationship exists between Narthecium saponin levels and the occurrence of alveld outbreaks.

Egoism and altruism.

Unto Others: The Evolution and Psychology of Unselfish Behavior by E. Sober and D.S. Wilson Harvard University Press, 1998. $19.95 hbk (394 pages) ISBN 0 674 93046 0.

[Genes, behavior and disease. A sceptic's view of gene mapping and gene therapy]. / Gener, atferd og sykdom. En skeptikers syn på genkartlegging og genterapi.

This paper contains four parts. The first focuses on The Human Genome Project (HGP). The concept of a "normal sequence" seems problematic. The second part reviews what is meant by "genetically-caused" and by "a (several) gene(s) for a trait". Genes work in concert, and it is likely that many genes together influence most complex traits. A difference in traits between two individuals, however, can be due to a difference in a single gene, as is the case for several thousand rare "genetic diseases". Such diseases were the original focus of gene therapy. Could gene therapy also be applied to more common complex traits? Diagnostic problems and the unsuccessful attempts to find a single gene difference in patients with manic depressive disorder, schizophrenia and Alzheimer's disease are discussed. Part three reviews future genetic research into complex traits and what kind of treatment can realistically be expected. It is concluded that improved diagnostics is the most likely outcome, not therapy. Part four raises arguments from the emerging Darwinian approach to medicine and states that it is far too early to even think of gene therapy. The needed knowledge about genes, behaviour and disease will not come from the one-sided genetic effort represented by HGP, and the resources should instead be invested in several different approaches to these complex issues.

Mortality of domestic sheep in free-ranging flocks in southeastern Norway.

Lamb mortality during three summer grazing seasons (1988 to 1990) among 1,399 lambs in three flocks of free-ranging domestic sheep in southeastern Norway was modeled using logistic regression. Ewe mortality during the same three seasons among the 295 ewes in one of the three flocks was also modeled. During the period, mortality among the 1,399 lambs and 295 ewes was 7.2% and 12.5%, respectively. Other work has shown predation by brown bears to be the single most important mortality factor in all three flocks, especially among ewes. Year, herd, sex, age of dam, and spring growth rate (i.e., from birth to release onto summer range) were statistically significant (P < or = .05) in explaining mortality among lambs. Lamb mortality was higher in 1989 and 1990, higher in HerdA (the most isolated herd that grazed adjacent to the Swedish border), higher among lambs of yearlings, among male lambs, and among lambs with low spring growth rate. Ewe mortality increased with age (P = .07). Adjustment of age for weight weakened the statistical association between age and mortality, however (P = .16). The negative association between lamb mortality and age of dam and the positive association between ewe mortality and ewe age may both be related to the quality of maternal care provided by ewes of different ages. Subsequently, attempts to compensate for losses, especially those due to predation by bears, lead to a younger herd that may increase the herd's overall vulnerability.

Mortality transmitters--new instrument for animal loss research on Norwegian ranges.

In 1988, 315 lambs from 4 sheep (Ovis aries) herds comprised of 1003 animals were marked with silent mortality transmitters in Gammeldalen in Hedmark County, southern Norway. The aim was to identify causes of death and the so-called "hidden loss" of lambs on summer range. A total of 22 animals, 19 lambs and 3 ewes were found dead. Of these, 18 lambs were marked with radio transmitters. A total of 10 animals died of disease (45.5%) and 12 were killed by predators (54.5%). Of the 18 radio-located lambs, 6 died of disease (33.3%) and 12 due to predators (66.7%). Various common lamb diseases were diagnosed, e.g. lung, thoracic and intestinal infections. Eleven lambs were killed by lynx (Lynx lynx), a 12th was found chased to exhaustion, presumably by a predator. Use of mortality transmitters is concluded to be useful in investigating sheep losses on Norwegian ranges.