50 Years Ago

Recent reports on the chromosomes and total DNA of the chicken cell nucleus show that they differ from those of typical placental mammals in an unusual pattern of chromosome sizes and a DNA content equal to half of that of most mammals ... anomalies include incomplete dominance ... and alteration of phenotypic sex without visible alterations in the karyotype. One explanation ... could be that three-fourths of the normal genetic dose occurs fairly frequently in the chicken. Three-fourths of the normal gene dose could occur if each of the arms of the major chromosomes in the chicken were isochromosomes ... which double back on themselves for transcription but straighten out and are apposed in the orthodox manner for meiosis ... A chromosome pair would provide four readings of the message, and a cell with three out of four of the normal readings might well be viable ... One evolutionary advantage of the looped isochromosome system proposed here might be that such a chromosome would be better able to withstand the damage to the DNA ... caused by the relatively high internal temperature of birds.

From Nature 12 November 1966

100 Years Ago

In Nature of October 5 it is stated that the cause of the optical deterioration of the atmosphere in July and August “is for the time being still in doubt. Up to the present no reports of volcanic eruptions have come to hand from any part of the globe.” I wish to state that in July a strong outburst occurred of the Stromboli volcano ... there was an extraordinary eruption of fluid and incandescent lava to a great height, followed by a thick rain of lapilli and ashes.

From Nature 9 November 1916 Footnote 1