Description | Slide shows a description of an experiment with male and female chromosomes, based on the Goldschimdt equation. Text of the slide is described in full, as follows: 'These are all normal individuals and the females all contain a neutral F in their Y-chromosome. b. a male by reversal fertilises.' There are then four diagrams labelled 5 to 8, which show the male fertilisation. The text follows on to say: 'No. 5 with the two Y will die; no. 6 is a female with a neutral F, no. 7 a female with a weak F, no. 8 a male. Result therefore 2 females: 1 male and half of the females have a weak F though the maternal line was neutral, but the father having been an XY male. If now the F is actually situated within the Y chromosome a simple test can be made: mated to a strong male, the females with a neutral Y must produce normal offspring, but the females with a weak Y only sons, namely [equation]. This experiment, performed with hundreds of such females, yielded only normal sex ratios, which finally rules out the Y chromosome as carrier of F; F then must be a cytoplasmic property. (Details see Goldschimdt 61). The ratios of this experiment have already been mentioned in connection with the male by reversal and pictured in Fig 9B. This leaves the forementioned extra-females unexplained. The only visible explanation is a sudden change of F from weak to strong after the pattern of gene mutation.' |