21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-05-03 04:58:00

linkedin post 2020-05-03 04:58:00

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MODIFYING GENES. “In species with genotypic sex determination, the chromosome pair that determines sex can change rapidly over time. Transitions are particularly likely when the ancestral sex chromosome exhibits little genetic differentiation, since WW or YY combinations are then less likely to be lethal. New sex-determining genes (or copies of the original gene in a new location) can lead to transitions within and between different XY and ZW system.” http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001899 View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments
linkedin post 2020-05-03 05:00:39

linkedin post 2020-05-03 05:00:39

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VARIOUS MECHANISMS. “In many animals, sex determination involves the entire genome. With haplodiploidy (found in about 12% of animal species, including all ants, wasps, and bees) and paternal genome elimination (found in scale insects), males only transmit their maternal set of genes.” http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001899 View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-05-03 05:04:13

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GYNODIOECIOUS. “Females are actually hermaphrodites which have lost their male function, and they are referred to as male-steriles. This character is genetically determined, and females are similar to hermaphrodites in morphology with the exception of their flowers.” https://lnkd.in/d4QE8Rq View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-05-03 05:06:22

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MALE STERILES. “Female flowers are generally smaller, and this reduction in size has been related to the lack of anthers and, more precisely, to the male hormones present in them. Male-steriles do not produce pollen and, due to reallocation of resources, they are expected to produce more seeds, which could explain their maintenance in a population.” https://lnkd.in/d4QE8Rq View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-05-03 05:11:07

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SO ENDS this first of two weekends looking at the issue of the enormous diversity of sex determination mechanisms in organisms. As ever, nature turns out to be very experimental and creative in this issue, and considerable biological capital is invested in this function. The coming weekend will offer a variety of hypotheses for why having different sexes is biologically important. View in LinkedIn
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21Sep 2022 by Nigel Fleming No Comments

linkedin post 2020-05-04 04:17:18

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BRAIN UPLOADING? When I first read Ray Kurtzweil's ideas about putting consciousness on a computer or the web, I simply thought that he had lost it, despite his evident credentials. Such an outrageously novel idea seemed similar to claims that death was old hat (wait for this theme!). I was troubled by the biochemical and anatomical conundrum of putting your brain on a pen-drive. We have nothing to lose but to gander down this lane and take a look. View in LinkedIn
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