Month: September 2022

INTERMEDIATE STEP. "Although a direct transition has sometimes been suggested, the transition probably involved intermediate steps in most cases, as it seems unlikely that male and female sterility mutations arise simultaneously in hermaphroditic species." https://lnkd.in/guzeMTD View in LinkedIn

CRITICAL TRANSITION. "The evolution from hermaphroditism to dioecy (separate sexes) is considered one of the most important evolutionary transitions in the reproductive history of angiosperms. Although relatively rare (approx. 6 % of species), dioecy is a widespread reproductive system in angiosperms (reported in approx. 38 % of families." https://lnkd.in/guzeMTD View in LinkedIn

REPEATED EVENTS IN PLANTS. "It is now well established that plants have an important place in studies of sex chromosome evolution because of the repeated independent evolution of separate sexes and sex chromosomes." https://lnkd.in/exrSaeb View in LinkedIn

STRANGE PHENOMENA. "There is wide interest in understanding sex chromosome evolution, which involves strange phenomena such as selection for suppression of genetic recombination (which is widespread throughout the genomes of most organisms, other than in parts of the sex chromosomes), and the resulting ‘genetic degeneration’ involving loss of function, or complete loss, of many genes on the non-recombining chromosome; this chromosome is the Y in XY systems, and the W in ZW systems such as that of birds and Lepidoptera, and a few plants." https://lnkd.in/exrSaeb View in LinkedIn

LOSS OF RECOMBINATION. "Understanding the evolution of sex chromosomes is impossible without first understanding the evolution of separate sexes, because the genetic changes involved in the latter lead with high probability to the chromosomes involved losing recombination, and it is loss of recombination that leads to the special properties of sex chromosomes." https://lnkd.in/exrSaeb View in LinkedIn

RECENT DIVERGENCE. "Studies of species that have recently evolved separate sexes are ideal for testing the idea that hermaphrodites are selected to ‘compromise’ between male and female functions, an important test case for the existence of trade-offs between different functions." https://lnkd.in/exrSaeb View in LinkedIn

The Earth may not be flat, but it just might be doomed https://www.theguardian.com/commentisfree/2017/nov/19/the-earth-may-not-be-flat-but-it-is-possibly-doomed-fake-news?CMP=Share_iOSApp_Other View in LinkedIn

HERMAPHRODITE COMPROMISE. "If this idea is correct, then changing from being hermaphrodite to becoming purely female or male ought to trigger a burst of adaptation, as females optimize their female functions, and males optimize their male functions." https://lnkd.in/exrSaeb View in LinkedIn

TWO SUPPRESSIONS. "Dioecy in flowering plants must often have evolved through at least two mutations, a male-sterility mutation (creating females) and one or more female-sterility mutations (creating males)." https://lnkd.in/exrSaeb View in LinkedIn

CO-SEXUAL FORMS. "First, dioecy in flowering plants seems often to have evolved from either hermaphroditism or monoecy, or, using the combined term, from co-sexuality. It follows directly that, during the evolution of dioecy, either females or males must first have arisen, and become established in the population (creating a situation with both co-sexuals and unisexuals, either gynodioecy or androdioecy), and then mutations must have spread among the co-sexuals, making them become the complementary unisexual form." https://lnkd.in/exrSaeb View in LinkedIn