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DIVERSE PROCESSES. “On the other hand, the vast evolutionary distance that separates any given extant species from the LECA necessarily implies that other features of sex will be derived.” (LECA = last eukaryotic common ancestor). https://lnkd.in/dn4azG7 View in LinkedIn

INBREEDING CONSEQUENCES. “And in humans there are the examples of consanguineous marriages, resulting for example from cousin–cousin pairings, which lead to considerable inbreeding with the risk of exposure of recessive alleles in a homozygous configuration.” https://lnkd.in/dn4azG7 View in LinkedIn

COMMON FEATURES. “Given the antiquity of sex, there are features of sexual reproduction that are ancient and ancestral, and thus shared in diverse extant organisms.” https://lnkd.in/dn4azG7 View in LinkedIn

CORE MECHANISMS AND MODES. “Beyond the commonalities in the mechanisms of sex, there are also shared features to the modes of sexual reproduction. This includes outbreeding between genetically divergent members of the population, but also types of inbreeding that can involve the ability of the yeast S. cerevisiae to undergo mating type switching that allows mother cells to mate with their daughter cells.” https://lnkd.in/dn4azG7 View in LinkedIn

CONSERVED SINGLE EVENT. “Sexual reproduction is conserved throughout each supergroup within the eukaryotic tree of life, and therefore thought to have evolved once and to have been present in the last eukaryotic common ancestor (LECA).” https://lnkd.in/dn4azG7 View in LinkedIn

INVARIANT CORE. “These conserved features include: 1) ploidy changes from haploid to diploid to haploid (or diploid to haploid to diploid), 2) the process of meiosis that enables meiotic recombination and halves the ploidy of the genome, and 3) cell–cell fusion between mating partners (a and α cells) or gametes (the sperm and the egg). This ubiquity of the conserved features of sex again speaks to the antiquity of the process.” https://lnkd.in/dn4azG7 View in LinkedIn

FRAGMENT FROM NATURE focuses on a 2015 article entitled ‘Evolution of sexual reproduction: A view from the fungal kingdom supports an evolutionary epoch with sex before sexes’ by Professor Joseph Heitman from the Duke Medical Center. Fungi are astonishingly diverse and rightfully offer a fresh perspective on this old question about why sexual reproduction arose, when asexual systems seem to work well and are less costly. View in LinkedIn

DEEP COMMONALITY. “The core features of sexual reproduction are conserved in organisms as diverse as the model budding yeast Saccharomyces cerevisiae and humans, despite a billion years or more of evolution separating us from our last common shared ancestor.” https://lnkd.in/dn4azG7 View in LinkedIn

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A COSTLY BUSINESS. “However, these potential benefits of sex are pitted against well-known costs of sexual reproduction: that only 50 % of a parental genome is transmitted to any given progeny, the time and energy required to locate mates, and the breaking apart of well adapted genomic configurations.” https://lnkd.in/dn4azG7 View in LinkedIn