Month: September 2022

"A MAJOR TASK for evolutionary biology has been to develop and test theories for the origin of novelty that are consistent with the fundamental genetic principles of gradual populational change." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

NOVELTY BY HYBRIDIZATION. "The idea that hybridization can rapidly produce novel forms is familiar among botanists, but rarely appeared in mainstream discussions of speciation until recently thanks to several case studies of homoploid hybrid speciation." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

BEYOND PARENTAL PHENOTYPES. "Recombination of fixed genetic differences between two populations in the F2 and later generations can produce hybrids with phenotypes novel to both parental populations. When these recombinant phenotypes have fitness beyond the range of parental phenotypes they are transgressive." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

SUDDEN NOVELTY. "Although these ideas were easily dismissed by the insights of the Modern Synthesis, a lingering fascination with the possibility of sudden, dramatic change has persisted. Recent work on hybridization and gene exchange suggests an underappreciated mechanism for the sudden appearance of evolutionary novelty that is entirely consistent with the principles of modern population genetics." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

MACROMUTATIONS. "Some theorists have invoked special phenomena such as genome-wide “macromutations” or “genetic revolutions” to get around perceived difficulties with the emergence of profound change as the accumulation of subtle changes by the conventional dynamics of mutation, gene flow, drift and selection." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

EVOLUTION BY LUCK. "Goldschmidt proposed that a novel phenotype (such as insect wings, a character associated with higher level taxonomy) must first arise as an instantaneous product of a single “macromutation” or “systemic mutation”. Individuals bearing such macromutations were characterized as “hopeful monsters” by Goldschmidt to emphasize that their appearance is neither purposeful nor gradual, and their prospects for success are a matter of luck." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

NO SUSPENDED DISBELIEF. "A hopeful monster is an individual phenotypically discontinuous from the range of phenotypes of its population, and whose hopes of establishing a new lineage lie in finding a novel niche for which its monstrosity happens to be preadapted. Such a mechanism of speciation was criticized early for being so improbable as to “overtax one’s credulity” because of the rarity of the initial mutation of large effect, and the resulting improbability of finding an equally monstrous mate." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

THE GENETIC CONFIRMATION. "Modern evolutionary theory and empirical research in genetics have consistently reaffirmed the ability of conventional population genetics to explain the origin of new species and phenotypes, and simultaneously exposed flaws in the alternatives." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

CREDIBLE HYBRID SPECIATION. "Recent empirical and theoretical research on hybrid speciation might have revived the hopeful monster in a new, more credible form. Recombination of parental chromosomes in the F2 and later generations during hybridization can generate genotypes that express phenotypes outside the normal range of variation observed in either parental gene pool, a phenomenon termed “transgressive segregation”.” http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn

NEW POSSIBILITIES ALLOWED. "Genetic recombination in hybrids can produce transgressive phenotypes, “monstrous” phenotypes beyond the range of parental populations. Transgressive phenotypes can be products of epistatic interactions or additive effects of multiple recombined loci." http://link.springer.com/article/10.1007/s11692-012-9209-0 View in LinkedIn