Category: Uncategorized

GENOMIC VARIATION. “Variations are caused by a multitude of mechanisms and range from single nucleotide polymorphisms to large-scale genomic rearrangements. The latter may result in translocation, duplication, and deletion of genetic material, thereby affecting chromosomal size and gene content.” https://lnkd.in/eC8eb-V View in LinkedIn

MORE RESTRICTIVE. “If selfing evolves because of reproductive assurance, the conditions for a reversal are even more restrictive than if selfing evolves principally because of its transmission advantage, assuming that all else is equal.” https://lnkd.in/dj9hK7n View in LinkedIn

DYNAMIC GENOMES. “Genomes are highly dynamic and vary considerably between, and often even within, species with respect to structure and content. This dynamics is caused by mutations that are either neutral, and may thus be transient, or mediate increased fitness and became fixed in the population by natural (Darwinian) selection.” https://lnkd.in/eC8eb-V View in LinkedIn

AMPLIFIED PENALTY BOX. “Although reversals to outcrossing are generally viewed as unlikely because of the concurrent reduction in outcrossing rate and inbreeding depression, it is widely underappreciated that the ecological context may amplify the costs of outcrossing.” https://lnkd.in/dj9hK7n View in LinkedIn

EUKARYOTES WITHOUT SEXUAL CYCLE. “Inspired by recent reports we argue that such organisms can be as persistent as organisms with conventional sexual cycles through the use of other mechanisms, such as genomic rearrangements, to foster adaptation.” https://lnkd.in/eC8eb-V View in LinkedIn

FRAGMENT FROM NATURE focuses for this and next weekend on the work of Professor Lluis Villarreal, who has proposed that viruses have played an intimate role in human evolution, and all major evolutionary transitions. He has been an outspoken and sometimes controversial voice for this biological dark matter at a time when most biologists dismiss viruses as oddball curiosities that are more chemical than living. They have left their traces in our genomes, have fashioned some of the great cycles on this planet, defy species limits, and outnumber other creatures. Enjoy this glimpse into biological dark matter that is mostly left in the biological rubbish bin. View in LinkedIn

GENE CHUNKING. “In addition to the transfer of single genes, also the transfer of entire chromosomes has been documented in pathogenic fungi. This typically involves conditionally dispensable chromosomes that are not required for growth, but confer an advantage when colonizing particular ecological niches.” https://lnkd.in/eC8eb-V View in LinkedIn

CROSS-BARRIER GENE SHARING. “The exchange of genes over species barriers – referred to as horizontal or lateral gene transfer – can play an important role in genome evolution.” https://lnkd.in/eC8eb-V View in LinkedIn

VARIOUS MECHANISMS. “Several mechanisms can alter the genetic material of eukaryotic species: A: DNA point mutations (stars) can alter single (or few) nucleotides. B: Genetic material can be transferred from a donor lineage over species barriers (dashed line) into the genome of an acceptor lineage. This can either be limited to single genes (horizontal gene transfer) or comprise entire chromosomes (horizontal chromosome transfer). C: Inter- or intra-chromosomal rearrangements can lead to a variety of genomic changes. Double-strand breaks are indicated by red arrows and dashed lines.” https://lnkd.in/eC8eb-V View in LinkedIn

KEY MECHANISM. “A plethora of processes can create genomic variation in eukaryotes, and we hypothesize that commonly observed chromosomal rearrangements provide a pivotal mechanism to promote adaptation.” https://lnkd.in/eC8eb-V View in LinkedIn