Year: 2022

PURIFYING SELECTION. "In natural selection, negative selection or purifying selection is the selective removal of alleles that are deleterious. This can result in stabilizing selection through the purging of deleterious variations that arise. Purging of deleterious alleles can be achieved on the population genetics level, with as little as a single point mutation being the unit of selection. In such a case, carriers of the harmful point mutation have fewer offspring each generation, reducing the frequency of the mutation in the gene pool." https://en.m.wikipedia.org/wiki/Negative_selection_(natural_selection) View in LinkedIn

NEUTRAL EVOLUTION. "Molecular evolutionary theory provides an excellent theoretical framework for the identification of functionally important sequences. As purifying selection operates against deleterious mutations, functionally important genes have either a low frequency of or even no such mutations, but this is not the case in stretches of neutrally evolving sequences." http://www.sciencedirect.com/science/article/pii/S0168952515000347 View in LinkedIn

MICRO-EVOLUTION. "New gene origination is a microevolutionary process. A protogene structure is first generated by a mutation in a single germ cell genome. This protogene structure must then spread through the population until it is fixed" as a permanent gene. https://lnkd.in/d__2shu View in LinkedIn

FIRST STEP. "Mutation toward a new gene structure is the first step of new gene evolution, and at least a dozen distinct molecular processes are known that contribute to the formation of new genes." https://lnkd.in/d__2shu View in LinkedIn

LAYERS OF BARRIERS. "A few basic tenets need to be met to give rise to a gene de novo. A stretch of DNA encoding an ORF needs to acquire signals that lead to the transcription and subsequent translation of encoded polypeptide. That polypeptide, in turn, needs to be biologically active for enough time to allow selective forces to operate for its retention in the genome." (ORF = open reading frame). https://lnkd.in/e3rTkFh View in LinkedIn

SELECTIVE PRESSURE DRIVER. "Although considered an extremely unlikely event, many genes emerge from previously noncoding genomic region. While most of the de novo genes are lost, a fraction of them becomes essential. De novo genes are most likely involved in the response to a rapidly changing environment." http://www.sciencedirect.com/science/article/pii/S0168952515000347 View in LinkedIn

MOLECULAR DOMESTICATION. "Viruses and transposable elements, once considered as purely junk and selfish sequences, have repeatedly been used as a source of novel protein-coding genes during the evolution of most eukaryotic lineages, a phenomenon called “molecular domestication”." https://lnkd.in/dmWa6Hy View in LinkedIn

JUMPING GENES IMPORTANT. "In mammals and other vertebrates, where many genes derived from long terminal repeat (LTR) retroelements (retroviruses and LTR retrotransposons). Retroelement-derived genes are involved in many important biological processes including placenta formation, cognitive functions in the brain and immunity against retroelements, as well as in cell proliferation, apoptosis and cancer." http://www.sciencedirect.com/science/article/pii/S1198743X16001063 View in LinkedIn

VERTEBRATES BENEFITED FROM JUMPING GENES. "These observations support an important role of retroelement-derived genes in the evolution and diversification of the vertebrate lineage." http://www.sciencedirect.com/science/article/pii/S1198743X16001063 View in LinkedIn

NEW GENES WIDESPREAD. "Today it is clear that new gene origination is a general process in evolution and that species-specific or lineage-specific genes exist in many, if not all, organisms." https://lnkd.in/d__2shu View in LinkedIn