Publication Date:
2003-11-25
Description:
Complete genomic sequences from diverse phylogenetic lineages reveal notable increases in genome complexity from prokaryotes to multicellular eukaryotes. The changes include gradual increases in gene number, resulting from the retention of duplicate genes, and more abrupt increases in the abundance of spliceosomal introns and mobile genetic elements. We argue that many of these modifications emerged passively in response to the long-term population-size reductions that accompanied increases in organism size. According to this model, much of the restructuring of eukaryotic genomes was initiated by nonadaptive processes, and this in turn provided novel substrates for the secondary evolution of phenotypic complexity by natural selection. The enormous long-term effective population sizes of prokaryotes may impose a substantial barrier to the evolution of complex genomes and morphologies.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lynch, Michael -- Conery, John S -- New York, N.Y. -- Science. 2003 Nov 21;302(5649):1401-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Indiana University, Bloomington, IN 47405, USA. mlynch@bio.indiana.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14631042" target="_blank"〉PubMed〈/a〉
Keywords:
Alleles
;
Animals
;
Bacteria/genetics
;
Body Constitution
;
Eukaryota/genetics
;
*Evolution, Molecular
;
Fungi/genetics
;
Gene Duplication
;
Gene Silencing
;
Genetic Drift
;
Genetic Variation
;
*Genome
;
Humans
;
Interspersed Repetitive Sequences
;
Introns
;
Invertebrates/genetics
;
Mutation
;
*Phylogeny
;
Plants/genetics
;
Population Density
;
Recombination, Genetic
;
Selection, Genetic
;
Spliceosomes
;
Vertebrates/genetics
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
