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Faster evolution of highly conserved DNA in tropical plants
Author(s) -
GILLMAN L. N.,
KEELING D. J.,
GARDNER R. C.,
WRIGHT S. D.
Publication year - 2010
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/j.1420-9101.2010.01992.x
Subject(s) - biology , internal transcribed spacer , gene , evolutionary biology , genetics , temperate climate , rate of evolution , ribosomal rna , concerted evolution , ribosomal dna , 18s ribosomal rna , genome , dna , phylogenetics , ecology
A faster rate of nuclear DNA evolution has recently been found for plants occupying warmer low latitudes relative to those in cooler high latitudes. That earlier study by our research group compared substitution rates within the variable internal transcribed spacer (ITS) region of the ribosomal gene complex amongst 45 congeneric species pairs, each member of which differed in their latitudinal distributions. To determine whether this rate differential might also occur within highly conserved DNA, we sequenced the 18S ribosomal gene in the same 45 pairs of plants. We found that the rate of evolution in 18S was 51% faster in the tropical plant species relative to their temperate sisters and that the substitution rate in 18S correlated positively with that in the more variable ITS. This result, with a gene coding for ribosomal structure, suggests that climatic influences on evolution extend to functionally important regions of the genome.