Thanks for the kudos & the great questions!
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Originally Posted by Spyral
I wish the paper would have described it a little more, but they probably assumed the audience saw it as obvious.
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Yes, it's a paper by taxonomic/systematic specialists, for specialists. They assume that anyone else reading it would have the same technical background.
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I hope I am understanding this correctly....So what you are saying, is that although we have these different groupings - the true Rhacs, the Correlophus group, and the Mniarogekko + Eurydactylodes clade, there is still evidence between particular individual species that show them more closely related to one another?
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Yes, the higher the number over and under the branch points in the diagram, the higher the confidence level
this particular genetic analysis shows for the groups being closely related. (This analysis is good, but for sure not the last word on this subject). Lower numbers and dashes both indicate low support for close relatedness. So, for instance,
R. trachyrhyncus and
R. trachycephalus are considered in this paper to be two different species in the same genus, and same with
C. belepensis and
C. ciliatus. (100/1 -- 100 in each case -- this indicates super-high support for identical results
for the genes tested in this study using both the maximum likelihood method (numbers above the lines) and the maximum parsimony bootstrap method (below the lines), as explained in the caption for this diagram (Figure 2 in the paper.)) However, cladograms alone don't tell the whole story -- they only show the results of the genetic analyses performed here. In both the crestie and trachy cases mentioned earlier, the authors further describe how each species can be told apart by morphological features and by where the populations live in the wild (see under "diagnosis" for each species in the paper, pp. 17 and 23-32 for
Correlopholus (cresties) and pp. 16-17 and 18-23 for
Rhacodactylus).
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Could you elaborate on what you see from the cladogram that makes aurics and cilatus in particular more closely related, than say, aurics and saras? Or is there an equal amount of relatedness?
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Just to repeat, the cladogram shows the results of comparisons of the similarities of patterns found in mitochondrial and nuclear genes sampled from individual geckos. The results were generated using heuristic and statistical methods, and the output is confidence levels in the idea that the similarities encountered between the same genetic patterns found in different samples come from a common ancestor and are not a fluke. This means that the higher numbers you see at each node/branch point, the greater support there is for close relatedness among the samples branching from it -- the inference is that the numbers match well because both samples inherited that pattern from a recent common ancestor.
You can see on the diagram that the genetic similarities among the samples tested from cresties (
C. belepensis +
C. ciliatus) and saras (
C. sarasinorum) have support values of 100/1 -- 97, i.e. they are closely related to each other, but
C. sarasinorum is a little less related to each crestie group than the two cresties are related to each other. On each subsequent node or branch point, moving left along the diagram, there is less and less support for a close genetic relationship (the numbers drop), so the aurics are less closely related to either the cresties or saras.
Hope this helps. . .
08-03-2012
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