Dear Xuziqiang35, the problem is that for several groups, you have just one or very few observations. It would be non sense to add more variables or to extrapolate them, and, then to expect that you will find "significant" differences. Some differences here can not be tested as within group sample variance can not be estimated.The one P value you observed would be better interpreted as Non Available pvalues. Think that the estimates of the mean, even if you have more than one observation, are also estimate and that they might be influenced by sampling too !!!
There has been several recent papers posted here recently (related to BgPCA) but not only (cf recent paper of J. Rohlf posted at the end of last year), maybe you should have a look. As some species are represented by just one specimens, I would recommend regrouping species and reformulating the problematic according to your sample (for avoiding to test something that cannot be tested). On one other point, it would be good in the future to put an object on message (it might help other people for archiving message they got from the list). best regards, Julien CLAUDE Institut des Sciences de l'Evolution de Montpellier De: "徐自强" <[email protected]> À: "Morphmet" <[email protected]> Envoyé: Mardi 23 Mars 2021 10:01:24 Objet: [MORPHMET2] BQ_BEGIN Hello, teachers. I am a student who recently learned to apply geometric morphometry to fossil wing variation studies, but I have run into some challenges I cannot solve on my own and would like to seek support. First, I considered using landmark, but the variability is not obvious. Since many data related to vein sequence curvature are not included, I next considered introducing semiland for analysis, but some important vein sequences are missing, making it difficult to obtain semiland points effectively. Finally, can the effect of too much semiland on the landmark data be reduced? Ag Bc Ca Nm No Sg Sp Ss represent different species respectively. The dashed part in the picture is repaired according to other fossils, but some fossils are more or less difficult to repair in the red circle part of the vestiges. I would like to get some advice, thank you very much! -- You received this message because you are subscribed to the Google Groups "Morphmet" group. To unsubscribe from this group and stop receiving emails from it, send an email to [ mailto:[email protected] | [email protected] ] . To view this discussion on the web visit [ https://groups.google.com/d/msgid/morphmet2/CADfVnE_LAWBwWbBB%2BVRPciT%3DO1XPEQsr6aFpbaVZ6PdCgdbM0w%40mail.gmail.com?utm_medium=email&utm_source=footer | https://groups.google.com/d/msgid/morphmet2/CADfVnE_LAWBwWbBB%2BVRPciT%3DO1XPEQsr6aFpbaVZ6PdCgdbM0w%40mail.gmail.com ] . BQ_END -- You received this message because you are subscribed to the Google Groups "Morphmet" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/morphmet2/1786279502.109169.1616574546363.JavaMail.zimbra%40umontpellier.fr.
