我是R的新手，我第一次尝试系统发育广义最小二乘（PGLS），使用addon包'caper'。我的系统发育由125种组成。当我读到我在Mesquite软件中创建的系统发育（保存为Nexus文件）时，我收到错误：
##reading in my phylogeny
reptilephylogeny <- read.nexus ("reptile_phylogeny_new_edit.nex", tree.names = NULL)
##it gives me the following warning message:
Warning message:
In matrix(x, ncol = 2, byrow = TRUE) :
data length [253] is not a sub-multiple or multiple of the number of rows [127]
##So I checked how R is treating the tip labels:
reptilephylogeny$tip.label
[1] "Apalone_spinifera" "Staurotypus_triporcatus"
[3] "Gehyra_variegata" "Egernia_whitii"
[5] "Ameiva_erythrocephala" "Lacerta_vivipara"
[7] "Lacerta_agilis" "Podarcis_muralis"
[9] "Podarcis_sicula" "Psammodromus_algirus"
[11] "Tropidurus_itambere" "Tropidurus_torquatus"
[13] "Cyclura_nubila" "Ctenosaura_bakeri"
[15] "Uta_stansburiana" "Sceloporus_graciosus"
[17] "Sceloporus_scalaris" "Sceloporus_jarrovi"
[19] "19" "20"
[21] "21" "22"
[23] "23" "24"
[25] "25" "26"
[27] "27" "28"
[29] "29" "30"
[31] "31" "32"
[33] "33" "34"
[35] "35" "36"
[37] "37" "38"
[39] "39" "40"
[41] "41" "42"
[43] "43" "44"
[45] "45" "46"
[47] "47" "48"
[49] "49" "50"
[51] "51" ""
[53] "Basiliscus_vittatus" "Emoia_atrocostata"
[55] "Lygosoma_laterale" "Tropidurus_albemarlensis"
[57] "Tropidurus_semitaeniatus" "Varanus_bengalensis"
[59] "Intellagama_lesueurii" "Alligator_mississippiensis"
[61] "Caiman_latirostris" "Caiman_crocodilus"
[63] "Caiman_yacare" "Caretta_caretta"
[65] "Carettochelys_insculpta" "Chelodina_longicollis"
[67] "Chelonia_mydas" "Chelydra_serpentina"
[69] "Chrysemys_dorsalis" "Chrysemys_picta"
[71] "Clemmys_guttata" "Crocodylus_acutus"
[73] "Crocodylus_moreletii" "Crocodylus_johnstoni"
[75] "Crocodylus_niloticus" "Crocodylus_porosus"
[77] "Crocodylus_palustris" "Crotalus_horridus"
[79] "Cuora_flavomarginata" "Deirochelys_reticularia"
[81] "Dermatemys_mawii" "Emydoidea_blandingii"
[83] "Emydura_macquarii" "Emys_orbicularis"
[85] "Eretmochelys_imbricata" "Gopherus_agassizii"
[87] "Gopherus_berlandieri" "n86"
[89] "n87" "n88"
[91] "n89" "n90"
[93] "n91" "n92"
[95] "n93" "n94"
[97] "n95" "n96"
[99] "n97" "n98"
[101] "n99" "n100"
[103] "n101" "n102"
[105] "n103" "n104"
[107] "n105" "n106"
[109] "n107" "n108"
[111] "n109" "n110"
[113] "n111" "n112"
[115] "n113" "n114"
[117] "n115" "n116"
[119] "n117" "n118"
[121] "n119" "n120"
[123] "n121" "n122"
[125] "n123" "n124"
[127] "1"
似乎R没有一致地填充数据行/列 - 在我的物种列表中，每个物种之间没有间隙，但很明显这里R认为物种名称之间存在空格（在本例中为数字） 。有没有人知道为什么会这样？
谢谢， 格雷格