Phylogenetics of the Antopocerus-Modified Tarsus Clade of Hawaiian Drosophila: Diversification across the Hawaiian Islands

Abstract

The Hawaiian Drosophilidae radiation is an ecologically and morphologically diverse clade of almost 700 described species. A phylogenetic approach is key to understanding the evolutionary forces that have given rise to this diverse lineage. Here we infer the phylogeny for the antopocerus, modified tarsus and ciliated tarsus (AMC) clade, a lineage comprising 16% (91 of 687 species) of the described Hawaiian Drosophilidae. To improve on previous analyses we constructed the largest dataset to date for the AMC, including a matrix of 15 genes for 68 species. Results strongly support most of the morphologically defined species groups as monophyletic. We explore the correlation of increased diversity in biogeography, sexual selection and ecology on the present day diversity seen in this lineage using a combination of dating methods, rearing records, and distributional data. Molecular dating analyses indicate that AMC lineage started diversifying about 4.4 million years ago, culminating in the present day AMC diversity. We do not find evidence that ecological speciation or sexual selection played a part in generating this diversity, but given the limited number of described larval substrates and secondary sexual characters analyzed we can not rule these factors out entirely. An increased rate of diversification in the AMC is found to overlap with the emergence of multiple islands in the current chain of high islands, specifically Oahu and Kauai.

The abiotic and biotic drivers of rapid diversification in Andean bellflowers (Campanulaceae)

“…550 extant species. The diversification rate for the centropogonids, estimated to be between 0.65 and 1.42 events Myr –1 per lineage, makes them one of fastest species radiations reported to date (Table ), with average overall rates of speciation exceeding iconic groups ranging from Espeletia (Madriñán et al ., ) and hummingbirds (McGuire et al ., ) in the Andes to the silverswords (Baldwin & Sanderson, ) and Drosophilidae of Hawaii (Lapoint et al ., ).…”

Multiple origins of Hawaiian drosophilids: Phylogeography ofScaptomyzaHardy (Diptera: Drosophilidae)

“…; Lapoint et al. , ). Although these split times were not directly calibrated from external information, they were all inferred from the same fossil calibration (Grimaldi ).…”

“…One was the split between Siphlodora and the Idiomyia + Scaptomyza clade, and the other was the split between Idiomyia and Scaptomyza. These nodes were calibrated by using a uniform prior ranging from 34.2 to 51.6 million years ago (Ma) for the former, and from 23.9 to 37.1 Ma for the latter, based on the ranges of split times inferred by previous studies (Russo et al 1995;Tamura et al 2004;Lapoint et al 2013Lapoint et al , 2014. Although these split times were not directly calibrated from external information, they were all inferred from the same fossil calibration (Grimaldi 1987).…”

Multiple, independent colonizations of the Hawaiian Archipelago by the family Dolichopodidae (Diptera)

“…This infrequent arrival and establishment has led to a flora and fauna that is disharmonic relative to those on the continents that served as sources (Gillespie & Roderick, 2002). Recently, several studies (reviewed in Heaney, 2007; Bellemain & Ricklefs, 2008) have shown that reverse colonization from Hawaii to continental landmasses is observed in birds (Filardi & Moyle, 2005), plants (Harbaugh & Baldwin, 2007) and insects (O’Grady & DeSalle, 2008; Lapoint, Magnacca & O’Grady, 2014), suggesting that dispersal plays a larger role than previously thought and evidence is accumulating to indicate that movement to and from island systems is more common, especially at geological time scales (Heaney, 2007; Cibois et al, 2011; Hembry et al, 2013; Casquet et al, 2015). If a lineage is vagile enough to repeatedly colonize an area, there is a reduced chance that it will generate the reproductive isolation necessary to speciate and then radiate.…”

“…Recent phylogenetic studies of Hawaiian insects (Jordan, Simon & Polhemus, 2003; Mendelson & Shaw, 2005; Shapiro, Strazanac & Roderick, 2006; Medeiros et al, 2009; Lapoint, Gidaya & O’Grady, 2011; Medeiros & Gillespie, 2011; O’Grady et al, 2011; Haines & Rubinoff, 2012; Bennett & O’Grady, 2013; Bess, Catanach & Johnson, 2013; Goodman & O’Grady, 2013; Lapoint, O’Grady & Whiteman, 2013; Goodman et al, 2014; Haines, Schmitz & Rubinoff, 2014; Lapoint, Magnacca & O’Grady, 2014), have begun to reveal the history of colonization to and diversification within the Hawaiian Archipelago, and it appears that history is somewhat idiosyncratic. Some large groups, such as Hawaiian Drosophilidae with an estimated 1,000 species, colonized the Hawaiian Islands tens of millions of years ago.…”