Phylogenies based on molecular sequence data and on morphology are surveyed and compared within animals (concentrating on vertebrates, mammals, and hominids in particular) and within plants (concentrating on Asterales, angiosperms, seed plants, and major groups of "green plants"). The theoretical problem of assessing congruence between trees generated from different data sets is still unsolved. However, in practice, we find that incongruence between molecular trees (generated from different data sets or by different analytical methods) is as striking or pervasive as is incongruence between trees generated by morphologists in the long history of their discipline. Morphologists achieved much during that time, and none of their well-supported phylogenies is overthrown by molecular data. So far, molecular sequences have contributed most significantly in areas where morphological data are inconclusive, deficient, nonexistent, or poorly analyzed. The interrelationships of extant hominines (Gorilla, Homo, Pan), where morphology is inconclusive, are exemplary. The pattern [Gorilla [Homo, Pan]] is significantly favored by nucleotide sequence data, but the effort necessary to achieve resolution in that simple case (ca. 30 kb of aligned sequences, sampling all four extant species) may foreshadow the workload that lies ahead.

Congruence Between Molecular and Morphological Phylogenies

(1968). The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian. Transactions of the British Bryological Society: Vol. 5, No. 3, pp. 602-602.

The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian

Phylogenetic relationships among embryophytes (tracheophytes, mosses, liverworts, and hornworts) were examined using 21 newly generated mitochondrial small-subunit (19S) rDNA sequences. The "core" 19S rDNA contained more phylogenetically informative sites and lower homoplasy than either nuclear 18S or plastid 16S rDNA. Results of phylogenetic analyses using parsimony (MP) and likelihood (ML) were generally congruent. Using MP, two trees were obtained that resolved either liverworts or hornworts as the basal land plant clade. The optimal ML tree showed hornworts as basal. That topology was not statistically different from the two MP trees, thus both appear to be equally viable evolutionary hypotheses. High bootstrap support was obtained for the majority of higher level embryophyte clades named in a recent morphologically based classification, e.g., Tracheophyta, Euphyllophytina, Lycophytina, and Spermatophytata. Strong support was also obtained for the following monophyletic groups: hornworts, liverworts, mosses, lycopsids, leptosporangiate and eusporangiate ferns, gymnosperms and angiosperms. This molecular analysis supported a sister relationship between Equisetum and leptosporangiate ferns and a monophyletic gymnosperms sister to angiosperms. The topologies of deeper clades were affected by taxon inclusion (particularly hornworts) as demonstrated by jackknife analyses. This study represents the first use of mitochondrial 19S rDNA for phylogenetic purposes and it appears well-suited for examining intermediate to deep evolutionary relationships among embryophytes.

https://bsapubs.onlinelibrary.wiley.com/doi/pdf/10.2307/2656759

Phylogenetic relationships of land plants using mitochondrial small-subunit rDNA sequences.

Activity-guided fractionation of an ethyl acetate extract of the aerial parts of Tithonia diversifolia, using an antiproliferation bioassay performed with human colon cancer (Col2) cells, led to th...

Sesquiterpenoids from Tithonia diversifolia with potential cancer chemopreventive activity.

Local empirical knowledge about medicinal properties of plants is the basis for their use as home remedies. Particularly in developing countries such remedies still are an indispensable resource for everyday health care. They form the basis for numerous studies on drugs from natural sources. Like other indigenous groups across the world, the Ch'orti' Maya in Eastern Guatemala are currently experiencing a phase of dramatic cultural change, with their traditional knowledge about plants being in great danger of disappearing. During 17 months of fieldwork, medicinal plant uses were documented using a semi-quantitative approach and analysed using ethnopharmacological methods. The most important groups of illnesses treated with plants were gastrointestinal complaints and illnesses associated with pain and fever. Field data were compared with mostly unpublished historical data collected in the 1930s by the anthropologist Charles Wisdom. This comparison showed that medicinal plant uses that are more consistent over time are also shared by a larger number of people. A literature search on the most frequently mentioned medicinal plants showed that, even for widely used medicinal species, phytochemical and pharmacological data are insufficient for fully understanding their therapeutic profile. Whereas a few examples of potentially dangerous practices were encountered, the limited amount of information available mostly supports local medicinal plant usage.

Alan T. Whittemore

Papers

A heliangolide from Chromolaena glaberrima

Sesquiterpene lactones from Chromolaena opadoclinia

Sesquiterpene lactones from Helianthus niveus subsp. niveus

Transition to a land flora: a critique

A guaianolide from Chromolaena glaberrima