scholarly journals Tracing the History of LINE and SINE Extinction in Sigmodontine Rodents

2018 ◽  
Author(s):  
Lei Yang ◽  
Holly A Wichman
Keyword(s):  
Evolutionary History ◽  
Selective Pressure ◽  
Mammalian Genome ◽  
Group Activity ◽  
South American ◽  
Long Period ◽  
Strong Selective Pressure ◽  
Basal Group ◽  
History Of ◽  
Entire History

AbstractBackgroundL1 retrotransposons have co-evolved with their mammalian hosts for the entire history of mammals and currently make up to 20% of a typical mammalian genome. B1 retrotransposons are dependent on L1 for retrotransposition and span the evolutionary history of rodents since their radiation. L1s were found to have lost their activity in a group of South American rodents, the Sigmodontinae, and B1 inactivation preceded the extinction of L1 in the same group. Consequently, a basal group of sigmodontines have active L1s but inactive B1s and a derived clade have both inactive L1s and B1s. It has been suggested that B1s became extinct during a long period of L1 quiescence and that L1s subsequently reemerged in the basal group.ResultsHere we investigate the evolutionary histories of L1 and B1 in the sigmodontine rodents and show that L1 activity continued until after the split of the L1-extinct clade and the basal group. After the split, L1s had a small burst of activity in the former group, followed by extinction. In the basal group, activity was initially low but was followed by a dramatic increase in L1 activity. We found the last wave of B1s retrotransposition was large and probably preceded the split between the two rodent clades.ConclusionsGiven that L1s had been steadily retrotransposing during the time corresponding to B1 extinction and that the burst of B1 activity preceding B1 extinction was large, we conclude that B1 extinction was not a result of L1 quiescence. Rather, the burst of B1 activity may have contributed to L1 extinction both by competition with L1 and by putting strong selective pressure on the host to control retrotransposition.

Evolution of physiological dormancy multiple times in Melastomataceae from Neotropical montane vegetation

2011 ◽  
Vol 22 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Fernando A.O. Silveira ◽  
Rafaella C. Ribeiro ◽  
Denise M.T. Oliveira ◽  
G. Wilson Fernandes ◽  
José P. Lemos-Filho
Keyword(s):  
Phylogenetic Tree ◽  
Seed Dormancy ◽  
Rainy Season ◽  
Evolutionary History ◽  
Selective Pressure ◽  
Strong Selective Pressure ◽  
Montane Vegetation ◽  
Physiological Dormancy ◽  
History Of ◽  
Seed Coats

AbstractWe investigated seed dormancy among species of Melastomataceae from Neotropical montane vegetation of Brazil. Four out of 50 studied species had dormant seeds:Miconia corallina(Miconieae), Tibouchina cardinalis(Melastomeae), Comolia sertularia(Melastomeae) andChaetostoma armatum(Microlicieae). For these four species, germinability of seeds collected in different years was always < 10% and the percentages of embryoless seeds and non-viable embryos were both insufficient to explain low or null germinability. This is the first unequivocal report of seed dormancy in tropical Melastomataceae. The production of seeds with permeable seed coats and fully developed, differentiated embryos indicates the occurrence of physiological dormancy. The reconstructed phylogenetic tree of the 50 species suggests that physiological dormancy evolved multiple times during the evolutionary history of Melastomataceae in this vegetation. Physiological dormancy evolved in species and populations associated with xeric microhabitats, where seeds are dispersed in unfavourable conditions for establishment. Therefore, drought-induced mortality may have been a strong selective pressure favouring the evolution of physiological dormancy in Melastomataceae. We argue that dormancy may have been independently selected in other lineages of Cerrado plants colonizing xeric microhabitats and dispersing seeds at the end of the rainy season. The contributions of our data to the understanding of seed dormancy in tropical montane vegetation are discussed.

scholarly journals Extensive introgression and mosaic genomes of Mediterranean endemic lizards

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weizhao Yang ◽  
Nathalie Feiner ◽  
Catarina Pinho ◽  
Geoffrey M. While ◽  
Antigoni Kaliontzopoulou ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Mediterranean Islands ◽  
The Past ◽  
Island Endemics ◽  
Extant Species ◽  
Mediterranean Island ◽  
History Of ◽  
Entire History ◽  
The Mediterranean ◽  
The Mediterranean Basin

AbstractThe Mediterranean basin is a hotspot of biodiversity, fuelled by climatic oscillation and geological change over the past 20 million years. Wall lizards of the genus Podarcis are among the most abundant, diverse, and conspicuous Mediterranean fauna. Here, we unravel the remarkably entangled evolutionary history of wall lizards by sequencing genomes of 34 major lineages covering 26 species. We demonstrate an early (>11 MYA) separation into two clades centred on the Iberian and Balkan Peninsulas, and two clades of Mediterranean island endemics. Diversification within these clades was pronounced between 6.5–4.0 MYA, a period spanning the Messinian Salinity Crisis, during which the Mediterranean Sea nearly dried up before rapidly refilling. However, genetic exchange between lineages has been a pervasive feature throughout the entire history of wall lizards. This has resulted in a highly reticulated pattern of evolution across the group, characterised by mosaic genomes with major contributions from two or more parental taxa. These hybrid lineages gave rise to several of the extant species that are endemic to Mediterranean islands. The mosaic genomes of island endemics may have promoted their extraordinary adaptability and striking diversity in body size, shape and colouration, which have puzzled biologists for centuries.

scholarly journals First monk seal from the Southern Hemisphere rewrites the evolutionary history of true seals

2020 ◽  
Vol 287 (1938) ◽  
pp. 20202318
Author(s):  
James P. Rule ◽  
Justin W. Adams ◽  
Felix G. Marx ◽  
Alistair R. Evans ◽  
Alan J. D. Tennyson ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
North Atlantic ◽  
Marine Mammals ◽  
Evolutionary History ◽  
Major Change ◽  
The North ◽  
History Of ◽  
Entire History ◽  
The North Atlantic ◽  
Monk Seals

Living true seals (phocids) are the most widely dispersed semi-aquatic marine mammals, and comprise geographically separate northern (phocine) and southern (monachine) groups. Both are thought to have evolved in the North Atlantic, with only two monachine lineages—elephant seals and lobodontins—subsequently crossing the equator. The third and most basal monachine tribe, the monk seals, have hitherto been interpreted as exclusively northern and (sub)tropical throughout their entire history. Here, we describe a new species of extinct monk seal from the Pliocene of New Zealand, the first of its kind from the Southern Hemisphere, based on one of the best-preserved and richest samples of seal fossils worldwide. This unanticipated discovery reveals that all three monachine tribes once coexisted south of the equator, and forces a profound revision of their evolutionary history: rather than primarily diversifying in the North Atlantic, monachines largely evolved in the Southern Hemisphere, and from this southern cradle later reinvaded the north. Our results suggest that true seals crossed the equator over eight times in their history. Overall, they more than double the age of the north–south dichotomy characterizing living true seals and confirms a surprisingly recent major change in southern phocid diversity.

scholarly journals Floral-oil-producing Plantaginaceae species: geographical distribution, pollinator rewards and interactions with oil-collecting bees

2013 ◽  
Vol 13 (4) ◽  
pp. 77-89 ◽  
Author(s):  
Aline Cristina Martins ◽  
Isabel Alves-dos-Santos
Keyword(s):  
Geographical Distribution ◽  
Evolutionary History ◽  
Neotropical Region ◽  
South American ◽  
Oil Glands ◽  
Especial Case ◽  
History Of ◽  
Plant Families ◽  
Floral Oil ◽  
Pollinator Rewards

Floral oils as reward to pollinators occur in eleven plant families and appeared at least 28 times in the evolutionary history of flowering plants. They are produced in epithelial or tricomatic glands and collected by oil bee visitors. The present paper focuses on floral-oil-producing species of Plantaginaceae, a Neotropical group namely Angelonia clade. This group comprises around 40 described species in the genera Angelonia, Basistemon, Monttea, Monopera and the oil-less Melosperma. We present a revision of all species of the Angelonia clade, their geographical distribution, resources offered to pollinators and records of flower visitors, especially oil-collecting bees. These plants rely only on oil-collecting species in the tribe Centridini and Tapinotaspidini for a successful pollination, being the interaction between both partners an especial case of bee/flower adaptation in Neotropical region. Some bee species depend only on the oil of Plantaginaceae flowers to survive, while others can collect on several floral oil sources. The pollinating bees explore the oil glands located in sacs using specialized hairs in the forelegs. With this study, we hope to inspire further research relating to this fascinating group of plants, in which most species are rare and occur in highly endangered habitats in South American open vegetation biomes.

scholarly journals The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: the youngest record of Presbyornithidae

2016 ◽  
Vol 3 (2) ◽  
pp. 150635 ◽  
Author(s):  
Vanesa L. De Pietri ◽  
R. Paul Scofield ◽  
Nikita Zelenkov ◽  
Walter E. Boles ◽  
Trevor H. Worthy
Keyword(s):  
Evolutionary History ◽  
South Australia ◽  
First Record ◽  
South American ◽  
Crown Group ◽  
Term Survival ◽  
Skeletal Morphology ◽  
Ancient Lineage ◽  
History Of

Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi , long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined.

Development and evolution of the gynoecium in Myrteae (Myrtaceae)

2014 ◽  
Vol 62 (4) ◽  
pp. 335 ◽  
Author(s):  
Rafael R. Pimentel ◽  
Natália P. Barreira ◽  
Diego P. Spala ◽  
Nathane B. Cardim ◽  
Marcelo C. Souza ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Floral Anatomy ◽  
Structural Diversity ◽  
Morphological Characters ◽  
Fleshy Fruit ◽  
South American ◽  
Transmission Electron ◽  
History Of ◽  
Ovule Number ◽  
Development And Evolution

Characters of the gynoecium are considered potentially significant for the systematics of Myrtaceae. However, only two such characters – ovule number and placentation – have been addressed from an evolutionary perspective. Colleter presence in flowers is a synapomorphy of Myrtales; however, no morphological and histochemical descriptions of such structures have been done in Myrtaceae. Here we analysed the ontogeny and anatomy of the gynoecium combined with the ontogeny, anatomy, ultrastructure, and histochemistry of the colleters to study the evolution of these characters and map their states in the Myrteae phylogenetic tree. Our findings may help elucidate the evolutionary history of this tribe of fleshy-fruit producers so important towards maintaining ecological balance in the rainforest. Floral anatomy and ontogeny were analysed using light microscopy. Colleter samples were processed using standard methods for light and transmission electron microscopy. The main metabolites in colleters were detected via histochemistry. To map character states the program Mesquite version 2.71 was used. The morphological characters of the South American Myrteae here analysed provided an overview of the evolution of gynoecium – with cauline or carpellate placenta – and of colleters, as well as synapomorphies for the clades Plinia + Myrcia and Eugenia + Pimenta. The presence of two integuments in the ovules associated with sclereids and colleters in the gynoecium and the young fleshy fruit assures the efficient dispersal of their seeds. Our findings regarding gynoecium structural diversity of the tribe Myrteae give a new insight on their morphologically uniform flowers.

Evolutionary History of the South American Mistletoe Tripodanthus (Loranthaceae) Using Nuclear and Plastid Markers

2012 ◽  
Vol 37 (1) ◽  
pp. 218-225 ◽  
Author(s):  
Guillermo C. Amico ◽  
Romina Vidal-Russell ◽  
Miguel A. Garcia ◽  
Daniel L. Nickrent
Keyword(s):  
Evolutionary History ◽  
South American ◽  
The South ◽  
History Of ◽  
Plastid Markers ◽  
History Of The South

scholarly journals The diverging evolutionary history of opsin genes in Diptera

2020 ◽  
Author(s):  
Roberto Feuda ◽  
Matthew Goulty ◽  
Nicola Zadra ◽  
Tiziana Gasparetti ◽  
Ezio Rosato ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Turnover Rate ◽  
Selective Pressure ◽  
Ecological Factors ◽  
Peculiar Behaviour ◽  
Opsin Genes ◽  
History Of ◽  
Phylogenetic Framework ◽  
Independent Expansion ◽  
Dipteran Species

AbstractOpsin receptors mediate the visual process in animals and their evolutionary history can provide precious hints on the ecological factors that underpin their diversification. Here we mined the genomes of more than 60 Dipteran species and reconstructed the evolution of their opsin genes in a phylogenetic framework. Our phylogenies indicate that dipterans possess an ancestral set of five core opsins which have undergone several lineage-specific events including an independent expansion of low wavelength opsins in flies and mosquitoes and numerous family specific duplications and losses. Molecular evolutionary studies indicate that gene turnover rate, overall mutation rate, and site-specific selective pressure are higher in Anopheles than in Drosophila; we found signs of positive selection in both lineages, including events possibly associated with their peculiar behaviour. Our findings indicate an extremely variable pattern of opsin evolution in dipterans, showcasing how two similarly aged radiations - Anopheles and Drosophila - can be characterized by contrasting dynamics in the evolution of this gene family.

β-Defensin evolution: selection complexity and clues for residues of functional importance

2006 ◽  
Vol 34 (2) ◽  
pp. 257-262 ◽  
Author(s):  
C.A.M. Semple ◽  
K. Taylor ◽  
H. Eastwood ◽  
P.E. Barran ◽  
J.R. Dorin
Keyword(s):  
Positive Selection ◽  
Evolutionary History ◽  
Mammalian Genome ◽  
Functional Importance ◽  
Selective Pressures ◽  
History Of ◽  
Orthologous Loci ◽  
Window Approach ◽  
First Time ◽  
Evolutionary Lineages

We have examined the evolution of the genes at the major human β-defensin locus and the orthologous loci in a range of other primates and mammals. For the first time, these data allow us to examine selective episodes in the more recent evolutionary history of this locus as well as in the ancient past. We have used a combination of maximum-likelihood-based tests and a maximum-parsimony-based sliding window approach to give a detailed view of the varying modes of selection operating at this locus. We provide evidence for strong positive selection soon after the duplication of these genes within an ancestral mammalian genome. During the divergence of primates, however, variable selective pressures have acted on β-defensin genes in different evolutionary lineages, with episodes of both negative and, more rarely, positive selection. Positive selection appears to have been more common in the rodent lineage, accompanying the birth of novel rodent-specific β-defensin gene clades. Sites in the second exon have been subject to positive selection and, by implication, are important in functional diversity. A small number of sites in the mature human peptides were found to have undergone repeated episodes of selection in different primate lineages. Particular sites were consistently implicated by multiple methods at positions throughout the mature peptides. These sites are clustered at positions that are predicted to be important for the function of β-defensins.

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