An evolutionary scenario: the early hominids

2019 ◽  
pp. 116-128
Author(s):  
Robert Langs ◽  
James O. Raney ◽  
David Smith
Keyword(s):  
Evolutionary Scenario ◽  
Early Hominids

scholarly journals The diversity of opsins in Lake Baikal amphipods (Amphipoda: Gammaridae)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Polina Drozdova ◽  
Alena Kizenko ◽  
Alexandra Saranchina ◽  
Anton Gurkov ◽  
Maria Firulyova ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Visual Pigments ◽  
Ancient Lake ◽  
Climate History ◽  
Habitat Depth ◽  
Long Wavelength ◽  
Evolutionary Scenario ◽  
Evolutionary Changes ◽  
Evolutionary Success ◽  
Multiple Species

Abstract Background Vision is a crucial sense for the evolutionary success of many animal groups. Here we explore the diversity of visual pigments (opsins) in the transcriptomes of amphipods (Crustacea: Amphipoda) and conclude that it is restricted to middle (MWS) and long wavelength-sensitive (LWS) opsins in the overwhelming majority of examined species. Results We evidenced (i) parallel loss of MWS opsin expression in multiple species (including two independently evolved lineages from the deep and ancient Lake Baikal) and (ii) LWS opsin amplification (up to five transcripts) in both Baikal lineages. The number of LWS opsins negatively correlated with habitat depth in Baikal amphipods. Some LWS opsins in Baikal amphipods contained MWS-like substitutions, suggesting that they might have undergone spectral tuning. Conclusions This repeating two-step evolutionary scenario suggests common triggers, possibly the lack of light during the periods when Baikal was permanently covered with thick ice and its subsequent melting. Overall, this observation demonstrates the possibility of revealing climate history by following the evolutionary changes in protein families.

scholarly journals Generalized olfactory detection of floral volatiles in the highly specialized Greya-Lithophragma nursery pollination system

2021 ◽  
Author(s):  
Florian P. Schiestl ◽  
Erika A. Wallin ◽  
John J. Beck ◽  
Magne Friberg ◽  
John N. Thompson
Keyword(s):  
Selective Advantage ◽  
Floral Volatiles ◽  
Pollination System ◽  
Allopatric Populations ◽  
Evolutionary Scenario ◽  
Plant Recognition ◽  
Hexahydrofarnesyl Acetone ◽  
Electroantennographic Detection ◽  
Local Host ◽  
Olfactory Detection

AbstractVolatiles are of key importance for host-plant recognition in insects. In the pollination system of Lithophragma flowers and Greya moths, moths are highly specialized on Lithophragma, in which they oviposit and thereby pollinate the flowers. Floral volatiles in Lithophragma are highly variable between species and populations, and moths prefer to oviposit into Lithophragma flowers from populations of the local host species. Here we used gas chromatography coupled with electroantennographic detection (GC-EAD) to test whether Greya moths detect specific key volatiles or respond broadly to many volatiles of Lithophragma flowers. We also addressed whether olfactory detection in Greya moths varies across populations, consistent with a co-evolutionary scenario. We analyzed flower volatile samples from three different species and five populations of Lithophragma occurring across a 1400 km range in the Western USA, and their sympatric female Greya politella moths. We showed that Greya politella detect a broad range of Lithophragma volatiles, with a total of 23 compounds being EAD active. We chemically identified 15 of these, including the chiral 6, 10, 14-trimethylpentadecan-2-one (hexahydrofarnesyl acetone), which was not previously detected in Lithophragma. All investigated Lithophragma species produced the (6R, 10R)-enantiomer of this compound. We showed that Greya moths detected not only volatiles of their local Lithophragma plants, but also those from allopatric populations/species that they not encounter in local populations. In conclusion, the generalized detection of volatiles and a lack of co-divergence between volatiles and olfactory detection may be of selective advantage for moths in tracking hosts with rapidly evolving, chemically diverse floral volatiles.

scholarly journals Crystal structures of aconitase X enzymes from bacteria and archaea provide insights into the molecular evolution of the aconitase superfamily

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Seiya Watanabe ◽  
Yohsuke Murase ◽  
Yasunori Watanabe ◽  
Yasuhiro Sakurai ◽  
Kunihiko Tajima
Keyword(s):  
Molecular Evolution ◽  
Agrobacterium Tumefaciens ◽  
Crystal Structures ◽  
Epr Spectroscopy ◽  
Binding Sites ◽  
Active Sites ◽  
Type I ◽  
Type Ii ◽  
Thermococcus Kodakarensis ◽  
Evolutionary Scenario

AbstractAconitase superfamily members catalyze the homologous isomerization of specific substrates by sequential dehydration and hydration and contain a [4Fe-4S] cluster. However, monomeric and heterodimeric types of function unknown aconitase X (AcnX) have recently been characterized as a cis-3-hydroxy-L-proline dehydratase (AcnXType-I) and mevalonate 5-phosphate dehydratase (AcnXType-II), respectively. We herein elucidated the crystal structures of AcnXType-I from Agrobacterium tumefaciens (AtAcnX) and AcnXType-II from Thermococcus kodakarensis (TkAcnX) without a ligand and in complex with substrates. AtAcnX and TkAcnX contained the [2Fe-2S] and [3Fe-4S] clusters, respectively, conforming to UV and EPR spectroscopy analyses. The binding sites of the [Fe-S] cluster and substrate were clearlydifferent from those that were completely conserved in other aconitase enzymes; however, theoverall structural frameworks and locations of active sites were partially similar to each other.These results provide novel insights into the evolutionary scenario of the aconitase superfamilybased on the recruitment hypothesis.

scholarly journals Evolution of O stars and the WR connection

1979 ◽  
Vol 83 ◽  
pp. 431-445 ◽  
Author(s):  
Peter S. Conti
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
High Luminosity ◽  
Loss Mechanism ◽  
Evolutionary Scenario ◽  
Processed Material ◽  
Dominant Process ◽  
Highly Evolved ◽  
Loss Rates ◽  
Enriched Composition

The stellar wind mass loss rates of at least some single Of type stars appear to be sufficient to remove much if not all of the hydrogen-rich envelope such that nuclear processed material is observed at the surface. This highly evolved state can then be naturally associated with classic Population I WR stars that have properties of high luminosity for their mass, helium enriched composition, and nitrogen or carbon enhanced abundances. If stellar wind mass loss is the dominant process involved in this evolutionary scenario, then stars with properties intermediate between Of and WR types should exist. The stellar parameters of luminosity, temperature, mass and composition are briefly reviewed for both types. All late WN stars so far observed are relatively luminous like Of stars, and also contain hydrogen. All early WN stars, and WC stars, are relatively faint and contain little or no hydrogen. The late WN stars seem to have the intermediate properties required if a stellar wind is the dominant mass loss mechanism that transforms an Of star to a WR type.

Molecular analysis of glyceraldehyde-3-phosphate dehydrogenase in Trypanoplasma borelli: An evolutionary scenario of subcellular compartmentation in Kinetoplastida

1995 ◽  
Vol 40 (4) ◽  
pp. 443-454 ◽  
Author(s):  
Erik A. C. Wiemer ◽  
Véronique Hannaert ◽  
Paul R. L. A. van den Ijssel ◽  
Joris Van Roy ◽  
Fred R. Opperdoes ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Evolutionary Scenario ◽  
Subcellular Compartmentation

Hominid carnivory and foraging strategies, and the socio-economic function of early archaeological sites

1991 ◽  
Vol 334 (1270) ◽  
pp. 211-221 ◽  
Keyword(s):  
Predation Risk ◽  
Foraging Strategies ◽  
Archaeological Sites ◽  
Olduvai Gorge ◽  
Marrow Fat ◽  
Density Dependent ◽  
Early Hominids ◽  
Competing Hypotheses ◽  
New Evidence ◽  
Economic Function

New evidence for the tissue types exploited by early hominids from carcasses possibly acquired through scavenging is derived from the larger mammal bone assemblages from FLK I, level 22 ( Zinjanthropus floor), and FLKN levels 1 and 2 from Bed I, Olduvai Gorge, Tanzania. Published skeletal part profiles from the two archaeological sites are evaluated using (i) modern observations on the sequence by which carnivores consume carcass parts in order to assess the timing of hominid access to carcasses, and (ii) measurements of flesh and marrow yields to assess the tissue types sought and acquired. These results suggest that the maximization of marrow (fat) yields, not flesh (protein) yields, was the criterion shaping decisions about carcass processing. Because of evidence for density-dependent destruction of some flesh-bearing parts by scavengers of the hominid-butchered assemblages, however, it is uncertain whether carcass parts were transported and acquired by hominids in a largely defleshed condition. The results on tissue types acquired are combined with a discussion of predation risk, feeding competition and the equipment needs of carcass processing in an attempt to identify archaeological test implications of competing hypotheses for the socio-economic function of the earliest archaeological sites.

scholarly journals Unidentified Infrared Emission Features

2012 ◽  
Vol 10 (H16) ◽  
pp. 699-700 ◽  
Author(s):  
Christine Joblin
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Infrared Emission ◽  
Interstellar Matter ◽  
Physical Conditions ◽  
Evolutionary Scenario ◽  
Polycyclic Aromatic ◽  
Aromatic Species ◽  
Hydrocarbon Molecules ◽  
Uv Photons ◽  
Ir Bands

AbstractWhen referring to unidentified infrared emission features, one has in mind the series of aromatic IR bands (AIBs) between 3.3 and 15 μm that are observed in emission in many environments where UV photons irradiate interstellar matter. These bands are now used by astronomers to classify objects and characterize local physical conditions. However, a deep analysis cannot proceed without understanding the properties of the band carriers. Large polycyclic aromatic hydrocarbon molecules are attractive candidates but interstellar species are still poorly characterized. Various studies emphasize the need for tackling the link between molecular aromatic species, aliphatic material and very small carbonaceous grains. Other unidentified emission features such as the 6.9, 21 and 30 μm bands could be involved in the evolutionary scenario.

scholarly journals Pitviper Scavenging at the Intertidal Zone: An Evolutionary Scenario for Invasion of the Sea

BioScience ◽  
2008 ◽  
Vol 58 (10) ◽  
pp. 947-955 ◽  
Author(s):  
Harvey B. Lillywhite ◽  
Coleman M. Sheehy ◽  
Frederic Zaidan
Keyword(s):  
Intertidal Zone ◽  
Evolutionary Scenario
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