| 1. |
- Orlando, Ludovic, et al.
(författare)
-
Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse
- 2013
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 499:7456, s. 74-
-
Tidskriftsartikel (refereegranskat)abstract
- The rich fossil record of equids has made them a model for evolutionary processes(1). Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr BP)(2,3). Our data represent the oldest full genome sequence determined so far by almost an order of magnitude. For comparison, we sequenced the genome of a Late Pleistocene horse (43 kyr BP), and modern genomes of five domestic horse breeds (Equus ferus caballus), a Przewalski's horse (E. f. prze-walskii) and a donkey (E. asinus). Our analyses suggest that the Equus lineage giving rise to all contemporary horses, zebras and donkeys originated 4.0-4.5 million years before present (Myr BP), twice the conventionally accepted time to the most recent common ancestor of the genus Equus(4,5). We also find that horse population size fluctuated multiple times over the past 2 Myr, particularly during periods of severe climatic changes. We estimate that the Przewalski's and domestic horse populations diverged 38-72 kyr BP, and find no evidence of recent admixture between the domestic horse breeds and the Przewalski's horse investigated. This supports the contention that Przewalski's horses represent the last surviving wild horse population(6). We find similar levels of genetic variation among Przewalski's and domestic populations, indicating that the former are genetically viable and worthy of conservation efforts. We also find evidence for continuous selection on the immune system and olfaction throughout horse evolution. Finally, we identify 29 genomic regions among horse breeds that deviate from neutrality and show low levels of genetic variation compared to the Przewalski's horse. Such regions could correspond to loci selected early during domestication.
|
|
| 2. |
- Parry, Luke A., et al.
(författare)
-
The Annelid Fossil Record
- 2019
-
Ingår i: Handbook of Zoology : Annelida - Volume 1: Annelida Basal Groups and Pleistoannelida, Sedentaria I - Annelida - Volume 1: Annelida Basal Groups and Pleistoannelida, Sedentaria I. - 9783110291469 - 9783110381788 ; , s. 69-88
-
Bokkapitel (refereegranskat)
|
|
| 3. |
- Rasmussen, Sune Olander, et al.
(författare)
-
Ice-core data used for the construction of the Greenland Ice-Core Chronology 2005 and 2021 (GICC05 and GICC21)
- 2023
-
Ingår i: Earth System Science Data. - 1866-3508 .- 1866-3516. ; 15:8, s. 3351-3364
-
Tidskriftsartikel (refereegranskat)abstract
- We here describe, document, and make available a wide range of data sets used for annual-layer identification in ice cores from DYE-3, GRIP, NGRIP, NEEM, and EGRIP. The data stem from detailed measurements performed both on the main deep cores and shallow cores over more than 40 years using many different setups developed by research groups in several countries and comprise both discrete measurements from cut ice samples and continuous-flow analysis data.The data series were used for counting annual layers 60 000 years back in time during the construction of the Greenland Ice-Core Chronology 2005 (GICC05) and/or the revised GICC21, which currently only reaches 3800 years back. Now that the underlying data are made available (listed in Table 1) we also release the individual annual-layer positions of the GICC05 timescale which are based on these data sets.We hope that the release of the data sets will stimulate further studies of the past climate taking advantage of these highly resolved data series covering a large part of the interior of the Greenland ice sheet.
|
|
| 4. |
- Skovsted, Christian, 1974-, et al.
(författare)
-
SMALL SHELLY FOSSILS AND CARBON ISOTOPES FROM THE EARLY CAMBRIAN (STAGES 3–4) MURAL FORMATION OF WESTERN LAURENTIA
- 2021
-
Ingår i: Papers in Palaeontology. - : Wiley. - 2056-2799 .- 2056-2802. ; 7:2, s. 951-983
-
Tidskriftsartikel (refereegranskat)abstract
- The extraordinary window of phosphatized and phosphatic small shelly fossils (SSF) during the early and middle Cambrian is an important testament to the radiation of biomineralizing metazoans. While SSF are well known from most Cambrian palaeocontinents during this time interval, western Laurentia has relatively few SSF faunas. Here we describe a diverse SSF fauna from the early Cambrian (Stages 3–4) Mural Formation at three localities in Alberta and British Columbia, Canada, complemented by carbon isotope measurements to aid in a potential future bio-chemostratigraphic framework. The fauna expands the recorded SSF assemblage diversity in western Laurentia and includes several brachiopods, four bradoriids, three chancelloriids, two hyoliths, a tommotiid and a helcionellid mollusc as well as echinoderm ossicles and specimens of Microdictyon, Volborthella and Hyolithellus. New taxa include the tommotiid genus Canadiella gen. nov., the new bradoriid species Hipponicharion perforata sp. nov. and Pseudobeyrichona taurata sp. nov. Compared with contemporaneous faunas from western Laurentia, the fauna is relatively diverse, particularly in taxa with originally phosphatic shells, which appear to be associated with archaeocyathid build-ups. This suggests that the generally low faunal diversity in western Laurentia may be at least partly a consequence of poor sampling of suitable archaeocyathan reef environments. In addition, the tommotiid Canadiella filigrana appears to be of biostratigraphical significance in Cambrian Stage 3 strata of western Laurentia, and the unexpected high diversity of bradoriid arthropods in the fauna also suggests that this group may prove useful for biostratigraphical resolution in the region.
|
|
| 5. |
- Vinther, Jakob, et al.
(författare)
-
The Mouth Apparatus Of The Cambrian Gilled Lobopodian Pambdelurion Whittingtoni
- 2016
-
Ingår i: Palaeontology. - : Wiley. - 0031-0239 .- 1475-4983. ; 59:6, s. 841-849
-
Tidskriftsartikel (refereegranskat)abstract
- Omnidens is a large feeding apparatus composed of circlets of teeth, first documented from the early Cambrian of China. Originally interpreted as the oral cone of a radiodontan, it was later reinterpreted as the introvert of a priapulan. In both cases the Omnidens mouthparts underpinned estimates of gigantic (c. 2 m) body size. Recent evidence has been used to suggest that pharyngeal teeth and radially-arranged oral plates in the stem-group onychophoran Hallucigenia and the lower stem-group euarthropod Jianshanopodia are homologous to structures of the introvert in priapulans and other scalidophorans, and are thus primitive characters for moulting animals (Ecdysozoa) as a whole. Here we show that the early Cambrian gilled lobopodian Pambdelurion whittingtoni from Sirius Passet, Greenland, possesses a mouth apparatus identical to Omnidens, being composed of the same three zones with detailed similarities of sclerites in each zone. An oral cone with rings of pharyngeal teeth, radial plates and outer scalid-like plates are ecdysozoan characters retained in the euarthropod stem group. Omnidens from China probably belongs to an unrecognized Pambdelurion-like animal rather than being part of a giant priapulan.
|
|
| 6. |
- Zolotarov, Grygoriy, et al.
(författare)
-
MicroRNAs are deeply linked to the emergence of the complex octopus brain
- 2022
-
Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 8:47
-
Tidskriftsartikel (refereegranskat)abstract
- Soft-bodied cephalopods such as octopuses are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their nervous tissues, we hypothesized that RNA regulation may play a major role in the cognitive success of this group. We thus profiled messenger RNAs and small RNAs in three cephalopod species including 18 tissues of the Octopus vulgaris. We show that the major RNA innovation of soft-bodied cephalopods is an expansion of the microRNA (miRNA) gene repertoire. These evolutionarily novel miRNAs were primarily expressed in adult neuronal tissues and during the development and had conserved and thus likely functional target sites. The only comparable miRNA expansions happened, notably, in vertebrates. Thus, we propose that miRNAs are intimately linked to the evolution of complex animal brains.
|
|
