ORCID Profile
0000-0002-1457-676X
Current Organisations
City University of New York, Baruch College
,
Max Planck Institute for Evolutionary Biology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Related Links
Publications
X-ray computed tomography of two mammoth calf mummies
Publisher: Cambridge University Press (CUP)
Date: 07-2014
DOI: 10.1666/13-092
Abstract: Two female woolly mammoth neonates from permafrost in the Siberian Arctic are the most complete mammoth specimens known. Lyuba, found on the Yamal Peninsula, and Khroma, from northernmost Yakutia, died at ages of approximately one and two months, respectively. Both specimens were CT-scanned, yielding detailed information on the stage of development of their dentition and skeleton and insight into conditions associated with death. Both mammoths died after aspirating mud. Khroma's body was frozen soon after death, leaving her tissues in excellent condition, whereas Lyuba's body underwent postmortem changes that resulted in authigenic formation of nodules of the mineral vivianite associated with her cranium and within diaphyses of long bones. CT data provide the only comprehensive approach to mapping vivianite distribution. Three-dimensional modeling and measurement of segmented long bones permits comparison between these in iduals and with previously recovered specimens. CT scans of long bones and foot bones show developmental features such as density gradients that reveal ossification centers. The braincase of Khroma was segmented to show the approximate morphology of the brain its volume is slightly less (∼2,300 cm 3 ) than that of neonate elephants (∼2,500 cm 3 ). Lyuba's premaxillae are more gracile than those of Khroma, possibly a result of temporal and/or geographic variation but probably also reflective of their age difference. Segmentation of CT data and 3-D modeling software were used to produce models of teeth that were too complex for traditional molding and casting techniques.
Taxonomic overview and tusk growth analyses of Ziegler Reservoir proboscideans
Publisher: Cambridge University Press (CUP)
Date: 11-2014
DOI: 10.1016/J.YQRES.2014.07.010
Abstract: At an altitude of 2705 m in the Colorado Rockies (USA), the Ziegler Reservoir fossil site gives a rare look at a high-elevation ecosystem from the late Pleistocene (especially MIS 5) of North America. Remains of more than four mammoths and about 35 mastodons dominate the macrofossil assemblage. Mammoth remains are attributed to Mammuthus columbi , and mastodon remains are referred to the well-known, continent-wide Mammut americanum . Mastodon remains occur within and between several lake-margin slump deposits. Their deposition must therefore have occurred as events that were to some degree separate in time. We treat the mastodon assemblage in each stratigraphic unit as a source of information on environmental conditions during the lives of these in iduals. Mastodon mandibular tusks are abundant at the site and represent both males and females, from calves to full-grown adults. This study presents the first attempt to use microCT, thin-section, and isotope records from mandibular tusks to reconstruct features of life-history. We recognize an up-section trend in δ 18 O profiles toward higher values, suggestive of warmer temperatures. Throughout this sequence, mastodon growth histories show low mean sensitivities suggestive of low levels of environmental stress. This work helps frame expectations for assessing environmental pressures on terminal Pleistocene populations.
Female chacma baboons modulate their sexual receptivity in response to male coercion
Publisher: Cold Spring Harbor Laboratory
Date: 17-09-2022
DOI: 10.1101/2022.09.16.508123
Abstract: Research in social mammals has revealed the complexity of female counter-strategies to reproductive competition and sexual conflict. For ex le, comparative research has shown that the length of female sexual receptivity varies with infanticide risk, but whether in iduals can strategically adjust their period of receptivity from cycle to cycle remains unknown. This study addresses this gap by exploring whether wild female chacma baboons ( Papio ursinus ) modulate their receptivity in response to the social environment. Given that female chacma baboons (a) compete for paternal care and (b) that infanticide risk and coercion are high, we predicted that: females could (a) shorten their receptive period to reduce intrasexual aggression and (b) male coercion, or (c) increase their conceptive period to access multiple or their preferred male. We quantified 158 receptivity cycles from 47 females recorded over 15 years. Females’ swelling duration, but not maximal-swelling, had low repeatability between females, but most variation in both phases stemmed from within females. We found evidence that females decrease their oestrous duration in response to an increasing number of in-group males, possibly to decrease their exposure to sexual coercion. We thus present preliminary evidence for an unexplored mechanism under sexual selection: female cycle length manipulation.
Whole-genome sequencing of spermatocytic tumors provides insights into the mutational processes operating in the male germline
Publisher: Public Library of Science (PLoS)
Date: 22-05-2017
Summary of the Snowmastodon Project Special VolumeA high-elevation, multi-proxy biotic and environmental record of MIS 6–4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, US
Publisher: Cambridge University Press (CUP)
Date: 11-2014
DOI: 10.1016/J.YQRES.2014.07.004
Abstract: In North America, terrestrial records of bio ersity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.
Related Organisations
University Of California, San Francisco
Location: United States of America
City University Of New York, Baruch College
Location: United States of America
American Museum Of Natural History
Location: United States of America
University College London
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
No related grants have been discovered for Fragkiskos Darmis.