Entity

Time filter

Source Type


Lommelen E.,Zoological Institute | Wenseleers T.,Zoological Institute | Johnson C.A.,The American Museum of Natural History | Drijfhout F.P.,Keele University | And 2 more authors.
Journal of Insect Behavior | Year: 2010

Approximately 150 ant species are facultatively or obligately queenless whereby mated workers assume the role of the queen. In many of these species a reproductive dominance hierarchy is established by way of aggressive interactions. Top-ranking workers, which are typically the most fecund, acquire a characteristic cuticular hydrocarbon profile. We studied the temporal dynamics of this chemical change and associated interplay with observed aggressive interactions in an experimentally orphaned colony of the facultatively queenless ant Gnamptogenys striatula. Our observations and chemical analyses demonstrate that chemical fertility signals played a major role in the establishment of a dominance hierarchy and aggression settled dominance relationships only when ants had identical hydrocarbon profiles. Moreover, individuals with a higher potential fertility, in this experiment reflected in a higher ovariole number, are shown to have a better chance of becoming a reproductive. © 2010 Springer Science+Business Media, LLC. Source


Burbrink F.T.,The American Museum of Natural History | Burbrink F.T.,City University of New York | Burbrink F.T.,CUNY - College of Staten Island | McKelvy A.D.,City University of New York | And 4 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2015

Predicting species presence and richness on islands is important for understanding the origins of communities and how likely it is that species will disperse and resist extinction. The equilibrium theory of island biogeography (ETIB) and, as a simple model of sampling abundances, the unified neutral theory of biodiversity (UNTB), predict that in situations where mainland to island migration is high, species-abundance relationships explain the presence of taxa on islands. Thus, more abundant mainland species should have a higher probability of occurring on adjacent islands. In contrast to UNTB, if certain groups have traits that permit them to disperse to islands better than other taxa, then phylogeny may be more predictive of which taxa will occur on islands. Taking surveys of 54 island snake communities in the Eastern Nearctic along with mainland communities that have abundance data for each species, we use phylogenetic assembly methods and UNTB estimates to predict island communities. Species richness is predicted by island area, whereas turnover from the mainland to island communities is random with respect to phylogeny. Community structure appears to be ecologically neutral and abundance on the mainland is the best predictor of presence on islands. With regard to young and proximate islands, where allopatric or cladogenetic speciation is not a factor, we find that simple neutral models following UNTB and ETIB predict the structure of island communities. © 2015 The Author(s) Published by the Royal Society. All rights reserved. Source


News Article | March 21, 2016
Site: http://www.techtimes.com/rss/sections/earth.xml

The American Museum of Natural History (AMNH) opens a new exhibit entitled "Dinosaurs Among Us," which intricately explores the link between birds and dinosaurs. Birds are everywhere and in today's world, the species generally look harmless and can even pass as pets. The truth is, even the sweetest lovebirds have in its system the genes of ferocious and humongous theropod dinosaurs such as Tyrannosaurus rex. While it might sound creepy, it is actually a good thing, knowing that the world today is still somewhat connected to the dinosaur age through birds - dinosaurs' only living heirs. The exhibit aims to redirect people's thinking of birds by presenting the ancient family tree of the species, while giving a fresh and more accurate view of dinosaurs. The link between birds and dinosaurs have long been recognized by scientists. In fact, this idea has been around since the mid-19th century. Modern paleontologists have also collected subtle evidences that support this claim. Among the supportive information that solidifies bird and dinosaur link are nesting behaviors, toothless beaks, the similar structures of the brain and bones and even feathers, which are said to have evolved from coarse spikes. The exhibit, which will open Monday, March 21, will feature a Yutyrannus huali, which is a tyrannosaurus that was found in China in 2012. The 23-feet long dinosaur has proto-feathers that resembles quill. The physical appearance is quite terrifying as it looks like a cross between an anteater and a roadrunner. The exhibit also includes an interactive booth that allows guests to make and fly their own dinosaur creations. This experience entails dinosaur puzzle pieces of different weight, wingspan and body parts, which the visitors may insert into a dinosaur illustration. The Elusive Link Between Birds And Dinosaurs In Modern Times With popular movies such as the "Jurassic Park," today's generation are given the idea that dinosaurs and birds do have a connection, yet the former is being portrayed as featherless. AMNH paleontologist Mark Norell says it may be because the characters may not look mean enough if presented like they are pigeons. No matter how scarcely depicted the link between birds and dinosaurs are, people should be aware that, one thing is certain, birds are the modern dinosaurs. "Dinosaurs never really vanished from Earth," AMNH writes. In fact, majority did not go extinct and is now living among us in the form of birds.


Janies D.A.,Ohio State University | Treseder T.,Ohio State University | Alexandrov B.,Ohio State University | Habib F.,Indian Institute of Science | And 6 more authors.
Cladistics | Year: 2011

Novel pathogens have the potential to become critical issues of national security, public health and economic welfare. As demonstrated by the response to Severe Acute Respiratory Syndrome (SARS) and influenza, genomic sequencing has become an important method for diagnosing agents of infectious disease. Despite the value of genomic sequences in characterizing novel pathogens, raw data on their own do not provide the information needed by public health officials and researchers. One must integrate knowledge of the genomes of pathogens with host biology and geography to understand the etiology of epidemics. To these ends, we have created an application called Supramap to put information on the spread of pathogens and key mutations across time, space and various hosts into a geographic information system (GIS). To build this application, we created a web service for integrated sequence alignment and phylogenetic analysis as well as methods to describe the tree, mutations, and host shifts in Keyhole Markup Language (KML). We apply the application to 239 sequences of the polymerase basic 2 (PB2) gene of recent isolates of avian influenza (H5N1). We map a mutation, glutamic acid to lysine at position 627 in the PB2 protein (E627K), in H5N1 influenza that allows for increased replication of the virus in mammals. We use a statistical test to support the hypothesis of a correlation of E627K mutations with avian-mammalian host shifts but reject the hypothesis that lineages with E627K are moving westward. Data, instructions for use, and visualizations are included as supplemental materials at: © The Willi Hennig Society 2010. Source


Iles D.T.,Utah State University | Peterson S.L.,Utah State University | Gormezano L.J.,The American Museum of Natural History | Koons D.N.,Utah State University | Rockwell R.F.,The American Museum of Natural History
Polar Biology | Year: 2013

Behavioral predictions based on optimal foraging models that assume an energy-maximizing strategy have been challenged on both theoretical and empirical grounds. Although polar bears (Ursus maritimus) are specialist predators of seal pups on the Arctic ice pack, the use of terrestrial food sources during the ice-free period has received increased attention in recent years in light of climate predictions. Across a 10-day period of observation, we documented between four and six individual polar bears successfully capture at least nine flightless lesser snow geese (Chen caerulescens caerulescens) and engage in at least eight high-speed pursuits of geese. The observed predatory behaviors of polar bears do not support predictions made by energy-optimizing foraging models and suggest that polar bears may frequently engage in energy inefficient pursuits of terrestrial prey. Further study of the nutritional needs and foraging behaviors of polar bears during the ice-free period is warranted, given that polar bears are predicted to spend more time on land as climate change advances. © 2013 Springer-Verlag Berlin Heidelberg. Source

Discover hidden collaborations