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Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Rewiring The Sex-Determination Pathway During The Evolution Of Self-Fertility., Yongquan Shen, Shin-Yi Lin, Jonathan Harbin, Richa Amin, Allison Vassalotti, Joseph Romanowski, Emily Schmidt, Alexis Tierney, Ronald E Ellis
Rewiring The Sex-Determination Pathway During The Evolution Of Self-Fertility., Yongquan Shen, Shin-Yi Lin, Jonathan Harbin, Richa Amin, Allison Vassalotti, Joseph Romanowski, Emily Schmidt, Alexis Tierney, Ronald E Ellis
Rowan-Virtua School of Osteopathic Medicine Departmental Research
Although evolution is driven by changes in how regulatory pathways control development, we know little about the molecular details underlying these transitions. The TRA-2 domain that mediates contact with TRA-1 is conserved in Caenorhabditis. By comparing the interaction of these proteins in two species, we identified a striking change in how sexual development is controlled. Identical mutations in this domain promote oogenesis in Caenorhabditis elegans but promote spermatogenesis in Caenorhabditis briggsae. Furthermore, the effects of these mutations involve the male-promoting gene fem-3 in C. elegans but are independent of fem-3 in C. briggsae. Finally, reciprocal mutations in these genes show …
Advancing Behavioural Genomics By Considering Timescale, Clare C. Rittschof, Kimberly A. Hughes
Advancing Behavioural Genomics By Considering Timescale, Clare C. Rittschof, Kimberly A. Hughes
Entomology Faculty Publications
Animal behavioural traits often covary with gene expression, pointing towards a genomic constraint on organismal responses to environmental cues. This pattern highlights a gap in our understanding of the time course of environmentally responsive gene expression, and moreover, how these dynamics are regulated. Advances in behavioural genomics explore how gene expression dynamics are correlated with behavioural traits that range from stable to highly labile. We consider the idea that certain genomic regulatory mechanisms may predict the timescale of an environmental effect on behaviour. This temporally minded approach could inform both organismal and evolutionary questions ranging from the remediation of early …
Post-Darwin Skepticism And Run-Of-The-Mill Suicide, John Hadley
Post-Darwin Skepticism And Run-Of-The-Mill Suicide, John Hadley
Animal Sentience
Peña-Guzmán’s depiction of the opponent of animal suicide as a conservative is a straw man. It is possible to accept that animals are self-conscious and reflexive yet still reject the view that they have the mental wherewithal to commit run-of-the-mill suicide. That animal behaviour can be positioned on a continuum of self-destructive behaviour does not establish that animals can intentionally kill themselves.
Animals Aren’T Persons, But Is It Time For A Neologism?, Helen Steward
Animals Aren’T Persons, But Is It Time For A Neologism?, Helen Steward
Animal Sentience
Mark Rowlands argues that at least some animals are persons, based on the idea that (i) many animals have a property he calls “pre-reflective awareness,” (ii) the capacity for pre-reflective awareness is sufficient to satisfy the traditional Lockean definition of personhood, and (iii) satisfaction of the traditional Lockean definition of personhood is sufficient for being a person. I agree with (i) and can see that there is a persuasive case for (ii), but I think the case against (iii) blocks the conclusion that animals are persons. I suggest that we may need instead to coin a neologism in order to …
Unconscious Higher-Order Thoughts (Hots) As Pre-Reflective Self-Awareness?, Rocco J. Gennaro
Unconscious Higher-Order Thoughts (Hots) As Pre-Reflective Self-Awareness?, Rocco J. Gennaro
Animal Sentience
Rowlands argues that many nonhuman animals are “persons,” contrary to the prevailing orthodoxy which rests on a mistaken conception of the kind of self-awareness relevant to personhood. He argues that self-awareness bifurcates into two importantly different forms — reflective self-awareness and pre-reflective self-awareness — and that many animals can have the latter, which is sufficient for personhood. I agree that there is good reason to think that many animals can have pre-reflective self-awareness, but I think Rowlands is mistaken about its nature. His account runs the risk of leading to an infinite regress objection, and his notion of pre-reflective self-awareness …
Are Animals Persons?, Mark Rowlands
Are Animals Persons?, Mark Rowlands
Animal Sentience
It is orthodox to suppose that very few, if any, nonhuman animals are persons. The category “person” is restricted to self-aware creatures: humans (above a certain age) and possibly some of the great apes and cetaceans. I argue that this orthodoxy should be rejected, because it rests on a mistaken conception of the kind of self-awareness relevant to personhood. Replacing this with a sense of self-awareness that is relevant requires us to accept that personhood is much more widely distributed through the animal kingdom.
Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon
Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon
Dartmouth Scholarship
Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that …
Tree Climbing And Human Evolution, Vivek V. Venkataraman, Thomas S. Kraft, Nathaniel J. Dominy
Tree Climbing And Human Evolution, Vivek V. Venkataraman, Thomas S. Kraft, Nathaniel J. Dominy
Dartmouth Scholarship
Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion …
Aspm And The Evolution Of Cerebral Cortical Size In A Community Of New World Monkeys, Fernando A. Villanea, George H. Perry, Gustavo A. Gutiérrez-Espeleta, Nathaniel J. Dominy
Aspm And The Evolution Of Cerebral Cortical Size In A Community Of New World Monkeys, Fernando A. Villanea, George H. Perry, Gustavo A. Gutiérrez-Espeleta, Nathaniel J. Dominy
Dartmouth Scholarship
The ASPM (abnormal spindle-like microcephaly associated) gene has been proposed as a major determinant of cerebral cortical size among primates, including humans. Yet the specific functions of ASPM and its connection to human intelligence remain controversial. This debate is limited in part by a taxonomic focus on Old World monkeys and apes. Here we expand the comparative context of ASPM sequence analyses with a study of New World monkeys, a radiation of primates in which enlarged brain size has evolved in parallel in spider monkeys (genus Ateles) and capuchins (genus Cebus). The primate community of Costa Rica is perhaps a …
Episodic Radiations In The Fly Tree Of Life, Brian M. Wiegmann, Michelle D. Trautwein, Isaac S. Winkler, Norman B. Barr, Jung-Wook Kim, Christine Lambkin, Matthew Bertone, Brian Cassel, Keith Bayless, Alysha Heimberg
Episodic Radiations In The Fly Tree Of Life, Brian M. Wiegmann, Michelle D. Trautwein, Isaac S. Winkler, Norman B. Barr, Jung-Wook Kim, Christine Lambkin, Matthew Bertone, Brian Cassel, Keith Bayless, Alysha Heimberg
Dartmouth Scholarship
Flies are one of four superradiations of insects (along with beetles, wasps, and moths) that account for the majority of animal life on Earth. Diptera includes species known for their ubiquity (Musca domestica house fly), their role as pests (Anopheles gambiae malaria mosquito), and their value as model organisms across the biological sciences (Drosophila melanogaster). A resolved phylogeny for flies provides a framework for genomic, developmental, and evolutionary studies by facilitating comparisons across model organisms, yet recent research has suggested that fly relationships have been obscured by multiple episodes of rapid diversification. We provide a phylogenomic …
Micrornas Reveal The Interrelationships Of Hagfish, Lampreys, And Gnathostomes And The Nature Of The Ancestral Vertebrate, Alysha M. Heimberg, Richard Cowper-Sal{Middle Dot}Lari, Marie Semon, Philip C. J. Donoghue, Kevin J. Peterson
Micrornas Reveal The Interrelationships Of Hagfish, Lampreys, And Gnathostomes And The Nature Of The Ancestral Vertebrate, Alysha M. Heimberg, Richard Cowper-Sal{Middle Dot}Lari, Marie Semon, Philip C. J. Donoghue, Kevin J. Peterson
Dartmouth Scholarship
Hagfish and lampreys are the only living representatives of the jawless vertebrates (agnathans), and compared with jawed vertebrates (gnathostomes), they provide insight into the embryology, genomics, and body plan of the ancestral vertebrate. However, this insight has been obscured by controversy over their interrelationships. Morphological cladistic analyses have identified lampreys and gnathostomes as closest relatives, whereas molecular phylogenetic studies recover a monophyletic Cyclostomata (hagfish and lampreys as closest relatives). Here, we show through deep sequencing of small RNA libraries, coupled with genomic surveys, that Cyclostomata is monophyletic: hagfish and lampreys share 4 unique microRNA families, 15 unique paralogues of more …
Micrornas And The Advent Of Vertebrate Morphological Complexity, Alysha M. Heimberg, Lorenzo F. Sempere, Vanessa N. Moy, Phillip C. J. Donoghue, Kevin J. Peterson
Micrornas And The Advent Of Vertebrate Morphological Complexity, Alysha M. Heimberg, Lorenzo F. Sempere, Vanessa N. Moy, Phillip C. J. Donoghue, Kevin J. Peterson
Dartmouth Scholarship
The causal basis of vertebrate complexity has been sought in genome duplication events (GDEs) that occurred during the emergence of vertebrates, but evidence beyond coincidence is wanting. MicroRNAs (miRNAs) have recently been identified as a viable causal factor in increasing organismal complexity through the action of these ≈22-nt noncoding RNAs in regulating gene expression. Because miRNAs are continuously being added to animalian genomes, and, once integrated into a gene regulatory network, are strongly conserved in primary sequence and rarely secondarily lost, their evolutionary history can be accurately reconstructed. Here, using a combination of Northern analyses and genomic searches, we show …