ABSTRACT
[This corrects the article DOI: 10.1016/j.patter.2021.100340.].
ABSTRACT
In this paper, we critique ICT's current and projected climate impacts. Peer-reviewed studies estimate ICT's current share of global greenhouse gas (GHG) emissions at 1.8%-2.8% of global GHG emissions; adjusting for truncation of supply chain pathways, we find that this share could actually be between 2.1% and 3.9%. For ICT's future emissions, we explore assumptions underlying analysts' projections to understand the reasons for their variability. All analysts agree that ICT emissions will not reduce without major concerted efforts involving broad political and industrial action. We provide three reasons to believe ICT emissions are going to increase barring intervention and find that not all carbon pledges in the ICT sector are ambitious enough to meet climate targets. We explore the underdevelopment of policy mechanisms for enforcing sector-wide compliance, and contend that, without a global carbon constraint, a new regulatory framework is required to keep the ICT sector's footprint aligned with the Paris Agreement.
ABSTRACT
We consider sex differences in human facial morphology in the context of developmental change. We show that at puberty, the height of the upper face, between the lip and the brow, develops differently in males and females, and that these differences are not explicable in terms of sex differences in body size. We find the same dimorphism in the faces of human ancestors. We propose that the relative shortening in men and lengthening in women of the anterior upper face at puberty is the mechanistic consequence of extreme maxillary rotation during ontogeny. A link between this developmental model and sexual dimorphism is made for the first time, and provides a new set of morphological criteria to sex human crania. This finding has important implications for the role of sexual selection in the evolution of anthropoid faces and for theories of human facial attractiveness.
Subject(s)
Biometry , Face/anatomy & histology , Hominidae/anatomy & histology , Selection, Genetic , Sex Characteristics , Adolescent , Adult , Animals , Anthropometry , Biological Evolution , Child , Child, Preschool , Facial Bones/anatomy & histology , Female , Fossils , Humans , Infant , Male , Maxillofacial Development , Primates/anatomy & histology , Puberty , Young AdultABSTRACT
The Notch gene of Drosophila encodes a single transmembrane receptor that plays a central role in the process of lateral inhibition. This process results in the selection of individual mesodermal and neural precursors during the development of the muscular and nervous systems. The activation of Notch during lateral inhibition is mediated by the transmembrane ligand Delta (Dl) and effected by the transcription factor Suppressor of Hairless (Su(H)). The same functional cassette plays a role in other processes, in particular, the development and patterning of the wing. Genetic analysis has suggested that, in addition to the Su(H)-dependent pathway, Notch can signal in an Su(H)-independent manner. This process seems to be tightly associated with signalling by Wingless, a member of the Wnt family of signalling molecules. Here, we have analyzed further the possibility that the Notch protein encodes two different functions. To do so, we have studied the activities and genetic properties of different Notch receptors bearing deletions of specific regions of the intracellular and the extracellular domains in different developmental processes, and have sought to correlate the activity of these mutant proteins with those of existing mutants in Notch. Our results support the existence of at least two different activities of Notch each of which can be associated with specific structural domains.
Subject(s)
Body Patterning , Drosophila/genetics , Receptors, Notch/genetics , Receptors, Notch/metabolism , Signal Transduction , Animals , Drosophila/embryology , Embryo, Nonmammalian , Gene Deletion , Gene Expression Regulation, Developmental , Genetic Engineering , Protein Structure, Tertiary , Receptors, Notch/chemistry , Transgenes , Wings, Animal/embryologyABSTRACT
Hominids display marked body size dimorphism, suggestive of strong sexual selection, yet they lack significant sex differences in canine size that are commonly associated with intrasexual competition in primates. We resolve this paradox by examining sex differences in hominoid facial morphology. We show that chimpanzees, but not gorillas, exhibit clear sexual dimorphism in face width, over and above that expected based on sex differences in body size. We show that this facial dimorphism, expressed as an index, is negatively correlated with canine dimorphism among anthropoid primates. Our findings suggest that a lack of canine dimorphism in anthropoids is not owing to weak sexual selection, but rather is associated with strong sexual selection for broader face width. Enlarged cheek-bones are linked with attractiveness in humans, and we propose that the evolution of a broad face and loss of large canines in hominid males results from mate choice.
