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Full-Text Articles in Life Sciences

Why Do Antibiotics Exist?, Fabrizio Spagnolo, Monica Trujillo, John J. Dennehy Jan 2021

Why Do Antibiotics Exist?, Fabrizio Spagnolo, Monica Trujillo, John J. Dennehy

Publications and Research

In the struggle with antibiotic resistance, we are losing. There is now a serious threat of moving into a postantibiotic world. High levels of resistance, in terms of both frequency and strength, have evolved against all clinically approved antibiotics worldwide. The usable life span of new clinically approved antibiotics is typically less than a decade before resistance reaches frequencies so high as to require only guarded usage. However, microbes have produced antibiotics for millennia without resistance becoming an existential issue. If resistance is the inevitable consequence of antibiotic usage, as has been the human experience, why has it not become …


Hip Extensor Mechanics And The Evolution Of Walking And Climbing Capabilities In Humans, Apes, And Fossil Hominins, Elaine E. Kozma, Nicole M. Webb, William Harcourt-Smith, David A. Raichlen, Kristiaan D’Août, Mary H. Brown, Emma M. Finestone, Stephen R. Ross, Peter Aerts, Herman Pontzer Apr 2018

Hip Extensor Mechanics And The Evolution Of Walking And Climbing Capabilities In Humans, Apes, And Fossil Hominins, Elaine E. Kozma, Nicole M. Webb, William Harcourt-Smith, David A. Raichlen, Kristiaan D’Août, Mary H. Brown, Emma M. Finestone, Stephen R. Ross, Peter Aerts, Herman Pontzer

Publications and Research

The evolutionary emergence of humans’ remarkably economical walking gait remains a focus of research and debate, but experi- mentally validated approaches linking locomotor capability to postcranial anatomy are limited. In this study, we integrated 3D morphometrics of hominoid pelvic shape with experimental mea- surements of hip kinematics and kinetics during walking and climbing, hamstring activity, and passive range of hip extension in humans, apes, and other primates to assess arboreal–terrestrial trade-offs in ischium morphology among living taxa. We show that hamstring-powered hip extension during habitual walking and climbing in living apes and humans is strongly predicted, and likely constrained, by …


Oldest Skeleton Of A Plesiadapiform Provides Additional Evidence For An Exclusively Arboreal Radiation Of Stem Primates In The Palaeocene, Stephen B. Chester, Thomas E. Williamson, Jonathan I. Bloch, Mary T. Silcox, Eric J. Sargis May 2017

Oldest Skeleton Of A Plesiadapiform Provides Additional Evidence For An Exclusively Arboreal Radiation Of Stem Primates In The Palaeocene, Stephen B. Chester, Thomas E. Williamson, Jonathan I. Bloch, Mary T. Silcox, Eric J. Sargis

Publications and Research

Palaechthonid plesiadapiforms from the Palaeocene of western North America have long been recognized as among the oldest and most primitive euarchontan mammals, a group that includes extant primates, colugos and treeshrews. Despite their relatively sparse fossil record, palaechthonids have played an important role in discussions surrounding adaptive scenarios for primate origins for nearly a half-century. Likewise, palaechthonids have been considered important for understanding relationships among plesiadapiforms, with members of the group proposed as plausible ancestors of Paromomyidae and Microsyopidae. Here, we describe a dentally associated partial skeleton of Torrejonia wilsoni from the early Palaeocene (approx. 62Ma) of New Mexico, which …


Teaching Evolution: Blog As A Liminal Space, Shylaja Akkaraju, Alexander Wolf Jan 2016

Teaching Evolution: Blog As A Liminal Space, Shylaja Akkaraju, Alexander Wolf

Publications and Research

A threshold concept is a challenging concept that acts as a doorway leading to deeper understanding and a dramatic shift in perception. A learner that is in- volved in grasping a threshold concept is said to be undergoing a threshold expe- rience within a liminal space or learning environment. We used the blog as a lim- inal space for our students to engage with the theory of evolution, which is a threshold concept. In order to teach evolution effectively it is necessary to address both understanding and acceptance of evolutionary theory. To explore the latter in an introductory biology course, …


The Evolutionary Function Of Conscious Information Processing Is Revealed By Its Task-Dependency In The Olfactory System, Andreas Keller Feb 2014

The Evolutionary Function Of Conscious Information Processing Is Revealed By Its Task-Dependency In The Olfactory System, Andreas Keller

Publications and Research

Although many responses to odorous stimuli are mediated without olfactory information being consciously processed, some olfactory behaviors require conscious information processing. I will here contrast situations in which olfactory information is processed consciously to situations in which it is processed non-consciously. This contrastive analysis reveals that conscious information processing is required when an organism is faced with tasks in which there are many behavioral options available. I therefore propose that it is the evolutionary function of conscious information processing to guide behaviors in situations in which the organism has to choose between many possible responses.


Using A Paradigm Shift To Teach Neurobiology And The Nature Of Science—A C.R.E.A.T.E.-Based Approach, Sally G. Hoskins Apr 2008

Using A Paradigm Shift To Teach Neurobiology And The Nature Of Science—A C.R.E.A.T.E.-Based Approach, Sally G. Hoskins

Publications and Research

Decades ago, classic experiments established the phenomenon of “neural induction” (Spemann and Mangold, 1924; Holtfreter, 1933). It appeared clear that amphibian ectoderm was pre-programmed to form epidermis, and that the neural phenotype was induced by a chemical signal from mesoderm. The “ectoderm makes skin, unless induced to make nervous system” model appeared in many textbooks. This interpretation, however, was not simply incorrect but 180 degrees out of alignment with the actual situation. As subsequently demonstrated, the default state of amphibian ectoderm is neuronal, and the expression of the epidermal phenotype requires cell signaling (Hemmati-Brivanlou and Melton, 1992; 1994; 1997). In …


Measuring Knowledge Of Natural Selection: A Comparison Of The C.I.N.S., An Open-Response Instrument, And An Oral Interview, Ross Nehm, Irvin Sam Schonfeld Jan 2008

Measuring Knowledge Of Natural Selection: A Comparison Of The C.I.N.S., An Open-Response Instrument, And An Oral Interview, Ross Nehm, Irvin Sam Schonfeld

Publications and Research

Growing recognition of the central importance of fostering an in-depth understanding of natural selection has, surprisingly, failed to stimulate work on the development and rigorous evaluation of instruments that measure knowledge of it. We used three different methodological tools, the Conceptual Inventory of Natural Selection (CINS), a modified version of Bishop and Anderson's (Bishop and Anderson [1990] Journal of Research in Science Teaching 27: 415-427) open-response test that we call the Open Response Instrument (ORI), and an oral interview derived from both instruments, to measure biology majors' understanding of and alternative conceptions about natural selection. We explored how these instruments …


Does Increasing Biology Teacher Knowledge Of Evolution And The Nature Of Science Lead To Greater Advocacy For The Teaching Of Evolution In Schools?, Ross Nehm, Irvin Sam Schonfeld Jan 2007

Does Increasing Biology Teacher Knowledge Of Evolution And The Nature Of Science Lead To Greater Advocacy For The Teaching Of Evolution In Schools?, Ross Nehm, Irvin Sam Schonfeld

Publications and Research

This study investigated whether or not an increase in secondary science teacher knowledge about evolution and the nature of science gained from completing a graduate-level evolution course was associated with greater preference for the teaching of evolution in schools. Forty-four precertified secondary biology teachers participated in a 14-week intervention designed to address documented misconceptions identified by a precourse instrument. The course produced statistically significant gains in teacher knowledge of evolution and the nature of science and a significant decrease in misconceptions about evolution and natural selection. Nevertheless, teachers' postcourse preference positions remained unchanged; the majority of science teachers still preferred …