Feed on
Posts
Comments

Category Archive for 'Evolutionary biology'

This past December, science writer David Dobbs published an essay (2013) in the online magazine Aeon (aeon.co/magazine/) that purports to explain why the ‘selfish gene’ concept is outmoded and should be retired.  It elicited a good deal of commentary, and in early March, Aeon published responses (Sapolsky et al., 2014) to the original article from […]

Read Full Post »

Biomedical scientists and biologists routinely consider how selection shapes the structure and function of proteins of interest.  Less commonly, I suspect, do we consider how selection for attributes other than protein structure and function can favor or disfavor nucleotide sequences that encode particular amino acid sequences.   A new study (Stergachis et al., 2013) published in […]

Read Full Post »

Three new papers (Kilpinen et al., 2013; McVickers et al., 2013; Kasowski et al., 2013) published earlier this month in Science all address the effects on human patterns of gene expression and other phenotypes of 1) genetic variation in non-protein coding regions of the genome and 2) covalent modifications of chromatin, the complex of DNA […]

Read Full Post »

In his 1987 book, “The Evolution of Individuality,” Leo Buss addressed a fundamental biological question: “How could individual multicellular animals (known as metazoans), like sea anemones, insects, frogs, and humans arise?”  Buss focused on a key challenge confronting any multicellular animal with differentiated cell types performing different functions: the potential conflict between selection on the […]

Read Full Post »

A central focus of recent research aimed at developing a vaccine for HIV-1 is the identification of potent broadly-neutralizing antibodies (bNAbs).  Due to work from several laboratories, many such antibodies have now been identified, produced in quantity as monoclonal antibodies, and characterized with respect to key properties such as epitope specificity, affinity for the corresponding […]

Read Full Post »

Currently, I am on vacation near the beach in South Carolina.  Consequently, I have opted for a topic that is bit different than the majority of my monthly commentaries in that it focuses not on a recent original report but instead on a conceptual point made in a book over thirty years ago.  Nevertheless, after […]

Read Full Post »

The term “genetic code” is associated with a measure of ambiguity.  For molecular biologists, “genetic code” has historically referred to a table that provides for each messenger RNA ribonucleotide triplet the corresponding amino acid that is incorporated into the growing end of a nascent polypeptide chain, i.e. the translation from RNA sequence to protein sequence.  […]

Read Full Post »

The consortium of investigators known as ENCODE (ENCyclopedia Of DNA Elements) published, with much publicity, a series of about thirty papers last fall purporting to “identify all functional elements in the human genome sequence” (https://www.genome.gov/ENCODE/).  Dan Graur, an evolutionary geneticist at the University of Houston, and his associates have published a paper in Genome Biology […]

Read Full Post »

In the past six months, I have encountered a review, by Thomas Nagel in The New York Review of Books (2012), of Alvin Plantinga’s latest book (Where the Conflict Really Lies: Science, Religion, and Naturalism, 2011 ) and a review, by Alvin Plantinga in The New Republic (2012), of Thomas Nagel’s latest book (Mind and Cosmos: […]

Read Full Post »

  Recently, a valued friend and scientific colleague of mine (Jonathan Yewdell of the NIAID in Bethesda) made me aware of a netcast (http://www.twiv.tv/) and associated blog (http://www.virology.ws/) relating to virology.  The originator of both is Vincent Racaniello, a well-known and highly regarded virologist and professor of microbiology at Columbia University.  Dr. Racaniello currently happens […]

Read Full Post »

In 1996, Dean et al. (Science), demonstrated that a loss-of-function allele (CCR5Δ32) encoding a version of the chemokine receptor, CCR5, confers very substantial resistance to infection with HIV-1 in the homozygous state and slows progression in the heterozygous state.  Given the relatively recent origin of HIV-1, this finding raised the question of what source of […]

Read Full Post »

A major problem confronting physicians, nurses, and other hospital personnel is transmission of pathogens among inpatients or between medical personnel and inpatients (in either direction).  A crucial component in efforts to control such infectious outbreaks in hospital wards is determining whether particular cases are linked by instances of person-to-person transmission.  Standard methods of analysis involve […]

Read Full Post »

A paper recently appearing in Science (Näsvall et al. 2012) offers a new insights into the mechanisms by which gene duplication can lead to new genes, gene products, and functions.  The new scheme is termed the innovation-amplification-divergence (IAD) model. 

Read Full Post »

Peter and Rosemary Grant have been responsible for what must be among the longest-running continuous field studies in evolutionary biology (2011).  It will reach forty years in 2013.  In this work, the Grants closely follow multiple species of finches on the Galápagos Island of Daphne Major.  Their results have provided numerous valuable insights into the […]

Read Full Post »

Influenza A viruses continue to be of enormous interest to biomedical researchers and clinicians alike.  In addition to the annual influenza epidemics, which have been inferred to cause substantial excess mortality, there is the ever-present threat of a global pandemic due to several features of influenza virus biology.  A high mutation rate associated with a […]

Read Full Post »

In the book, The Winner-Take-All Society (1995), Robet H. Frank and Philip J. Cook discuss a hypothetical scenario in which a new genetic technique allows babies to be engineered so that they have a 99% chance of performing 15% better on the standardized tests used in American college admissions, such as the Scholastic Aptitude Test […]

Read Full Post »

A common consequence of the evolutionary process in many species is extensive genetic diversity.  As has become apparent in recent studies (Tennessen et al., Science 2012; Nelson et al., Science 2012), the growth of the human population coupled with what is believed to be reduced selective pressure, presumably in part due to the life-promoting and […]

Read Full Post »

There have been claims that variations in the composition of the intestinal flora influence individual health going back at least to the early years of the 1900s.  Late in his career, Ilya Mechnikov, co-receipient of the Nobel Prize for Physiology or Medicine in 1908 (along with Paul Ehrlich) and a pioneer in the study of […]

Read Full Post »

Both Nature and Science are currently celebrating the 100th anniversary of the birth of an icon of logic, computer science, and mathematical biology: Alan Turing.  In reading Andrew Hodges’s spectacular biography of Turing (1983) many years ago I came to appreciate that the subject of the book was both a deeply creative and extraordinarily rigorous […]

Read Full Post »

The new tools for determining nucleotide sequences for whole genomes can sometimes present a problem of data analysis: How can mutations that influence important phenotypes be distinguished from mutations that may be of minimal or no impact on fitness, so-called passenger mutations that arise and persist primarily by chance and can greatly outnumber adaptive genetic […]

Read Full Post »

Older Posts »