Randy Moore

Growth, graviresponsiveness and abscisic-acid content of Zea mays seedlings treated with fluridone

Ten-d-old seedlings of Zea mays L. cv. Tx 5855 treated with 1-methyl-3-phenyl-5-(3-[trifluoromethyl]phenyl)-4-(1H)-pyridinone (Fluridone) were analyzed for abscisic acid (ABA) content using high-performance liquid chromatography with an analysis sensitivity of 2.5 ng ABA g-1 fresh weight (FW). Seedlings were divided into three portions: leaves, detipped roots, and root tips (terminal 1.5 mm). Control plants (water treatment only; no Fluridone) were characterized by the following amounts of ABA: leaves, 0.114±0.024 (standard deviation) μg ABA g-1 FW; detipped roots, 0.260±0.039±μg ABA g-1 FW; root tips, no ABA detected. We did not detect any ABA in tissues of Fluridone-treated plants. Primary roots of treated and untreated seedlings were strongly graviresponsive, with no significant differences between the curvatures or the growth rates of primary roots of Fluridone-treated and control seedlings. These results indicate that 1) Fluridone completely inhibits ABA synthesis, and 2) ABA is not necessary for positive gravitropism by primary roots of Zea mays.

Graviresponsiveness and abscisic-acid content of roots of carotenoid-deficient mutants of Zea mays L.

The abscisic-acid (ABA) content of roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays was analyzed using gas chromatography-mass spectrometry with an analysis sensitivity of 6 ng ABA g−1 fresh weight (FW). Roots of normal seedlings of the same lines were characterized by the following amounts of ABA (as ng ABA g−1 FW,±standard deviation): w-3, 279±43; vp-5, 237±26; vp-7, 338±61. We did not detect any ABA in roots of any of the mutants. Thus, the lack of carotenoids in these mutants correlated positively with the apparent absence of ABA. Primary roots of normal and mutant seedlings were positively gravitropic, with no significant differences in the curvatures of roots of normal as compared with mutant seedlings. These results indicate that ABA 1) is synthesized in maize roots via the carotenoid pathway, and 2) is not necesary for positive gravitropism by primary roots of Z. mays.

IS THE AGE OF THE EARTH ONE OF OUR “SOREST TROUBLES?” STUDENTS’ PERCEPTIONS ABOUT DEEP TIME AFFECT THEIR ACCEPTANCE OF EVOLUTIONARY THEORY

When Charles Darwin was developing his ideas for On the Origin of Species, the most widely accepted estimates of Earth’s age were those of William Thomson (later Lord Kelvin). Kelvin used calculations involving thermodynamics to argue that Earth is only 20–100 million years old—an age far too brief to accommodate evolution by natural selection. Darwin referred to Thomson’s claim as one of his “sorest troubles,” for Darwin understood that the history of life on Earth ultimately relies on geology. Darwin suspected that Earth was much older than Thomson claimed, but Thomson’s enormous stature as a scientist obliged Darwin to reconcile his claims with Kelvin’s data. To accommodate Kelvin’s timeline, Darwin proposed pangenesis as an explanation of inheritance (i.e., every sperm and egg contained “gemmules thrown off from each different unit throughout the body”). Darwin’s explanation sped evolution while avoiding Lamarck’s quasi-spiritual sources of acquired traits. However, Darwin’s explanation of inheritance was wrong (see discussion in Moore et al. 2009a). The age of Earth remains a divisive topic in the modern evolution–creationism controversy. Whereas mainstream science has long acknowledged that Earth is approximately 4.5 billion years old, a vocal group of citizens and religious activists continue to insist that Earth is less than 10,000 years old. Although most geocentrists and flat-Earth advocates have capitulated to scientific evidence, young-Earth creationists continue to reject scientific evidence in favor of religious dictum to claim that Earth is less than 10,000 years old. These antiscience claims have been surprisingly popular with the public. For example, a Gallup Poll in early 2009 reported that “On Darwin’s [200th] Birthday, Only 4 in 10 Believe in Evolution” (Newport 2009), and Berkman et al. (2008) noted that “16% [of biology teachers] believed that human beings were created by God in their present form at one time within the last 10,000 years.” In another study, 12.5% of students were young-Earth creationists (Rutledge and Warden 2000), as are 10%–14% of biology majors (Moore and Cotner 2009). Answers in Genesis’ (AiG) Creation Museum, along with the

Educational Malpractice: The Impact of Including Creationism in High School Biology Courses

27 million in donations required to build it, attest to the appeal of young-Earth creationism. Indeed, AiG’s income for 2005 exceeded

Graft incompatibility between pear and quince: the influence of metabolites of Cydonia oblonga on suspension cultures of Pyrus communis

13 million, and that of the Institute for Creation Research (ICR, another religious organization based on young-Earth creationism) exceeded

Studies of vegetative compatibility-incompatibility in higher plants: VI. Grafting ofSedum andSolanum callus tissuein vitro

7 million. For comparison, the 2005 income of National Center for Science Education—the nation’s leading organization that defends the teaching of evolution in public schools—was

The Lingering Impact of the Scopes Trial on High School Biology Textbooks

College students whose recollections of their high school biology courses included creationism were significantly more likely to invoke creationism-based answers on questions derived from the Material Acceptance of the Theory of Evolution (MATE) instrument than were students whose recollections of their high school biology courses included evolution but not creationism. On average, students who were taught neither evolution nor creationism in their high school biology courses exhibited intermediary responses on the MATE instrument. These results suggest that (1) high school teachers’ treatments of evolution and creationism have a lasting impact and (2) the inclusion of creationism in high school biology courses increases the probability that students accept creationism and reject evolution when they arrive at college. These results are discussed relative to the impact of high school biology courses on students’ subsequent acceptance of evolution and creationism.

Movement of calcium across tips of primary and lateral roots of Phaseolus vulgaris.

The fresh weights of suspension cultures of pear (Pyrus communis) and quince (Cydonia oblonga) increased exponentially for 30 to 40 days after subculturing. Transferring pear cultures to media in which quince cultures had grown for 10 days resulted in a 70% inhibition of callus growth. Transferring quince cultures to media in which pear cultures had grown for 10 days resulted in less than a 20% inhibition of growth. Addition of the cyanogenic glycosides amygdalin and prunasin (as 50 ppm CN _ ) killed pear cultures, while growth of quince cultures was inhibited by only approximately 50%. Addition of 50 ppm CN- severely inhibited growth of both cultures. These results indicate that 1) suspension cultures of quince release factor(s) that significantly inhibit growth of pear cultures, 2) quince cultures are relatively unaffected by metabolites released by pear cultures, 3) the severe inhibition of pear growth by quince metabolites is mimicked by the addition of cyanogenic glycosides ubiquitous to vegetative portions of quince, 4) direct cellular contact is not necessary to elicit incompatibility between pear and quince, and 5) incompatibility between pear and quince need not be associated with any particular stage of graft development.

Supplemental Instruction and the Performance of Developmental Education Students in an Introductory Biology Course.

SummaryIn order to determine whether graft incompatibility betweenSedum telephoides andSolanum pennellii required a prior wounding of tissues, we monitored the cellular events that occurred during grafting of intact (i.e., non-wounded) surfaces ofSedum andSolanum callus tissuein vitro. The only cytological events that occurred in response to autografting ofSedum callusin vitro were (1) dilation of the endoplasmic reticulum in cells adjacent to the graft interface, and (2) the formation of a conspicuously thickened cell wall between the grafted cells. The only cytological event that occurred in callus cells ofSolanum that were heterografted to callus cells ofSedum was a slightly reduced staining intensity of the cytoplasm.Sedum cells of the heterograft, on the other hand, underwent a progressive cellular necrosis when grafted toSolanum in vitro. These results indicate that (1) a prior wounding of tissues is not necessary to elicit the incompatibility response betweenSedum andSolanum, although the wounding induced from an initial graft incision acts to exaggerate and accelerate incompatibility, and (2) graft incompatibility betweenSedum andSolanum occursin vitro between callus cells as it doesin vivo between stems. Thus, the incompatibility factor is probably a normal component of the ground tissue and not the exclusive product of more highly differentiated tissues. Finally, the mechanism of autografting of non-wounded callus cells is compared to the known mechanism of postgenital tissue fusions.

Characterization of root agravitropism induced by genetic, chemical, and developmental constraints.

The publication of Charles Darwin’s On the Origin of Species by Means of Natural Selection in 1859 began a scientific revolution that changed many people’s view of the world. Although Darwin’s ideas were controversial, in the United States he had a powerful advocate: Harvard’s Asa Gray, an evangelical Christian who was America’s leading botanist and president of the American Association for the Advancement of Science (of which William Jennings Bryan— one of John Scopes’s prosecutors—was a member). Gray, who helped arrange for the publication of Origin in the United States, was the only American taken into Darwin’s confidence before Origin was published (Larson 1989). Gray espoused a progressive, God-driven evolution of life. Although some people were disturbed by Darwin’s ideas, Gray’s reconciliation of God and evolution eased many people’s concerns about evolution (Scott 1994, Moore 1997). Gray’s First Lessons in Botany and Vegetable Physiology (1857; later renamed The Elements of Botany) was the leading botany textbook of the late 19th century and the first high school textbook after the publication of Origin to include Darwin’s ideas about evolution. Early in the 20th century the public’s concerns about evolution resurfaced, for by the end of World War I, religious attitudes in the United States had shifted. A perceived decline in morality, along with a collective longing for the seeming simplicity of prewar life, prompted many people to reexamine and increasingly rely on their religious faith for comfort and stability. Religious fundamentalism, based on a literal interpretation of the Bible, became increasingly popular. People who endorsed biblical literalism got their name—fundamentalists—from a series of 12 small pamphlets (containing 90 articles) entitled The Fundamentals that were written between 1910 and 1915. These pamphlets, whose publication was funded by Lyman and Milton Steward (the founders of the Union Oil Company), proclaimed biblical literalism as the antidote to “modernism.” Millions of the pamphlets were distributed (Larson 1989, Clouse 1995). In the 1920s, fundamentalists tried to translate their beliefs into political reform and thereby save the nation’s morality. After a successful crusade to outlaw liquor, fundamentalists set out to eliminate discussions of evolution in public schools. Led by religious leaders such as William Bell Riley, J. Frank Norris, and—most prominently—William Jennings Bryan, fundamentalists began a campaign that blamed Darwin’s ideas for the decline of the nation’s morality. Fundamentalist preachers such as Billy Sunday (a former Chicago Cubs outfielder) used theatrical services to link evolution with eugenics, prostitution, and crime; Aimee Semple McPherson presided at ritual hangings of “monkey teachers”; other preachers claimed that Darwin’s ideas promoted the four P’s: prostitution, perversion, pornography, and permissiveness