FN ISI Export Format VR 1.0 PT J AU Haase, M TI Rapid and convergent evolution of parental care in hydrobiid gastropods from New Zealand SO JOURNAL OF EVOLUTIONARY BIOLOGY DE comparative method; convergence; Hydrobiidae; New Zealand; ovoviviparity; parental care; Potamopyrgus; punctuated equilibrium; sympatric speciation ID SYMPATRIC SPECIATION; POTAMOPYRGUS-ANTIPODARUM; DISCRETE CHARACTERS; SEXUAL SELECTION; PHYLOGENIES; PACHYCHILIDAE; CERITHIOIDEA; SUBSTITUTION; RISSOOIDEA; MORPHOLOGY AB Although parental care occurs in most phyla encompassing a wide array of forms, little is known about its evolution in invertebrates. Two types of egg capsules have been known among ovoviviparous New Zealand hydrobiid gastropods, elastic capsules and simple membranes. Based on a phylogenetic analysis using two mtDNA sequence fragments, I asked whether the second state was derived from the first or whether brooding had multiple origins. The evolution of ovoviviparity was also investigated in the context of habitat transition between brackish and freshwater. Maximum parsimony and Markov chain models of character state transformations in a maximum likelihood framework suggested that hydrobiids have invaded freshwater three times independently. Two of these invasions were followed by the evolution of ovoviviparity, probably in adaptation to changing water levels during periods of irregular precipitation. The syntopy of two congeneric species, one oviparous and the other one brooding, indicated that the transition between reproductive modes must have occurred rapidly. PD JUL PY 2005 VL 18 IS 4 BP 1076 EP 1086 UT ISI:000230047800039 ER PT J AU Carvalho, P Diniz-Filho, JAF Bini, LM TI The impact of Felsenstein's "phylogenies and the comparative method" on evolutionary biology SO SCIENTOMETRICS ID PHYLOGENETICALLY INDEPENDENT CONTRASTS; SCIENCE; JOURNALS; ADAPTATION; REGRESSION; CITATIONS; PATTERNS; PROGRESS; POWER AB Felsenstein's (1985) method of phylogenetic independent contrasts is probably the most commonly used technique in evolutionary biology to study adaptation of organisms to their environment, taking phylogeny into account. Here, we performed a scientometric evaluation of all 1462 articles that cited Felsenstein (1985) between 1985 and 2002, in order to analyze the impact of his comparative method on the evolutionary research program and what has been done since it. We found that Felsentein's (1985) article can be classified as a "hot paper" or a breakthrough contribution, since it was the most cited article from The American Naturalist published in 1985. Also, it can be considered as a "citation classic", since it is the third more cited paper in The American Naturalist from 1945 to 2002. In general, papers that cited Felsenstein (1985) were published in high-impact journals, and most of them are theoretical articles indicating that biologists are aware of statistical and conceptual problems in dealing with comparative methods. PD JAN PY 2005 VL 62 IS 1 BP 53 EP 66 UT ISI:000227040500003 ER PT J AU Federle, W Rheindt, FE TI Macaranga ant-plants hide food from intruders: correlation of food presentation and presence of wax barriers analysed using phylogenetically independent contrasts SO BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY DE adaptation; ant competition; biotic defence; coevolution; comparative method; epicuticular wax; extrafloral nectaries; mutualism; myrmecophyte ID BORNEAN DIPTEROCARP FOREST; GENUS MACARANGA; CREMATOGASTER-BORNEENSIS; ANTIHERBIVORE DEFENSE; COMPUTER-SIMULATION; EUPHORBIACEAE; ASSOCIATION; ADAPTATION; PROTECTION; EVOLUTION AB Many tropical ant-plants provide specialized ant partners with food, which may attract foreign ants parasitizing the mutualism. We present evidence for the ant-plant genus Macaranga, showing that ant competition has forced host plants to hide food resources and restrict access to the mutualists. In Macaranga myrmecophytes, the influence of ant competition strongly depends on the presence of slippery 'wax barriers'. Of all Macaranga ant-plant species, 50% have waxy stems that can be climbed only by the specific ant partners and not by other ant species. We compared the presentation of food (food bodies and extrafloral nectar) between waxy and non-waxy Macaranga host plants using traditional and phylogenetic comparative methods. Consistent with the hypothesized effect of ant competition, wax-free Macaranga host species had fewer extrafloral nectaries and more often produced food bodies under recurved or tubular stipules inaccessible to other ants; closed stipules were less persistent in waxy hosts. Several traits showed phylogenetic signal, but our finding of a more promiscuous food presentation in waxy Macaranga hosts was still supported by phylogenetic comparative analyses. We conclude that competition among ants is an important factor in the evolution of myrmecophytism, and that it has given rise to traits acting as protective filter mechanisms. (C) 2005 The Linnean Society of London. PD FEB PY 2005 VL 84 IS 2 BP 177 EP 193 UT ISI:000226970700002 ER PT J AU Hutcheon, JM Kirsch, JW Garland, T TI A comparative analysis of brain size in relation to foraging ecology and phylogeny in the chiroptera SO BRAIN BEHAVIOR AND EVOLUTION DE mammals; chiroptera; comparative method; brain evolution; brain allometry; foraging; phylogeny ID PHYLOGENETICALLY INDEPENDENT CONTRASTS; EVOLUTIONARY RELATIONSHIPS; MAMMALIAN BRAINS; SONG REPERTOIRE; BATS; ECHOLOCATION; HIPPOCAMPUS; PRIMATES; FLIGHT; FLOWER AB Variations in total brain mass and in the mass of three brain regions (main olfactory bulb, hippocampus, auditory nuclei) were examined using a data set for 63 species of bats (Chiroptera). Using both conventional and phylogenetically based analysis of covariance (log body mass as covariate), we tested several hypotheses that relate total brain mass or the size of the components to variation in foraging ecology, categorized as phytophagous, gleaner, and aerial insectivore. In some analyses, the category phytophagous was split into phytophagous pteropodid and phytophagous phyllostomid to examine differences between two distinct clades of bats. Because the Megachiroptera orient primarily by vision and olfaction, whereas all other bats rely on laryngeal echolocation to locate their prey, we hypothesized that the former would differ in size of the main olfactory bulb, as compared with all other bats. This hypothesis was supported by our analyses. Our more general prediction was that insectivorous bats, which rely heavily on echolocation for the pursuit and capture of their prey, would have larger auditory nuclei than do phytophagous species. This, too, was supported. We also compared phytophagous (fruit or nectar consuming) bats in two families, the Pteropodidae and the Phyllostomidae. We hypothesized that the phyllostomids, which use echolocation while foraging, would have larger auditory nuclei. Although statistical power is low in phylogenetically informed comparisons of the two clades, we did find weak evidence in support of this hypothesis. We conclude that bat brains show evidence of adaptation to foraging ecology. Copyright (C) 2002 S. Karger AG, Basel. PY 2002 VL 60 IS 3 BP 165 EP 180 UT ISI:000179463300003 ER PT J AU Martins, EP Diniz, JAF Housworth, EA TI Adaptive constraints and the phylogenetic comparative method: A computer simulation test SO EVOLUTION DE adaptation; comparative method; computer simulation; generalized least squares; mixed model; phylogeny; spatial autoregression ID PHENOTYPIC EVOLUTION; INDEPENDENT CONTRASTS; CORRELATED EVOLUTION; INTERSPECIFIC DATA; AUTOCORRELATION; PERFORMANCE; INFORMATION; ADAPTATION; CHARACTERS; SELECTION AB Recently. the utility of modern phylogenetic comparative methods (PCMs) has been questioned because of the seemingly restrictive assumptions required by these methods. Although most comparative analyses involve traits thought to be undergoing natural or sexual selection, most PCMs require an assumption that the traits be evolving by less directed random processes, such as Brownian motion (BM). In this study, we use computer simulation to generate data under more realistic evolutionary scenarios and consider the statistical abilities of a variety of PCMs to estimate correlation coefficients front these data. We found that correlations estimated without taking phylogeny into account were often quite poor and never substantially better than those produced by the other tested methods. In contrast, most PCMs performed quite well even when their assumptions were violated. Felsenstein's independent contrasts (FIC) method gave the best performance in many cases, even when weak constraints had been acting throughout phenotypic evolution. When strong constraints acted in opposition to variance-generating (i.e., BM) forces, however, FIC correlation coefficients were biased in the direction of those BM forces. In most cases, all other PCMs tested (phylogenetic generalized least squares, phylogenetic mixed model. spatial autoregression, and phylogenetic eigenvector regression) yielded good statistical performance, regardless of the details of the evolutionary model used to generate the data, Actual parameter estimates given by different PCMs for each dataset, however, were occasionally very different front one another, suggesting that the choice among them should depend on the types of traits and evolutionary processes being considered. PD JAN PY 2002 VL 56 IS 1 BP 1 EP 13 UT ISI:000174248200001 ER PT J AU Perez-Barberia, FJ Gordon, IJ Illius, AW TI Phylogenetic analysis of stomach adaptation in digestive strategies in African ruminants SO OECOLOGIA DE allometry; body mass; comparative method; feeding styles; gut morphology ID EVOLUTIONARY RELATIONSHIPS; TEMPERATE RUMINANTS; RELATIVE ROLES; ACTIVITY TIME; FEEDING TYPE; BODY-SIZE; BOVIDAE; STATISTICS; MORPHOLOGY; MAMMALS AB The stomach morphology of 28 species of artiodactyls that differ in feeding style (browser, mixed feeder, grazer) was analysed using a multivariate approach and phylogenetic correction in order to test whether stomach morphology was correlated with feeding style when body mass was controlled for. A total of 25 morphological traits of the stomach were used in the analysis. After the effects of body mass and phylogeny on stomach morphology were taken into account, there was no significant grouping of species according to feeding style. When information about the feeding style of each species was included in the analysis, the set of morphological traits separated the mixed feeders from the other two feeding styles, but grazers and browsers had similar morphological features. Most of the variance in stomach morphology was explained by body mass and a lesser proportion by phylogeny. The main morphological features that have previously been proposed as being adaptations in grazing species, namely, lengthening of the retention time of ingesta to achieve an increase in their fibre digestion capability by means of a larger relative stomach capacity, a greater subdivision of chambers and smaller openings, are not supported by the findings of this study. Thus, there is no consistent evidence to support a significant adaptive effect of stomach morphology to different diets in the Artiodactyla. PD DEC PY 2001 VL 129 IS 4 BP 498 EP 508 UT ISI:000172685100003 ER PT J AU Ruber, L Adams, DC TI Evolutionary convergence of body shape and trophic morphology in cichlids from Lake Tanganyika SO JOURNAL OF EVOLUTIONARY BIOLOGY DE adaptation; comparative method; ecomorphology; Eretmodini; geometric morphometrics; phylogenetic regression; thin-plate spline ID PHYLOGENETIC-RELATIONSHIPS; CHARACTER DISPLACEMENT; THREESPINE STICKLEBACK; GASTEROSTEUS-ACULEATUS; FISHES; TELEOSTEI; MORPHOMETRICS; SPECIATION; REGRESSION; DIVERSITY AB A recent phylogenetic analysis of mitochondrial DNA sequences from eretmodine cichlids from Lake Tanganyika indicated independent origins of strikingly similar trophic specializations, such as dentition characters. Because genetic lineages with similar trophic morphologies were not monophyletic, but instead were grouped with lineages with different trophic phenotypes, raises the question of whether trophic morphology covaries with additional morphological characters. Here, we quantified morphological variation in body shape and trophically associated traits among eretmodine cichlids using linear measurements, meristic counts and landmark-based geometric morphometrics. A canonical variates analysis (CVA) delineated groups consistent. with dentition characters. Multivariate regression and partial least squares analyses indicated that body shape was significantly associated with trophic morphology. When the phylogenetic relationships among taxa were taken into account using comparative methods, the covariation of body shape and trophic morphology persisted, indicating that phylogenetic relationships were not wholly responsible for the observed pattern. We hypothesize that trophic ecology may be a key factor promoting morphological differentiation, and postulate that similar body shape and feeding structures have evolved multiple times in independent lineages, enabling taxa to invade similar adaptive zones. PD MAR PY 2001 VL 14 IS 2 BP 325 EP 332 UT ISI:000169755900014 ER PT J AU Nunn, CL Barton, RA TI Comparative methods for studying primate adaptation and allometry SO EVOLUTIONARY ANTHROPOLOGY ID PHYLOGENETICALLY INDEPENDENT CONTRASTS; ANCESTRAL CHARACTER STATES; CORRELATED EVOLUTION; BODY-WEIGHT; DISCRETE CHARACTERS; SOCIAL-ORGANIZATION; COMPUTER-SIMULATION; PHYLOGENY; TREES; BRAIN AB A well-known comparative biologist was once asked by a field biologist whether the latter's detailed and painstaking field study of orangutan behavior, carried out over many years, qualified as an example of the comparative method. "No," replied the comparative biologist, "that's an anecdote." The reply is somewhat harsh, as useful comparisons can be conducted both within and across species. The reply does emphasize, however, that analysis of patterns across species is fundamental to the study of adaptive evolution, particularly when variation needed to test hypotheses is present only at this interspecific level.(1-5) Examples in primatology include the occurrence of female sexual swellings in species with habitually multimale, rather than single-male, breeding systems,(6,7) the relationship between polygynandrous mating and relatively large testes size,(3 8) and the association between brain size and social group size.(9) Thus, in many cases, interspecific variation is required to test adaptive hypotheses(10). PY 2001 VL 10 IS 3 BP 81 EP 98 UT ISI:000169682000003 ER PT J AU Schondube, JE Herrera-M, LG del Rio, CM TI Diet and the evolution of digestion and renal function in phyllostomid bats SO ZOOLOGY-ANALYSIS OF COMPLEX SYSTEMS DE bats; comparative method; diet; digestive and renal function; stable isotopes ID URINE CONCENTRATING ABILITY; ANCESTRAL CHARACTER STATES; INTESTINAL ENZYMES; NEOTROPICAL BATS; ADAPTATION; NECTAR; PHYLOGENIES; LIMITATIONS; MODULATION; PHYSIOLOGY AB Bat species in the monophyletic family Phyllostomidae feed on blood, insects, small vertebrates, nectar, fruit and complex omnivorous mixtures. We used nitrogen stable isotope ratios to characterize bat diets and adopted a phylogenetically informed approach to investigate the physiological changes that accompany evolutionary diet changes in phyllostomids. We found that nitrogen stable isotopes separated plant-eating from animal-eating species. The blood of the latter was enriched in N-15. A recent phylogenetic hypothesis suggests that with the possible exception of carnivory, which may have evolved twice, all diets evolved only once from insectivory. The shift from insectivory to nectarivory and frugivory was accompanied by increased intestinal sucrase and maltase activity, decreased trehalase activity, and reduced relative medullary thickness of kidneys. The shift from insectivory to sanguinivory and carnivory resulted in reduced trehalase activity. Vampire bats are the only known vertebrates that do not exhibit intestinal maltase activity. We argue that these physiological changes are adaptive responses to evolutionary diet shifts. PY 2001 VL 104 IS 1 BP 59 EP 73 UT ISI:000169227800007 ER PT J AU Perez-Barberia, FJ Gordon, IJ TI Differences in body mass and oral morphology between the sexes in the Artiodactyla: Evolutionary relationships with sexual segregation SO EVOLUTIONARY ECOLOGY RESEARCH DE allometry; body mass; comminution; comparative method; food selection; intake ID PHYLOGENETICALLY INDEPENDENT CONTRASTS; SIZE DIMORPHISM; RED DEER; CERVUS-ELAPHUS; DIET SELECTION; RUMINANTS; REGRESSION; ALLOMETRY; PHYLOGENY; BEHAVIOR AB It has been hypothesized that the evolution of sexual dimorphism could lead to sexual dimorphism in trophic structures, mainly the mouthparts, through inter-sexual niche partitioning. This hypothesis is based on the assumption that females select habitats on the basis of their requirements for diets with high nutrient concentrations (due to pregnancy and lactation), whereas males select for habitats with abundant resources (due to their larger body size and higher absolute nutrient requirement). We analysed a data set of the morphological traits of the mouth and teeth, which have been proposed as being functionally related to food selection ability (muzzle width, incisor protrusion), food comminution (molar occlusal surface area) and intake (incisor breadth), in males and females of species from the mammalian order Artiodactyla. Our analyses showed that all of the morphological traits studied covaried isometrically with body mass. The effect of sharing common ancestors did not have a significant effect on oral morphology, which indicates that oral morphology evolved in parallel in both sexes. We detected differences in body mass between the sexes and these differences remained when phylogeny was taken into account. Our results demonstrate that the dimensions of the oral traits result primarily from differences in body mass between the sexes rather than differences in niche adaptation between the sexes. The relationship between sexual dimorphism in body mass and differences in niche partitioning between the sexes in the Artiodactyla is discussed. PD JUL PY 2000 VL 2 IS 5 BP 667 EP 684 UT ISI:000087854100007 ER PT J AU Gonzalez, DS Jordan, IK TI The alpha-mannosidases: Phylogeny and adaptive diversification SO MOLECULAR BIOLOGY AND EVOLUTION DE alpha-mannosidase; glycoside hydrolase; gene duplication; positive selection; adaptation ID SEQUENCE-BASED CLASSIFICATION; GLYCOSYL HYDROLASES; GENE DUPLICATION; GLYCOPROTEIN-BIOSYNTHESIS; MOLECULAR EVOLUTION; GOLGI MEMBRANES; FAMILIES; DROSOPHILA; EXPRESSION; SELECTION AB alpha-Mannosidase enzymes comprise a class of gylcoside hydrolases involved in the maturation and degradation of glycoprotein-linked oligosaccharides. Various alpha-mannosidase enzymatic activities are encoded by an ancient and ubiquitous gene superfamily. A comparative sequence analysis was employed here to characterize the evolutionary relationships and dynamics of the alpha-mannosidase superfamily. A series of lineage-specific BLAST searches recovered the first ever recognized archaean and eubacterial alpha-mannosidase sequences, in addition to numerous eukaryotic sequences. Motif-based alignment and subsequent phylogenetic analysis of the entire superfamily revealed the presence of three well-supported monophyletic clades that represent discrete alpha-mannosidase families. The comparative method was used to evaluate the phylogenetic distribution of alpha-mannosidase functional variants within families. Results of this analysis demonstrate a pattern of functional diversification of alpha-mannosidase paralogs followed by conservation of function among orthologs. Nucleotide polymorphism among the most closely related pair of duplicated genes was analyzed to evaluate the role of natural selection in the functional diversification of alpha-mannosidase paralogs. Ratios of nonsynonymous and synonymous variation show an increase in the rate of nonsynonymous change after duplication and a relative excess of fixed nonsynonymous changes between the two groups of paralogs. These data point to a possible role for positive Darwinian selection in the evolution of alpha-mannosidase functional diversification following gene duplication. PD FEB PY 2000 VL 17 IS 2 BP 292 EP 300 UT ISI:000085139200009 ER PT J AU Sasal, P Trouve, S Muller-Graf, C Morand, S TI Specificity and host predictability: a comparative analysis among monogenean parasites of fish SO JOURNAL OF ANIMAL ECOLOGY DE comparative analysis; fish; monogenean; predictability; specificity ID LIFE-HISTORY TRAITS; INDEPENDENT CONTRASTS; COMMUNITY STRUCTURE; SPECIES RICHNESS; MARINE FISHES; PHYLOGENY; EVOLUTION; ECOLOGY; SIZE; PLATYHELMINTHES AB 1, This article compares generalist (parasite species found on two or more host species) and specialist (found on only one host species) monogenean parasite species of fish. The reduction of the host range - that is an increase in host specificity - may correspond with a better adaptation of the parasite to a more predictable host environment. A more predictable environment may allow the parasite species to develop specific adaptations. 2, We assume that the more predictable host environment can be evaluated by host body size, since numerous life-traits, such as longevity, are positively correlated with size. 3. We found that specialist parasites parasitize larger hosts species than generalist parasites. We also found a good relationship between host body size and parasite body size for specialist parasite species. 4. An adaptation to the mechanical problems encountered in the host's gill chamber may lead to an increase in parasite body size. The infection of a larger part of the host population in order to decrease the chances of local extinction due to fluctuations of host abundance may be another adaptive mechanism. 5, We found a negative correlation between parasite body size and prevalence for generalist parasite species. This relationship disappeared when using the comparative method controlling for phylogeny, which proved that it was a phylogenetic effect. PD MAY PY 1999 VL 68 IS 3 BP 437 EP 444 UT ISI:000081723100001 ER PT J AU Holden, C Mace, R TI Phylogenetic analysis of the evolution of lactose digestion in adults SO HUMAN BIOLOGY DE lactose digestion capacity; cultural evolution; pastoralism; phylogeny ID CULTURE HISTORICAL HYPOTHESIS; LACTASE PHENOTYPES; HIGH PREVALENCE; GREEK ADULTS; MALABSORPTION; INTOLERANCE; POPULATIONS; ABSORPTION; DEFICIENCY; MILK AB In most of the world's population the ability to digest lactose declines sharply after infancy, High lactose digestion capacity in adults is common only in populations of European and circum-Mediterranean origin and is thought to be an evolutionary adaptation to millennia of drinking milk from domestic livestock, Milk can also be consumed in a processed form, such as cheese or soured milk, which has a reduced lactose content, Two other selective pressures for drinking fresh milk with a high lactose content have been proposed: promotion of calcium uptake in high-latitude populations prone to vitamin-D deficiency and maintainance of water and electrolytes in the body in highly arid environments, These three hypotheses are all supported by the geographic distribution of high lactose digestion capacity in adults. However, the relationships between environmental variables and adult lactose digestion capacity are highly confounded by the shared ancestry of many populations whose lactose digestion capacity has been tested, The three hypotheses for the evolution of high adult lactose digestion capacity are tested here using a comparative method of analysis that takes the problem of phylogenetic confounding into account, This analysis supports the hypothesis that high adult lactose digestion capacity is an adaptation to dairying but does not support the hypotheses that lactose digestion capacity is additionally selected for either at high latitudes or in highly arid environments. Furthermore, methods using maximum likelihood are used to show that the evolution of milking preceded the evolution of high lactose digestion. PD OCT PY 1997 VL 69 IS 5 BP 605 EP 628 UT ISI:A1997XW18200002 ER PT J AU Ezcurra, C Ruggiero, A Crisci, JV TI Phylogeny of Chuquiraga sect Acanthophyllae (Asteraceae-Barnadesioieae), and the evolution of its leaf morphology in relation to climate SO SYSTEMATIC BOTANY ID SOUTH-AMERICA; INDEPENDENT CONTRASTS; BIOGEOGRAPHY; GRASSES AB Phylogenetic relationships among the 11 species and subspecies of the Andean-Patagonian Chuquiraga sect. Acanthophyllae were resolved by parsimony cladistic analysis using 22 morphological characters. The comparative method was used to test whether a reduction in leaf width occurred in species due to an adaptation to warmer desert climates. Mean values of annual precipitation, January (summer) temperature and July (winter) temperature were estimated for each taxon. independent comparisons for leaf width and climatic variables were calculated at each node of the cladogram and a regression analysis of leaf variation versus climatic variation was performed. The probable ancestral geographic area for the group was determined using Bremer's method. Results of these analyses suggest that marked involution and reduction in leaf width occurred twice independently in the evolution of the group. Reduction of leaf width was correlated with an increase in temperature. The Puna, Patagonia and the High Andes have the highest probability of having been part of the ancestral area of this section, which currently also extends to the Monte, Prepuna and Chilean Desert. This study suggests a relatively recent climatic effect on the evolution of leaf morphology. PD JAN-MAR PY 1997 VL 22 IS 1 BP 151 EP 163 UT ISI:A1997XT48400011 ER PT J AU Snook, RR TI Is the production of multiple sperm types adaptive? SO EVOLUTION DE adaptation; Drosophila obscura species group; nonfertilizing sperm; phylogenetic autoregression; sperm heteromorphism; sperm length ID PLODIA-INTERPUNCTELLA LEPIDOPTERA; DROSOPHILA-OBSCURA GROUP; APYRENE SPERM; MATING PATTERN; SPECIES GROUP; COMPETITION; SIZE; PSEUDOOBSCURA; SPERMATOZOON; BUTTERFLIES AB Males of many species concurrently produce more than one sperm type, now called sperm heteromorphism. In the Drosophila obscura group, all species examined to date produce multiple sperm types that differ in sperm length. Short sperm types in at least three obscura group species do not participate in fertilization, leading to questions regarding the adaptive value of sperm heteromorphism. The common and pervasive inheritance of this trait in the obscura group, however, may indicate that sperm heteromorphism is phylogenetically constrained and therefore does not reflect an adaptive response to selection pressures. I measured interspecific Variation in sperm length and determined the number of sperm types produced in 10 obscura group species. I subsequently tested if interspecific variation in sperm length is significantly associated with phylogeny by using an autoregressive comparative method. All obscura group species examined produce two visually distinct sperm lengths, short and long. Phylogenetic autoregression analyses indicated that 22% of the interspecific Variation in long sperm is related to phylogeny, whereas short sperm are not significantly correlated with phylogeny. These results suggest different selection pressures on the two sperm length types; long sperm have evolved in response to fertilization demands and short sperm have been decoupled from these requirements. PD JUN PY 1997 VL 51 IS 3 BP 797 EP 808 UT ISI:A1997XM06500013 ER PT J AU Ward, D Seely, MK TI Adaptation and constraint in the evolution of the physiology and behavior of the namib desert tenebrionid beetle genus Onymacris SO EVOLUTION DE beetles; behavior; comparative method; morphology; Namib desert; phylogeny; physiology; Tenebrionidae ID CORRELATED EVOLUTION; BODY-TEMPERATURE; PHYLOGENETIC TREE; CHARACTERS; LIZARDS; COADAPTATION; ENVIRONMENT; MORPHOLOGY AB A comparative phylogenetic approach was used to test the following adaptive hypotheses pertaining to the physiological abilities of the Namib desert tenebrionid beetle genus Onymacris to withstand the hot, dry desert environment: (1) Desert-interior species evolved longer legs (relative to body size) than beetles in the cooler coastal region to facilitate stilting, i.e., elevating their bodies our of the hot boundary layer of air close to the substrate. (2) Wax blooms on the exoskeleton, which reduce evaporative water loss, are more likely to evolve in desert-interior species than in coastal species. (3) The high costs of activity in the extreme climates select for perfect coadaptation of preferred body temperatures (i.e., optimal temperatures for activity) and those they achieve in the field. All three of these adaptive hypotheses were supported by the results of squared-change parsimony and independent-contrasts analyses. Additionally, a parsimony approach suggested that a novel means of obtaining water from periodic fogs, known as fog basking, has evolved independently on two occasions. PD JUN PY 1996 VL 50 IS 3 BP 1231 EP 1240 UT ISI:A1996UY55500025 ER PT J AU GARLAND, T HARVEY, PH IVES, AR TI PROCEDURES FOR THE ANALYSIS OF COMPARATIVE DATA USING PHYLOGENETICALLY INDEPENDENT CONTRASTS SO SYSTEMATIC BIOLOGY DE ALLOMETRY; BODY SIZE; BRANCH LENGTHS; COMPARATIVE METHOD; EVOLUTIONARY RATES; FUNCTIONAL MORPHOLOGY; HOME RANGE; STATISTICS ID CORRELATED EVOLUTION; BODY-WEIGHT; PHYLOGENIES; CHARACTERS; TREE; ADAPTATION; STATISTICS; REGRESSION; MODEL; BRAIN AB We discuss and clarify several aspects of applying Felsenstein's (1985, Am. Nat. 125:1-15) procedures to test for correlated evolution of continuous traits. This is one of several available comparative methods that maps data for phenotypic traits onto an existing phylogenetic tree (derived from independent information). Application of Felsenstein's method does not require an entirely dichotomous topology. It also does not require an assumption of gradual, clocklike character evolution, as might be modeled by Brownian motion. Almost any available information can be used to estimate branch lengths (e.g., genetic distances, divergence times estimated from the fossil record or from molecular clocks, numbers of character changes from a cladistic analysis). However, the adequacy for statistical purposes of any proposed branch lengths must be verified empirically for each phylogeny and for each character. We suggest a simple way of doing this, based on graphical analysis of plots of standardized independent contrasts versus their standard deviations (i.e., the square roots of the sums of their branch lengths). In some cases, the branch lengths and/or the values of traits being studied will require transformation. An example involving the scaling of mammalian home range area is presented. Once adequately standardized, sets of independent contrasts can be analyzed using either linear or nonlinear (multiple) regression. In all cases, however, regressions (or correlations) must be computed through the origin. We also discuss ways of correcting for body size effects and how this relates to making graphical representations of relationships of standardized independent contrasts. We close with a consideration-of the types of traits that can be analyzed with independent contrasts procedures and conclude that any (continuous) trait that is inherited from ancestors is appropriate for analysis, regardless of the mechanism of inheritance (e.g., genetic or cultural). PD MAR PY 1992 VL 41 IS 1 BP 18 EP 32 UT ISI:A1992JL28900003 ER EF