From Stephen Jay Gould, The Panda`s Thumb I. The Panda`s Thumb
... The panda's "thumb" is not, anatomically, a finger at all. . It is constructed from a bone called the radial sesamoid, normally a small component of the wrist. In pandas, the radial sesamoid is greatly enlarged and elongated until it almost equals the metapodial bones of the true digits in length. T ...
... The panda's "thumb" is not, anatomically, a finger at all. . It is constructed from a bone called the radial sesamoid, normally a small component of the wrist. In pandas, the radial sesamoid is greatly enlarged and elongated until it almost equals the metapodial bones of the true digits in length. T ...
The Effect of Variation in the Effective Population Size on the Rate of
... However, the correlation between a and Ne might be misleading because a depends on the rate of effectively neutral and advantageous substitution, variation in either of which could be caused by Ne (Gossmann et al. 2010), that is, a 5 Dadaptive/(Dadaptive þ Dnonadaptive) where Dadaptive and Dnonadapt ...
... However, the correlation between a and Ne might be misleading because a depends on the rate of effectively neutral and advantageous substitution, variation in either of which could be caused by Ne (Gossmann et al. 2010), that is, a 5 Dadaptive/(Dadaptive þ Dnonadaptive) where Dadaptive and Dnonadapt ...
Fisher`s geometrical model of evolutionary adaptation—Beyond
... optimum than that of its parent—see Fig. 1. The mutational changes considered by Fisher were taken to have the simplest distribution, namely that of being equally likely to occur in all directions in the character space (spherically symmetric). Fisher’s considerations amount to an explicit model of ...
... optimum than that of its parent—see Fig. 1. The mutational changes considered by Fisher were taken to have the simplest distribution, namely that of being equally likely to occur in all directions in the character space (spherically symmetric). Fisher’s considerations amount to an explicit model of ...
Intralocus sexual conflict
... phenotypic optimum. It arises because many shared traits have a common genetic basis but undergo contrasting selection in the sexes. A recent surge of interest in this evolutionary tug of war has yielded evidence of such conflicts in laboratory and natural populations. Here we highlight outstanding ...
... phenotypic optimum. It arises because many shared traits have a common genetic basis but undergo contrasting selection in the sexes. A recent surge of interest in this evolutionary tug of war has yielded evidence of such conflicts in laboratory and natural populations. Here we highlight outstanding ...
Inference of Positive and Negative Selection on the 59 Regulatory
... D. melanogaster and one line from D. simulans. The ratio of divergence at the amino-acid replacement sites (A) over that at the synonymous sites (S) was twice the ratio for common polymorphism. Interestingly, the 59 region shows the same trend, with the 59/S divergence ratio being 1.8 times higher t ...
... D. melanogaster and one line from D. simulans. The ratio of divergence at the amino-acid replacement sites (A) over that at the synonymous sites (S) was twice the ratio for common polymorphism. Interestingly, the 59 region shows the same trend, with the 59/S divergence ratio being 1.8 times higher t ...
Why the Gene Will Not Return* Elisabeth A. Lloyd
... of selection must be overcome in order to generate the adequate geniclevel theory that they take as one of their “many, equally adequate, representations” (KSW 1990, 161). Debates over interactors, therefore, are not ‘pseudoproblems’, and this fact ultimately has fatal consequences for their claims ...
... of selection must be overcome in order to generate the adequate geniclevel theory that they take as one of their “many, equally adequate, representations” (KSW 1990, 161). Debates over interactors, therefore, are not ‘pseudoproblems’, and this fact ultimately has fatal consequences for their claims ...
The development of evolutionary theory since Darwin
... “[F]ifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that ...
... “[F]ifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that ...
The devil is in the details: genetic variation in
... Dobzhansky 1965; Mayr 1965b). A separate debate was had at the symposium about whether any lost variation would meaningfully influence the evolutionary and ecological success of founding populations. In line with his hypothesis of the general-purpose-genotype, Baker (1965) suggested that while genet ...
... Dobzhansky 1965; Mayr 1965b). A separate debate was had at the symposium about whether any lost variation would meaningfully influence the evolutionary and ecological success of founding populations. In line with his hypothesis of the general-purpose-genotype, Baker (1965) suggested that while genet ...
Lesson Overview
... Darwin hypothesized that the Galápagos finches he observed had descended from a common ancestor. He noted that several finch species have beaks of very different sizes and shapes. Each species uses its beak like a specialized tool to pick up and handle its food. Different types of foods are most eas ...
... Darwin hypothesized that the Galápagos finches he observed had descended from a common ancestor. He noted that several finch species have beaks of very different sizes and shapes. Each species uses its beak like a specialized tool to pick up and handle its food. Different types of foods are most eas ...
Evolutionary Psychology 101
... lead to survival, evolutionary psychologists are interested in processes that may lead to reproductive benefits—sometimes even at a cost to survival. In fact, this broad mechanism of evolutionary change, referred to as sexual selection, may well be the dominant force in helping us understand many un ...
... lead to survival, evolutionary psychologists are interested in processes that may lead to reproductive benefits—sometimes even at a cost to survival. In fact, this broad mechanism of evolutionary change, referred to as sexual selection, may well be the dominant force in helping us understand many un ...
Laws impressed on Matter by the Creator?
... For religious thinkers the matter did not end there. This was because several different constructions could be placed on this relationship between God as lawgiver and the order of nature. One could envisage a deity who, having impressed laws upon matter at Creation, ceased to have anything further ...
... For religious thinkers the matter did not end there. This was because several different constructions could be placed on this relationship between God as lawgiver and the order of nature. One could envisage a deity who, having impressed laws upon matter at Creation, ceased to have anything further ...
“Laws impressed on matter by the Creator”? The Origin and
... For religious thinkers the matter did not end there. This was because several different constructions could be placed on this relationship between God as lawgiver and the order of nature. One could envisage a deity who, having impressed laws upon matter at Creation, ceased to have anything further t ...
... For religious thinkers the matter did not end there. This was because several different constructions could be placed on this relationship between God as lawgiver and the order of nature. One could envisage a deity who, having impressed laws upon matter at Creation, ceased to have anything further t ...
1 to appear in R. Singh, D. Paul, C. Krimbas, and J. Beatty (eds
... the more recent paper, they “turn critics.” Should fitness be defined in terms of a one-generation time frame -- why focus on expected number of offspring, rather than grandoffspring, or more distant descendants still? And is the concept of mathematical expectation the right one to use? The details ...
... the more recent paper, they “turn critics.” Should fitness be defined in terms of a one-generation time frame -- why focus on expected number of offspring, rather than grandoffspring, or more distant descendants still? And is the concept of mathematical expectation the right one to use? The details ...
Chapter 6
... generally induces complications and makes the theoretician’s job challenging. This can be seen in Table 6.1 by simply comparing the exact Robertson-Price result for within-generation change with results for cross-generational change. The surprising result is not that Fisher’s and Robertson’s theorem ...
... generally induces complications and makes the theoretician’s job challenging. This can be seen in Table 6.1 by simply comparing the exact Robertson-Price result for within-generation change with results for cross-generational change. The surprising result is not that Fisher’s and Robertson’s theorem ...
ppt.
... remains constant over the generations • In a nonevolving population – The shuffling of alleles that accompanies sexual reproduction does not alter the genetic makeup of the population ...
... remains constant over the generations • In a nonevolving population – The shuffling of alleles that accompanies sexual reproduction does not alter the genetic makeup of the population ...
Word
... according to WH he was bored by society women. Furthermore intellectual women scared him—perhaps because Darwin did not think very highly of his own intellectual abilities. When Darwin does determine that marriage was “necessary,” he then worried about when the best time was to do so—being well-born ...
... according to WH he was bored by society women. Furthermore intellectual women scared him—perhaps because Darwin did not think very highly of his own intellectual abilities. When Darwin does determine that marriage was “necessary,” he then worried about when the best time was to do so—being well-born ...
Why Do Animals Survive or Die?
... Watch the Evolution video and answer the following questions: 1. What is the most “interesting,” principal evidence for evolution? 2. Name one difference and one similarity between whales and humans. ...
... Watch the Evolution video and answer the following questions: 1. What is the most “interesting,” principal evidence for evolution? 2. Name one difference and one similarity between whales and humans. ...
Evolution
... DARWIN’S THEORY AND THE MODERN SYNTHESIS 13.4 Darwin proposed natural selection as the mechanism of evolution through differential reproduction • Darwin observed that – Reproduction: organisms produce more offspring than the environment can support – Variation: organisms vary in many characteristic ...
... DARWIN’S THEORY AND THE MODERN SYNTHESIS 13.4 Darwin proposed natural selection as the mechanism of evolution through differential reproduction • Darwin observed that – Reproduction: organisms produce more offspring than the environment can support – Variation: organisms vary in many characteristic ...
15-1 The Puzzle of Life`s Diversity
... and reproduce. These organisms pass their heritable traits to their offspring. This process of natural selection causes species to change over time. ...
... and reproduce. These organisms pass their heritable traits to their offspring. This process of natural selection causes species to change over time. ...
15-3 PowerPoint
... In 1859 On the Origin of Species ____________________ evidence presented _______ and proposed a mechanism ________ for evolution that he called NATURAL SELECTION __________________ http://www.loc.gov/exhibits/world/images/s125.jpg ...
... In 1859 On the Origin of Species ____________________ evidence presented _______ and proposed a mechanism ________ for evolution that he called NATURAL SELECTION __________________ http://www.loc.gov/exhibits/world/images/s125.jpg ...
Adaptation in a spider mite population after long
... week and they were discarded when they were too old (c. 10 days later). Five populations per host plant species were established. Each host plant represents a different selection regime. Traits were measured after all populations had been on the new host plants for approximately 15 generations. Owin ...
... week and they were discarded when they were too old (c. 10 days later). Five populations per host plant species were established. Each host plant represents a different selection regime. Traits were measured after all populations had been on the new host plants for approximately 15 generations. Owin ...
Natural selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype; it is a key mechanism of evolution. The term ""natural selection"" was popularised by Charles Darwin, who intended it to be compared with artificial selection, now more commonly referred to as selective breeding.Variation exists within all populations of organisms. This occurs partly because random mutations arise in the genome of an individual organism, and these mutations can be passed to offspring. Throughout the individuals’ lives, their genomes interact with their environments to cause variations in traits. (The environment of a genome includes the molecular biology in the cell, other cells, other individuals, populations, species, as well as the abiotic environment.) Individuals with certain variants of the trait may survive and reproduce more than individuals with other, less successful, variants. Therefore, the population evolves. Factors that affect reproductive success are also important, an issue that Darwin developed in his ideas on sexual selection, which was redefined as being included in natural selection in the 1930s when biologists considered it not to be very important, and fecundity selection, for example.Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype that gives a reproductive advantage may become more common in a population (see allele frequency). Over time, this process can result in populations that specialise for particular ecological niches (microevolution) and may eventually result in the emergence of new species (macroevolution). In other words, natural selection is an important process (though not the only process) by which evolution takes place within a population of organisms. Natural selection can be contrasted with artificial selection, in which humans intentionally choose specific traits (although they may not always get what they want). In natural selection there is no intentional choice. In other words, artificial selection is teleological and natural selection is not teleological.Natural selection is one of the cornerstones of modern biology. The concept was published by Darwin and Alfred Russel Wallace in a joint presentation of papers in 1858, and set out in Darwin's influential 1859 book On the Origin of Species, in which natural selection was described as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favoured for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, nothing was known of modern genetics. The union of traditional Darwinian evolution with subsequent discoveries in classical and molecular genetics is termed the modern evolutionary synthesis. Natural selection remains the primary explanation for adaptive evolution.