Natural Selection
Natural Selection 1. The number of prey decreases whilst the number of predators remains constant however, there might be an increase in the population of the fittest predator even though the total number would not change. In addition to that each predator has different capabilities and those capabilities allow them to survive much better than the other predators, for example the hands were the fittest because they were equipped with the best tools for gathering food, whilst the clothes pegs were the least effective. 2. Predators are predators because they are physically more fit or advantaged than those on who they prey. The predator's phenotypes allow them to survive much better than the prey because they can overpower the prey. However the preys also have their own phenotypic capabilities which enable them to survive by feeding on other organisms, where they become predators momentarily. 3. The variety of predators creates very tough competition amongst the predators in similar regions, and thus the theory of survival of the fittest, the most efficient predator at 'hunting' has a better chance of survival. The forks and pegs definitely would have had a much better chance of survival and a longer lifespan, had the hands not been there; however, the forks would have eventually dominated over the pegs because, as the data shows, the forks were still better predators than
Darwin and Natural Selection
Natural Selection Charles Darwin’s theory on Natural Selection, or “The Survival of the Fittest” was the basis of his work on evolution. Darwin proposed that all living organisms are descended from common ancestors and that organisms have adapted by a natural selection of traits that aid survival and reproduction (Hide, G. 2011).Whilst studying at Cambridge, Darwin had the opportunity to join the HMS Beagle on a survey voyage around the world. For almost five years, 1831-1836, Darwin travelled around the world studying rocks, plants and animals. Most notably he visited the Galapagos Islands where he made his famous study of finches and observed the slight variations in species from island to island. On his return, Darwin continued his research, which in 1858 culminated in his book, On the Origin of Species (Sadava, D. 2011). “Can the principle of selection, which we have seen is so potent in the hands of man, apply under nature?” (Darwin, C. 1859) Humans have been breeding domestic animals for favourable traits for centuries and it was Darwin’s knowledge of domestic pigeon breeding that gave him an insight into how this “artificial selection” might have existed for millennia in nature. (Sadava, D. 2011) Using artificial selection, pigeon breeders can pick and choose traits from specific birds to produce offspring with the most favourable aspects. This is
Adaptation and Natural selection
International Baccalaureate Nattapat Khongchumchuen Biology Adaptation and Natural selection Introduction Adaptation that is, the way that species' anatomy, physiology, and behaviour appear to be well suited to the demands of their environments. Adaptation is pervasive in nature. Moreover, once created, species were believed to change little, through time. In his Origin of Species, published in November 1859, Darwin explained the purpose of the book as follows: "I had two distinct objects in view; firstly to show that species had not been separately created, and secondly, that natural selection had been the chief agent of change." Natural selection, Darwin believed, explained how species became adapted to their environments. Natural selection, then, is differential reproductive success, with heritable favourable traits bestowing a survival advantage on those individuals that possess them. Generation by generation, favourable traits will become ever more common in the population, causing a micro-evolutionary which shift within the species. Such traits will remain favoured, however, only if prevailing conditions remain the same. A species' environment usually does not remain constant in nature. A change in a species' physical or biological environment may alter a population's adaptive landscape, making a less advantageous trait more favourable.
Evolution, Natural selection and Darwinism
Evolution, Natural selection and Darwinism Introduction Evolution refers to the processes that have transformed life on Earth from its earliest forms to the vast diversity that characterizes today. <Ref.1 - p414> Up until eighteenth century, biology in Europe and America was dominated by natural theology. <Ref.1 - p415> People believed that a supernatural being like God created each and every species as it is now for a particular purpose, at a particular time. However there are differences in people's interpretation of the length of the "day" mentioned in Genesis. Some Christians believe that the day was of 24hours and the world was created in 6 days. In 1650AD, Archbishop Ussher of Armagh calculated that God, created the world in October 4004BC, beginning on October the 1st and finishing with Man at 9:00am, which is not possible as we have no, archaeological evidence that suggest that a civilised life was already established in the Middle East by then. <Ref.2 - p879> Alternatively, there was the theory of spontaneous generation. A number of Greek philosophers believed in he gradual evolution of life. Amongst those philosophers, Plato (427BC-347BC) and Aristotle (384BC-322BC) influenced the western cultures the most. Plato believed in two worlds: a real world that is ideal and eternal, and illusory world of imperfection that perceive through our senses. He believed that
Predation and natural selection simulation
Juan Pablo Sanucci Pl 2 Standar level. Predation and natural selection simulation Design: Aim: The aim of this is to investigate wich of the breaks of three different species: Cucharita cucharita (spoon beak), Tenedoricus toritlla (fork beak), Cuchillaria cuchillaria (knife beak) is better for catching different types of food, like grass seeds and more. Variables: fix variable: the time(in seconds) and the floor. Independent variable: The type of beak. Dependent variable: This is the units of food collected. Method: ) Set up any material needed. 2) Collect different types of food. 3) Spread the food on the floor. 4) Start to collect the food with the different beaks in a period of time of 20 seconds. 5) Count the food collected 6) Annotate the results on a table. 7) Repeat all this steps until all the different foods are tested. 8) Put all the results in a table. Table design: Species of birds Grass Av Seeds Av Roots Av Worms Av Cucharita cucharita Tenedoricus tortilla Cuchillaria cuchillaria Data collection: Results: Species of birds Grass Av Seeds Av Roots Av Worms Av Cucharita cucharita 8 9 7 8 6 5 8 6,3 4 5 5 4,6 46 40 25 37 Tenedoricus tortilla 2 2 3 2,3 8 6 0 8 6 7 6 6,3 38 40 34 37,3 Cuchillaria cuchillaria 7 6 6 6,3 2 3 2 0 0 0,3 36 30 5 27 Graph: Conclusión: We can
natural selection and the effects of environmental change
Natural Selection and the Effects of Environmental Change Human beings-as is every form of life on Earth-are the product of millions of years of random, unintentional mutations to the DNA of, at every stage, a less complex and more poorly suited organism. It is a process whereby something of low entropy keeps decreasing; whereas in the physical world, the general rule is the opposite, and things become less ordered as time unfolds, increasing in entropy1. There exists many qualms as to the origin of life on Earth, how it got here in the first place being the question scientists fail currently to categorically answer. But the defiant achievement to be even at the starting line is just the first improbable event (although a different topic to evolution) that allows such biodiversity, immensely complex structures such as the human brain (the most complex structure, in the universe, known to man) and a universal law, describing how every known organism got to the state it is at, to even exist at all, let only be, via completely unconscious mutations to DNA (a nucleic acid), malleable to its environment. The theory of evolution began with the work of an Austrian born scientist, whom used the freedom of being a monk to carry out genetic research in plants. His work provided the means to eliminate the idea of blending inheritance (this theory possessed flaws that simply don’t
Charles Darwin and his Theory of Natural Selection
Charles Darwin & his theory of Natural Selection On modern day Earth, there are over four million different life forms. Because we live in such a diverse environment it is not rare nor difficult to discover an unknown plant or animal species. Spend a day in the tropical rainforests of South America, turning over logs, looking beneath bark, sifting through the moist litter of leaves, followed by an evening shining a mercury lamp on a white screen, and one way or another you will collect hundreds of different kinds of small creatures. Moths, caterpillars, spiders, long-nosed bugs, luminous beetles, harmless butterflies disguised as wasps, wasps shaped like ants, sticks that walk, leaves that open wings and fly- the variety will be enormous and one of the creatures you come across will almost certainly be undescribed by science. Often the difficulty we face in identification of a new species is finding specialists who know enough about the group concerned to be able to single out a new one. No one can say just how many species of animals there are in these greenhouse- humid dimly lit jungles. They contain the richest and most varied assemblage of animal and plant life to be found anywhere on earth. Not only are there many major categories of creatures - monkeys, rodents, spiders, hummingbirds, butterflies - but most of these types exist in many different forms. There are over
Practical Investigation. How does biodiversity favour survival through natural selection?
Ishaan Khanna Candidate Number: 0026011 ESS Practical Planning Research Question: How does biodiversity favour survival through natural selection? Natural Selection: The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.[1] Biodiversity: The variety of life on Earth, its biological diversity is commonly referred to as biodiversity. The number of species of plants, animals, and microorganisms, the enormous diversity of genes in these species, the different ecosystems on the planet, such as deserts, rainforests and coral reefs are all part of a biologically diverse Earth.[2] Hypothesis: The rate of survival should be higher when there is more diversity. Method: I took 5 light colour crayons and 5 dark colour crayons and broke each of them into 2 pieces each. I then stripped off their covers. First I put 10 pieces of the light coloured crayons on the grass and selected as many crayons as I could in 5 seconds. Then I put 10 pieces of light coloured crayons and 10 pieces of dark coloured crayons on the grass and tried to select as many as I could in 5
Explain, with examples, how the processes of natural selection and sexual selection are thought to have contributed to modern-day human behaviour
Explain, with examples, how the processes of natural selection and sexual selection are thought to have contributed to modern-day human behaviour Human physical and psychological mechanisms are subject to an environment which is ever changing. Selection enables us to develop and so cope with these random changes by selecting the mechanisms which enable us to cope with these external factors and thus making them much more likely to be inherited by our next generation (Clegg, 2007). It is the survival of the gene to which selection refers to as opposed to the species, for example, the gene which enables the individual to reproduce effectively or the gene that predisposition certain behaviours which are most suitable to it's environment will be passed down to future generations. This means that genes that are less effective for survival or reproduction are less likely to be inherited (Barrett et al., 2002 as cited in Clegg, 2007 p121) It is common practice to divide selection into two process: natural selection; and sexual selection (Clegg, 2007). Natural selection refers to the process of genes which are responsible for physical and behavioural characteristics and are most suitable for survival, being inherited by the next generation. Sexual selection (which could also be argued as being a sub-process of natural selection) refers to the process of genes which influence
There are many examples of natural selection. One of the most famous is that of Darwins finches.
Examples of natural selection There are many examples of natural selection. One of the most famous is that of Darwin’s finches. He observed these birds when he travelled to the Galapagos Island when on his travels on the HMS Beagle. He observed the differences in the size and shape of the bird’s beaks on the different islands, as they had evolved to eat different food types on the different islands of the archipelago. He brought back samples of the birds and these are now preserved in the Darwin Centre in the National History Museum in London. Some examples are: The large ground finch had a strong beak with which to crack nuts open. The large tree finch has a strong, sharp beak and it uses this to grasp large insects like beetles. A warbler finch has a small pointed beak and it catches flying insects on the wing. The cactus finch has a long thin beak so that it can probe between the spines to take nectar from the cactus flowers and eat the seeds. The woodpecker finch has a very hard beak that it uses to hammer wood, and it is able to use a cactus spine to probe the bark for insect larvae. Another commonly referenced example of natural selection was observed in the 19th century in Great Britain, and was caused due to polymorphism of colouration in moths. The peppered moth, Biston betularia, had two main forms – a pale wing with darker speckled markings and
