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Science Illustrated “Lie is changing before our very eyes�
BIOLOGICAL EVOLUTION Biological evolution at first can seem a very confusing and complicated topic. Although this can be the case, this article explains the ways biological evolution can be studied through investigating the age of the earth, past fossils and other things relating the living organisms.
THE LOREM IPSUMS
SPRING 2016
EVOLUTION What is it? Evolution is the process that all life on Earth shares a common ancestor and continuously changing and developing and has been doing so for millions and millions of years. Evolution also relates to the change in heritable characteristics over many generations to different species when exposed to many kinds of environments causing mutations in these genes resulting in heritable differences.
Natural Selection Natural Selection is the idea that organisms best suited to their environment are more likely to survive long enough to produce offspring and a better chance of having a large number of offspring as a result. In accordance, organisms not well suited to their environment die young, out-competed for food and produce few or no offspring.
Evolutions Role through Biodiversity Evolution has played a big role in the development of new species and biodiversity in populations all over the world. When species evolve as a result of this new species are created and biodiversity occurs where there are plenty of different animals and organisms in that particular habitat.
Speciation Speciation is the idea that organisms within the same group of species can develop and evolve over time. These organisms are capable of interbreeding to produce fertile offspring although forming new species within their group at the same time. One species that shows the occurrence of speciation are Larus Gulls also known as Ivory Gulls. These seabirds originated in North America and have since spread to all parts of the world and although all these 2
seabirds can look close to the same, there are some small differences between them. The beaks of the Larus are longer and their bodies are quite larger in size compared to some other similar species of seabird. Larus gulls have also obtained a theory Darwin proposed about breeding in a ring around the North Pole, where they would only breed in areas like Norway, Greenland, North America, Great Britain and other parts of that area.
THE LOREM IPSUMS
SPRING 2016
Fossil Research Fossil record is a way scientists can determine lived millions and millions of years ago through how our old the Earth and other species of palaeontologists and geologists researching these animals are over a large scale of time. It fossils to determine the age and other factors. determines life's evolution lasting around four There are many dating methods that can be used billion years with the genetic and environmental by scientists to interpret many things about fossils conditions changing over time in relation with such as the age, where it’s from and how it has Natural Selection. Although fossils can be a very developed overtime. These methods include reliable source the problem faced when using Carbon Dating, Absolute Dating, Radiometric Dating them is that only a small fraction of the frames and sometimes Isotopes. Archaeologists, to and sources found are preserved. Fossils can determine the absolute age of rocks or fossils tell us how long the age of the earth is and the preferably use one of these methods being Carbon length of time the earth has been evolving dating, by using the properties of radiocarbon. through sources and fossils. These fossils can also tell us the different species and animals that
Absolute Dating Methods Radiometric Dating
Carbon Dating
Radiometric Dating is a method that uses the radioactive minerals in rocks as geological clocks to determine the age of the rocks. Scientists find this one of the easiest methods and also use Isotopes to help their research where the Isotopes break down overtime in a process called radioactive decay. This method of absolute dating also helps us earn about the half-life of rocks and how it is used in different dating methods, such as uraniumlead dating and radiocarbon dating.
Carbon Dating, also known as C14 dating, is another form of dating that uses the radioactive isotope carbon-14 to determine the age of objects. Most organic matter contains carbon so this method can relate to a lot of objects all over the world. This method makes it possible to tell the age of substances that contain carbon and tells us the age up to about 60,000 years old.
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THE LOREM IPSUMS
SPRING 2016
Evidence of Evolution The theory of evolution can be proved through many things and is the way we explain the formation of life. One way that can clearly demonstrate evolution exists is the theory of natural selection, in which Charles Darwin spent most of his life developing. One clear piece of evidence to show evolution takes place is the species of finch on the Galapagos Islands. The island contains at least 13 species of finch, the different species were similar in size and colour although the variations in their beaks made them best suited to the food sources on the island. Charles Darwin proposed that all these species of finch came from one descendant of finch on the island but overtime have developed to their best-suited environment and feeding habits they possess.
Traits in Embryos Another way we can tell evolution has taken place is through the similarities between embryos being fish, dogs, snakes, monkeys, eels and other life forms. One feature very similar is that all these organisms have gill slits, tails, and specific anatomical structures involving the spine showing that evolution has occurred. Scientists have always thought chordate embryos looked similar although it was not until they determined this theory that it became clear.
Bacterial resistance Another theory is that bacteria has reacted to evolution and have developed the ability to become resistant to antibiotics. This has changed over generations and generations with different colonies of bacteria becoming resistant which then causes these bacteria to reproduce forming new colonies where not every bacteria is resistant to that particular antibiotic.
The Fossil Record The fossil record shows that the simplest fossils will be found in the oldest rocks, and it can also show a smooth and gradual transition from one form of life to another. This demonstrates evolution because it shows how the fossils have developed over the years they have been in the rocks. 4
THE LOREM IPSUMS
SPRING 2016
Natural Selection Natural Selection is the idea that organisms best suited to their environment are more likely to survive long enough to produce offspring and a better chance of having a large number of offspring as well. In accordance, organisms not well suited to their environment die young, outcompeted for food and produce few or no offspring.
started to outnumber the original ‘peppered’ moth. This occurred a lot quicker than normal evolution because moths have shorter life spans of other animals. The peppered moth also became affected by other factors of the environment whether it is the trees or other species. When the trees became dark due to the industrial evolution, the light-coloured moths were simply easy to see. Birds ate them more A clear example of natural selection is the easily then ever and this started to become a peppered moth originating in Britain and Ireland. huge issue in their species. This then caused the The peppered moth has developed over many moth with darker wings have a much higher years through genetic mutation causing some survival rate also playing a role in why the moths to have almost completely black wings evolution of this species occurred. These moths compared to the original white with black then passed their dark-coloured genes onto their speckled wings. These black forms of wings are offspring therefore causing more of these species not camouflaged as well as normal ‘peppered’ of moths. forms so causes the moths to be seen more easily by birds and other predators. This particular species of moth started out as having many white and black speckles on their wings compared to all black although over successive generations the black moth
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SCIENCE ILLUSTRATED
MAY 2016
Human Evolution Case Study
Evolution is a theory that explains the development of different species over many generations and where they originated. Human evolution is especially important as it relates to the change that has occurred in order for us to gain certain characteristics and features originating back to apelike ancestors millions of years ago. The evolution lasted for a very long time, just over four million years, in which we obtained many traits throughout that time and became the species we are today. It was the study done by Sir Charles Darwin where he unfolded many facts about evolution through the studies of palaeontology, geology, genetics and developmental biology. He found that human evolution took place over millions of years through natural selection and how animals adapted differently in many environments affecting either their heritable physical or behavioural traits, which contributes to evolution of not only humans but other species as well. The theory of
biological evolution itself states that all forms of life resign from one common ancestor and this is clearly displayed for human evolution as well. With humans originating from apelike species it has given us many traits including the ability to walk on two feet, reproducing organs and factors to help us survive in different environments as well as many others. Although we obtained these traits from our apelike ancestors we gained our knowledge and human intelligence from other species and organisms along the way.