Newer Scientist

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The Theory of Evolution is a subject that is misunderstood internationally and statistics show that only half of the United States actually believes in this theory, although it is the unifying theory of biology. In this article we will go through the definition of biological, the fossil record, natural selection, speciation, how we know that this theory is accurate and a case study on human evolution. This article will make you believe in the theory of evolution and inform you on why the theory is so popular

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internationally!

Volume 1, Issue 1 Newsletter Date

Introduction I N S I D E T H I S I S S U E :

The Theory Of Evolution

Biological Evolution

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Biological Evolution is the idea that all forms of life can be traced back to one common ancestor. Evolution allows

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organisms to adapt to the environment as it changes; it is responsible for the major diversity on the earth. Biological

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Evolution is any kind of genetic change in a species that is passed on through several generations. The changes can

Introduction 1

Biological Evolution 1

The Fossil Record 2

Natural Selection 3

Speciation 4

Is evolution accurate 5

Case Study 6

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The Fossil Record is like a story of how animals have changed over time and is shown through fossils. Fossils give Paleontologists (Scientists whom

The Fossil Record

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study fossils) information on life forms that used to live on Earth. Fossils are found in sedimentary rocks. The different types of layers of rocks can help

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determine the age of a fossil as the fossil would be around the same age of the rock. The fossil record relates to the age of the Earth as the deeper the fossil is in

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vary in size and can be noticeable or unnoticeable. For a change to be officially called an instance of evolution it has to happen on a genetic level and be passed down one generation to the next. A change on the genetic level is a

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small-scale change and is known as microevolution. The theory that all of life is connected to the one ancestor is known as macroevolution.

Charles Darwin who is famous for his work in the Theory of Evolution, put the Theory of Evolution

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forward in his book On the Origin of Species which was published in 1859. He noticed that all animals had similar properties, which was what made him come to the conclusion that all animals came from a common ancestor and that animals changed from natural selection.

White Tigers have white fur from biological evolution

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Natural selection is one of Darwin’s theories where organisms survive by adapting to its environment meaning only the organisms that are adapted will

Natural Selection

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reproduce becoming the succeeding generation. It is the most powerful and most important cause of evolution. There are four main principals in Natural

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Selection, which are variation, overproduction, adaptation and descent with modification. Variation is the heritable differences

Speciation

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the Earth the older the fossil is. The fossil record shows how long life on Earth has been evolving as it shows the different forms of animals and how they have changed over time. Paleontologists use many different methods to determine the age of a fossil. Some of these methods can be more accurate than others. Dating methods scientists use to interpret the fossil record is

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sedimentary rock layers that have layered on top of each other over time, and carbon dating, which is measured by measuring the ratio of carbon-14 to carbon-12, which change over time. Another type of method is Radiometric dating which is a technique used to determine the absolute age of rocks and fossils. Dendrochronology is another technique, which is the study of

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data from tree ring growth. The other method is the molecular clock, which is a technique that uses the mutation rate of biomolecules to work out the time in prehistory when two or more life forms diverged.

A diagram showing the age of the layers from periods of

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that exist in every population and is the basis of Natural Selection. Overproduction is when to many of one population are produced with not enough life recourses like food and water. Adaptation is a trait that helps an organism survive and reproduce. The last principal is Descent of Modification, which is the result in species with adaptation that are well suited for survival and reproduction. An example of Natural Selection that Charles Darwin talked about is the shape of Finch beaks. Finches that lived in different environments, obviously had to eat different foods, therefore finches that had to eat hard seeds their beaks would be thick, if they ate insects their beaks would be skinny and pointed and if they ate cactus fruits the beaks would be sharp to puncture the skin of the fruit. Another example is Antibiotic Resistance, which is when bacteria changes to protect themselves against an antibiotic. The bacteria that should have been killed reproduces spreading more bacteria.

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Speciation is the formation of new and distinct species in the course of evolution. Speciation involves the splitting of a single evolutionary lineage into two or more genetically independent lineages. There are four main types of speciation allopatric, peripatric, parapatric and sympatric.

Allopatric speciation happens when one species separates into two different groups, which are completely separated from one another. The types of things that separate a species include things like rivers, which makes it impossible for them to breed. After the species separate they then start to develop differently and adapt to the habitat they are in.

Peripatric speciation happens when small groups of individuals break away from a large species to form new species. Both Allopatric speciation and Peripatric speciation are very similar with the only differences being in peripatric speciation one group is much smaller than the other.

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Speciation

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When a species is spread over a large geographic area it is known as parapatric speciation. It is still possible for any member of the species to mate with another member, the individual’s only mate with those in their own geographic region. The species are not separated from a physical barrier but they are separated by differences in the same environment.

The last type of speciation is Sympatric speciation. This occurs when there are no physical barriers preventing any members of a species from mating with another, and all members are close to one another. A new species develops based on a different food source or characteristic, seems to develop spontaneously. Many scientists do not believe in this theory.

Is the Evolutionary Theory Accurate?

Charles Darwin and Alfred Wallace based their theory of evolution on natural selection and many other observations when they travelled the world. With their research and observations other scientists have been able to come forward with more evidence supporting the theory. The fossil record shows us evolution is accurate as it shows how species have changed over time and species that have become extinct. An example of this is ancient horse fossils have been found, they show the differences and changes the species has gone through over time. Another reason the theory of evolution is accurate is comparative anatomy. Comparative anatomy is different species and different groups having the same structural features. This is the same idea that every species and animal group all comes from the one common ancestor. Comparative embryology is the idea that organisms in embryonic development went through similar stages. In early stages of development, the human embryo and the embryos of other animals appear to be quite similar for example the embryos of fish, amphibians, reptiles, birds and humans initially have gills.

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Case Study on Human Evolution

Human evolution is the theory that humans over millions of years evolved from ape like ancestors. One of the earliest defining human traits is the ability to walk on two legs, which evolved over 4 million years ago. Other characteristics we have in common are large and complex brains, the ability to create and use tools, and the ability to learn speak languages. These characteristics developed more recently. Physical and genetic similarities show the human beings have a very close relationship to the apes. Humans have the same common ancestor with chimpanzees and gorillas that lived between 8 and 6 million years ago. Humans first evolved in Africa, this is where most of human evolution occurred and all fossils of early humans from 2 to 6 million years ago were from Africa. Some scientists believe that there were 15 to 20 different human species of early humans and they all died out. The primary resource for detailing the path of human evolution will always be fossil specimens. The fossil specimens show the changes of species over time. Early Humans first migrated out of Africa to Asia around 2-1.8 million years ago. They migrated to Europe around 1.5-1 million years ago. Modern humans later on populated many other parts around the world including here in Australia, about 60,000 years ago.

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Bibliography    Core  Science  Stage  5  

http://nationalgeographic.org/encyclopedia/speciation/  

http://biology.about.com/od/evolution/a/aa110207a.htm  http://evolution.berkeley.edu/evolibrary/article/evo_02  

http://biologos.org/common-­‐questions/scientific-­‐evidence/fossil-­‐record/  

https://www.fossilera.com/pages/dating-­‐fossils  http://www.evolution.berkeley.edu/evosite/evo101/IIE1cMolecularclocks.shtml  http://evolution.berkeley.edu/evolibrary/article/evo_25  http://www.nps.org.au/medicines/infections-­‐and-­‐infestations/antibiotics/for-­‐individuals/what-­‐is-­‐antibiotic-­‐resistance  

http://www.britannica.com/science/speciation