Guide to Evolution / Paleontology
Paleontology is the study of ancient life through the study of fossil animals and plants. This science includes the evolution of life forms and their interaction with other organisms and the environment. Evolution is the process where living organisms descend from their ancient ancestors.There are different sources of evolution which are studied by paleontologists and geologists together to better understand the history of life on earth. Different factors cause various types of evolution in organisms that may result in the creation of a new species or the extinction of one. The study of evolution and paleontology has allowed us to look into the Earth's past and deliberate the possible future of currently living organisms.
Sources of Evidence
There are three major ways through which paleontologists gather evidence of evolution. They are:
Body Fossils: Being the most informative form of fossils, body fossils include dinosaur bones, ancient seashells and other skeletal structures. To leave behind a useful fossil, the organism must have a hard skeleton or shell. Animals such as the ancestors of the jellyfish can't be observed via this source since they do not fossilize well.
Trace Fossils: This form of fossil allows paleontologists to study the interaction of the organism with their environment such as feces, footprints and teeth marks. These allow paleontologists to study animals which couldn't leave behind body fossils. Trace fossils can also often be dated back before body fossils.
Geochemical Observations: Paleontologists and geologists work together to study geochemical properties of fossils and rocks to find micro-cellular life, climate and time period information. Such findings can actually help scientists discover when life first appeared on the Earth.
Evidence of Evolution: Provides a description of what evolution is, how scientists know that evolution occurred, diagrams of fossil records and the reaction of people to the theory of evolution.
The Causes of Evolution: (.pdf file) A detailed paper the causes of microevolution with focus on natural selection.
How Does Evolution Occur: This resource dives Darwin's Theory into five segments for easy comprehension. It also gives good examples with photos.
Mechanisms of Change
The causes of evolution in various species have always been an interest to scientists. For example, why is it that some birds change over time while others in the same area remain the same? Below are the four major reasons why some animals undergo evolutionary change.
Mutation: Random mutations occur between parents and offspring causing genetic variations. The mutated offspring then introduce their genes in the population of the species.
Natural Selection: This form of evolution occurs when the best adapted organisms pass on their genetic code to their offspring's while those that are less adapted slowly become eliminated.
Genetic Drift: Chance changes from one generation to the next are fall under the genetic drift categories. In this process two or more inherited traits in the population are randomly changed.
Migration: Also known as gene flow this form of evolution occurs when an exchange of genes between populations and even between species occurs due to migration of the organism.
Mechanisms of Change: Berkeley University gives simple definitions of the different mechanisms of change with excellent diagrammed examples using beetles.
A Comparison of Evolution Mechanisms: (.pdf file) This resource is an excellent fact sheet that provides a comparison of different types of mechanisms for evolution including common misconceptions.
Cliffs Notes: This website provides the definition of different types of mechanism of evolution.
Outcomes of Evolution
The result of evolution on a species can vary based on the cause of evolution and the degree of change that occurred in the population. These outcomes are summarized as follows.
Adaptation: Adaptation results in a behavior, feature or chemical change which allows the organism to be better suited to their habitat. Examples include larger beaks, repositioning of eyes or producing toxins to keep predators away.
Co-Evolution: When species interacts they sometimes develop matching evolutionary traits. The best examples of co-evolution are seen in the plant and insect worlds. The process of pollination is thought to be one of co-evolution where insects and plants are so dependent a change in one usually causes a change in another.
Cooperation: This is a form of behavioral evolution where one organism is selected due to the benefits it provides for another organism. Mutually beneficial cooperation occurs when both the organisms benefit from the interaction.
Speciation: Speciation is the process where one species diverges into two or more different species. There are different levels and forms of speciation's involving the cause for diverging, reproduction and interaction after the second species is formed.
Extinction: Extinction occurs with the disappearance of an entire species. The process may be dramatic such as that with the dinosaurs or even unnoticed with the extinction of a species of insect. There are different types of extinction events which may eventually lead to the evolution of a surviving species.
Where Do New Species Come From, Where do They Go, and what Is A Species? An overview of what species are, the continental drift, species formation, adaptation and more information.
ActionScience: A resource from the American Institute of Biological Sciences this website offers numerous links on evolution and history of life, evolution in action, investigation human evolution and more.
Evolutionary Trends: This is a presentation including the topics of adaptation, convergence, extinction, macro and micro evolution, mutation, selection and speciation.
Examples of Evolution
Whales: Fossils suggest that whales actually started out on land and ended up in the sea. Modern day whales such as the baleen whale even have bones in their flippers which may have been feet in their ancestors.
Birds: Most paleontologists believe that birds are descends from certain dinosaurs. This is the result of a fossil found in 1861 which was first thought to be a bird and later recognized as a feathered dinosaur.
Mammals: It is said that the evolution of egg-laying tetrapods to basal animals is the most complete and continuous records of fossils.
12 Elegant Examples of Evolution: Wired science provides a fascinating look into examples of evolution complete with photos and resources. Their examples range from dinosaurs to fish and even water fleas.
Evolution and the Fossil Record: The American Geology Institute provides a nontechnical insight to evolution with an option to a printable version. Sections include fossil records, examples of evolution, nature of species and much more!
10 Evolution Stories Darwin Would Love: This resource has 10 examples of evolutions that Charles Darwin, father of the evolution theory would have loved to study.
Other Resources for Evolution and Paleontology
Understanding Evolution: A one stop resource to the beginning of evolution. This information introduction includes information on how evolution affects life, the process of evolution and how species evolve.
What is Paleontology? A look into what paleontologists do, the history of the science and even a paleontology glossary.
Teach Evolution and Make it Relevant: Resources and materials for teaching evolution at the high school level. This resource focuses on seven topics and includes links for additional resources.
Causes of Evolution: A simple explanation of five causes for evolution including natural selection, genetic drift, mutation, gene flow, and nonrandom mating.
|You May Like|
Car / Auto
|Beauty Salons||Estate Agents||Dentists||Wreckers|
|Tatoo Artists||Electricians||Physiotherapists||Used Cars|
|Child Care||Party Supplies||Obstetricians||New Cars|
|Martial Arts||Plumbers||Dermatologists||Trailer Hire|