EvolutionEvolution

EvolutionEvolutionThis unit explains the scientific aspect of

evolution.There are multiple views on evolution all of which

have significant evidence for backing.Everyone is entitled to their own opinion and we

will discuss multiple views and opinions.

What is Evolution?What is Evolution?Evolution is a scientific explanation for the

diversity of life based on a collection scientific data, observations and hypotheses.

The Theory of Evolution- Change over time by which a modern organism has descended from an ancient organism.

This unit explores multiple explanations for evolutionary change.

Charles DarwinCharles DarwinOne of many scientists who has studied evolution.He has contributed the most amount of data and

research to the theory of evolution.Sailed on a ship (H.M.S. Beagle) around the world,

most notably in the Galapagos Islands, making observations and collected evidence which supports his theory.

Published the results of his work in the book; On the Origin of Species.

Descent with ModificationDescent with Modification

Idea that Darwin proposed also know as Darwinism:

States that over long periods of time natural selection produces organisms that have different structures, establishes different niches or occupy different habitats.

Define the Following Terms Define the Following Terms

FossilsArtificial SelectionStruggle for ExistenceFitnessAdaptation

Survival of the FittestNatural SelectionCommon DescentHomologous StructuresVestigial Organs

Darwin’s Evidence of Evolution

Darwin’s Evidence of EvolutionDarwin argued that living things have been

evolving on Earth for millions of years.His evidence for this process could be found

in the fossil records, geographical distribution of species, homologous structures of living organisms and embryology.

Population GrowthPopulation GrowthThe increase in number of a species as well as

sustaining the existence of the species on earth.Certain factors must occur for population growth

to occur.Many factors influence population growth. Population growth and population dynamics can

impact population genetics.Genetics has a direct relationship to evolution.

Summary of Darwin’s Theory

Summary of Darwin’s TheoryIndividual Organisms differ, and some of this variation is

heritable (first connection between evolution & genetics).Organisms produce more offspring than can survive

(creates competition), and not all can reproduce.The offspring will fight for limited resources in order to

survive.Each has advantages & disadvantages in the struggle

for existence. Those organisms that survive, pass these traits on to their offspring.

Species alive today are descendents of those that survived in the past.

Other Thoughts of Evolution

Other Thoughts of EvolutionJames Hutton- Earth shaped by geological

forces that took place over extremely long periods of time.

Thomas Malthus- Principle of Population, predicts that human population will grow faster then food & space needed to sustain life.

Jean-Baptiste Lamark- Says that organisms gain or lose traits based on the organisms selective use of those traits over time.

Other Thoughts of Evolution

Other Thoughts of Evolution

Charles Lyell- Principles of Geology explains that processes occurring now have shaped the Earth’s geological features over long periods of time.

Alfred Wallace- Writes to Darwin about evolution by natural selection based on his study of plants & animals