Evolution Notes

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Evolution Notes
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Evolution

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Evolution

• A change in a kind of organism over time
• Charles Darwin (1809-1882)
• Wasnt the first person to recognize that
  evolution has happened and is happening
• Was the first to propose a feasible mechanism for
  evolution. It is called descent with
  modification .
• Scientists have found large amounts of evidence
  to support Darwins views of evolution.

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• Theory

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• Theory well-tested explanation that unifies a
  broad range of observations
• Remember The word theory in everyday language
  and in scientific language means very different
  things.
• In everyday language, people use the word theory
  to mean a hypothesis or an educated guess.
• In science, people use the word theory to
  represent an idea that is strongly supported by
  evidence. It is accepted and used to explain
  many observations.

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Other examples of theories

• Cell theory all living things are made up of one
  or more cells, etc.
• Atomic theory all matter is made up of one or
  more atom, etc.

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What was Darwins theory of evolution by natural
selection?
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What was Darwins theory of evolution by natural
selection?

• Darwin published his book, On the Origin of
  Species by Means of Natural Selection, in 1859.
  In it, he outlines the major points of his
  theory.

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What was Darwins theory of evolution by natural
selection?

• Darwin published his book, On the Origin of
  Species by Means of Natural Selection, in 1859.
  In it, he outlines the major points of his
  theory.
• Natural selection

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What was Darwins theory of evolution by natural
selection?

• Darwin published his book, On the Origin of
  Species by Means of Natural Selection, in 1859.
  In it, he outlines the major points of his
  theory.
• Natural selection Process by which individuals
  that are better suited to their environment to
  survive and reproduce most successfully also
  called survival of the fittest

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What was Darwins theory of evolution by natural
selection?

• Darwin published his book, On the Origin of
  Species by Means of Natural Selection, in 1859.
  In it, he outlines the major points of his
  theory.
• Natural selection Process by which individuals
  that are better suited to their environment to
  survive and reproduce most successfully also
  called survival of the fittest
• You can remember the main points behind natural
  selection as VISTA

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VISTA
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VISTA

• Variation

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance Certain traits can be passed down
  through generations

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance Certain traits can be passed down
  through generations
• We know that heritable variation is due to genes.
  Variation in genetic material is due to

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance Certain traits can be passed down
  through generations
• We know that heritable variation is due to genes.
  Variation in genetic material is due to
• Mutations
• Sexual reproduction

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance Certain traits can be passed down
  through generations
• We know that heritable variation is due to genes.
  Variation in genetic material is due to
• Mutations changes in a DNA sequence that affect
  genetic information
• Sexual reproduction

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VISTA

• Variation Members of the same population have
  different characteristics no organism is exactly
  the same as another
• Inheritance Certain traits can be passed down
  through generations
• We know that heritable variation is due to genes.
  Variation in genetic material is due to
• Mutations changes in a DNA sequence that affect
  genetic information
• Sexual reproduction process by which cells from
  two different parents unite to produce the first
  cell of a new organism

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VISTA
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VISTA

• Survival and reproduction
  

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VISTA

• Survival and reproduction Organisms must
  survive in their environment and successfully
  mate and reproduce with another member of their
  species

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VISTA

• Survival and reproduction Organisms must
  survive in their environment and successfully
  mate and reproduce with another member of their
  species
• Natural selection is often referred to as
  survival of the fittest. What is fitness?

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VISTA

• Survival and reproduction Organisms must
  survive in their environment and successfully
  mate and reproduce with another member of their
  species
• Natural selection is often referred to as
  survival of the fittest. What is fitness?
• Certain characteristics and behaviors make an
  organism more likely to survive in a given
  environment when competing with other members of
  the population

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VISTA
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VISTA

• Time

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful
• Adaptation

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful
• Adaptation any inherited characteristic that
  increases an organisms chance of survival

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful
• Adaptation any inherited characteristic that
  increases an organisms chance of survival
• Darwin referred to this accumulation of
  adaptations over time as

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful
• Adaptation any inherited characteristic that
  increases an organisms chance of survival
• Darwin referred to this accumulation of
  adaptations over time as natural selection

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VISTA

• Time Generation after generation, individuals
  continue to compete to survive and produce
  offspring, and not all are successful
• Adaptation any inherited characteristic that
  increases an organisms chance of survival
• Darwin referred to this accumulation of
  adaptations over time as natural selection
• He believed that descent with modification had
  created the great diversity of life

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Lets explain the giraffes long neck using the
theory of evolution by natural selection.

• V Giraffes had different neck lengths
• I The lengths of the necks could be passed on
  from one generation to the next
• S Giraffes with longer necks were able to get
  more food and so they could survive to
  reproduce
• T Gradually, each succeeding generation of
  giraffes had longer necks because the longer
  necked giraffes were surviving more often than
  the short necked giraffes
• A Overall, the populations of giraffes all had
  long necks.

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How did Darwin develop his idea of natural
selection?

• Voyage of the Beagle
• After graduating from college, Darwin took a job
  as the naturalist on the H.M.S. Beagle, a boat
  that was traveling around the world with the
  purpose of creating better maps.
• Darwin collected living organisms, fossils and
  other evidence of living things every time the
  ship landed in a new area.

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Fossils

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Fossils preserved remains or evidence of an
  ancient organism

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Fossils preserved remains or evidence of an
  ancient organism
• Darwin wondered Why had so many of these species
  disappeared? How were they related to living
  species?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Fossils preserved remains or evidence of an
  ancient organism
• Darwin wondered Why had so many of these species
  disappeared? How were they related to living
  species?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Organisms on Islands

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Organisms on Islands
• Studied the finches and giant tortoises of the
  Galapagos Islands

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Organisms on Islands
• Studied the finches and giant tortoises of the
  Galapagos Islands
• Found that organisms on the islands were similar
  to those on the mainland, but had slightly
  different characteristics that allowed them to
  survive in their new habitats

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?
• Organisms on Islands
• Studied the finches and giant tortoises of the
  Galapagos Islands
• Found that organisms on the islands were similar
  to those on the mainland, but had slightly
  different characteristics that allowed them to
  survive in their new habitats
• Darwin wondered Why was there so much diversity?
  Is there a way that leads to such a variety of
  ways of reproducing?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?

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How did Darwin develop his idea of natural
selection?

• What did Darwin observe on his travels?

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Influence of Other Scholars Work

• Lamarcks Theory of Evolution Through the
  Inheritance of Acquired Characteristics
• Use and disuse
• Organisms can alter the size or shape of their
  body by using their bodies in new ways
• Parts of their body would decrease in size if
  they werent used, and over the course of
  generations, completely disappear

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Influence of Other Scholars Work

• Lamarcks Theory of Evolution Through the
  Inheritance of Acquired Characteristics
• Inheritance of acquired characteristics
• Acquired characteristics are passed down to
  future generations
• If you spent a lot of time lifting weights and
  building muscles, your children will be born with
  big muscles

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Influence of Other Scholars Work

• Lamarcks Theory of Evolution Through the
  Inheritance of Acquired Characteristics
• Example Giraffes long neck
• Giraffes necks got longer because they would
  stretch to reach the highest leaves
• Their offspring were born with these stretched
  necks, and continued to stretch them even longer,
  giving birth to offspring with even longer
  necks
• Does Lamarcks theory of evolution work?

NO!!!!
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Key Ideas

• Lamarck was wrong, but we can learn from his
  mistakes.
• Acquired traits arent inherited.
• Only traits determined by our genes are
  inherited.
• During Darwins time people did not know how
  traits were inherited. They had no knowledge of
  genes and DNA.

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Personal Studies

• Darwin wanted to ensure that he had as much
  research as possible to support his ideas.
• Studied the diversity of barnacles collected
  specimens from all he could find to study their
  differences amongst the populations
• Bred Fancy Pigeons bred pigeons for a period of
  time to examine their different beaks and how
  they were inherited
• Artificial Selection selection by humans for
  breeding of useful traits from the natural
  variation among different organisms

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Evidence for Evolution

• Fossil Record
• Different layers of rock are formed at different
  times during Earths history
• The deeper the rock, the older it is
• Fossils found in deeper layers are older
• Can be used to see how organisms have changed
  over time

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Evidence for Evolution

• Biogeography
• Different animals found on different continents
  but in similar climates and environments
  demonstrated similar behaviors or had similar
  anatomy

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Evidence for Evolution

• Comparative Anatomy
• Homologous Structures structures that have
  different mature forms but develop from the same
  embryonic tissues
• Examples Human arm, cat leg, whale fin, bat
  wing

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Evidence for Evolution

• Vestigial Organs Organs that are reduced in
  size and serve little or no function
• Examples Traces of leg bones in snakes, human
  appendix

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Evidence for Evolution

• Comparative Embryology
• The early stages of many animals with backbones
  are very similar (be careful ? Not identical!)

Fish
Chicken
Pig
Human
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Evidence of Evolution

• Molecular Biology
• All living organisms are made of the same basic
  materials
• Proteins, nucleic acids, carbohydrates, lipids

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Current Examples of Evolution by Natural Selection

• It is incorrect to think of evolution by natural
  selection as a process that takes a long time to
  see occurring. We can see changes in groups of
  organisms from generation to generation. Here
  are some examples of evolution that is occurring
  around us.

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Antibiotic Resistant Bacteria

• Antibiotics drugs intended to kill or interfere
  with the growth of bacteria
• Used to be known as magic bullets or wonder
  drugs because they were so effective
• Mutations have resulted in antibiotic resistant
  bacteria that can survive the medication
• If they survive, they reproduce more antibiotic
  resistant bacteria
• Bacteria reproduce really quickly so once
  powerful antibiotics are now sometimes useless.

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Pesticide Resistant Insects

• We use pesticides to keep insects from destroying
  crops
• Mutations result in insects that are resistant or
  immune to certain pesticides
• Pesticide resistant insects then survive and
  reproduce, resulting in more pesticide resistant
  insects.