Evolution Notes

What exactly is evolution?

______is the biological change process by which descendants come to differ from their ancestors.

Or, simply ______.

Theories of ______change set the stage for the evolutionary theory.

Catastrophism

  • Natural disasters such as ______and ______have happened often during Earth’s long history
  • These events shaped ______and caused species to become ______in the process

Gradualism

  • Landforms result from ______changes over a ______period of time
  • Creation of canyons, laying down of soil

Uniformitarianism is the prevailing theory of geologic change.

  • Geologic processes that shape Earth are ______through time

Evidence for evolution came from several sources.

  • Fossils provide ______of evolution.
  • Fossils in ______layers are more primitive than those in the upper layers.
  • Older layer = older fossil

The study of ______provides evidence of evolution.

  • island species most closely resemble nearest mainland species
  • populations can show variation from one island to another
  • Biogeography is the study of the ______of organisms around the world

______provides evidence of evolution.

  • identical larvae, different adult body forms
  • similar embryos, diverse organisms

The study of ______provides evidence of evolution.

  • Homologous structures are ______in structure but different in function.
  • Homologous structures are evidence of a ______ancestor.
  • Examples: human hand, mole foot and bat wing
  • Analogous structures have a ______function
  • Analogous structures are not evidence of a common ancestor.
  • Examples: insect wing and bat wing
  • Vestigial structures are remnants of organs or structures that had a function in an ______ancestor.
  • Ostrich wings are examples of vestigial structures.

Early scientists proposed ideas about evolution.

  • ______: classification system from kingdom to species
  • ______: species shared ancestors rather than arising separately
  • ______: more-complex forms developed from less-complex forms
  • ______: environmental change leads to use or disuse of a structure

Then there was Charles Darwin.

  • Influenced by ______views of gradual geologic change
  • 1831 - ______traveled to South America
  • Found much evidence to support Lyell’s views
  • Formulated his own opinions

Darwin observed differences among island species.

  • Variation is a difference in a______trait.
  • Galápagos tortoises that live in areas with tall plants have long necks and legs.
  • Galápagos finches that live in areas with hard-shelled nuts have strong beaks.

Species may somehow be able to ______to their surroundings…

  • An adaptation is a feature that allows an organism to ______survive in its environment.
  • Species are able to adapt to their environment.
  • Adaptations can lead to ______change in a population.

Darwin observed fossil and geologic evidence supporting an ancient Earth.

  • Darwin found fossils of extinct animals that ______modern animals.
  • Darwin found fossil shells high up in the Andes mountains.
  • He saw land move from underwater to above sea level due to an ______.
  • Darwin’s observations supported Lyell’s theory that daily geologic processes can add up to great change over a ______period of time.
  • Darwin extended his observations to the ______of organisms.

Several key insights led to Darwin’s idea for natural selection.

  • Darwin noticed a lot of ______in domesticated plants and animals.
  • Traits that weren’t in their wild relatives
  • In order for artificial or natural selection to occur, the trait must be ______.
  • Heritability is the ability of a trait to be passed down.

Artificial Vs. Natural Selection

  • Artificial selection is the process by which humans ______traits through breeding.
  • Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce______offspring on average than do other individuals.

Natural selection explains how evolution can occur.

  • There are four main principles to the theory of natural selection.
  • Variation
  • Overproduction
  • Adaptation
  • Descent with modification

Principle / What is it?
Variation
Overproduction
Adaptation
Descent with modification

Survival of the Fittest?

  • Fitness is the measure of ______ability and ability to produce more offspring.
  • Jaguars with larger teeth and jaws have a higher fitness than other jaguars in a population.
  • Other jaguars reproduce less because they were less fit.

Natural selection acts on ______variation.

  • Natural selection can act ______on traits that already exist.
  • Structures take on______functions in addition to their original function.

New ______is furthering our understanding of evolution.

Fossils provide a ______of evolution.

  • Paleontology is the study of ______or extinct organisms.
  • Paleontology provides ______to support evolution.
  • Molecular and genetic evidence ______fossil and anatomical evidence.
  • Two closely-related organisms will have ______DNA sequences.
  • Evolution ______all fields of biology.
  • Scientist from many fields contribute to the understanding of evolution.
  • The basic principles of evolution are used in many scientific fields.