Evolution And Classification Test Study Guide
Evolution and Classification Test
Darwin/Lamarck
Darwin’s observations:
Usually the numbers of offspring produced are far greater than the ones that survive
Natural resources are limited. This leads to a struggle for existence with only a fraction of offspring surviving to the next generation
Slight variations (mutations) occur by chance within a population
These variations are inheritable
Darwin concluded that living organisms were evolving through gradual changes over time
Lamarck speculated that more complex forms of organisms arose from simpler forms based on acquired characteristics
Lamarck believed that new species were produced by an internal drive toward greater complexity modified and the change was directed to meet the needs of the organism
Darwin believed that new species were produced through natural selection and that variation exists regardless of an organisms’ needs.
Natural Selection: a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
In nature, the environment is the selective agent.
In nature, characteristics are selected only if they give advantages to individuals in the environment as it is now.
Natural selection is based upon 4 principles:
Overproduction
Variation
Adaptation
Descent with modification
Artificial Selection: the process by which humans change a species of breeding it for certain traits.
Humans make use of the genetic variation in plants/animals by acting as the selective agents.
Homologous structures: Features that are similar in structure but appear in different organisms and have different functions.
Share a common ancestor
Example: forelimbs of humans, bats, and moles
Analogous structures: Features that serve related functions, but do not show common ancestry.
Example: wings of bats and insects
Adaptive Radiation: Divergent and Convergent evolution
Darwin/Lamarck
Darwin’s observations:
Usually the numbers of offspring produced are far greater than the ones that survive
Natural resources are limited. This leads to a struggle for existence with only a fraction of offspring surviving to the next generation
Slight variations (mutations) occur by chance within a population
These variations are inheritable
Darwin concluded that living organisms were evolving through gradual changes over time
Lamarck speculated that more complex forms of organisms arose from simpler forms based on acquired characteristics
Lamarck believed that new species were produced by an internal drive toward greater complexity modified and the change was directed to meet the needs of the organism
Darwin believed that new species were produced through natural selection and that variation exists regardless of an organisms’ needs.
Natural Selection: a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
In nature, the environment is the selective agent.
In nature, characteristics are selected only if they give advantages to individuals in the environment as it is now.
Natural selection is based upon 4 principles:
Overproduction
Variation
Adaptation
Descent with modification
Artificial Selection: the process by which humans change a species of breeding it for certain traits.
Humans make use of the genetic variation in plants/animals by acting as the selective agents.
Homologous structures: Features that are similar in structure but appear in different organisms and have different functions.
Share a common ancestor
Example: forelimbs of humans, bats, and moles
Analogous structures: Features that serve related functions, but do not show common ancestry.
Example: wings of bats and insects
Adaptive Radiation: Divergent and Convergent evolution