Chapter 22: Descent with Modification(1) Flashcards
What are the two ways we describe evolution?
As a pattern and Process.
The pattern of evolutionary change is revealed by data from a range of scientific disciplines, including biology, geology, physics, etc.
The process of evolution consists of the mechanisms that produce the observed pattern of change.
How did Aristotle classify organisms?
He concluded that life forms could be arranged on a ladder, or scale, of increasing complexity, later called the scala naturae.
Each form of life, perfect and permanent, had its allotted rung on this ladder.
What is the format for for naming species?
Linnaeus developed the two-part, or binomial, format for naming species (such as Homo sapiens for humans) that is still used today
Darwin drew from the work of scientists studying _______, the remains or traces of organisms from the past.
Fossils.
New layers of sediment cover older ones and compress them into superimposed layers of rock called ______.
New layers of sediment cover older ones and compress them into superimposed layers of rock called strata.
How did Lamarck explain the several lines of descent findings?
- Use and disuse, the idea that parts of the body that are used extensively become larger and stronger, while those that are not used deteriorate.
- Inheritance of acquired characteristics, stated that an organism could pass these modifications to its offspring.
What were the 2 observations made from fossils?
- The older the stratum, the more
dissimilar its fossils were to current life forms. - From one stratum to another…..
– new species appear
– others disappear
Cuvier advocated __________, speculating that each boundary between strata represents a catastrophic event.
Cuvier advocated catastrophism, speculating that each boundary between strata represents a catastrophic event.
What was Lamarck’s visionary recognition?
Lamarck’s visionary recognition:
– evolutionary change explains patterns in fossils
– the match of organisms to their environment
Define natural selection.
Natural selection is a process in which individuals that have certain
inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Darwin collected specimens of
South American plants and animals, What were his observations?
- fossils resembled living species from the same region
– living species resembled other species from nearby regions
Descent with modification by natural selection explains three broad observations about nature. What are these observations?
- unity of life
– diversity of life
– match between organisms and their environment
What led Darwin to perceive the unity of life?
Organisms share many characteristics, leading Darwin to perceive unity in life.
He attributed the unity of life to the descent of all organisms from an ancestor that lived in the remote past.
What is artificial selection?
Humans have modified other species over many generations by selecting and breeding individuals that possess desired traits, a process called artificial selection
What are the 2 inferences Darwin made on his observations?
Inference #1: Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals.
Inference #2: This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations.
