Evolution - Ch 22 - Evolution by Natural Selection Flashcards
What are the two parts of a scientific theory? (What do each part mean?)
- pattern: a statement summarizing many observations of the natural world
- process: a mechanism that produces this pattern
What are the 5 key attributes of life? (not tested probably)
- obtain and use energy
- made up of cells
- process info
- reproduce
- evolve through time
What is typological thinking?
species are immutable (unchangeable), and variation in individuals should be ignored
What type of thinking was associated with Plato?
typological thinking
What two ideas were associated with Aristotle?
- typological thinking
- scale of nature/Great Chain of Being
What two ideas were associated with Lamarck?
- species change through time
- scale of nature/Great Chain of Being
[An individual’s phenotype changes as they respond the challenges in the environment, and they pass these modifications onto their offspring. Organisms climb the scale of nature over time.]
What type of thinking did Darwin partake in?
-population thinking
What is population thinking?
emphasizes the variation that exists among individuals in a population
What is the scale of nature?
species are organized based on size and complexity; ex. God then humans at top, rocks at the bottom
How does evolution by natural selection work?
(1) heritable variations that exist within a population
(2) leads to differential reproductive success
The theory of evolution predicts what two patterns?
- species change through time
- species are related through common ancestry
What is fitness?
the measure of how many viable offspring an individual can successfully reproduce, compared to others in the population
What evidence supports that species change through time?
- Life on Earth is old (fossil record)
- Law of Succession
- transitional features
- vestigial traits
- variance in populations today and this variance can be observed changing
What evidence supports that species are related by common ancestry?
-similar species are found living in the same geographical area
-homologous traits are common
(genetic, developmental, and structural)
-speciation seen today
What is an adaptation?
a heritable trait that ameliorates the fitness of an individual in a particular environment (relative to those without this trait)
What is an acclimatization?
changes in an individual’s phenotype in response to environmental changes
What is internal consistency?
data from many different, independent sources agreeing on predictions made in a theory
What is homology, and its three levels?
likeness between species due to common ancestry:
- genetic: similarity in genetic sequences
- developmental: similarities in embryo structures and processes
- structural: similarities in adult structures
What is radiometric dating?
observing decay rates of parent -> daughter atoms and their ratios in rocks to give absolute age of fossils
What are transitional features?
a trait that seems to be in the middle of change between an older fossil and a younger species
What is a vestigial trait?
common structures in extant species that have reduced or no purpose anymore, but are functional in closely related species
What are Darwin’s four postulates? Does evolution happen if and only if all four are true?
- Variance of traits in populations exist
- These traits are heritable
- More offspring are born than can survive
- Certain individuals survive to reproduce more than others
Yes.
Is evolution progressive, or goal-orientated?
no
Do organisms become perfected with evolution?
no
What is a fitness tradeoff?
a compromise between two traits that cannot be optimized at the same time
In what three ways are traits limited?
genetic, historical, and environmental constraints
What is genetic correlation?
a type of evolutionary constraint where selection in one trait can cause changes in another as well (pleiotropy)
How does history constrain traits?
all traits have evolved from previously existing traits, so they depend on past traits
How does the environment constrain traits?
the environment, including abiota and biota, is constantly changing over time and over space
