Evolution Flashcards
FOSSIL RECORD - EVIDENCE
Provides a historical timeline of life on Earth.
* Demonstrates the emergence and extinction of species over time.
* Offers evidence of common ancestry and evolutionary relationship
VESTIGIAL FEATURES - EVIDENCE (Provide Examples)
- Certain traits may lose their use, as behavior or environment change
- Shows species change over time
- Provide evidence of common ancestry and evolutionary history
Examples: human appendix, the pelvic bone of a snake, and the wings of flightless birds.
EMBRYOLOGY EVIDENCE
- Different species share early developmental stages
- These patterns indicate a shared evolutionary origin, meaning they evolved from the same species
MOLECULAR EVIDENCE
- Show common ancestry through similarities in DNA and protein sequences.
- Reveals species relationships by comparing genetic data
Lamarck vs Darwin
Lamarck -
Organisms adapt to their environments within their lifetime
- Then they pass on these acquired characteristics to their offspring
Darwin -
* Populations show variation, with individuals differing slightly from one another.
- Competition for resources like food, mates, and nesting sites leads to some individuals having better survival odds due to their distinct variations.
- Successful individuals pass on their advantageous variations to their offspring
Homologous structures (Provide Examples)
Structures that are built in a similar way because the species share a common ancestor but serve different functions.
Example: limbs of humans, cats, whales, and bats
Analogous Structures (Provide Examples)
Structures that are built differently because the species evolved independently, but serve a similar function
Example: Wings of birds, bats, and insects.
Divergent
Different species have unique versions of a common ancestral trait
Occurs when species adapt to different environments
Convergent
Different species develop similar traits independently.
Occurs due to similar environmental pressures
Natural selection
Individuals with advantageous traits are more likely to survive and pass on the genes of the advantageous traits.
Fitness
Refers to an individual’s ability to survive and reproduce in a given environment.
Selective pressure
A selective pressure is an environmental factor that influences the survival and reproductive success of individuals within a population.
Directional Selection
his type of selection favors one extreme of a trait, causing a shift in the population towards that trait over time
Stabilizing Selection
Stabilizing selection favors the average form of a trait.
Disruptive Selection
Disruptive selection favors the extremes of a trait while selecting against the average.
