Chapter 15 - Evolution & Classification Flashcards
Wrote “The Origin of Species” after travelling the world
Charles Darwin
New species come from ___ species
- Old species
- Discovered by Charles Darwin
The process by which species change
Natural selection
Evidence of evolution
- Fossils of extinct organisms
- Similar organisms found in similar habitats across the world
- Similar, but different organisms, found near each other geographically
About the same time Darwin was developing his theories, ________ and _______ studied geological processes and concluded that the world is very old
Charles Lyell and James Hutton
Darwin’s theory of evolution
- Organisms produce more offspring that can survive (overproduction)
- There is competition between organisms for resources
- There is variation between individuals within a population
What classifies individuals as being the “fittest?”
- Have the best traits for the environment
- Will be able to survive and reproduce
Adaptation
A trait that helps an organism survive in its environment
Homologous structures
Similar structures in different organisms that have different purposes
Analogous structures
- Similar features that evolved because of the environment even though they don’t have a recent common ancestor
- Ex: a bird wing and a butterfly wing – they both fly, but one is a bird and one is an insect
Vestigial structures
Structures that are no longer needed by an organism
What evolves (individuals or populations)?
Populations
What does natural selection act on?
Phenotype
On a genetic level, evolution involves the change of _____ ________ within a population
Allele frequency
Polygenic traits usually fall into a ____-_____ or _______ _________
- Bell-shaped or normal distribution
Directional selection
When one end of the curve is favored
Stabilizing selection
When the middle of the curve is favored
Disruptive selection
When both ends of a curve are selected
When does speciation occur?
When a population becomes reproductively isolated
Geographic isolation
Where populations are separated due to geography
Behavioral isolation
Where one population won’t mate with another due to a different behavior
Temporal isolation
Where populations mate at different times of the year
3 domains
- Eukarya
- Eubacteria (or Bacteria)
- Archaea
Eukaryotes can be broken down into the following kingdoms
- Protists (can have single or multiple cells) -> autotrophs/heterotrophs
- Animals -> heterotrophs
- Plants -> autotrophs
- Fungi -> heterotrophs
King Philip Came Over For Good Soup
Kingdom, Phylum, Class, Order, Family, Genus, species
Binomial nomenclature
- Genus species
- The scientific name of a species
Cladogram
Looks at evolutionary relationships between organisms
Branch point (or node)
Represents where two groups of organisms had a most recent common ancestor
Derived characteristic
- Written on a cladogram
- Indicates all organisms to the right of that point share the characteristic
