U2L13 L14 L15 Flashcards
True or false: natural selection will result in an organism being a perfect match to its environment
False
True or false: an individual can evolve in its lifetime
False
True or false: natural selection is a random process
False
How did Darwin define evolution
Descent with modification
How did the study of fossils help lay the groundwork for Darwin’s ideas
Fossils are remains of organisms from the past found in sedimentary rock which appears in layers of strata
What did Darwin perceive about adaptation?
That adaptation to the environment and the origin of new species were closely related processes
Natural selection can only ______ or ______ heritable traits that vary in a population
Increase or decrease
What is the criteria for natural selection
- Characters may vary
- Variation must be heritable
- More offspring produced than survive
- Characters confer differential survival/reproductive benefit
Equation for natural selection
Variation + heritable + differential survival -> natural selection
What are the 4 types of data that document the pattern of evolution
- Direct observations
- Homology
- The fossil record
- Biogeography
What 2 examples provide evidence for natural selection
- natural selection in plant species
- evolution of drug resistant bacteria
Natural selection does not
Create new traits but edits or selects traits that are already present in the population
What is homology
Similarity resulting from common ancestry
What are homologous structures?
Anatomical resemblances representing variations on a structural theme present in a common ancestor - mammalian forelimbs
What are vestigial structures
Remnants of features that served important functions in the organism’s ancestors
What are evolutionary trees?
Hypotheses about relationships among different groups
What is convergent evolution?
Evolution of similar or analogous features in distantly related groups
What is biogeography
Study of the geographic distribution of species which provides evidence of evolution
What are endemic species?
Species that are not found anywhere else in the world
Lactase Permanence table
Macromolecule: lactase is the enzyme responsible for digestion of lactose and its production decreases after the weaning phase in most mammals
Cell: continues to produce lactase past the weaning stage
Organism: can digest milk and obtain nutrients and energy from dairy
Population: different mutations in Africa, Middle East and Europe has evolved multiple times - example of convergent evolution
