1.3, 1.4- Jan 12 Flashcards
(33 cards)
What was the paradigm before Darwin?
Special creation
What is another name for special creation
Natural theology
Describe the special creation model
- all species were created separately, and are unrelated to one another
- each species is unchanging and there is little variation within each
Define species
A distinct, identifiable type of organism
What sparked a challenge to special creation?
Early paleontologists (Mary Anning) discovered fossils of life that no longer existed
- why would God “snuff out” creation?
What were Darwin and Russel’s claims regarding the natural world
- all species are related by common ancestry
- characteristics of species can be modified from generation to generation (descent with modification)
Define microevolution
Species changing over time
Define macroevolution
Species splitting and diverging
Define evolution
A change in the characteristics of a population over time
Define population
A group of individuals of the same species
- living in the same area at the same time
Was Darwin the first to challenge the idea that species were unchanging?
No, he was the first to show evidence to back it up
Who proposed the theory of natural selection
Darwin and Wallace
What two conditions must be met for natural selection to occur in a population?
- individuals must vary in traits that are heritable (can be passed on)
- in a particular environment, certain versions of these heritable traits help individuals reproduce more than other versions
How do some traits become more common in the population
Certain heritable traits lead to increased success in producing offspring
What does natural selection act on
Individuals
Where does evolutionary change take place?
In populations
When does speciation occur?
When populations diverge to form new species
What is plasticity?
Body traits change over a lifetime
How is evolution demonstrated with plasticity?
Plastic trait increases in next generation
Describe “fitness”
The ability of an individual to produce offspring
- individuals with high fitness produce many surviving offspring
Define “adaptation”
A heritable trait that increases the fitness of an individual in a particular environment
Describe natural selection with the finches in the Galapagos islands
There is a variation in finch beak size and shape
What caused the shift in beaks of finches
Consistent rainfall caused small soft seeds to become more abundant
- more finches with small, pointed beaks
How were small beaks an adaptation
Those finches had higher fitness and the beak size was heritable (increased finches ability to thrive)
