Topic 5 Flashcards
What are the two main points Darwin made on Natural Selection?
i) Species show evidence of “descent with modification” from common ancestors (AKA evolution)
ii) Natural selection is the mechanism for “descent with modification”
What is the process in which individuals with favourable inherited traits are more likely to survive and reproduce?
Natural selection
What are the main principles of natural selection?
i) There is variation within a population of organisms that can be inherited
ii) Individuals with inherited traits that are better suited for growth and reproduction in a given environment contribute disproportionately to the next generation
What did Georges Cuvier speculate about fossils?
He noted that fossils from older strata were dissimilar to living organisms so he speculated that each boundary between strata represented a catastrophic event
What did Jean-Baptiste Lamarck hypothesize?
He thought that species evolve through use and disuse of body parts and inheritance of acquired characteristics
What is an inherited characteristic of organisms that enhance their survival and reproduction to a specific environment?
Adaptation
What is the process of artificial selection?
Humans modifying other species by selecting and breeding individuals with desired traits
What are Darwin’s two observations?
i) Members of a population vary in their inherited traits
ii) Populations produce more offspring than the environment can support and many of these offspring fail to survive and reproduce
What is the genetic variation within a population and between populations within a species?
Genetic diversity
What provides the raw material for natural selection?
Genetic diversity
What are Darwin’s two inferences?
i) Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment leave more offspring
ii) The unequal ability of individuals to survive and reproduce will lead to the accumulation of favourable traits in the population
Two types of variation are?
Genotypic and phenotypic
What is genetic variation among individuals caused by differences in genes?
Genotypic variation
What are an organism’s observable characteristics?
Phenotype
What is a selective agent?
A component of the natural environment that consistently causes differential survival and/or reproduction
