natural selection & evolution Flashcards
(13 cards)
What explains how species evolve over time?
Natural selection
Natural selection involves processes such as variation, isolation, and selection.
What causes variation in a population?
Mutations or genetic recombination
Variation refers to differences in traits among individuals in a population.
What is isolation in the context of natural selection?
Separation of a population into groups by physical barriers or behavioral changes
Isolation prevents gene flow between separated groups.
What role does selection play in natural selection?
Environmental pressures favor certain traits that help individuals survive and reproduce
Beneficial traits are passed to the next generation.
What is an example of artificial selection?
Dog breeding with desired traits
Humans select traits such as size, coat type, or temperament in dogs.
How does artificial selection differ from natural selection?
Artificial selection is human-driven, while natural selection is environment-driven
Artificial selection leads to new breeds through human choice.
What is the relationship between genetic characteristics and survival rates?
Favorable genetic traits increase chances of survival and reproduction
Organisms without these traits may die before reproducing.
What does the fossil record provide evidence for?
Gradual changes in species over time
Example: horse evolution from small forest dwellers to large grassland animals.
What do chemical similarities in DNA indicate?
Species sharing recent common ancestors have more similar DNA
Example: humans and chimpanzees share ~98% DNA.
What are homologous structures?
Structures with the same origin but different functions
Example: human hand, whale flipper, and bat wing suggest common ancestry.
What does biogeography study?
Geographical distribution of similar species
Example: flightless birds like emus in Australia and ostriches in Africa.
What is biodiversity?
The variety of life forms on Earth
Biodiversity is influenced by evolution through various processes.
How does evolution affect biodiversity?
It creates new species and adaptations over time
Processes like natural selection, mutation, gene flow, and genetic drift increase biodiversity.
