Chapter 6 Test Flashcards
What is a species?
A group of similar organisms that can mate with each other and produce fertile offspring.
What are variations?
Differences between members of the same species
Scientists combine evidence from what to determine the evolutionary relationships among species?
Fossils, body structures, early development, DNA, and protein structures
What are homologous structures?
Similar structures that related species have inherited from a common ancestor
What is an adaptation?
A trait that helps an organism survive and reproduce
What is natural selection?
The process by which individuals that are better adapted to their environment are more likely to survive and reproduce
Darwin concluded that on the Galapogos islands what had happened?
Organisms on the island had changed over time
What did darwin observe about finches?
Their beaks were adapted to what foods they ate
What is evolution?
A gradual change in a species over time
When does a new species form?
When a community becomes isolated from the rest of its species for many generations
Similarities in the early development of chickens and opossums suggest what?
These animals share a common ancestor
What are examples of homologous structures?
The forelimbs of a bird
What is a scientific theory?
A well tested concept that explains a wide range of observations
These three animals share adaptations to which aspect of their environment?
The animals share adaptations to their watery environment
What body parts help the animals above to survive in their environment through natural selection? How?
Fins, wings, and flippers help the animals move to escape predators and to hunt for food
A horse and a donkey can mate with each other. Their offspring, called a mule, is not fertile. Do horses and donkeys belong to the same species?
No, horses and donkeys are not in the same species. Two organisms belong to the same species only if they can mate and produce fertile offspring.
A scientist collects wild rabbits that live at sea level and moves them to the mountains. One year later, the scientist discovers that the same rabbits have larger lungs. The scientist returns the rabbits to sea level. Will the offspring of the rabbits have larger lungs? Explain.
The offspring will most likely not have larger lungs. Their environment, not their genes, produced the larger than normal lungs of the rabbits kept in the mountains. Oly traits that are controlled by genes can be acted upon by natural selection and passed on to offpsring.
