Q6.4. The 14 species of finches on the Galapagos Islands evolved from a single species that migrated to the islands several million years ago. Different finch species live on different islands. A major difference among finch species is in their beaks: both size and shape vary greatly. Assume that a population of one of these finch species is undergoing evolution by natural selection with respect to beak size and shape. What changes occur gradually over time that indicate the population is evolving? Within their lifetimes, some individual finches' beaks change in size or shape. The proportions of finches having different beak sizes/shapes change across generations. Each finch's learned ability to use its beak is automatically passed on to its offspring. All finches in each new generation develop the same new, improved beak size and shape.
Added by Victoria T.
Close
Step 1
Individual Variation: Within the population of finches, there is variation in beak size and shape. Some finches may have larger, stronger beaks, while others may have smaller, more delicate beaks. This variation is key to the process of evolution. Show more…
Show all steps
Your feedback will help us improve your experience
Sri K and 95 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
The 14 species of finches on the Galapagos Islands evolved from a single species that migrated to the islands several million years ago. Different finch species live on different islands. A major difference among finch species is in their beaks: both size and shape vary greatly. Assume that a population of one of these finch species is undergoing evolution by natural selection with respect to beak size and shape. What changes occur gradually over time that indicate the population is evolving? Within their lifetimes, some individual finches' beaks change in size or shape. The proportions of finches having different beak sizes/shapes change across generations. Each finch's learned ability to use its beak is automatically passed on to its offspring. All finches in each new generation develop the same new, improved beak size and shape.
Dominador T.
Scientists have long believed that the 14 species of finches on the Galapagos Islands evolved from a single species of finch that migrated to the islands one to five million years ago. Recent research suggests that the original finches came from the Caribbean Islands. Different species live on different islands. For example, the medium ground finch and the cactus finch live on one island. The large cactus finch occupies another island. Among the major differences in finch species are their beak sizes and shapes. Evolutionary changes occur by many processes, one of which is natural selection. Choose the answer that best reflects how an evolutionary biologist would answer the following question with natural selection in mind. What is the best way to characterize the evolutionary changes that occur in a finch population over time? A) The traits of each individual finch in the population change over time. B) The proportions of finches with different traits in the population change over time. C) Mutations occur to meet the changing needs of the finches. D) The environment causes specific mutations in individual finches to help them survive and reproduce.
Sri K.
Red crossbills (Loxia curvirostra species complex) are small finches specialized for eating seeds pried out of the cones of conifer trees. They fly thousands of kilometers each year in search of productive cone crops. Despite their mobility, crossbills have diverged into several "types" that differ in bill shape, body size, and vocalizations. Each type prefers to feed on a different species of conifer, and each species of conifer is found only in certain forests. Bill size and shape affect how efficiently a bird can open cones of a certain conifer species. Explain how a highly mobile animal such as the red crossbill could have diverged into different types in the absence of any geographic barrier. If crossbills could not fly, do you think speciation would occur more quickly or more slowly? If conifer species were not patchily distributed (i.e., in different forests $),$ do you think crossbill speciation would occur more quickly or more slowly? Compare your answers to the analyses and data presented in Benkman (2003)
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD