Question

Q - Today there are now at least thirteen species of finches on the Galapagos Islands and all of them evolved from one ancestral species, which colonized the islands a few million years ago. What steps lead to speciation and a diverse range of finch types?
Choices -

a - The ancestral finch was a ground-dwelling, seed-eating finch.

b - The ecological niches throughout the islands exert selection pressures that push specific birds in various directions.

c - In the original population of finches, variations existed.

d - Interbreeding among the various finch types resulted in greater physical and genetic variations.

e - Birds physically changed over time to be able eat the food resources that were available.

f - Different physical traits helped certain finches survive in certain niches, eating specific food.

Answer 1

Species of finches

Explanation:

a),b),d),e) are the correct steps which lead to speciation and a diverse range of finch types

Darwin's finches, inhabiting the Galapagos island constitute an iconic model for studies of speciation and adaptive evolution

• Darwin's finches have evolved into 13 recognized species differing in body size, beak shape, song and feeding behavior
• Changes in the size and form of the beak have enabled different species to utilize different food resources such us insects, seeds, nectar from cactus flowers as well as blood from iguanas, all driven by Darwinian selection
• Gene flow between species has played a prominent role throughout the evolutionary history of Darwin's finches
• Interspecies hybridization has played a critical role in the evolution of the finches, and has contributed to maintaining their genetic diversity
• The ecological niches exert the selection pressures that push the populations in various directions
• On various islands, finch species have become adapted for different diets: seeds, insects, flowers, the blood of seabirds, and leaves
• The ancestral finch was a ground-dwelling, seed-eating finch and after the outbreak of speciation in the Galapagos, a total of 13 species would exist