Charles Darwin found that finches from different islands had different sized beaks. Explain why one island may have finches with large short beaks and another may have finches with long thin beaks.

The differences in the birds' beaks are due to evolution and natural selection. One island may have an abundance of seeds and nuts which require a large beak to crack them open, meaning that birds with a phenotype for larger beaks had an advantageous allele that allowed them to outcompete other birds with smaller beaks and to reproduce, passing their allele on tottheir offspring. Over time the unfavourable allele is selected against and disappears from the population. 

 The other island may have more small insects,  requiring long thin beaks to reach them, and so birds with larger beaks were selected against and those with the advantageous small beak allele survived to pass on their phenotypes to their offspring. 

Answered by Poppy B. Biology tutor

1816 Views

See similar Biology GCSE tutors

Related Biology GCSE answers

All answers ▸

How are blood vessels fit for purpose?


Why is the heart known as a double pump?


What is photosynthesis?


Q4: Some small organisms do not have a specialised gas exchange system like humans. Instead they absorb oxygen through their skin. What is this process called? • Transpiration • Respiration • Diffusion • Photosynthesis


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences