Test your'self 1. Joshua investigated variation in his class. He looked at people's thumbs. He found out that some people have straight thumbs and some people have hitchhiker's thumbs. Look at Figures 13 and 14 . He did a survey and found that of the 45 learners in the class 39 had straight thumbs and six had hitchhiker's thumbs.

Did you know that thumb shape is a classic example of a hereditary trait? The difference between straight thumbs and hitchhiker's thumbs is due to a genetic variation. The hitchhiker’s thumb, which allows the thumb to bend back farther than usual, is often linked to a specific allele, showcasing the fascinating world of genetics right at our fingertips! Now, when it comes to surveys like Joshua's, it's crucial to have a well-defined sample population! In his case, studying an entire class of 45 learners gives him a clear picture, but he should also consider if the results are representative of a larger group. Ensuring diversity and a larger sample size would provide even more solid findings about thumb variations across different populations!