Sukrutha Jambur Sachin
How do genetic variations affect fingerprints?
I hypothesize that the farther related the two people are, the fewer will be the similarities in fingerprint patterns and positions between them since the size, shape and spacing of fingerprint pattern types (i.e., whorl, loop or arch) are genetically inherited from parents.
- Fingerprints are unique patterns made by friction ridges and furrows which appear on the pads of the fingers and thumbs.
- There are 3 basic fingerprint patterns which are whorl, loop and arches.
- From studies and research, we can see that no two people have ever been found to have the same fingerprints—including identical twins. Also, no single person has ever had 2 fingers sharing the same fingerprints.
- A person’s fingerprints remain unchanged throughout their lifetime.
- Humans, as well as apes and monkeys, have friction ridge skin covering the surfaces of their hands and feet.
- Pattern types are often genetically inherited, but the individual details such as breaks, forks and islands in the ridges are not.
- Pattern types are inherited from either the mother or father.
- Independent variable:
- Different relationships
- Different people
- Dependent variable:
- Which category the fingerprint patterns fall under
- Controlled variables:
- Same fingers
- Control design:
- My control design will be the comparison between person’s right thumb and their left thumb finger prints
- Collect the fingerprint of the right thumb of one person and compare it with their left thumb, and then parent/child, sibling and first cousin.
- Repeat the same procedure with different families.
- Steps to collect fingerprints:
- Press the pad of the finger against an inkpad and press it gently on a piece of paper.
Once all the fingerprints from different families are collected, create a table specific for a family.
Once all the fingerprints have been added to the table, analyze the matching patterns between different fingerprint combinations.
Please click on the below links to view the charts individually:
In 83.33% of the cases, the left and right thumb of an individual shares the same fingerprint pattern (i.e., loop, whorl or arc) but in opposite direction with a different position and different counts of forks and deltas.
In all of the cases, the fingerprint pattern of parent and the child is same but the count and position of forks and deltas are completely different.
In 83.3% of the cases, the fingerprint pattern of siblings is same but the count and position of forks and deltas are completely different.
In 33.33% of cases, the fingerprint pattern of cousins is same however the count and position of forks and deltas are different.
In all cases, even ones having similar pattern types, the count and position of forks and deltas are different, thereby making no two fingerprints alike
The background research conducted on role of genetics on fingerprint patterns revealed that there is an inheritable quality to fingerprints. Pattern types are often genetically inherited, but the individual details that make a fingerprint unique such as count and position of forks and deltas are not.
In conclusion, the fingerprints of the parents and children had the same fingerprint patterns since they are genetically inherited but the unique details such as the counts and positions of forks and deltas are not inherited so they were completely different.
The fingerprints of the siblings had the same fingerprint patterns but there were a few exceptions as one sibling can inherit the pattern from one parent and the other one can inherit it from the other parent.
The fingerprints of the cousins did not have the same fingerprint patterns in most cases since the cousin would be related either maternally or paternally, so there would be fewer chances of sharing the same pattern with them.
The experimental results and associated findings concur with the hypothesis based on the study conducted as part of the background research.
This experiment can be improved by collecting and analysing fingerprints across multiple generations to establish commanalities in fingerprint patterns among them.
- Fingerprint patterns are used to provide biometric security like controlling access to secured areas or systems using the uniqueness of an individual's fingerprint
- FIngerprints are used to perform background check on an individual as it is able to uniquely identify a person
- Fingerprints are used to identify individuals as part the process of issuing passports
- Fingerprints are heavily used to criminal justice system to identify potential suspects.
Sources Of Error
- Method of capturing the fingerprints can lead to error due to movement of finger, camera shake while taking the picture causing lack of clarity in the appearance of fingerprint patterns, forks and deltas
- Errors could also occur due to insufficient zoom capability while reading the fingerprints, since the images tend to get blurry as we zoom in to study the patterns
- Incorrectly captured fingerprints due to lack of ink covering all parts of the finger and leading to uncaptured fingerprint patterns, forks and deltas
Here are the websites that I used to do my background research:
Credits for the header image:
I would like to thank the HUB project coordinator, Mr. Joshua Downey, for supporting and guiding me through this project.
I would also like to acknowledge and thank all the people who co-operated in providing their fingerprints for the analysis.