Hour 5
Biology 2012
Mr. Athman
Heredity Study
Abstract
I tested my family for a cleft chin, widow’s peak, attached earlobes, able to roll tongue,
and if their second toe was bigger than there big toe. I found out that most of my family had
similar traits on most of the characteristics I did examine. The only data that wasn’t the same was
the ability to roll their tongue and that might be because my two younger sisters are too young to
be able to roll their tongue. My family is part of the majority in: no cleft chin, no widow’s peak,
unattached earlobes, straight thumb, and a longer second toe than big toe. Only my two younger
sisters are part of a minority of not being able to roll their tongue. The rest of my family is part of
the majority when it comes to rolling there tongue. One error I made was testing my younger
sisters, Davotion and Devinity, to see if they were able to roll their tongues because they don’t
have great motor control.
Introduction
Genetics is the scientific study heredity. Heredity is the transmission of genetic characters
from parents to offspring. The dominate genes are the genes that show up over the recessive
traits. The recessive traits are passive to the dominate traits and if you had a heterozygous trait
the dominate trait would show up. If it was homozygous it would only have dominate traits or
recessive traits.
Background
The widow’s peak is a dominant gene compared to a straight hair line. When your
hairline curves downward to form a point in the middle of the forehead you have a widow’s
peak. It got its name from a myth that if a woman possessed it she would outlive her husband.
About 35 percent of the world population has a widow’s peak.
The trait of Cleft chin is dominant compared to a round chin. It is a dimple or cleft that
splits down the middle of the chin. When the bottom jaw bone has a small area where the bone
didn’t completely fuse together, it forms an indent. The tissue then forms over and creates a
dimple in the middle of the chin. The world percentage that has a cleft chin is about five percent.
People that have an unattached earlobe carry a dominant trait. When trying to justify if
the earlobe is attached or not you have to look at the lobe and determine how it is connected to
the head. If it looks like it connects straight to the head it is attached. If it curves down and back
to the head it is unattached. The world percentage that has an attached earlobe is 37 percent.
The tongue is a big muscle in your mouth and some people have great control of it.
People who can roll their tongue carry a dominate gene. To roll your tongue you need to be able
to form a U without using your hands. 65 to 81 percent of people can roll their tongue.
Sometimes people have more control and can roll their tongue in more than just one way.
If your second toe is longer than your first, you have a dominant trait. The world
percentage that has a longer second toe than their big toe is 90 percent. The statue of liberty also
has a longer second toe than her big toe. It got its name after Thomas C. Morton. In some studies
they claim that if you have Morton’s toe you can have more back pains than people without
Morton’s toe. It might be due to the fact that most shoes are designed for people without
Morton’s toe even though 90 percent of the world population has it.
If you have a hitchhiker’s thumb you have a recessive trait. When you stick your thumb
out and there is a distinct curve from the knuckle to the nail, that’s hitchhiker’s thumb. Some
people have a hitchhiker’s thumb that bends from 50 to 45 degrees. The world percentage that
has hitchhiker’s thumb is 25 percent.
Methods
In my testing I will look at special trait people have in my family and compare the results.
I will test everyone and check what kind of hair line they have, if it’s a widow’s peak (has a v
shape to it) or not. Next I will test if they have an attached ear lobe or free ear lobe. Third I will
test if they have a cleft chin or not. Fourth I will test if they have a hitchhiker’s (has an arc) or if
they have a straight thumb. Next I will test if they can form a roll their tongue or not, if they can
I will check it they can clover it. Finally I will test if their second toe is longer then their big toe.
My hypothesis would be that more people will have; a longer second toe, no widow’s peak, free
ear lobes, no cleft chin, have a straight thumb, can roll their tongue. The independent variables
will be; no widow’s peak, free ear lobes, straight thumb, rolled tongue, longer second toe, and no
cleft chin. Dependent variables would be Mom, Dad, Grandpa, Grandma, Destine, Devinity, and
Davotion.
People tested
Cleft chin
Widow's Peak
Attached
earlobes
Roll tongue
Hitchhiker thumb
Larger second
toe
Mom
no
no
no
yes
no
yes
Dad
Destine
Davotion
Devinity
Grandma
Grandpa
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
no
yes
yes
no
no
yes
yes
no
no
no
no
no
no
yes
yes
yes
yes
yes
yes
Percent of no
percent of yes
100%
0%
100%
0%
100%
0%
25%
75%
100%
0%
0%
100%
number of yes
number of no
0
7
0
7
0
7
5
2
0
7
7
0
4.84%
35%
37%
65% 80%
25%
10%
65%
20% 63% 35%
75%
90%
world percent yes
world percent no
95.16%
Male has trait
Male doesn’t have trait
Trait has trait
Female
Cleft Chin (dominant)
Female doesn’t have trait
Didn’t test
rr
rr
rr
rr
rr
rr
rr
rr
Me
Male has trait
Male doesn’t have trait
trait has trait
Female
Widow’s Peak (dominant)
Female doesn’t have trait
Didn’t test
rr
rr
rr
rr
rr
rr
rr
rr
Me
Male has trait
Male doesn’t have trait
Female has trait
Female doesn’t have trait
Hitchhiker’s Thumb (recessive)
Didn’t test
R_
R_
R_
R_
R_
R_
R_
R_
Me
Male has trait
Male doesn’t have trait
Female has trait
Longer Second Toe (dominant)
Female doesn’t have trait
Didn’t test
R_
R_
R_
R_
R_
R_
R_
Me
Male has trait
Male doesn’t have trait
Female has trait
R_
Rolling Tongue (dominant)
Female doesn’t have trait
Didn’t test
R_
Rr or rr
Rr
rr
R_
rr
R_
Me
R_
Male has trait
Male doesn’t have trait
Female has trait
Attached Earlobes (recessive)
Female doesn’t have trait
Didn’t test
R_
R_
R_
R_
R_
R_
R_
Me
R_
Discussion
A 100 percent of my family has a no widow’s peak which is a recessive trait. A 100
percent of my family has unattached earlobes which is one trait that they posses that is dominant.
A 100 percent of my family doesn’t have a hitchhiker’s thumb which is also a dominant trait.
Everyone in family has a longer second toe than their big toe, it might be because we are part of
a German decent and most Germans have a longer second toe than big toe, it is also a dominant.
A 100 percent of my family has no Cleft chin; they all have a recessive trait. 75 percent of my
family has the ability to roll their tongue, they have a dominant trait. 25 percent of my family,
Davotion and Devinity, can’t roll their tongue. They might not be able to roll their tongues
because they are too young and don’t have as much control of their tongue and they would if
they were a couple years older. My results compared to my hypothesis were very similar. I
found out that I predicted that all my family would share the same traits. I figured out I was
wrong after testing but only on one trait, rolling tongue. I predicted that all seven family
members and I would be able to roll our tongues. I was of by 25 percent because my two
younger sisters, Davotion and Devinity, couldn’t roll their tongue. If I could retest everyone in
my family in four to five years then all my results would match my hypothesis.
References
http://faculty.stcc.edu/BIOL102/labs/genetics/humangenetics.htm
http://www.blinn.edu/socialscience/ldthomas/feldman/handouts/0203hand.htm
http://www.brighthub.com/science/genetics/articles/34508.aspx
http://www.integrative-healthcare.org/mt/archives/2010/12/mortons_toe_one.html
http://learn.genetics.utah.edu/content/begin/traits/tour_trait.html