What is inheritance?
Inheritance is the way that parents pass traits onto their offspring. It happens in plants, animals, and, yes, even humans!
You might have noticed that family members look similar, even though they’re not identical. It might be that someone’s hair and eyes are the same color as their parents, or their face has the same shape. These are inherited characteristics that you don’t have any control over.
Environmental characteristics also have nothing to do with what’s passed on from a parent to a child. Think about how you style your hair, clothes, scars, or piercings.
What are some examples of inherited characteristics?
Examples of Inherited Characteristics in Humans
Some characteristics that are passed down from parent to child in humans include:
- Eye color
- Hair color and texture
- Skin tone
- Blood group (A, B, AB, O)
- Colour blindness
- Dominant hand
- Earlobe attachment
- Hairline shape
Some of these can be seen physically, like the color of your eyes or whether you have freckles. Others are invisible to the human eye, as your blood will look the same as anyone else’s, even if you have a different blood group, and people who are color-blind can’t be identified by sight alone.
There are hundreds, if not thousands, of other inherited characteristics we don’t know about because they’re hidden in our genetic code or DNA.
Examples of Inherited Characteristics in Animals
Like humans, animals take many physical characteristics from their parents. Though there are a lot of species to cover, here are just a few key inherited traits that will come up again and again:
- Eye color
- Fur color and pattern (e.g., patches, spots)
- Height and length
- Ear size and shape
- Tail size and length
- Scale color and pattern
This is how you get recognizable cat and dog breeds, like Russian Shorthairs or Golden Retrievers. People raising these animals sometimes carefully select inherited traits to occur in the next generation.
Examples of Inherited Characteristics in Plants
All living things share characteristics with their parents. Even plants! Think about these traits found in flowers, trees, and shrubbery:
- Flower color and shape
- Seed shape (round or wrinkled)
- Seed color
- Pod color and shape
- Leaf pattern
- Stem height
- Flower position
Both animals and plants can undergo selective breeding. Farmers look for specific inherited characteristics to increase their crops’ yield or make them hard enough to survive harsh weather or diseases.
How are inherited characteristics passed on?
Inherited traits are carried in your genes. In the past, people thought that inherited characteristics were passed on through our blood, but that can’t be the case. Red blood cells have no DNA in them! Everything from your hair color to whether you are left, or right-handed must be coded in these twisty double-helix shapes.
What are environmental characteristics?
Unlike inherited characteristics, environmental characteristics are not passed down from parent to child. These can include:
- Favorite genres of music
- Languages spoken
- Fashion sense
- Pierced ears
- Ability to ride a bike
- Favorite color
- Preference for dogs or cats (or any other pet!)
Did you know a few plants change color based on the type of soil they’re planted in? In these cases, flower color isn’t an inherited trait but closer to an environmental one!
How can you tell if a trait is inherited or environmental?
It’s tricky. Environmental characteristics can be misleading, especially if shared across multiple family members.
One way to describe the difference between inherited and environmental traits is nature vs. nurture.
A helpful example is ‘pierced ears’ because you can see it in someone’s physical appearance. You might have had your ears pierced to wear earrings like your mother and grandmother before, but when you were a baby, your ears weren’t naturally pierced.
Even though this trait is shared over different generations, it isn’t inherited. Instead, piercing your ears happens after you are born due to contact with the environment.
If you grew up in a place where piercing ears were not a common thing to do, you might not have them pierced.
Consider the example of ‘knowing how to ride a bike. What if you grew up in a place where there were no bikes? This trait is influenced by your environment rather than inherited, so you would not be able to instinctively know how to ride a bike – not without practice, at least.
How do we know about inherited characteristics?
We know about inherited characteristics because of the work of Gregor Mendel, an Austrian man born in 1822 who is sometimes known as the ‘Father of Genetics’.
When he became a friar, Mendel went to live in an abbey. Here, he continued his education by studying the plants in the garden. Afterward, he became a priest, and although he originally intended to become a high school teacher, he could not pass the tests required.
As a priest in the abbey, he studied pea plants closely – over 30,000 of them! As a result, he was the first to recognize that baby pea plants could look similar or different from their parent plants. In addition, some of the physical traits they could inherit were more common than others. These included dominant (more powerful) and recessive (less powerful) traits.
No one knew how vital Gregor Mendel’s work was until years later, when scientists created the field of genetics.
Fun Experiments about Inheritance
One of the best ways to demonstrate inherited characteristics in humans is to look around the classroom. These time-tested experiments are a classic way of showing children how it affects their daily lives.
First, collecting information about how many people in the class have what eye color is a fun statistical experiment. It’s an excellent opportunity to show how science and maths go hand-in-hand. How many students have brown eyes, green eyes, or blue eyes? You can do the same for hair color, too!
As a homework task, children could compare their eye color or hair color to siblings, parents, or grandparents, trying to track inherited characteristics through the generations.
Another good one is to see who can roll their tongue and who can’t, but this one comes with a caveat. Although it’s a ‘traditional’ example of an inherited trait, scientists now believe this is a myth! At the very least, it also has environmental factors. Nevertheless, trying it out in class is still a good way for learners to explore the subject’s history and how we’re still learning more about inheritance daily.