Discrete V.S Concrete Data

The article explores the differences between discrete and continuous data in the context of human genetics and heredity. It delves into the distinctive characteristics of these data types and their crucial roles in genetic research.

AUTHOR

Mr. Calvin Musk, Chief executive officer at Calvin Industries Corporation and President of Calvin State University

Image Source : Ask The Scientists, Genetic 101

Learning Intention

I can define and understand discrete and continuous genetic traits and describe how they are connected to our lives and the diversity we observe in our classroom community.

There are two primary types of inherited variation. Inherited variation refers to the difference in DNA amongst individuals and the core behind diversity in populations among the same species. Examples of inherited variations include hair colors, dimples, freckles, blood types, height, eye color, and various others. In this article, we'll explore the two primary types of inherited variations, how they play a role in our personal identity and genetics, and how they connect to us, our family, and the diversity observed in our classrooms.

We can either refer to a trait as inherited or non-heritable. Inherited means that this trait is derived from our parents and has been genetically passed down to us. These examples can include hair color, eye color, immune composition, color blindness, freckles, dimples, height, and intelligence. Examples of non-heritable traits are mainly our personality and skill traits. Whether or not you're a fan of Ryan Reynolds or not is not heritable and is influenced by environmental factors.

1. Continuous Variation

We can refer to continuous variations as quantitative variations. They refer to specific traits or characteristics that can take on a wide range of values within a population without distinct categories. They can be influenced by multiple genes and environmental factors, leading to a continuous spectrum of possible outcomes. They can be height, weight, blood pressure, and intelligence (IQ). For example, our height can vary from very short to very tall, with individuals falling at various points along the height spectrum. Not everyone is exactly 5 feet or 6 feet. They can be a little shorter, or a little taller. Continuous variations are typically represented as a bell-shaped curve, reflecting the distribution of these traits within a population.

2. Discrete Variations

The opposite of continuous variations is discrete variations. We can also refer to such as "qualitative variations". These are traits or characteristics that have distinct and non-overlapping categories with clear-cut boundaries. These traits are typically controlled by one or a few genes, and individuals in a population can be categorized into discrete groups based on their expression of these traits. Examples include blood type, eye color, ability to roll their tongue, hitch hikers thumb, and only exhibit a spectrum of possibilities.

In this lab, we will use observational data to identify specific traits and then collaboratively analyze the data as a class to distinguish between continuous and discrete traits, ultimately exploring the most suitable types of graphs for representing discrete data.

This bar graph above showcases the total students who qualify for the following traits and those who do not. This data was taken on September 6th, 2023 from 9-10. We rarest trait from 9-10 was "having a larger toe than the other", while the most common trait was being right handed, with mid-digit hair shortly behind. But, why are so many people right-handed? It's still a debated theory amongst scientists, but many believe that genetics, brain lateralization, and evolution each play a role in the reason. Cultural and societal norms can influence handedness. In many societies, right-handedness is considered the norm, and left-handedness has historically been stigmatized or discouraged. This social pressure may lead some left-handed individuals to adapt to right-handed behaviors. Environments and genetics both have a role to play.

The bar graph above showcases the total number of students who qualify for the following traits and those who do not. This data was taken on September 6th, 2023 from 9-11.From 9-11, the rarest trait was the "widow's peak hairline" while the most common trait was having the ability to roll your tongue, with being right-handed shortly behind.

This data is similar to the ones conducted in 9-10, with being right-handed and being able to roll your tongue being the most common trait. On the other hand, having a larger toe, cleft chin, widow's peak hairline, and being left-handed being the rarest among the few. But why are certain specific traits rarer than others, while others are more common? The prevalence of specific traits in a population is determined by a complex interplay of genetic, evolutionary, and environmental factors. Common traits often result from common genetic variations, potential evolutionary advantages, or widespread environmental influences. In contrast, rare traits can arise from less common genetic variations, mutations, or factors that don't significantly impact survival or reproduction. The specific traits mentioned, such as right-handedness and tongue rolling, likely have a combination of genetic and evolutionary reasons for their commonality. Traits like larger toes, cleft chins, widow's peak hairlines, and left-handedness may be rarer due to less common genetic variations or a lack of strong evolutionary advantages, allowing for greater variation within the population.

Analysis and Inquiry

1. In your own words, what is the difference between continuous and discrete traits?

Continuous traits, in the context of genetics and biology, refer to characteristics or traits that exhibit a wide range of possible values along a continuous spectrum. Examples include height, weight, skin color, blood pressure, IQ, and eye color. These traits have a diverse range of observable characteristics. On the other hand, discrete traits are traits that have distinct categories. They are controlled by one or a few genes with well-defined alleles. These include tongue rolling, the widow's peak hairline, the hitchhiker's thumb, and various others.

2. What can you conclude about the way traits vary among your class members? Why do you think some students show one form of a trait while others show a different form?

3. Now that you know how to recognize a continuous or discrete trait, define and give two examples (not from the lab) of continuous traits.

Continuous traits as mentioned are traits that consist of a wide range of different possible values among a continuous spectrum. They're not one or the other; they're not red or black, they're not blue or red, but they are instead a variety of different possibilities. This can be weight. You can weigh 10 pounds, 20 pounds, 30 pounds, 500 pounds, anywhere in between, etc depending on your personal health. Some other examples include your blood pressure, IQ, finger length, metabolism, and various others.

4. How does this apply to ecosystems, evolution, and adaptations? How does this enable the survival of different species within our ecosystems?

Traits vary because of genetic variation. When two parents come together and conceive, these combinations of gene variants lead to variations in traits. Nobody has exactly the same DNA as somebody else (unless you're both twins), and therefore this can lead to a variation in our traits. Exposure to different environments, diets, climates, and environmental toxins can also lead to variations in traits. In our study of statistics and probability, traits exhibit variation simply due to random chance. . For example, in a population of a tree species with a range of height variations (a continuous trait), taller individuals may have an advantage in accessing sunlight in a denser forest, while shorter ones may thrive in more open areas. As environmental conditions shift due to changing climates and human activities (deforestation, climate change, etc.), these height variations can become issues but also advantages. By preserving the full spectrum of height traits within the species, we can ensure that some are better suited to the evolving environment, enabling the species to persist.

Google Sites

Report abuse