What is Microevolution?

S4-SA3-0710

Grade Level:

Class 6

Space Technology, EVs, Climate Change, Biotechnology, HealthTech, Robotics, Chemistry, Physics

Definition

What is it?

Microevolution is a small change in the traits of a group of living things over a short period. It happens when certain features become more or less common in a population, like a group of plants or animals, from one generation to the next.

Simple Example

Quick Example

Imagine a group of stray dogs in your neighbourhood. If over a few years, you notice that more and more new puppies are born with slightly darker fur than before, this is a small change in their group. This small, noticeable shift in fur colour over generations is an example of microevolution.

Worked Example

Step-by-Step

Let's say a farmer has a field of corn. Some corn plants produce bigger cobs, and some produce smaller cobs.---Step 1: The farmer wants more big cobs, so he only uses seeds from the plants that produced the biggest cobs for the next planting season.---Step 2: In the next generation, a slightly higher percentage of corn plants now produce big cobs compared to before.---Step 3: The farmer continues this selection process, always picking seeds from the biggest cobs.---Step 4: After several generations, the average size of corn cobs in his field has increased significantly. This small, gradual change in cob size over generations is microevolution in action.---Answer: The corn plants have microevolved to produce larger cobs.

Why It Matters

Understanding microevolution helps us see how living things adapt to changes around them. It's important in biotechnology for creating new crop varieties or understanding how bacteria become resistant to medicines. This knowledge can lead to careers in agriculture, medicine, and environmental science.

Common Mistakes

MISTAKE: Thinking microevolution is about one animal changing its features during its lifetime. | CORRECTION: Microevolution is about changes in a *group* of animals or plants over *generations*, not an individual changing in its own life.

MISTAKE: Confusing microevolution with a huge change that creates a new species. | CORRECTION: Microevolution is only small, gradual changes within an existing species, like a slight change in size or colour, not the formation of entirely new types of life.

MISTAKE: Believing microevolution only happens in wild animals. | CORRECTION: Microevolution also happens in plants and animals we breed, like different types of domestic dogs or new varieties of rice, due to human selection.

Practice Questions

Try It Yourself

QUESTION: A group of ladybugs usually has red spots. Over 10 years, scientists notice more ladybugs are being born with orange spots. Is this microevolution? | ANSWER: Yes, because there's a small change in a trait (spot colour) in a group over generations.

QUESTION: A gardener observes that his rose plants are getting taller each year because he always selects seeds from the tallest plants. What biological process is he observing? | ANSWER: Microevolution.

QUESTION: A certain type of bacteria can be killed by an antibiotic. After many years, some bacteria are found that are not affected by the same antibiotic. Explain how this is an example of microevolution. | ANSWER: Over time, some bacteria with a natural resistance survived the antibiotic, reproduced, and passed on their resistance. This led to a higher number of resistant bacteria in the group, showing a small evolutionary change.

MCQ

Quick Quiz

Which of these is the best example of microevolution?

A single person learning a new language

A new species of animal forming from an old one

A group of birds showing a slight change in beak size over several generations

A caterpillar changing into a butterfly

The Correct Answer Is:

Option C describes a small, gradual change (beak size) within a group of organisms (birds) over generations, which is the definition of microevolution. Options A and D are changes within an individual's lifetime, and Option B is a larger change (speciation).

Real World Connection

In the Real World

Farmers in India constantly work with microevolution when they select seeds from their best-yielding crops, like wheat or rice, to plant next year. This process, called artificial selection, slowly changes the traits of the crop over time, making them more productive or resistant to diseases. This helps ensure food security for our country.

Key Vocabulary

Key Terms

TRAIT: A specific feature or characteristic of a living thing, like eye colour or plant height.| GENERATION: All the individuals born and living at about the same time, usually referring to parents and their offspring.| POPULATION: A group of individuals of the same species living in the same area.| SELECTION: The process where certain traits become more or less common in a population.

What's Next

What to Learn Next

Now that you understand microevolution, you can explore 'What is Macroevolution?'. Macroevolution looks at much bigger changes over very long periods, leading to new species and major groups of life. It builds directly on the small changes you've learned about here!