NCERT Solutions for Class 12 Biology Chapter 6 Evolution

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January 30, 2026

Evolution class 12 NCERT solutions explain the story of how life started on Earth and how it changed over a very long time. It shows us how tiny living things turned into the big plants and animals we see today. This chapter helps us understand why humans, birds, and fish look different but still share some similar traits.

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Here is the NCERT Solution for Class 12 Biology Chapter 6 Evolution: Chapter 6 of Class 12 Biology focuses on the concept of evolution, the process by which species change over time. The chapter discusses various theories, evidence, and mechanisms that explain how life on Earth has evolved over millions of years. 1. Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

Answer:

According to Darwin’s theory, organisms with beneficial traits survive better in their environment. In the case of bacteria, when antibiotics are used, most bacteria die, but a few with mutations that make them resistant survive. These resistant bacteria multiply quickly because there’s less competition after the sensitive bacteria die. Over time, this leads to a population of antibiotic-resistant bacteria. These bacteria can also share their resistance genes with others, making the problem worse.

2. Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Answer:

A fascinating fossil discovery related to dinosaurs reveals their evolution during the Jurassic era. This finding helped scientists understand how reptiles evolved and how mammals and birds emerged. Recently, fossils like Confuciusornis , an ancient bird from China, sparked debates about how birds evolved from dinosaurs.

3. Attempt giving a clear definition of the term species.

Answer:

A species is a group of organisms that can interbreed and produce healthy, fertile offspring.

4. Trace the various components of human evolution.

Answer:

Human evolution involved changes in brain size, body posture, diet, and physical features over time. The stages are as follows:

Human Stage	Brain Size	Posture	Diet	f
*Dryopithecus africans*	-	Ape-like, knuckle-walking	Leaves, fruits	Equal arms and legs, large canines
*Ramapithecus*	-	Semi-erect	Nuts, seeds	Large molars, small canines
*Australopithecus africanus*	450 cm³	Fully erect	Herbivorous	Used tools, lived on trees
*Homo habilis*	735 cm³	Fully erect	Carnivorous	First to make tools
*Homo erectus*	800–1100 cm³	Fully erect	Omnivorous	Used advanced tools for hunting
*Homo sapiens fossils*	1650 cm³	Fully erect	Omnivorous	Developed culture, made art
*Homo sapiens sapiens*	1200–1600 cm³	Fully erect	Omnivorous	Highly intelligent, modern humans

5. Do animals other than humans have self-consciousness?

Answer: Yes, some animals, like dolphins, show self-consciousness. They recognize themselves in mirrors and communicate using unique whistles and movements. Other self-aware animals include chimpanzees, parrots, crows, and orangutans.

6. List 10 modern-day animals and their corresponding ancient fossils.

Answer:

Modern Animal	Fossil Name
Horse	Eohippus
Man	Ramapithecus
Elephant	Moeritherium
Whale	Protocetus
Fish	Arandaspis
Giraffe	Palaeotragus
Dog	Leptocyon
Camel	Protylopus
Tetrapod	Ichthyostega
Bat	Archaeonycteris

7. Practice drawing various animals and plants.

Answer: Start by tracing outlines of animals and plants from books or magazines. Use encyclopedias and the internet for more examples. Begin with simple drawings, gradually adding details like leaves, flowers, or feathers.

8. Describe one example of adaptive radiation.

Answer: Adaptive radiation occurs when one species evolves into several different species to adapt to various environments or food sources. A good example is Darwin’s finches on the Galapagos Islands. From a common ancestor, finches developed different beak shapes based on their diets, such as seed-eating, insect-eating, and even blood-sucking.

9. Can we call human evolution adaptive radiation?

Answer: No, human evolution isn’t considered adaptive radiation. Although humans evolved from a common ancestor, this evolution didn’t lead to the formation of multiple new species. Adaptive radiation refers to the diversification of one species into many, which isn’t the case for humans.

10. Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal, say horse.

Answer: The evolution of the horse began during the Eocene era with Eohippus and progressed as follows:

Eohippus → Mesohippus → Merychippus → Pliohippus → Equus

Key evolutionary traits:

Body size increased over time.
Neck lengthened for better feeding.
Third digit expanded, while other digits disappeared.
Teeth became stronger for eating grass.
Limbs became broader and more robust.

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1. Basics of Evolution Class 12 NCERT Solutions

Evolution is like a slow movie that has been playing for billions of years. In these evolution class 12 ncert solutions, we look at the big ideas that explain where we came from. We don't just guess; we look at clues left behind in rocks and bones.

Origin of Life: Scientists believe the Earth started as a hot ball, and later, the first tiny life forms appeared in the water.
Natural Selection: This is a rule where animals that are better at finding food or hiding stay alive and have babies.
Variation: No two animals are exactly the same. These small differences help some of them do better in nature.
Common Ancestors: This means that a long time ago, different animals might have come from the same "great-great-grandparent" family.

Idea	Simple Meaning
Fossils	Old bones or prints stuck in rocks
Adaptation	Changing to fit in a new home
Big Bang	A giant blast that started the universe

2. Evidence in Evolution Class 12 NCERT Solutions PDF

When you look at an evolution class 12 NCERT solutions pdf, you will find "clues" that prove evolution is real. Scientists use these clues to build the family tree of all living things. It is like being a detective for nature.

Homologous and Analogous Parts

Homologous Parts: These are body parts that look the same inside because the animals are related. For example, the arm of a human and the wing of a bird have similar bones.
Analogous Parts: These are parts that do the same job but look different inside. A butterfly wing and a bird wing both help them fly, but they are not built the same way.

Industrial Melanism

This is a famous story about moths. In a city with lots of black smoke from factories, the dark moths could hide better on trees than white moths. Because birds couldn't see the dark moths, those moths stayed alive. This is a great example found in the evolution class 12 NCERT solutions notes.

3. Darwin and Lamarck for Class 12 Biology

Two famous men had big ideas about how animals change. Your evolution class 12 NCERT solutions PW will explain their thoughts in a way that is easy to remember for your tests.

Darwin’s Idea: He said nature chooses the strongest or smartest animals to survive. He called this "Survival of the Fittest." If a giraffe has a slightly longer neck, it can eat more leaves and stay healthy.
Lamarck’s Idea: He thought if an animal used a body part a lot, it would grow bigger and pass that to its babies. Scientists now know this is not usually how it works, but it was a good early guess.

Getting an evolution class 12 NCERT solutions pdf download will show you the differences between these two men's ideas in a neat table.

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4. How New Species are Made

How do we get so many different kinds of animals? The evolution class 12 NCERT solutions explain that sometimes groups of animals get separated.

Moving to New Homes

If some birds fly to a new island with different food, their beaks might change over many years to help them eat. Darwin saw this with birds called Finches. This is called "Adaptive Radiation." It is like one family of birds moving to different houses and learning new jobs.

Tiny Changes (Mutations)

Sometimes, a baby is born with a tiny change in its DNA code. If this change is good, it helps the animal. Over a very long time, many tiny changes add up to make a brand new kind of animal. You can find more about this in the evolution class 12 NCERT solutions class 12 study guides.

5. Human History and Hardy-Weinberg Rule

The last part of the chapter is about us! The evolution class 12 NCERT solutions show that humans have changed a lot too. We used to have bigger teeth and smaller brains, but we changed to become who we are now.

Hardy-Weinberg Rule: This is a math rule that says if nothing changes in a group of animals, the "mix" of traits stays the same. But in real life, things like moving to new places or new babies always change the mix.
Human Path: We started in Africa and slowly moved to all parts of the world. We learned to walk on two legs and use tools.
Genetic Drift: This is when a random event, like a big storm, changes which animals in a small group stay alive.

For your exam, make sure to check the Evolution Class 12 NCERT solutions pdf download for the chart that shows the names of early humans like Homo habilis and Homo erectus.

Also Check: CBSE Class 12 Last 3 Years Previous Year Paper

NCERT Solutions for Class 12 Biology Chapter 6 FAQs

1. What is the "Big Bang" theory?

It is the idea that the whole universe started with one giant blast a very, very long time ago.

2. What are fossils?

Fossils are the remains of plants or animals that lived long ago, which have turned into stone or left marks in rocks.

3. Who is the "Father of Evolution"?

Charles Darwin is often called that because he came up with the idea of natural selection.

4. What is the difference between "Homologous" and "Analogous"?

Homologous parts show that animals are related because their bones are similar. Analogous parts just do the same job but the animals aren't close relatives.