Ever wondered why you look similar to your parents but... Show more
English Literature
SociologySign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
89
•
23 Dec 2025
•
Understanding Evolution and Natural Selection Today
Evelyn Ridley
@ev_alice
1 / 3
Evolution and Natural Selection Basics
Think of natural selection as nature's way of picking winners. In any group of organisms, some individuals are naturally better at surviving in their environment than others. Maybe they're faster, stronger, or better camouflaged - whatever gives them an edge.
These "winners" are more likely to survive long enough to have babies and pass on their helpful traits. Over time, more and more individuals in the population will have these useful characteristics. When the environment changes, different traits become valuable, and the process repeats.
Evolution is simply the result of this process - it's how populations change their inherited characteristics over time. When two groups of the same species face different challenges, they can evolve so differently that they eventually become separate species entirely. Scientists believe all life evolved this way from simple organisms that appeared over 3 billion years ago.
Quick Fact: Evolution isn't just ancient history - it's happening right now! Bacteria evolving resistance to antibiotics is natural selection in action.
Unfortunately, not all species make it through this process. Extinction occurs when a species can't adapt fast enough to environmental changes, faces new predators or diseases, or gets wiped out by catastrophic events like volcanic eruptions.
Darwin, Wallace, and the Birth of Evolution Theory
Charles Darwin gets most of the credit, but he wasn't working alone when he figured out evolution. After years of travelling the world and observing countless animals and plants, Darwin noticed that individuals within species showed lots of variation. He realised this meant some were better suited to survival than others.
Darwin spent years experimenting and discussing his ideas before going public. He also connected his observations to new discoveries about geology and fossils, building a comprehensive theory about how life changes over time.
Alfred Russel Wallace deserves equal recognition - he independently came up with the same theory! The two scientists actually published their work together in 1858, which pushed Darwin to release his famous book "On the Origin of Species" the following year. Wallace's research on animal colouration and speciation has been crucial to our modern understanding.
Did You Know? Darwin sat on his theory for years because he knew it would be controversial - Wallace's independent discovery finally gave him the confidence to publish!
Speciation happens when populations of the same species become isolated (like on different islands) and face different environmental pressures. Over time, natural selection favours different traits in each group until they become so different they can't breed together anymore - creating two new species.
Why Evolution Was So Controversial
When Darwin and Wallace first published their theory of evolution, it caused absolute uproar. The idea that all life had evolved over millions of years directly contradicted the widely-held religious belief that God had created all species exactly as they appeared.
Many people simply couldn't accept the evidence Darwin and Wallace presented. The biggest problem was that nobody could explain how variation actually happened or how traits were passed from parents to offspring. Without understanding these mechanisms, the whole theory seemed a bit far-fetched to many.
It took 50 years for science to catch up and vindicate Darwin and Wallace. Scientists finally discovered that mutations create variation and that genes carry inherited characteristics from one generation to the next. These discoveries provided the missing pieces that made evolution's puzzle complete.
Think About It: Even today, some people struggle with evolution - but the scientific evidence is now overwhelming, supported by genetics, fossils, and direct observation.
This controversy shows how revolutionary scientific ideas often face resistance, especially when they challenge deeply-held beliefs. Today, evolution is one of the most well-supported theories in all of science.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Understanding Evolution and Natural Selection Today
Evelyn Ridley
@ev_alice
Ever wondered why you look similar to your parents but different from your mates? Evolution and natural selection explain how all life on Earth has changed over billions of years, creating the incredible diversity we see today. These processes are... Show more
Evolution and Natural Selection Basics
Think of natural selection as nature's way of picking winners. In any group of organisms, some individuals are naturally better at surviving in their environment than others. Maybe they're faster, stronger, or better camouflaged - whatever gives them an edge.
These "winners" are more likely to survive long enough to have babies and pass on their helpful traits. Over time, more and more individuals in the population will have these useful characteristics. When the environment changes, different traits become valuable, and the process repeats.
Evolution is simply the result of this process - it's how populations change their inherited characteristics over time. When two groups of the same species face different challenges, they can evolve so differently that they eventually become separate species entirely. Scientists believe all life evolved this way from simple organisms that appeared over 3 billion years ago.
Quick Fact: Evolution isn't just ancient history - it's happening right now! Bacteria evolving resistance to antibiotics is natural selection in action.
Unfortunately, not all species make it through this process. Extinction occurs when a species can't adapt fast enough to environmental changes, faces new predators or diseases, or gets wiped out by catastrophic events like volcanic eruptions.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Darwin, Wallace, and the Birth of Evolution Theory
Charles Darwin gets most of the credit, but he wasn't working alone when he figured out evolution. After years of travelling the world and observing countless animals and plants, Darwin noticed that individuals within species showed lots of variation. He realised this meant some were better suited to survival than others.
Darwin spent years experimenting and discussing his ideas before going public. He also connected his observations to new discoveries about geology and fossils, building a comprehensive theory about how life changes over time.
Alfred Russel Wallace deserves equal recognition - he independently came up with the same theory! The two scientists actually published their work together in 1858, which pushed Darwin to release his famous book "On the Origin of Species" the following year. Wallace's research on animal colouration and speciation has been crucial to our modern understanding.
Did You Know? Darwin sat on his theory for years because he knew it would be controversial - Wallace's independent discovery finally gave him the confidence to publish!
Speciation happens when populations of the same species become isolated (like on different islands) and face different environmental pressures. Over time, natural selection favours different traits in each group until they become so different they can't breed together anymore - creating two new species.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Why Evolution Was So Controversial
When Darwin and Wallace first published their theory of evolution, it caused absolute uproar. The idea that all life had evolved over millions of years directly contradicted the widely-held religious belief that God had created all species exactly as they appeared.
Many people simply couldn't accept the evidence Darwin and Wallace presented. The biggest problem was that nobody could explain how variation actually happened or how traits were passed from parents to offspring. Without understanding these mechanisms, the whole theory seemed a bit far-fetched to many.
It took 50 years for science to catch up and vindicate Darwin and Wallace. Scientists finally discovered that mutations create variation and that genes carry inherited characteristics from one generation to the next. These discoveries provided the missing pieces that made evolution's puzzle complete.
Think About It: Even today, some people struggle with evolution - but the scientific evidence is now overwhelming, supported by genetics, fossils, and direct observation.
This controversy shows how revolutionary scientific ideas often face resistance, especially when they challenge deeply-held beliefs. Today, evolution is one of the most well-supported theories in all of science.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
1
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar content
AQA Biology Specification Overview
Explore the comprehensive AQA AS and A-level Biology specification, covering essential topics such as photosynthesis, cellular respiration, genetics, and ecosystem dynamics. This resource provides insights into key concepts, practical skills, and assessment objectives crucial for mastering the subject. Ideal for students preparing for their exams.
Biology12
Natural Selection & Evolution
Explore the key concepts of evolution, including natural selection, genetic variation, and the contrasting theories of Lamarck and Darwin. This summary highlights how species adapt over time and the role of fossils in understanding evolutionary history.
Biology9
Population Dynamics & Genetics
Explore key concepts in population dynamics, genetics, and ecological succession. This comprehensive summary covers essential topics such as competition, predation, speciation, and inheritance patterns, including monohybrid and dihybrid crosses. Ideal for students preparing for exams in biology, this resource provides a clear understanding of how species interact within ecosystems and the principles of evolution. Type: Revision Summary.
Biology13
Fossils and Evolution
Explore the critical role of the fossil record in understanding evolution and natural selection. This summary covers key concepts such as extinction events, transitional fossils, and the evidence supporting Darwin's theory of evolution. Ideal for biology students preparing for exams.
Biology9
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user