Charles Darwin, Evolution, &

Natural Selection: An Introduction

HMS Beagle

Charles Darwin

HMS Beagle

- Charles Darwin was a British naturalist (someone who studies nature) who worked on a sailing ship named, the Beagle

- Darwin observed nature and took notes on everything he saw

Galapagos Islands- One of the Beagle’s stops was the Galapagos Islands off the coast of South America

- Here Darwin observed many new plants and animals

Marine vs. Land Iguanas

Marine Iguana

Land Iguana

- Two new animals Darwin saw were marine and land iguanas

- Darwin noticed the marine iguanas had long claws and flat noses to help them grip slippery rocks and eat seaweed

- Darwin also noticed the land iguanas had short claws which allow them to climb trees and eat leaves

Yummy seaweed…

Darwin’s Finches- Darwin also observed birds called finches

- Darwin noticed that some finches had beaks for grabbing insects, some had beaks for crushing seeds, and others had beaks used for poking around in tree bark.

Iguanas & Finches- After observing the iguanas, finches, and many other organisms, Darwin made a very important conclusion…

- Darwin concluded that each animal was perfectly adapted to their own particular environment

Marine Iguana = adapted for eating seaweed underwater

Land Iguana = adapted for eating leaves in trees

Finches = beaks adapted to their food source

Adaptation, Natural Selection, & Evolution

Adaptation - When animals change in ways that help them to survive it is called an adaptation (ex. long claws, short claws, & special beaks)

- Darwin then combined the idea of adaptation with a newer idea called natural selection

Natural Selection - When nature “selects” the animals that are BEST adapted to their environment for survival (ex. nature “selects” the marine iguanas for the ocean because of their long claws – you don’t find short-clawed iguanas in the ocean)

- Darwin then created his famous theory of evolution where he explained how evolution happens

Theory of Evolution - Evolution, or change over time, occurs through the process of natural selection