Evolution
進化與適應
Living things change slowly over millions of years. In this lesson you will learn what evolution is, how natural selection works, and how fossils show us the history of life.
生物在數百萬年間緩慢地改變。在這一課，你會學習甚麼是進化、天擇如何運作，以及化石怎樣讓我們看到生命的歷史。
1 · What is evolution?
甚麼是進化？
Evolution is the slow change in living things over many generations. Over millions of years, species change to fit their environment better.
進化是生物在許多世代中緩慢的改變。經過數百萬年，物種會改變，以更適應牠們的環境。
2 · Natural selection
天擇
Charles Darwin explained evolution with natural selection. Living things have small differences called variation. Those best suited to survive and reproduce pass their traits to their young. This is called "survival of the fittest".
達爾文用天擇來解釋進化。生物之間有稱為變異的小差異。最適合生存和繁殖的生物會把特徵傳給後代。這稱為「適者生存」。
3 · Evidence: fossils
證據：化石
Fossils are the remains of ancient living things preserved in rocks. They show us how living things have changed over millions of years. Older fossils are found in deeper rock layers.
化石是保存在岩石中的古代生物遺骸。它們讓我們看到生物在數百萬年間的改變。較古老的化石在較深的岩層中發現。
4 · Extinction
滅絕
When a species cannot adapt to changes in its environment, it may die out. This is called extinction. The dinosaurs became extinct about 65 million years ago.
當物種無法適應環境的改變，牠們可能會滅絕。這稱為絕種。恐龍大約在 6500 萬年前滅絕。
5 · Quick check
小測驗