先有鸡还是先有蛋英语ppt课件.ppt

文档介绍：Which comes first, chicken or egg?
An old philosophical question
A hot topic of discussion
Biological evolution law
A historical story
诸
葛
亮
周
瑜
Which comes first,chicken or egg?
Egg first
If there is no chicken, then the egg come from?
If the first egg is hatching egg (种蛋），where the chicken come from?
So in the end which comes first?
Different people have different points of view
Let's take a look at online voting
Scientific discovery
小型肉食恐龙蛋巢穴
Dinosaur nest like birds nests
Dinosaur eggs are similar to bird eggs
Quantity
Arrangement
Each producing two eggs
similar to birds
恐龙蛋化石
Archaeopteryx（始祖鸟）
Similar to dinosaur
Similar to bird
Variation(变异） egg
Lengthy process