關於地球你知道多少（上）

05-12

中文字：966，建議閱讀時間：1.2分鐘；英文字：578

When talking about early earth and life, some people can』tbelieve that something so

big has happened. The main problem is that humans do not have a great concept

of time, there is a way to think about how long time takes and you can do it

with simply counting.

See how long it can take you to count from 1 to 100, let』s say it takes you 25 seconds,so how long will it take you to count to 1000.

1 to 100 =25 seconds

1 to 1000 =10 minutes

1 to 10,000= 2 hours

1 to100,000 = 40 hours

1 to1,000,000 = 400 hours just over 16 days

1 to10,000,000 = 4000 hours just over 166 days

1 to100,000,000 = 40,000 hours just over 4 and half years

1 to1,000,000,000 = 400,000 hours just over 45 and a half years

Knowing this will help you understand how old the earth is and how long evolution

takes, just think what happens in your life in 45 years compared to the earth

which is calculated to be 4.54 billion years old.

Pangaea and Animals

Without evolution there wouldn』t be any creatures or plants on this planet, evolution is one of the greatest things that as ever happened on this planet. Even the

planet looked different before we appeared on it, the planet had one continent,

which is called a supercontinent the name of the supercontinent is called

Pangaea. The name Pangaea comes from the ancient Greek, Pan means all, entire,

whole and Gea which was Gaia means mother earth or land. The name translates

into the whole mother earth.

You might be thinking what evidence do we have about this supercontinent, well if you look at the globe you can see that some of the edges of countries can fit into

to other countries. We can also look at how the countries are moving now and calculate at where they use to be. One of the biggest clues to the supercontinent is the animals,fossils of similar animals and the same animals are found great distances

apart.

What would happen if Pangea didn』t break apart and give us the countries we know about today. Well for animals and plants to evolve there needs to be change in the

environment, so if the continent doesn』t change the animals will evolve to a

peak level and stay the same, also humans would not have been able to survive

on Pangea. Not much is known about the animals on the planet, but what is known

is the descendants of crocodiles and alligators where on Pangaea. Around 175

million years ago the supercontinent started to break apart and form the

countries that we know today.

The forms of the planet are

Late Triassic, 251 million to 199 million years ago

Jurassic,199.6 to 145.5 million years ago

Early Cretaceous 145.5 to 100 million years ago

Late Cretaceous, 100 to 66 million years ago

As you can see the countries we have today have slowly started to form.

With the continents moving apart animals needed to be able to adapt to the new

environment, this would have killed a lot of animals as they would not be ready

for the changes in weather. The animals that ruled the world was the dinosaurs.

They ruled the planet between 230 and 65 million years ago. So these creatures

where on the planet while the supercontinent was still together.

中文翻譯：

當談論地球早期生命時，一些人肯定不會相信有如此之大的生物曾經存在過。這主要的問題是人們對於時間沒有一個很好的概念，這裡有一個簡單方法來讓你對於時間有一個更好得體會，你要做的就是數數。

你可以計算下從1數到100需要耗費多少時間，這很容易得到答案，大約25秒鐘，那麼數到1000需要多少時間呢？

1到100 = 25 秒

1到 1000 =10 分鐘

1到 10,000 =2 小時

1 到100,000 =40小時

1 到1,000,000 = 400 小時，超過16天

1 到10,000,000 = 4000小時，超過66天

1 到100,000,000 = 40,000 小時，超過4.5年

1 到1,000,000,000 = 400,000 ，超過45.5年

光數數就得花這麼久，你就能明白地球有多古老，進化是多麼漫長的一件事，你花45年只是數數，那才等於地球45.4億年的年齡。

泛大陸與動物

如果沒有進化，那麼此刻這片地球上就沒有任何生物，進化是地球上發生得最美妙的事之一，在我們人類誕生之前，地球也是另一幅面紗。當時地球只有一塊大陸，被稱為超級大陸，也就是後來人們熟知的泛大陸。泛大陸（Pangaea）是來源於古希臘語，Pan是指所有、整個、全部的意思；Gea是指大地之母，連起來的意思就是地球的萬物之母。

你可能會問，有什麼證據證明曾經存在過超級大陸呢，了解地質學的同學就會發現，現存的大陸板塊邊緣是與其他板塊邊緣是吻合的，也就是說互相匹配。我們可以觀察現存板塊的運動模式，並且計算出這些板塊原來的位置。針對泛大陸說最有力的證據就是動物遺骸，相似與相同動物的化石被發現散落在相距很遠的不同位置。

如果原先的整塊大陸並沒有被分裂，想像一下會是什麼樣子。對於動物與植物來說進化方向肯定是隨著周圍的環境，如果大陸環境沒有發生改變，那麼動物的進化水平就會在達到某一峰值後，始終停留在那個水準，當然人類也就不能在泛大陸中進化出來。關於當時生存的動物我們了解的並不多，但是可以確定的是，當時的大陸上生存了許許多多鱷魚與短吻鱷。大約從175000000年前，大陸開始陸續分裂，逐漸形成我們現在的大陸板塊。

以下就是不同時期板塊的構成

三疊紀晚期，251000000到199000000年前

侏羅紀，199600000到145500000年前

白堊紀早期，145500000到100000000年前

白堊紀晚期，100000000到66000000年前

正如你從圖片中觀察到的，我們現如今的大陸板塊是經過了成萬上億年的變更，才有如今這模樣的。

伴隨著板塊的移動，陸地上的動物也得適應不同的新環境，在這過程中，由於應對或進化不及時，不可避免的會滅絕一些物種。這其中的一類就是曾經的動物霸主——恐龍，它們在230000000到65000000年前統治了地球，但從圖片中可以看出，當時的大陸還基本聯結在一起。