Читать книгу Oceans For Dummies - Joseph Kraynak - Страница 41

IN THIS CHAPTER

Considering a couple theories on how the ocean came to be

Meeting a few of the ocean’s prior inhabitants

Checking the ocean’s current state and status

Projecting the ocean’s future

You can understand a great deal about people, places, and things by examining their past. This is even more true of the ocean, which has at least a 3.8 billion-year history, give or take a few hundred million years. Now that’s a lot of birthdays! Over the course of its existence, it went quickly from mostly fresh water to salt water, has seen entire populations of plants and animals evolve and go extinct, and has been divided into oceans (plural) as huge land masses drifted apart. It is even thought to have frozen over at least twice and possibly as many as four times in its long history. (Don’t worry, the last freeze was about 600 million years ago, and the bigger problem now is global warming, not cooling.)

In this chapter, we transport you back in time to the birth of the ocean and trace its long history of supporting the evolution of various forms of marine life, a few of which you’ll meet up close and personal. We then fast-forward to the present to describe the current condition of the ocean and its inhabitants, along with the impact it has on Earth overall. We wrap things up by taking a peek into the possible future of the ocean to see where it may be heading. (This chapter gets wet, messy, and maybe a little hard to follow at times, so if you want to skip ahead, we would understand. But it’s also really cool, so we hope you stick with us.)