Everything You Know About Science is Wrong by Brown Matt

Author:Brown, Matt
Language: eng
Format: epub
ISBN: 978-1-849944-61-8
Publisher: Pavilion Books
Published: 2017-02-15T16:00:00+00:00

* FOOTNOTE This exceptional vehicle must rank alongside the Apollo 11 space capsule or the Hubble Space Telescope in its importance to exploration. As well as the discovery of hydrothermal vents, Alvin was also used to investigate the wreck of the RMS Titanic. It continues in service today, more than 50 years on from its first mission – though much upgraded and altered.

Fish were the first animals to leave the oceans

Ever seen a mudskipper? These peculiar creatures look like a cross between a frog and a fish, with protruding eyes and shiny skin. As the name implies, they can often be found skipping through the mud and sand of the seashore, using their front fins like legs. They are 100 per cent, bona fide fish, and yet they spend three-quarters of their lives out of water. They can even climb trees.

A creature similar to the mudskipper is thought to have been the ancestor of all four-legged vertebrates, including ourselves. At some point, a particularly plucky fish learnt how to venture onto land for short periods. Over time, its kind spent increasingly lengthy stays ashore. Gradually, gills gave way to lungs to produce the first amphibians, and thence reptiles, birds and mammals.

In 2004, the first well-preserved fossils of such a creature were unearthed in Canada. The so-called tiktaalik fish patrolled the world’s oceans around 375 million years ago. It probably used its lobe-shaped fins to haul itself through shallow water and perhaps over land, before splashing back into the brine. Although a fish, it bears many of the hallmarks of later tetrapod (four-legged) species. Nobody knows if the tiktaalik is a direct ancestor of any species alive today – it is more likely to be an offshoot of the line that led to tetrapods, and it would therefore be misleading to call it a ‘missing link’ between sea and land. However, the fossils offer a revealing glimpse into the kind of creatures that might have bridged the gap between water-dwelling fish and land-dwelling animals.

Tiktaalik and its cousins were not, however, the first animals to emerge from the sea. The land was already teeming with life. The earliest hints – the supposed tracks of a scuttling arthropod species – date back to 500 million years ago. Much earlier than this would pre-date the formation of the ozone layer, exposing venturesome life forms to UV radiation. Our pioneering arthropod would have found a dusty, barren land. It may have encountered the odd patch of algae here and there, but land plants had yet to appear.

The oldest fossilized animal found so far is a millipede called Pneumodesmus newmani, which rippled over the dirt 428 million years ago. We know of this creature from a single fossil, found on the Scottish coast by bus driver Mike Newman in 2004. The artifact shows the presence of spiracles, the small openings used in respiration that only work out of water.

From such beginnings, myriad forms of life flourished on the land, including the earliest insects. Those crawling fish had plenty of company when they first flopped onto the land.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.