The Natural History Museum’s Professor Richard Fortey presented us with a BBC Four series exploring how some of the world’s creatures have survived catastrophic events on planet Earth.
Having studied fossils and dinosaurs all his life, Professor Fortey travels the globe to investigate why some animals survived mass extinction events on earth. Each episode concentrates on a different event, showing us how the climate will have changed and how tough it would have been for anything to survive. The first episode concentrates on cataclysms over a million year period, 250 million years ago. He explains how a creature would have to have been incredibly tough to survive such harsh climates.
Fortey researches how each animal has traits that have been key to their survival over millions of years. The horseshoe crab, often found in Thailand and Japan, is still around today because of its reproduction. Each female can lay twenty clutches of eggs each containing several thousand eggs. As the eggs are laid across an open beach (an ideal food source for migrating birds) only a few will get to hatch, but it is their ability to reproduce on such a scale and a broad diet that means they have been around for half a billion years. The species is now considered a ‘living fossil’. Other factors such as blue copper-based blood rather than usual iron-based blood means they would have been able to survive the poisonous seas when the atmosphere turned toxic during the cataclysmic events known as ‘The Great Dying’.
250 million years ago 90% of all life almost died. Many species vanished during The Great Dying, as many became casualties of volcanism that made the earth almost uninhabitable. The programme doesn’t just look at crustaceans, but also explores how plants, seeds and birds have survived for such a long time.
Fortey goes on to explore the reasons why some animals survived the asteroid collision that wiped out the dinosaurs 65 million years ago. The collision is also known as the K/T collision. Crocodiles also survived because of their specific characteristics. A slow metabolism means they can go without eating for 6-7 months which is enough time to survive a traumatic event on earth. Their ability to stay underwater with only eyes and the nose disc on the surface, means they could escape the fires of devastation that engulfed the planet.
When exploring the different animals and plants that escaped The Ice Age 2.8 million years ago, ox’s and wolverines have traits from their ancestors such as the Woolly Mammoths which ensured their survival. A mixture of thick coats, reliable teeth and defensive instincts meant these animals are still around today and still endure tough snowy climates that are common in the Northern hemisphere.
The Ice Age didn’t just affect the North of the planet though; there is evidence to suggest that The Ice Age was responsible for deaths of species such as the Tazmanian Tiger in Australia. Limestone caves in Australise hold fossil records of these species, but there is no solid evidence as to what actually happened to cause it.
Marsupials survived through adaptation to harsher conditions. Wallaby’s metabolic rate is slow and they can control their reproduction. Kangaroos can extract water from the driest of plants. It is survival skills like these that mean we can still witness these extraordinary animals on earth today.
The plants and trees Fortey examines range from fireproof seeds to trees that can only germinate with fire. The Eucalyptus tree, a plant many have heard of, is completely incinerated in bushfires but its special survival skill lies in its germination – after the fire is out, it starts new shoots from among the ashes. A bush called Brown’s Banksia, is essentially a phoenix. The seed pods burst when fire hits them, without fire, the seeds cannot be released to germinate on the ground below.
As a documentary of the past and past events, it is inevitable that the earth is going to witness climate upheaval again at some point in its existence. Whether or not it will be a case of 90% of life on earth disappearing like 250 million years ago is anyone’s guess, but if animals have adapted to survive for longer than mankind has even been around, it is hard to believe that life on earth will ever cease to exist.
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