Squirrel wars

One hundred and fifty years ago, the oak woods near Nowhere would have been home to red squirrels. Now they have all disappeared.

The red squirrels have been replaced by grey squirrels that were introduced into the UK from the United States in the 1870s.

Grey squirrels spread to nearly all parts of the UK, replacing the red squirrels wherever they went. Now red squirrels are only found in a few places, where they are protected.

Grey squirrels are 60% better at digesting oak acorns than red squirrels, which seem to prefer hazel nuts. Oak acorns are much more common in Nowhere Wood than hazel nuts, and this favours the grey squirrel.

The success of grey squirrels at surviving and breeding in Nowhere Wood is due to the production of acorns, which varies from year to year.

Survival is a risky journey for any squirrel: the arrival of new competitors or interruptions to the food supply can pose real challenges.

 

Their lives are  adventures.

The word ‘adventure’ has two parts:

Ad means moving towards something.

Venture means attempting something dangerous or difficult, that is risky, with no guarantee of success.

Put the two together and you get the idea that the lives of all living organisms are risky journeys into the future, with no guarantee of success or survival.

If you like, you can think of life as:

organisms having adventures in time and space

  1. Think about the squirrels and the oak trees. In what ways are their lives adventures?  [Hint: think about what the word adventure means.]

 

Being and becoming in Nowhere Wood

Organise and stay alive

Living organisms have very organised structures.

Everything depends upon the way that the different parts of their bodies work together.

The parts of this watch work together, so that the hands of the watch move round in a rhythm that we use to tell the time. The hands do this because of the precise organisation of all of the parts of the watch.

The ability to tell the time emerges from the watch, only when all of the parts move together smoothly. If anything goes wrong, the watch “stops” and the ability to tell the time disappears.

Living organisms are alive because they are organised. Everything depends upon the way that the different parts of their bodies work together.

For an organism, life emerges and exists for only as long as its parts work together smoothly.

If anything goes wrong, the organism becomes ill. If it is very serious, then the organism dies and its life disappears. This is difficult to think about, but it is a fact of life.

  1. One of the important features of human society is that we have learned how to care for the sick and the elderly. Hows does this help the survival of humanity?

Moving things on

Being and becoming in Nowhere Wood

 

All living organisms are doing two things at the same time. They are:

Being (they are keeping themselves alive) and

Becoming (they are moving towards the next stage of their lives).

The butterfly is being and becoming at each stage of its life.

All of the animals and plants in Nowhere Wood are also “being” and “becoming”.

  1. How are the oak trees in nowhere Wood being and becoming?
  2. How are you being and becoming

 

Counting the ways to stay alive

Counting the ways to stay alive

No one knows how many different kinds of animals and plants are alive today, and, sadly, we never will.

A survey in 2011 suggested that there are nearly 8 million species of animals and nearly 300, 000 species of plants.  Astonishingly, nearly 90% of these species have yet to be discovered, described or named. Many are found in hard-to-reach places, such as tropical rain forests or the deep oceans. Given the rate of man-made habitat destruction, it is possible that many of these species will become extinct before they can be named by scientists.  

These 8.1 million species are, for now, the success stories of evolution. Each is a unique way of solving the problems of surviving and reproducing in an unforgiving and changing environment.

All species, like this humpback whale, have special characteristics that allow them to survive in their chosen habitats.

But if the habitats change too much, such as when when the oceans become acidified, rainforests are cut down or burned, then species may no longer be able to survive and they become extinct. Forever. 

  1. Why does it matter that species of organisms become extinct before scientists can discover them?

Organise and stay alive

Trampling acorns underfoot


I have never seen so many acorns in Nowhere Wood. Everywhere I step, I am treading on acorns. Acorns are the fruits of oak trees and this year it certainly has been a bumper harvest.  Biologists call this a “mast year”.

The air in Nowhere Wood in April and May was very hot and still. This allowed the oak pollen to hang in the air near the feathery stigmas of the oak flowers. Perfect conditions for pollination and making acorns.




July and August were warm and wet, ideal conditions for growing a record crop of acorns.

This is good news for the birds of the wood, like pigeons, jays and woodpeckers, which eat acorns. And for the squirrels and mice, too. Deer eat acorns, and I did once see one near the woods very early in the morning. The oak trees are producers and this is one way that they make food for the woodland herbivores.

The oak trees in the wood are perhaps seventy or eighty years old now and tower above the other trees. They are successful, but for how much longer? The oldest trees are falling down, some by lightning strikes during thunderstorms.

It is difficult for young acorns to grow into oak trees, because the floor of the wood is covered by thick ivy and brambles. There is a battle going on here for light, space and water that makes an episode of Eastenders look tame!

Some young shoots make it through to the light, but they are few and far between. The future of acorns in Nowhere Wood will depend on them.

Everything is connected together, and a change to one organism affects everything else. The squirrels and the jays will be needing the oaks to remain successful. This is the way of life in Nowhere.



 

  1. Walk round an open space or a park near where you live. How are the living organisms depending on each other to survive?



Squirrel wars

A life well lived

Sir Paul Nurse is one of the most important biologists in the world. He is Director of the Francis Crick Institute in London and has served as President of the Royal Society. In 2001, he shared the Nobel Prize in Physiology or Medicine for his work on the proteins that control the division of cells.

Sir Paul’s first book, ‘What Is Life?’ is one of the must-read books of the autumn. It has an accessible and engaging style and is likely to inspire many young people on a journey into biology.

The book has several themes, some autobiographical, as we follow Sir Paul into his laboratory to share his passion for the ways that “lowly” yeast cells divide. He is disarmingly modest, pointing out that he studied yeasts because he found them interesting. At the start he had no idea that the work would unlock the secrets of cancer and lead to the development of new treatments. He tells of how he almost failed to get into Birmingham University because he could not pass O-level French.

He recalls how once, when he was tired, he threw a contaminated petri dish away before going back to check it again, only to discover the holy grail of yeast cells, the one with the mutated cdc2 gene.

In this regard, his story is similar to the “accidental” discovery of penicillin by Alexander Fleming in 1928.  Fortune favours the prepared, though: both scientists had the foresight and self-discipline to go back their discarded dishes to discover something more valuable than gold.

Sir Paul guides the reader through five steps of biology: the cell, the gene, evolution, life as chemistry, life as information. These are brought together in a glorious conclusion to consider the biggest question” what is life?”

“The answer I got at school was something like the MRS GREN list, which states that living organisms exhibit Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion and Nutrition. It is a neat summary of the sorts of things that living organisms do, but it is not a satisfying explanation of what life is. I want to take a different approach. Based on the steps we have taken to understand five of biology’s great ideas, I will draw out a set of essential principles that we can use to define life.”

Nurse, Paul. What Is Life? (p. 96). David Fickling Books Ltd.

This is what makes the book so special and why it should sneak into the bookshelves of all teachers of biology and their students. It is a glorious and joyous read.

This hardback book is available now from booksellers, and for eager beaver readers, like me, on Amazon Kindle.