Are you a fan of the 19th Century

scientist, Charles Darwin?

If so, this website is for you!  

 

This website aims to draw together key publications, media and websites on Charles Darwin for the enthusiast.

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Darwin & The Squirrels - Lesson Ideas

1) Watch a video of Red Squirrels. Find out why Red squirrel numbers have

declined  and about their habits and habitats. Look at the distribution of Red

squirrels and Grey squirrels in the UK. Find out about Red squirrels around

the world. Find out about the work of the Red Squirrel Survival Trust.  

Download a fact sheet about Red squirrels and Grey squirrels. Discuss

whether the rise of Grey Squirrels and demise of Red Squirrels is 'Survival of the Fittest' in action.

This is a popular name for 'natural selection' postulating that those who are eliminated in the struggle for existence are 'unfit for their environment'.

 

2) Look at a video of spindle to see its leaves, stem, fruit and seeds. Look at a close up of a spindle flower. Read about how Darwin noted three types of spindle flowers growing around Downe.  Look at Darwin's drawings of spindle flowers. Look at a Victorian illustration of spindle from a identification book. Discuss Discuss the importance of good illustrations and descriptions of plants for botanists. Look up 'spindle' in a plant identification book.  What happens following pollination - the production of a pollen tube to enable fertilsation of male and female 'cells', the production of a seed and the development of a 'fruit wall'. Talk about the four stages of plant reproduction.

 

3) Look at an autumn gentian plant and read a description of it. Look at a close up of a normal ('single') autumn gentian flower. Consider Darwin's description of a double flower 'Each head consists of innumerable small petal-like purplish scales, having in their centre a tuft of still smaller green scales...the stamens are seen to become deformed, and gradually to pass into small petals and scales. The pistil also can be traced, becoming more and more foliaceous....The plants of the Gentiana bearing the little tufts are generally, but not always, dwarfer than the perfect plants; their leaves are less pointed, and the entire plant is much less symmetrical. The much greater number of the imperfect flowers on one plant than are ever produced of the perfect, shows, I presume, that the metamorphic change must be determined early in the plant's life. Except in their small size, less beauty, and in the occasional presence on the same stem of flowers in different stages of monstrosity, these purple tufts seem to be essentially similar in their nature to the double flowers of Horticulturists.' (Darwin, C. R. to  Gardeners' Chronicle, [late Aug 1843]' Draw what you think it would have looked like.

 

Consider double flowers in modern, horticultural plants.  Buy and grow single and double varieties of a species (eg.Bizzie Lizzie, Cherry, Poppies, Roses). What are the down sides of double flowers?  Do they have scent?  Do they produce nectar? Do they produce seeds? Are both types visited equally frequently by insects?

 

 

SUMMARY OF LEARNING POINTS IN THE STORY

* Plants can occur in different forms; hermaphrodite or dioecious (separate female and male flowers).  Spindle demonstrates both forms.

* In Spindle, the plants which specialise in having female flowers produce the most seeds/fruit (offspring).

* Different forms of plants (eg. double flowering) can develop in a population as aberrations (traits carried in a seed), but cannot be created in the the short-term by something as simple as a change in soil conditions.

* Though some animals have a particular feeding regime, some show adaptability, especially  in difficult situations. Red squirrels normally eat plant material but also are able to take advantage of insectivorous material.

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