First, changes in whole communities of organisms, such as from bare rock to a mature forest, are called succession. Here is a video outlining some of the major features of that process:

Video: “Ecological Succession – Change Is Good (Crash Course Ecology” (10:02)

Turning now to evolutionary changes, two of the most remarkable and often studied examples are the adaptive radiations of the Darwin’s finches in the Galapagos Islands, and the Hawaiian honeycreepers. Adaptive radiations are bursts of diversification that happen when organisms colonize a number of different kinds of habitats. In both of these cases, the different sorts of food these birds eat has fostered a divergence into many species on these island chains.

Video: “Galapagos Finch Evolution (HHMI)” (16:08)

Reading: “Hawaiian Honeycreepers (Guardian)”

Going back further in evolutionary history, since we are related to other organisms we should not be surprised to find that some body parts transform radically over long periods of time. Following on a popular science book by Dr. Neil Shubin on our fishy ancestry, this short video focuses on the history of our tiny ear bones:

Video: “Your Inner Fish – We Hear With the Bones That Reptiles Eat With (PBS)” (4:23)

Works

Look for examples of community succession today—how are the old plant individuals different from the young ones, for instance? You might also reflect on the variation in certain groups of organisms, such as bill shapes in birds and how they are suited to the sort of feeding they do; or the differences among insects in their wing styles and uses.

~Be adventurous but not foolhardy. Let somebody know where you are, or travel with somebody~

All nature has a feeling: woods, fields, brooks

Are life eternal: and in silence they

Speak happiness beyond the reach of books;

There’s nothing mortal in them; their decay

Is the green life of change; to pass away

And come again in blooms revivified.

Its birth was heaven, eternal it its stay,

And with the sun and moon shall still abide

Beneath their day and night and heaven wide.

-John Clare (1845)

THE GLADNESS OF NATURE

Is this a time to be cloudy and sad,

When our mother Nature laughs around;

When even the deep blue heavens look glad,

And gladness breathes from the blossoming ground?

There are notes of joy from the hang-bird and wren,

And the gossip of swallows through all the sky;

The ground-squirrel gaily chirps by his den,

And the wilding bee hums merrily by.

The clouds are at play in the azure space,

And their shadows at play on the bright green vale,

And here they stretch to the frolic chase,

And there they roll on the easy gale.

There’s a dance of leaves in that aspen bower,

There’s a titter of winds in that beechen tree,

There’s a smile on the fruit, and a smile on the flower,

And a laugh from the brook that runs to the sea.

And look at the broad-faced sun, how he smiles

On the dewy earth that smiles in his ray,

On the leaping waters and gay young isles;

Ay, look, and he’ll smile thy gloom away.

-William Cullen Bryant (1794-1878)