How Have Trees Evolved?

When modern man views a tree, we see how tall they are and contemplate how many years that tree could have been growing. However, trees have not always been in the same form as they are now and that sturdy tall tree you see today would have been something much different hundreds of millions of years ago.

All plant life began in the sea, with algae the first plant to begin to creep up and populate land. This early plant life began to develop adaptive characteristics in order to become tougher and survive, with supportive tissue and pores. Early plant life was low to the ground, having not yet developed the features that added the capability to grow up towards the sun.

Approximately 400 million years ago, a plant called Psilophyton first appeared. It was leafless and rootless, spineless with branches, and in fact its name comes from Greek words that mean "naked plant." Psilophyton reached a height of only one to three feet, but was taller than any other plant life at the time. Because of its comparative height, it had the ability to reach toward the sun, giving it an edge in survival over the neighboring plants.

As generations passed, some plants evolved a more woody tissue, which supported a greater height and made them stronger. One early tree was the Gilboa, which reached a height of 40 feet. It had long, fern-like leaves, and was able to reproduce by spore production. This type of species does not need a second "parent" plant and were the earliest type of real tree.

Later on, trees appeared which produced seeds rather than spores. These trees need two plants to produce the seeds, in simplified terms a male and female, but more accurately a blending of inherited traits from two plants. An ancestor of the modern conifer, the Cordaite, was one of the first trees known to produce seeds.

As various insects and animals came along, with their ability to cross-pollinate, as well as different water flow and delivery, trees have developed further into the fruit, flower, and cone-bearing varieties we see today.

Sources:
Joy of Nature - p. Reader's Digest, 1977