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How Have Fruits Contributed to the Success of Angiosperms?

Angiosperms or flowering plants produce fruit, by which they distribute their seeds. Of all plants, angiosperms are the most geographically widespread. Their reproductive strategies, which include flowers, seeds and fruit, have contributed in large measure to their evolutionary success. Approximately 250,000 species of angiosperms are known.

History
- Evidence from fossils show that angiosperms became prominent over 80 million years ago in temperate and tropical lands. This was also about the time period during which pollen, flowers and fruit developed. Some of the same plant families that grew then still exist today. Pollen and fruit not only help angiosperms spread over wide areas, they also contribute to genetic diversity, which helps them adapt to changing conditions. Fruiting begins after flowers are pollinated. There are a number of ways pollination can occur.
Pollination
- Bees help carry pollen as they fly between flowers
  
  Sometimes insects or other animals pollinate flowers. Wind and precipitation can also spread pollen grains, which fertilize the ovules or female sex organs of flowers. Once this occurs, the ovules begin to develop seeds. The wall of the ovary around the seeds thicken and become the fruit, which helps protects them. The fruit is also a mechanism for their dispersal. The fruits of different angiosperms are very diverse and have various features that assist in their dispersal.
Features
- Brightly colored berries attract various animals
  
  Fruits differ in color and size. Their color can attract different organisms, which feed on them and carry their seeds away. Many berries are a good example of brightly colored fruits. Some fruits, like that of the burrgrass, have spines that stick to passing animals; dandelions, milkweed, willow, cottonwood ash, elm and maple trees have fruit with specialized structures or protrusions that enable the wind to lift and carry them away. (reference 3)
Additional Information
- Coconuts have hard outer husks that help them float on water
  
  Other characteristics of the skin or covering of a fruit can play a role in its dispersal. A harder, thicker covering can help a fruit survive difficult conditions. In the case of the coconut, the tough husk allows it to float on water and be carried between islands, sometimes traveling very long distances before making landfall. The seeds of fruits do not automatically germinate. If conditions are not suitable, they may never germinate.

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