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Selective breeding of both plants and animals has been practiced since prehistory; key species such as wheat, rice, and dogs have been significantly different from their wild ancestors for millennia, and maize, which required especially large changes from teosinte, its wild form, was selectively bred in Mesoamerica.
Plant fruit: the fleshy nutritious part of plants that animal dispense by eating independently came about in flowering plants and in some gymnosperms like: ginkgo and cycads. [239] Water transport systems, like vascular plant systems, with water conducting vessels, independently came about in horsetails, club mosses, ferns, and gymnosperms. [240]
Humans have traded useful plants from distant lands for centuries, and plant hunters have been sent to bring plants back for cultivation. Human agriculture has had two important results: the plants most favoured by humans came to be grown in many places and (2) gardens and farms have provided some opportunities for plants to interbreed that would not have been possible for their wild ancestors.
Many protists reproduce sexually, as do many multicellular plants, animals, and fungi. In the eukaryotic fossil record, sexual reproduction first appeared about 2.0 billion years ago in the Proterozoic Eon , [ 64 ] [ 65 ] although a later date, 1.2 billion years ago, has also been presented.
Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. [1] It is used to improve the quality of plant products for use by humans and animals. [2] The goals of plant breeding are to produce crop varieties that boast unique and superior traits for a variety of applications.
Selective breeding of plants and animals has led to varieties that differ dramatically from their original wild-type ancestors. Examples are the cabbage varieties, maize, or the large number of different dog breeds. The power of human breeding to create varieties with extreme differences from a single species was already recognized by Charles ...
Selective breeding has been responsible for large increases in productivity. For example, in 2007, a typical broiler chicken at eight weeks old was 4.8 times as heavy as a bird of similar age in 1957, [36] while in the thirty years to 2007, the average milk yield of a dairy cow in the United States nearly doubled. [36]
Documented examples are found in a wide range of organisms: both vertebrates and invertebrates, fungi, and plants. The secondary contact of originally separated incipient species (the initial stage of speciation) is increasing due to human activities such as the introduction of invasive species or the modification of natural habitats . [ 6 ]