Would You Like a Liger?
Biologists have found that about 10 percent of animal species may sometimes breed with other species. This means that two animals of different species can produce offspring. Scientists have discovered more of these animals in the last 25 years. One example of a hybrid animal is the mule, which is a cross between a donkey and a horse.
It is more difficult for hybrid species to survive in the wild, however. Occasionally, species that are too different genetically might mate in nature. Many babies that come from the different species are unable to reproduce. This means that the hybrid species cannot grow in number. Zorses, which are a hybrid of a horse and a zebra, and mules, are two examples of species that cannot reproduce. Another problem that hybrid species have is that they face competition from the members of their parent species.
There are also positive things about producing hybrid species in the wild. Hybrids may develop adaptations to conditions that neither of their parents was able to live in. This could happen because of new gene combinations being produced in hybrids. Scientists have studied the adaptation of hybrid species using sunflower and honeysuckle plants.
Two common species of sunflower are the common sunflower and the prairie sunflower, and both species only grow in moist soil. Their hybrids can grow in desert climates and salt marshes, however. When parent sunflowers were planted in the desert, they failed to survive. Results of the studies done with plants are comparable to similar things that have happened in animals. The studies of animal and plant hybrids could help us discover how humans have adapted.
How does the author develop his or her point of view in the passage?
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by stating that studying animal and plant hybrids could help explain adaptation in humans
by describing the problems faced in producing hybrid animals and plants in the wild
by showing how hybrid species are forced to compete with their parent species for survival
by explaining how a lion needs to mate with a tiger in order to produce a liger