EVOLUTION
DARWIN’S THEORY OF NATURAL SELECTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Stretching to get food in high trees made their necks longer and this trait was passed to offspring
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Giraffes prefer other giraffes that have long necks as their mates
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Giraffe food contains hormones that cause their vertebrae to lengthen
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Giraffes born with the longest necks stayed alive when food was scarce and passed this trait on to their offpsring
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Detailed explanation-1: -This is ‘natural selection’. Consider the giraffe, for example. A Darwinian theory of evolution posits that it was through random variation that some giraffes had longer necks than others. Thanks to their long necks, they were able to reach leaves high up in the trees in their environment.
Detailed explanation-2: -Charles Darwin held up giraffes as a prime example of natural selection, his theory that’s often summarized as “survival of the fittest.” Giraffes with comparably longer necks could reach food high up in trees, which gave them an advantage over other animals and members of their own species with shorter necks.
Detailed explanation-3: -Since the days of Charles Darwin, the long necks of giraffes have been a textbook example of evolution. The theory goes that as giraffe ancestors competed for food, those with longer necks were able to reach higher leaves, getting a leg-or neck-up over shorter animals.
Detailed explanation-4: -He observed that giraffe’s neck became longer through the generation as the giraffe stretches its neck to reach the leaves on tall trees. It’s offsprings would inherit the longer neck, and continued stretching would make it longer still over several generation. This theory is referred to as law of use and disuse.