How did giraffes evolve through natural selection?

A Darwinian theory of evolution posits that it was through random variation that some giraffes had longer necks than others. Because they could access food, the giraffes with longer necks were better able to survive and reproduce, with their offspring inheriting their long necks.

How is natural selection in the evolution of longer necks in giraffes best explained?

In terms of the giraffe example, Darwin’s theory of evolution through natural selection would suggest that a giraffe was born with a longer neck by random chance. Because this individual had a longer neck, it was able to reach food sources that other animals couldn’t.

What is the evolution of a giraffe?

The accepted theory on giraffe evolution is that the giraffes with the longest necks passed on their genes through natural selection, and that it took millions of years to get the animal we see now. The two forces that drove giraffes towards elongating their necks are simple. The need to eat and the need to breed.

Why does having a long neck help the giraffe?

Feeding. With the aid of its long neck, a giraffe is able to reach leaves, fruit and flowers high up in Vachellia or Senegalia (formerly Acacia) and other sought after tree species. Giraffe are thus equipped to exploit a band of foliage beyond the reach of all other terrestrial browsers, except for elephant.

Why did giraffes have short necks?

But although their necks can measure up to 1.8 metres (6 feet) alone, they have, like most mammals, just seven neck vertebrae. Fossil evidence shows that, once upon a time, giraffes had much shorter necks. Lamarck’s idea suggested they stretched their necks and passed the stretching down through generations.

How giraffes neck gets longer and longer using the theories of modern synthesis?

According to Lamarck, the giraffe got its long neck because its ancestors stretched theirs to eat leaves that were just out of reach. Long necks were thus “selected for” in every generation, gradually lengthening the giraffe’s neck over evolutionary time.

How is natural selection in the evolution of long necks in giraffes best explained quizlet?

How have giraffes evolved by Natural Selection to have long necks? Giraffes faced the struggle for existence because short-necked giraffes would not be able to reach vegetation in the higher branches of trees whereas long-necked giraffes would be able to get food and thus survive.

How long did it take giraffes to evolve?

Within a mere 6 million years, they had evolved into animals that looked like modern giraffes, though the modern species only turned up around 1 million years ago. The tallest living land animal, a giraffe stands between 4.5 and 5 metres tall – and almost half that height is neck.

Why is giraffe neck so tall?

It appears obvious: the giraffe’s neck, which can grow to as much as two metres in length, has been selected because it gives its owner exclusive access to the topmost leaves of the trees, and no other animal can reach them. This, then, is an adaptation designed to avoid competition for food with other animals.

How does long neck of giraffe help in eating?

Since these shorter creatures pick over food at a lower level, giraffes’ necks allow them to reach food and nutrients that others cannot. This becomes especially important for survival in habitats where food can become scarce and droughts are fairly common.