rhlalbin
contestada

(05.01 MC)

Horses are mammals with a single hoof on each foot that has evolved to bear the full force of the horse's weight. Other mammals have many toes that help support the animals' weight. Horses and many-toed mammals share a common ancestor since horses are also mammals. Fossil evidence of intermediate species has been found that shows how horses evolved. Compare the limbs and body sizes of the modern horse and its ancestors shown in the diagram.

Five animals resembling horses are shown: Equus (modern horse), a very large animal with one toe on each foot in the form of a hoof; Pliohippus, slightly smaller than a modern horse with a shorter mane and tail hair and one hoof on each foot; Merychippus, similar in size to Pliohippus with three toes; Hyracortherium, a tiny animal with four toes; Mesohippus, a small animal with three toes on each foot. The single or middle toe on each foot of all the animals is the largest toe.

Which of the following answer choices lists the ancestors of the modern horse, in order, from the oldest that lived 60 million years ago to the most recent that lived 7 million years ago? (1 point)

Hyracotherium, Mesohippus, Merychippus, Pliohippus, because over time, the number of toes decreased and body size increased.

Pliohippus, Mesohippus, Merychippus, Hyracotherium, because over time, the number of toes increased and body size decreased.

Hyracotherium, Merychippus, Mesohippus, Pliohippus, because over time, the number of toes decreased and body size increased.

Pliohippus, Merychippus, Mesohippus, Hyracotherium, because over time, the number of toes increased and body size decreased.

Respuesta :

ReynProtogen
Hyracotherium, Mesohippus, Merychippus, Pliohippus, because over time, the number of toes decreased and body size increased is the right answer
GeoPanther

The correct answer is - Hyracotherium, Mesohippus, Merychippus, Pliohippus, because over time, the number of toes decreased and body size increased.

The first horses that appeared on the world scene were small plant eaters, living in forests, and having the initial four toes as most mammals had. As the landscape and the climate were changing, the horses had to adapt in order to survive. For the first time in the Earth's history, grasslands appeared, and the forests diminished. The horses were quick to change their diet from leafs to grasses. That gave them more nutrition, so they were becoming bigger, but another reason was that they had to watch out for predators in the tall grasses, so bigger size was an advantage. Also, on the grasslands, in order to escape the predators, the horses had to become fast runners, so the evolution of less toes was in order to have stronger and better support for the legs while  running. Eventually that led to the horses becoming hoofed animals, by having only one, hard toe, as we know them nowadays.

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