The diagram below shows illustrations of fossilized forefeet and molar teeth from horses that lived during different time periods. The diagram also shows how the body shape and size of horses has changed over time. This fossil evidence provides support for the idea that
evolution has occurred in horses.
The diagram shows a series of horse forefeet and molar teeth, starting from an early ancestor called Hyracotherium, which lived during the Eocene epoch around 55 million years ago. This ancestor had a small body size and three toes on its forefeet.
As we move through time, the forefeet and molar teeth of horses show gradual changes. The toes of the forefeet decrease in number, eventually leading to the presence of a single toe in modern horses. The molar teeth also change, becoming larger and more adapted to grazing on tougher grasses.
The body size and shape of horses also undergo significant transformations over time. Early ancestors were small, about the size of a dog, and had short legs, indicating a more forest-dwelling lifestyle. As time progresses, horses become larger with longer legs, suggesting adaptation to open grassland habitats.
The fossil evidence presented in the diagram provides support for the idea of evolution in horses. It shows a clear succession of anatomical changes over time, indicating that horses have evolved from small, multi-toed ancestors into larger, single-toed animals with adapted teeth for grazing.
This gradual change in body size, shape, and anatomy suggests that horses have undergone a process of natural selection, where individuals with beneficial traits for surviving and reproducing in different environments were more likely to pass on their genes to the next generation. Over millions of years, this selection pressure resulted in the evolution of horses into the forms we see today.
In summary, the fossil evidence provided in the diagram supports the idea that evolution has occurred in horses, with gradual changes in forefeet and molar teeth, as well as body size and shape, over time.