evolution of the horse Essay -- essays papers

evolution of the plyFor many people, the horse family remains the unspotted example of evolution. As more and more horse fossils have been found, some ideas about horseevolution have changed, but the horse family remains a good example ofevolution. In fact, we now have enough fossils of enough species in enoughgenera to examine details of evolutionary change.Evolution does not perish in a straight canal toward a goal, like a ladder rather,evolution is like a branching bush, with no predetermined goal. clamspecies were constantly branching off the evolutionary tree and evolvingalong various unrelated routes. Theres no discernable straight line of horseevolution. Many horse species were usually present at the same time, withvarious numbers of toes, and adapted to various diets. In other words, horseevolution had no inherent direction. We only have the impression of straightline evolution because only unity genus happens to still be alive, whichdeceives some people into thin king that the one genus was somehow thetarget of all the evolution. Instead, that one genus is merely the last survivingbranch of a once mighty and sprawling bush.Tracing a line of descent from Hyracotherium to Equus reveals severalapparent trends reduction of toe number, increase in size of cheek teeth,lengthening of the face, and increase in ashes size. But these trends are notseen in all of the horse lines. On the whole, horses got larger, bu...