Twenty thousand years ago during the time of the last ice age period, manycolossal mammals roamed North America. They survived during the times when much ofthe earth was covered by immense large bodies of ice that buried forests, fields, andmountains, but rapidly became extinct after the ice began to retreat and melt. Since thenthe human race has introduced many different theories to explain the extinction of theselarge mammals. One theory stands above all and explains the truth of this mysteriousdisappearance. The Paleo Indians that entered North America from Asia, the climatechange, soil, vegetation and water levels were all major factors in this extinction. Theresults of these factors left the biggest impact on the food chain of these animals. Thedomino-effect of all these factors is responsible for the extinction of the ice age mammals.
Animals, like all other living organisms have a tendency to adapt to theenvironment in which they live. A cold climate favors large animals, since large animalshave more body fat and lose heat at a slower rate then do smaller animals. That is whymany of the mammals that lived during the ice age were enormous. These large animalsconsisted of ground sloths and armadillos which came northward from South America,and horses, saber-toothed cats, mammoths, antelopes, and muskoxen that crossed over theland bridge from Asia into North America.
For the longest time fossils from many parts of North America were the onlyevidence that many of these large beasts had once roamed the land, but in the spring of1846 an unbelievable event happened that brought the world a step closer to the mysteryof this great extinction. A Russian explorer Benkendorf and his survey team from Russiawere heading for the mouth of the Indigirka River in Siberia. When they reached the spotof their destination, the land had disappeared and everything had changed. Left behindwas two miles wide of torn up land, and wild waters carrying rapidly masses of peat andloam. In the mixture of the mess they seemed to notice what was once one of themammoths who roamed the earth during the ice ages. (Chorlton 53) Our patience was tried. At last, however, a huge black horrible massbobbed up out of the water. We beheld a colossal elephants head, armedwith mighty tusks, its long trunk waving uncannily in the water, as thoughseeking something it had lost. Breathless with astonishment, I beheld themonster hardly 12 feet away, with the white of his half-open eyes showing. ‘A mammoth! A mammoth!’ someone shouted. (Chorlton 54)An elephant with a body covered with thick fur about thirteen feet in height andfifteen in length with tusks eight feet long that curved outward at the end. It had a trunksix feet long and colossal legs one and a half feet thick. The beast was fat and well grown. The outer hair was like wool, very soft, warm and thick, it was definitely well protectedfrom the cold.(Chorlton 54) Unfortunately the mammoth soon began to decay and wasswept away by the rapid waters. This dramatic find brought the world face to face withone of the great mysteries of the ice age, the sudden extinction of the great colossalmammals.
These large mammals at one time lived in peace and survived gracefully forthousands of years, they adapted to the cold climate and tundra surrounding them. Withan adequate food chain and nothing to affect it they were bound to survive forever, butbecause of simple changes that eventually triggered many other factors these animals areextinct and will never be on this earth again.
When the massive continental glaciers locked up great quantities of water, the sealevels lowered which exposed parts of the shallow sea floor, therefore, the Bering Straitdid not exist. Eleven thousand, years ago many Paleo Indians were able to cross the landbridge between Asia and North American which enabled them to populate North America. The great amount of large animals attracted these people to the frozen waste lands.In all hunting that ends with the extermination of a species, the motivation is never hunger. Money, and the greed for it, have been theincentive. The savage does not know these, he hunts to eat and so isunable to decimate the big game to any important extent (Cornwall 117)The large mammals of North American were never exposed to the intellectualminds of human beings. Therefore, this drastic change of humans living on their land andfeeding on there own kind was a big change. These animals were like helpless ants andhad no way to protect themselves from human beings. Due to their unintelligence theywere very easily killed, by being surrounded or by using fire to track them in the directionthey were intended to go. Deadly spears have been found in the remains of many of thesegiant animals, this was the Indians only way of survival. From hunting these mammalsweapons, shelters and clothing were made. Animals bones and tusks were often used forweapons, and homes were built out of bones, tusks and were covered with animals hides.
The left over carcasses of these animals were often burned for light and heat in the frigidclimate. In many parts of North America archaeologists found large storage pits, where these Indians stored fresh meat.
It is obvious that even though the Paleo Indians lived off these giant game animalsthere is no possible way they were single handedly responsible for their extinction, theclimate was also another big factor. As the glaciers retreated the tundra zone movedmuch further north which forced these animals to move northward. A succession ofwarm, wet springs wiped out many of these animals as they moved northward on theirregular springtime migrations. Hundreds of giant mammals have been found over theyears frozen in an upright position. “The ground on which the animals stepped gave wayunder the weight of the giant and he sank as he stood, on all four feet.” (Kurten 36)They gradually sank down when the permafrost in the tundra area thawed which turned alot of areas into huge bogs. Many other animals were simply separated from each other bybeing trapped as the glaciers melted and separated. They were left alone with no food andeventually died. (Kurten) The cool but equable climate of the ice age gave way to the warmer,more seasonable climate of the Holocene epoch. The rapid environmentalswitch from glacial to interglacial caused the forests and grasslands toshrink for a period of time. This might have disrupted the food chain ofseveral of the large mammals. Deprived of their nutritional resources,they simply disappeared. ( Erickson 57)These mammals were experiencing very drastic changes, every thing around themseemed to be moving and the simple things like the food they ate was difficult to find andif they could find it, they were lucky if it was in a good eating condition. This wasbecause the climate has an unbelievably great effect on the soil. As is still the case today,the tundra soil was frozen solid for much of the year, but with the little warmth of theArctic summer the permafrost could thaw a few inches to a few feet. This would allowgrasses, lichens, flowers, mosses and shrubs to grow and feed the plant eaters. The rest ofthe year, they lived off the left over twigs, shoots and lichens hidden beneath the snow. As the glaciers retreated what used to be permafrost was now thawing, that could be agood factor considering that now the soil can support vegetation that requires a longergrowing season. But with the retreat of the ice came a dry period and many spruce forestswere replaced by pine and hardwood. This crisis seemed to effect the grassland faunamore then the forest animals. They were used to available grassland all year long, even inthe winter the snow was shallow enough to reach the underlying grassland. But with thesea levels rising because of the melting glaciers many of the grassland areas were floodedwhich killed the vegetation.
All animals are directly or indirectly dependent on plants and since the vegetationdepends on climate and soil, the food that these animals were used to surviving on wasslowly disappearing. The vegetation these mammals ate was coarse and poor nutritionalvalue, which meant they needed vast quantities of food. This caused a tremendousproblem because the retreat of the ice left a limited amount of food and many animalsstarved to death. The tundra, extending across the northern part of North America washome to many of the giant mammal of the Ice Age. Mammoths, bison, horses, muskoxen,camels, caribou, and other plant eaters, along with cats, wolves and bears that preyed onthem. The drastic change of plant life as the climate had greatly changed, affected theeating habits of many of the plant eaters. This made them more vulnerable to hunting anda lot weaker to defend themselves from predators. Once these animals started to becomeextinct the carnivores which preyed on them started to diminish in population because ofthe lack of prey in the area. Some of these animals such as horses, camels, wolves andbears are alive today, but they have come from other parts of the world that did notexperience such dramatic changes as the ice retreated thousands of years ago.
It is probable that causes more general and powerful than the agency ofmen, alterations in climate, variations in the range of many species ofanimals, vertebrate and invertebrate, and of plants, geographical changesin the height, depth, and extent of land and sea, or all of these combined,have given rise in the vast series of years to the annihilation of many largemammalia. (Imbrie 17)Today we are furthermore uncovering discoveries of the intriguing mysteries thatthe ice age has left upon us. Everyday the amount of human knowledge on Earthincreases rapidly, the ice ages only being a microscopic part of this ample space ofknowledge. There is no doubt though that the ice ages has brought the earth manyphysical changes, both devastating and captivating. The extinction of the colossalmammals being one of them. Which is due to the domino-effect of many factors including, the Paleo Indians entering North America, climate change, soil, vegetation, water levelsand food chain of the animals lives being effected. These mammals not knowing how toreact slowly began to vanish from the earth.
