Read the article and write a summary in 500 to 700 words rticle 24 The Origin of

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Read the article and write a summary in 500 to 700 words

rticle 24 The Origin of Childhood CHRISTOPHER P SLOAN eresenay Alemseged has two babies. One is Alula, who spends most of his time in his mother's arms in a cozy bungalow in Addis Ababa, Ethiopia's capital. The other s a little girl of three, who spent 3.3 million years locked in sandstone, until the Ethiopian scientist and his team discov ered her remains and painstakingly teased them out of the rock. Fordecades the low-lying northern end of Africa's Great Rift Valley, the Afar depression, has been the domain of foreign-led expeditions. Zcresenay, one of a new generation of Ethiopian s, changed that in 1999 when he led a band of Ethiopian fossil hunters into the Afar badlands. By December 2000, the search had turned up plenty of fos- It was a long, slow second birth for a baby from the dawn of sil mammals, such as elephants, hippopotamuses, rhinoceroses and antelopes, but no hominins. Yet Zeresenay, who is based Until now all fossils of babies this ancient could have fit in a the Max Planck Institute for Evolutionary Anthropology a diaper. This new arrival is not only the most complete ancient in Leipzig. Germany. knew his team was looking in the right nfant but arguably the best fossil of her species, Australopithe place. These animals would have thrived in the gallery forest cus afarensis. That's the same species as the superstar fossil that flanked the ancestral Awash River. Early hominins would called Lucy, a 3.2-million-year-old adult female found in 1974. have lived in these shady woodlands as well. Unlike Lucy, the baby has fingers, a foot, and a complete torso The prehistoric forests of Dikika are long gone, and there But the most impressive difference between them" says Zere was no shade on December 10, when team members forced enay (Ethiopians' first names are their formal ones), "is that themselves out into the hot sun to look again. Tilahun Gebre- selassie was the first to see the Dikika baby's tiny face peering No bigger than a cantaloupe, the little bundle of bones may out from a dusty slope. It was no bigger than a monkey's, but a also bear witness to a key event in the evolution of homi smooth brow and short canine teeth told Zeresenay right away ins, as humans and their ancestors are known: the beginning that this was a small hominin. His team had struck fossil gold. of our long, dependent childhood, when we grow our large for not only was the baby's skull in perfect shape, but tucked brains. "Outside of its completeness, the major importance beneath the head in a hard ball of sandstone were many bones of this find is the light it will shed on how this species lived of the upper body as well. This is something you find once in his baby has a face? and grew." says Bill Kimbel, an expert on A. afarensis and a lifetime," Zeresenay says. a member of the study team. "Now we can begin to read its He doesn't know how the Dikika baby died, but the river must have rapidly buried the body in pebbles and sand, protecting it It is a curious coincidence that the world's oldest baby, who from scavengers and weather before gradually hardening into died while still of nursing age, lived her short life in a region rock. While most hominin fossils have to be glued together from named Dikika "nipple" in the local Afar language, after a dis- hundreds of fragments. Zeresenay faced the opposite challenge. inctly shaped hill. The hill is just across the winding Awash He had to etch away hard sandstone with a dentist's drill, navigat- River from Hadar, the site in Ethiopia's Rift Valley where Lucy ing between tiny vertebrae and ribs so anatomical details could and the fossils of many other hominins have been found. The beeen. "Icleaned it grain by grain," he says. "You don't want to biography." region is plagued by extreme heat, flash floods, malaria, and destroy it by rushing." The task has taken five years so far occasional shoot-outs between rival ethnic groups, not to men- e payoff: details rarely seen in a fossil australopith, among ion lions, hyenas, and other uninvited nocturnal guests. It is one em a full set of both milk teeth and unerupted adult teeth of the most difficult places on Earth to hunt for fossils-and one All of her tiny ribs were positioned, as in life, along a sinu- ous spinal column. One finger was still curled in a tiny grasp. and where her throat once was, Zeresenay found a rare exam- ple of a hyoid bone, a bone that later became crucial to human Heat, malaria, lions, and shoot-outs plague speech. The discovery ofers an early glimpse of the evolution of the human voice box, says, Fred Spoor of University College of the most fruitful. this harsh region. London, another member of the study team.

Explanation / Answer

The origin of childhood

Zeresenay Alemseged has two babies. One is Alula who spends most of his time in his mother's arms in cozy bungalow in Ethiopia capital. The other is a girl of three who spent million of years in sandstone until Ethiopian scientist discovered her remains.the new arrival of baby was not complete ancient infant but arguebly the best fossils of species. Most impressive difference between them is that one of them had fingers , a foot and a complete torso. No bigger than a cantaloupe the little buncle of bones may also bear witness to a key event in the evolution of hominin as humans and their ancestors. Ethiopia region is plagued by extreme heat, flash foods , malaria and occasional shoot out between ethic groups not to mention lions , hyenas and natural uninvited nocturnal guests. It is one of the most difficult places on earth to hunt for fossils and also fruitful. For decades low lying northern end of Africa's great rift Valley, the afar depression has been the domain of foreign led expeditions. By December 2000, the search had turned up.plenty of fossil mammals such as elephants, hippopotamuses, rhinoceros and antelopes but no hominin. The pre historic forest of dikika are long gone and there were no shade on December 10 when team memeber forced themselves out into the hot sun to look again. Tilahun Gebbresilassie was first to see the dikika baby tiny face peering out from dusty slope.it was no bigger than a monkey's but a smooth brow and short canine teeth . Zeresenay doesn' know how the dikika baby died but the river must have rapidly buried the body in pebbles and sand protecting it from scavenger and weather before gradually hardening into rock. Zeresenay found a rare example of a hyoid bone a bone that later became crucial to human speech. From the waist down the dikika baby looked like us . One of her human like knees was complete with a knee cap no bigger than a dried pea. But her upper body was apelike features. As apelite feet evolved to support and propel an upright body , they could no longer grasp objects with a thumb like big toe as the feet of chimps and other apes can. For hominin mothers and infants the consequences were monogamous unlike most apes. From the dikikas baby teeth the team estimated her age three years her brain preserved as a sandstone cast inside the skull, had a volume of about 330 cubic centimeters - roughly the same as a small three year old chimpanzees. This could mean her brain was grouping faster than a chimps. In most mammals including other primates the young move on the forage for themselves after they finish nursing. But during human evolution ever longer brain growth led to the extended period of dependence we call childhood.a cascade of other changes may have begun around that time . Its no good growing a big brain if you don' have a long life span. You need that for the investment in a big brain to pay a return. Emergence of childhood was seen as a sign that human ancestors were also living longer than their ape cousins. Growing bigger brain had other consequences. A fifth of the calorie we consume go to fuel our brain. Within million years of dikika baby our ancestors learned to supplement the mostly vegetarian diet . The dikika baby biography is short, but the evolutionary steps she smbodied have had profound and enduring effects . Although bipedalism and big brains carried a high cost , particularly for the mothers of our lineage , these traits ultimately combined to produce smarter babies who would eventually be able to master technologies , build civilisations and yes explore their own origins.

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