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Australopithecus
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<p><i>Australopithecus</i> (/ˌɒstrələˈpɪθɪkəs, -loʊ-/, OS-trə-lə-PITH-i-kəs, -loh-; or is a <a href="/facts/Genus/m8EFjSms">genus</a> of early <a href="/facts/Hominin/SflaMavS">hominins</a> that existed in Africa during the <a href="/facts/Pliocene/MjcIVQ86">Pliocene</a> and <a href="/facts/Early_Pleistocene/jPp2Cn7a">Early Pleistocene</a>. The genera <i><a href="/facts/Homo/qvJtEBr2">Homo</a></i> (which includes modern <a href="/facts/Humans/rlcTENsr">humans</a>), <i><a href="/facts/Paranthropus/7R9W8ABU">Paranthropus</a></i>, and <i><a href="/facts/Kenyanthropus/DfCj8nnL">Kenyanthropus</a></i> evolved from some <i>Australopithecus</i> species. <i>Australopithecus</i> is a member of the subtribe <a href="/facts/Australopithecina/25g1CUJG">Australopithecina</a>, which sometimes also includes <i><a href="/facts/Ardipithecus/fKUfolVk">Ardipithecus</a></i>, though the term "australopithecine" is sometimes used to refer only to members of <i>Australopithecus</i>. Species include <i><a href="/facts/Australopithecus_garhi/2UaV81ov">A. garhi</a></i>, <i><a href="/facts/Australopithecus_africanus/ET3Dxfa9">A. africanus</a></i>, <i><a href="/facts/Australopithecus_sediba/M1WqIlSJ">A. sediba</a></i>, <i><a href="/facts/Australopithecus_afarensis/3byc9ImU">A. afarensis</a></i>, <i><a href="/facts/Australopithecus_anamensis/tQW4Vzrj">A. anamensis</a></i>, <i><a href="/facts/Australopithecus_bahrelghazali/AwAdappp">A. bahrelghazali</a></i>, and <i><a href="/facts/Australopithecus_deyiremeda/kTLsLLjG">A. deyiremeda</a></i>. Debate exists as to whether some <i>Australopithecus</i> species should be reclassified into new genera, or if <i>Paranthropus</i> and <i>Kenyanthropus</i> are synonymous with <i>Australopithecus</i>, in part because of the taxonomic inconsistency. </p><p>Furthermore, because e.g. <i>A. africanus</i> is more closely related to humans, or their ancestors at the time, than e.g. <i>A. anamensis</i> and many more <i>Australopithecus</i> branches, <i>Australopithecus</i> cannot be consolidated into a coherent grouping without also including the <i>Homo</i> genus and other genera. </p><p>The earliest known member of the genus, <i>A. anamensis</i>, existed in eastern Africa around 4.2 million years ago. <i>Australopithecus</i> fossils become more widely dispersed throughout eastern and southern Africa (the Chadian <i>A. bahrelghazali</i> indicates that the genus was much more widespread than the fossil record suggests), before eventually becoming extinct 1.9 million years ago (or 1.2 to 0.6 million years ago if <i>Paranthropus</i> is included). While none of the groups normally directly assigned to this group survived, <i>Australopithecus</i> gave rise to living descendants, as the genus <i>Homo</i> emerged from an <i>Australopithecus</i> species[<i>excessive citations</i>] at some time between 3 and 2 million years ago. </p><p><i>Australopithecus</i> possessed two of the three duplicated genes derived from <i><a href="/facts/SRGAP2/chfUATy0">SRGAP2</a></i> roughly 3.4 and 2.4 million years ago (<i>SRGAP2B</i> and <i><a href="/facts/SRGAP2C/wlBky8CA">SRGAP2C</a></i>), the second of which contributed to the increase in number and migration of <a href="/facts/Neurons/G7CyTVdH">neurons</a> in the human brain. Significant changes to the hand first appear in the fossil record of later <i>A. afarensis</i> about 3 million years ago (fingers shortened relative to thumb and changes to the joints between the <a href="/facts/Index_finger/y2MjrVLJ">index finger</a> and the <a href="/facts/Trapezium_(bone)/UBmGBVlB">trapezium</a> and <a href="/facts/Capitate/MQwwkR52">capitate</a>). </p>