Genetic evidence sheds considerable light on the origins of the hominid lineage. An increasing body of fossil data helps us to understand where and when hominids came into existence. The first signs of hominid evolution are the morphological changes associated with bipedality, a locomotor pattern that offered fitness, advantages in a new environment. However, other behaviors remained similar to those of nonhuman primates. Dramatic progress came with the evolution of Homo erectus, who exhibited more "human" morphology and life ways. Thus, behavioral, fossil and artifact data couple to give us a glimpse into our evolutionary past.
The molecular clock is a method which determines how long ago a certain ancestor diverged into a new species. Up until the 1960's people believed that humans came into existence twenty million years ago, but Alan Wilson and Vincent Sarich came up with an idea to determine how closely related certain animals were and how much of their DNA was shared. They came up with something called DNA hybridization and mistakenly stumbled upon the molecular clock. Wilson and Sarich closely studied previous research done with pigs, elephants and horses, and according to these studies they had gotten an approximate number of how long ago these animal species came into existence. This measurement was called Genetic Distant Units. Using the DNA hybridization Wilson and Sarich compared pigs with boars, elephants with Indian elephants, and a horse and zebra. The difference between animals in genetic distance units matched up exactly to the millions of years these animals diverged into new species. This therefore, was named the Molecular Clock. The Molecular clock was used to figure out when humans diverged int...
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...orphism. Paternal investment was higher in the Homo erectus because of the higher levels of paternal certainty. This also helped with driving juvenile mortality down because juveniles were taken better care of by both parents. (Miller 11/10/05, 11/15/05, Jurmain et al. 2004:237-38, Boaz and Ciochon 2001: 131-132)
In conclusion, the evidence on the origins of the hominid lineage has helped us to further understand where and when hominids came into existence. Fossil evidence shows morphological changes associated with bipedality allowing fitness advantage in new environments. Other behaviors have been shown through these fossils as well as the information we have today about nonhuman primates. Dramatic changes between the early australopithecines and Homo erectus are shown through fossil and artifact evidence giving us a window into the evolutionary past.
Paabo’s team discovered an mtDNA sequence from a finger bone they found from around 40,000 years ago, as carbon dating is one of the most commonly used methods of determining a fossil’s age. (Hammer, 70). Also, Neanderthal mtDNA is differs severely from modern human mtDNA. For example, Microcephalin is a gene for brain size during the development of the organism.
The evolution of man is constantly in question. While we are reasonably sure that modern humans and primates are both related to the same common ancestor, there is constant debate over what initially caused the two species to split into early hominids and apes. According to some, our longest and most popular theory on the division of man and ape is profoundly wrong. However, those same individuals usually offer an equally controversial theory as a substitute, one that is almost impossible to scientifically test or prove. Both the Savanna Theory and the Aquatic Ape Theory offer solutions to how and why humans evolved into bipedal toolmakers. But with enough questioning, each loses its accountability to rhetorical science.
Australopithecus afarensis who existed 3.5 million years ago and a 4.4 million year old skeleton of an Ardipithecus ramidus are the closest science has come to discovering the human lineage. Shattered Ancestry an article written by Katherine Harmon discusses the remains of two hominids found within Ethiopia. These skeletal remains have created a huge controversy within the topic of evolution questioning many assumptions that have been made referencing the human lineage. The skeleton of the Australopithecus afarensis was named Lucy and was discovered in 1974. The evidence of her walking upright on her two feet essentially guaranteed her a spot in the human lineage line. Lucy was a chimplike ape that was said to walk upright making scientists believe the human ancestry was simple. The complete skeleton found in Ethiopia of an Ardipithecus ramidus named Ardi completely changed all assumptions made from scientists about the complexity of the human lineage. These remains have encouraged researches that the human line is not the only lineage to have evolved but the chimpanzee line has undergone drastic changes as well. There are many traits that researchers have always directly linked to the human lineage however since these discoveries occurred researchers are reconsidering. The recent discoveries that have shattered what has always suggested what linked a species to the human lineage have changed the certainty of whether it is possible to confidently identify the human’s last common ancestor. Majority of scientist had forgotten that there would have been many hominid species living together at one time. New theories have been suggested since scientists revealed that the foot of a hominid found called the Burtele site was found ju...
years ” (Quimby 2), since this epoch involved the fundamental evolution of mankind to the present. It is important to
Three incomplete skulls of Homo sapiens were discovered in 1997. Bruce Bower’s article “African Legacy: Fossils plug gap in human origins” discusses the fossils. These findings are important because according to the discoverers, they are the oldest known fossils of modern people. The skulls were found in Herto, Ethiopian located in eastern Africa. The fossils are dated between 154,000 and 160,000 years ago.i[1] The fossils were dated radioisotopically.ii[2] Since the fossils are the oldest known fossils of modern people, it is probable that these hominids represent the immediate ancestors of humans that are anatomically modern. Tim D. White’s (et al) article “Pleistocene Homo sapiens from Middle Awash, Ethiopia” describes the discovery of the Herto fossils and the research of the artifacts in great detail.
There is evidence to suggest that Homo neanderthalensis and Homo sapiens had coexisted for approximately 35-40,000 years, (Fagan 2010) from around 60,000 years ago to 25,000 years ago when they finally went extinct (Gibbon 2001). Anthropologists are still uncertain what the cause of their extinction was. This paper will analyze three main theories of Neanderthal extinction. The first theory is the competition theory, which claims that the Homo sapiens and Neanderthals had to compete for resources, ultimately leading to their demise. The second theory I will discuss is the climate change theory, which claims that Homo sapiens lived while Neanderthals died because they were better adapted to the climate. The last theory I will discuss is the possible “extinction through absorption” theory which claims the Neanderthal interbred with the Homo sapiens and became one species. In this paper I will also be comparing the technologies, and diets of both species. In addition, I will look at the anatomic relation between the Neanderthals and Homo sapiens, how their body shape and size differed, and if this gave any advantage to one side or the other. My thesis for this paper will state that Homo sapiens and Homo neanderthalensis had co-existed but the disappearance of the Neanderthal in Eurasia is due to the appearance of the more culturally advanced and genetically superior Homo sapiens and the failure of the Neanderthal to adapt in an evolving climate.
The species A. afarensis is one of the better known australopithecines, with regards to the number of samples attributed to the species. From speculations about their close relatives, the gorilla and chimpanzee, A. afarensis’ probable social structure can be presumed. The species was named by Johanson and Taieb in 1973. This discovery of a skeleton lead to a heated debate over the validity of the species. The species eventually was accepted by most researchers as a new species of australopithecine and a likely candidate for a human ancestor.
Bipedalism had many advantages, but it also had many disadvantages and provided dangers to early hominids. Some of these disadvantages included i...
From the ancient bones of the Neanderthals, scientists have been able to extract small amounts of DNA. The DNA comparisons to modern humans show no relationship, implying evolutionary separation (Kunzig, 159). Some anthropologists say the small sections of DNA found are not conclusive evidence, because modern humans show just as much variation in DNA. These people point out that individuals such as the “Portugal Kid” are hybrids of Neanderthals and modern humans, showing there was gene trading. One argument against this is that there is no skull from the ‘Portugal Kid” so it is hard to compare it to Neanderthals. Also, it is known that closely related species can breed and their offspring can be fertile, but they are still separate species (Kunzig, 161).
Paleoanthropology: Pliocene and Pleistocene Human Evolution. Paleobiology, 7:3:298-305. Frayer, David W. and Milford Walpoff 1985 Sexual Dimorphism. Annual Review of Anthropology, 14:429-473 Key, Catherine A. 2000 The Evolution of Human Life History.
Sankararaman S, Patterson N, Li H, Pa ̈a ̈bo S, Reich D (2012) The Date of Interbreeding between Neandertals and Modern Humans. PLoS Genet 8(10): e1002947. doi:10.1371/journal.pgen.1002947
“The scientific study of how humans developed did not begin until the 1800s in Europe. Until that time, people relied on religious explanations of how humans came into existence. Starting in the 1500s a scientific revolution began to sweep Europe. Thinkers started using scientific methods and experiments to try to better understand the world and the creatures living in it. Eventually these methods were turned to the question of human origins” (The Nature Of Human Origins, 1). Earth made it possible for species to change over time because Ancient Earth provides ability to plenty of time.The Homo Sapien a is very complex creature. The species started off very simple by living in caves and surviving with little food and then later evolved into a species that were able to do many more complex things. The first species was Sahelanthropus tchadensis They were one of the most simple humans in that time period and on. They had very small skulls compared to Homo Sapiens today and their motor skills were just the same. We have evolved and changed for the better both mentally and physically. The Evolution of Homo Sapiens started off simple, such as the Neanderthals, and now we are the most advanced species to ever walk the planet so far.
One of the most important and pivotal physical and biological adaptations that separate humans from other mammals is habitual bipedalism. According to Darwin, as restated by Daniel Lieberman, “It was bipedalism rather than big brains, language, or tool use that first set th...
The evidence for human evolution begins with the australopithecines. All the australopithecines were bipedal and therefore possible hominines. In details of their teeth, jaws, and brain size, however, they modify enough among themselves to be divided into five species: Australopithecus anamensis, A. afarensis, A. africanus, A. robustus, and A. boisei. Genus Homo are also divided in five different spices: Homo erectus, H. habilis, H. sapiens, and H. sapiens sapiens.
Throughout the long winding road that is human evolution; many species have helped shape who we are today. There was the early Australopithecus africanus which began to walk bipedally-upright with two feet and the Homo habilis which drastically developed the construction of handmade tools. But there is one species who is to be credited for the most critical advancements in human evolution; Homo erectus. Not only did Homo erectus advance us the most biologically, but also the most geographically.