Human Evolution

Stansfield Macmillan, , pp. All quotations are consecutive, except where noted. The quotations are presented here in the order in which they appear in the book; since Patton quotes them out of order, I have inserted notes to help keep track of them. Geologists now assume that most of the water in the oceans was produced by volcanic outgassings. There are now approximately active volcanoes and about 10, dormant ones. Six hundred volcanoes comparable to Paricutin could account for the present oceans in approximately 0. Since volcanic activity presumably was much greater during early earth history than at present, creationists argue that the age of the oceans would appear to be considerably less than 0. How much water vapor was lost to space during the early warmer stages of geological history is also a big unknown. Of course, half a billion years is still too long to help young-earth creationists. In this next quotation, Patton ignores inconvenient weaknesses:

Human Evolution Timeline Topples

Genetic data based on molecular clock estimates support a Late Miocene ancestry. Various Eurasian and African Miocene primates have been advocated as possible ancestors to the early hominins, which came on the scene during the Pliocene Epoch 5. Though there is no consensus among experts, the primates suggested include Kenyapithecus, Griphopithecus, Dryopithecus , Graecopithecus Ouranopithecus , Samburupithecus, Sahelanthropus, and Orrorin. Kenyapithecus inhabited Kenya and Griphopithecus lived in central Europe and Turkey from about 16 to 14 mya.

Successful combination of electron spin resonance, luminescence and palaeomagnetic dating methods allows reconstruction of the Pleistocene evolution of the lower Moulouya river (NE Morocco).

The finds – reported on the front cover of Nature – are dated to about , years ago and represent the oldest securely aged fossil evidence of our own species. Jebel Irhoud has been well known since the s for its human fossils and its Middle Stone Age artefacts but the interpretation of the Irhoud hominins has long been complicated because of persistent uncertainties surrounding their geological age.

The crania of modern humans living today are characterised by a combination of features that distinguish us from our fossil relatives and ancestors – a small and gracile face, and globular braincase. The fossils from Jebel Irhoud display a modern-looking face and teeth, and a large but more archaic-looking braincase. In the 90s there were a few sites found in Ethiopia dated to , years and now with these results the origins of modern humans are further pushed back to , years.

So there are only two or three fossils that document the arrival of modern humans in Europe some 45, ago. In contrast, Neanderthals buried their dead but they ate them as well, leading to bone accumulations in caves” he said.

Earliest Ever Homo Sapiens Discovered in Morocco Forces Major Rethink of Human Evolution

Evolution Before about it was widely thought that distinctively hominin fossils could be identified from 14 to 12 million years ago mya. However, during the s geneticists introduced the use of molecular clocks to calculate how long species had been separated from a common ancestor. The molecular clock concept is based on an assumed regularity in the accumulation of tiny changes in the genetic codes of humans and other organisms.

Evolution Encyclopedia Vol. 1. CHAPTER 7 – DATING METHODS PART 1. Introduction “In a billion years [from now], it seems, intelligent life might be as different from humans as humans are from insects.

Some paleoanthropologists lump Paranthropus robustus and other paranthropoids into the genus Australopithecus. They consider them to be a physically robust subgroup of australopithecines. Following that excavation, he dedicated the rest of his life to writing everything known about all of the early hominins. He completed this compendium work in He was 85 years old and ill.

As he finally finished his writing, he reportedly said “now it is done and so am I. Brain, using more thorough field and laboratory techniques than had been used by Robert Broom a generation earlier. Many thousands of bone fragments, including the remains of individual hominins, were recovered by Brain. These bones were from australopithecines and paranthropoids as well as early members of our genus, Homo.

Because many of the bones had chewing marks and at least one of the skulls had peculiar depressions reminiscent of punctures made by the canine teeth of a leopard, Brain hypothesized that some of the Swartkrans hominins had been eaten by these big cats. The early hominin fossil-bearing strata in the cave also contained stones that were from locations distant from the cave.

Finger bone points to early human exodus

Evolution Before about it was widely thought that distinctively hominin fossils could be identified from 14 to 12 million years ago mya. However, during the s geneticists introduced the use of molecular clocks to calculate how long species had been separated from a common ancestor. The molecular clock concept is based on an assumed regularity in the accumulation of tiny changes in the genetic codes of humans and other organisms.

Use of this concept, together with a reanalysis of the fossil record, moved the estimated time of the evolutionary split between apes and human ancestors forward to as recently as about 5 mya. Since then the molecular data and a steady trickle of new hominin fossil finds have pushed the earliest putative hominin ancestry back in time somewhat, to perhaps 8—6 mya. Possible pathways in the evolution of the human lineage.

Most scientists and many Christians believe that the radiometric dating methods prove that the earth is billion years old. The textbooks speak of the radiometric dating techniques, and the dates themselves, as factual information.

View images by clicking on link or reduced image: Each image opens into a new window. These primitive, medium sized apes lived in rain forests between 18 and 22 million years ago. This species and others such as Dryopithecus existed before the hominid line diverged on the path to humans. This lineage ancestral gibbons is believed to have diverged from the great ape and human lineages between 17 and 25 Mya Avers, Oreopithecus ‘s hand closely matches the pattern of early hominids, with a grasping capability including firm pad-to-pad precision gripping that apes are unable to perform presumably as a response to similar functional demands to hominids Moya-Sola et al, Bipedal activities made up a significant part of the positional behavior of this primate Kohler and Moya-Sola, Gorilla and human DNA only differs by 2.

The ‘hobbit’ was a separate species of human, new dating reveals

Hosted by the Smithsonian Institution. The Obstetrical Dilemma Revisited This article explores how the human birth process is unique among primates, the result of a compromise between a pelvis adapted to bipedal walking and a skull large enough to accommodate the human brain. Trevathan [Evolutionary Anthropology 4, no. Other Resources Human Evolution From Lucy to Language This large-format book by science writer Edgar and paleoanthropologist Johanson — discoverer of the famous partial skeleton of Lucy, a female hominid who lived 3.

Johanson and Blake Edgar [New York:

Cosmic-ray Exposure Dating: Overview of Scientific Dating Methods: Dating the Past: This is an excellent overview of dating methodologies, and is a chapter in a textbook on Archaeology. You may find it useful for the clear definitions, and for excellent links on a variety of topic.

Continue reading the main story But there are two very different kinds of innateness. Chomsky proposed that we are born with specific, genetically determined neural and cognitive structures, structures that go far beyond a few general learning mechanisms. This kind of innateness has become the established wisdom in cognitive science. The brain is not a blank slate. However, the other, more significant, kind of innateness concerns not the history of the mind but its future. Chomsky also argued that innate structure places very strong constraints on the human mind.

Evolutionary psychologists who echo Chomsky say we are stuck with the same brains as our hunter-gatherer ancestors, with just a little tinkering around the edges.

Human evolution

The research, reported in the journal PLoS One, offers new insights into the nature of human evolution, suggesting a different role for Homo erectus than had been previously thought. Modern humans never co-existed with Homo erectus—a finding counter to previous hypotheses of human evolution—new excavations in Indonesia and dating analyses show. Pictured are skulls of Homo erectus uncovered in the s in Indonesia. Homo erectus is widely considered a direct human ancestor—it resembles modern humans in many respects, except for its smaller brain and differently shaped skull—and was the first of our ancestors to migrate out of Africa, approximately 1.

See also human evolution. The name Homo sapiens was applied in by the father of modern biological classification (Omo 1 and Omo 2), were initially dated to kya, but through the application of more-sophisticated dating techniques in the .

So suggests new research that tracked changes in two genes thought to help regulate brain growth, changes that appeared well after the rise of modern humans , years ago. That the defining feature of humans — our large brains — continued to evolve as recently as 5, years ago, and may be doing so today, promises to surprise the average person, if not biologists. Lahn and colleagues examined two genes, named microcephalin and ASPM, that are connected to brain size. If those genes don’t work, babies are born with severely small brains, called microcephaly.

Using DNA samples from ethnically diverse populations, they identified a collection of variations in each gene that occurred with unusually high frequency. In fact, the variations were so common they couldn’t be accidental mutations but instead were probably due to natural selection, where genetic changes that are favorable to a species quickly gain a foothold and begin to spread, the researchers report.

Lahn offers an analogy: Medieval monks would copy manuscripts and each copy would inevitably contain errors — accidental mutations. Years later, a ruler declares one of those copies the definitive manuscript, and a rush is on to make many copies of that version — so whatever changes from the original are in this presumed important copy become widely disseminated. Scientists attempt to date genetic changes by tracing back to such spread, using a statistical model that assumes genes have a certain mutation rate over time.

For the microcephalin gene, the variation arose about 37, years ago, about the time period when art, music and tool-making were emerging, Lahn said. For ASPM, the variation arose about 5, years ago, roughly correlating with the development of written language, spread of agriculture and development of cities, he said. Other scientists urge great caution in interpreting the research.

Evolution’s Radiometric Dating Methods: Are they accurate?

A team of international scientists has broken new ground on the theory of human evolution. The advance is the result of new analysis of skulls from the famous Spanish archaeological site Sima de los Huesos, or “the pit of bones”. In a world first, six different dating techniques were used to validate the age of the fossils, resulting in a completely new age estimate of the remains.

Researchers say the results confirm the skulls belong to the oldest known population of early humans with Neanderthal features.

Potassium-argon dating, Argon-argon dating, Carbon (or Radiocarbon), and Uranium series. All of these methods measure the amount of radioactive decay of chemical elements; the decay occurs in a consistent manner, like a clock, over long periods of time.

At the cave site of Jebel Irhoud, researchers discovered the fossil remains of five individuals dating back , years. They were found alongside stone tools, animal bones and charcoal, indicating the controlled use of fire. This discovery pushes back the oldest fossil evidence of our own species by , years—the previous oldest Homo sapiens remains came from Omo Kibish, in Ethiopia, and date to , years ago.

Keep up with this story and more by subscribing now Two studies announcing the findings have been published in the journal Nature. In one, scientists document the morphological features of the fossils , showing how this early version of a human would have looked remarkably like what we do today. The other paper focuses on the dating of the site , with scientists using new techniques to establish how old the tools and remains were.

The fossils unearthed are not true Homo sapiens, the researchers note.

7. Do Dating Techniques Prove the Earth is Old?