Introduction Hominid or hominin? Some scientists use a broader definition of Hominidae which includes the great apes, and instead call the group I am discussing “hominins”. The word “hominid” in this website refers to members of the family of humans, Hominidae, which consists of all species on our side of the last common ancestor of humans and living apes. Hominids are included in the superfamily of all apes, the Hominoidea, the members of which are called hominoids. Although the hominid fossil record is far from complete, and the evidence is often fragmentary, there is enough to give a good outline of the evolutionary history of humans. The time of the split between humans and living apes used to be thought to have occurred 15 to 20 million years ago, or even up to 30 or 40 million years ago. Some apes occurring within that time period, such as Ramapithecus, used to be considered as hominids, and possible ancestors of humans. Later fossil finds indicated that Ramapithecus was more closely related to the orang-utan, and new biochemical evidence indicated that the last common ancestor of hominids and apes occurred between 5 and 10 million years ago, and probably in the lower end of that range Lewin Ramapithecus therefore is no longer considered a hominid. The field of science which studies the human fossil record is known as paleoanthropology.
Primary source references As a preface to this document, I want to point out that it is a shame that we have to continue to refute the same arguments that evolutionists keep bringing up over and over again in their attempts to argue against the fact of creation, which fact has been well established since the day the earth was created ex nihilo several thousand years ago. It is also a shame that the masses have bought all this based on some circular reasoning about fossils, where fossils tend to be found buried, similarities between various life forms, the presence of certain decay products in rocks, and other inherently speculative arguments about the past, based on phenomena that exist in the present.
If I hope to accomplish anything, it will be to simply encourage critical thinking. One must get past the arguments ad populum that its popularity counts for something , ad hominem that if you attack the person making the argument, this counts for something , and especially ad baculum that there are people who have the clout to decree it as true , to ask the key questions and challenge the unsubstantiated assumptions and thinking of those who would hold to the evolution position.
Articles home page Creation vs. Evolution 0. Introduction and table of contents The following is an organized presentation on the creation vs. evolution controversy.
Use the contact form to ask your question about our work and you may see your question — and answer — on this website, or in the ‘ Evolution FAQ’ kiosk in the David H. Koch Hall of Human Origins. How does evolution work? To survive, living things adapt to their surroundings. Occasionally a genetic variation gives one member of a species an edge.
That individual passes the beneficial gene on to its descendents. More individuals with the new trait survive and pass it on to their descendents. If many beneficial traits arise over time, a new species—better equipped to meet the challenges of its environment—evolves. What do scientists mean when they call evolution a theory? Like gravity and plate tectonics, evolution is a scientific theory.
In science, a theory is the most logical explanation for how a natural phenomenon works. It is well tested and supported by abundant evidence. It means quite the opposite from our informal use of the word theory, which implies an untested opinion or guess.
Geologic time scale
Lava tubes form during volcanic eruptions, when the top of a lava flow cools and solidifies but hot melt continues to flow underneath. When lava drains from these tube-like conduits, an empty space is left underground. These tunnels and fissures often contain sediment with fossil remains of terrestrial vertebrates . Here, small lakes and bogs, formed within inactive volcanic craters, can be found. The sediments filling the bottom of these small depressions contain fossil plant material [3, 4].
Rare, but sometimes found in these sediments, are skeletal fragments of marine and terrestrial vertebrates such as birds, lizards, and sea lions [1, 5, 7] Fig.
The age of a fossil may be specified in both relative terms (how old it is in relation to other fossils or rock units) and in absolute terms (approximately how many years old it is). One principle of relative dating is called superposition, which holds that in any one place, the lower rock layers (and fossils in them) are older than higher ones, unless there is evidence that the layers have.
Renaissance Now, let’s look at some specific examples. One type of atom that does not normally react is Neon. See the picture to the left. It already has the correct number of electrons in it’s outside electron layer so Neon does not react. Neon, along with Helium and Argon are known as non-reacting gasses because they do not need to react to be stable. Other types of atoms such as Hydrogen, Carbon, and Oxygen do not have the correct number of electrons to be stable by itself. Instead they have to share electrons in molecules to get the correct number of electrons in their outside electron layer.
Since we only have to look at the atom that is in the center of the molecule to find out it’s shape, we will concentrate only on Carbon and Oxygen. All the molecules illustrated on this page either have a Carbon or an Oxygen as the center atom. Carbon will especially be of interest since Carbon is the center atom for all the different Amino Acids. Both Carbon and Oxygen have a deficiency.
Radiometric Dating and the Geological Time Scale
The only direct way we have of learning about dinosaurs is by studying fossils. Fossils are the remains of ancient animals and plants, the traces or impressions of living things from past geologic ages, or the traces of their activities. Fossils have been found on every continent on Earth, maybe even near where you live. The word fossil comes from the Latin word fossilis, which means “dug up.
Sedimentary rock is rock that has formed from sediment, like sand, mud, small pieces of rocks.
Amino Acid Dating Introduction. Amino acid dating has an important attribute in common with Carbon 14 dating. While most other dating mechanisms date the rock surrounding fossils, both Amino Acid and Carbon 14 dating methods, date the actual fossil itself.
There are many methods employed by these scientists, interested in the old, to get to know the age of items. It is possible to tell the number of years ago a particular rock or archeological site had been formed. Two broad categories of classification methods are relative dating and absolute dating. Though using similar methods, these two techniques differ in certain ways that will be discussed in this article.
As the name implies, relative dating can tell which of the two artifacts is older. This is a method that does not find the age in years but is an effective technique to compare the ages of two or more artifacts, rocks or even sites. It implies that relative dating cannot say conclusively about the true age of an artifact. Absolute dating, on the other hand is capable of telling the exact age of an item using carbon dating and many other techniques that were not there in earlier times.
Accuracy of Fossils and Dating Methods
Lithostratigraphy – vertical changes in lithology rock type. At first glance all Chalk exposures appear similar, and relative to other rock sequences the chalk is pretty homogenous. But there are countless marl clay bands and flint seams, many of which can be traced for hundreds of miles, that can be used as lithological boundaries.
These boundaries allow the chalk to be split into various Formations and Beds; units of rock with similar lithological character. For example, the Seaford Chalk Formation is a unit of pure, soft white chalk with flints situated between Shoreham Marl 2 and Buckle Marl 1. By contrast the West Melbury Marly Chalk Formation is a unit of impure chalk with thick marls and lacking flints.
Against the pure white backdrop of the chalk, certain lithological features are very distinct. Most striking are the flint seams of the White Chalk, but there are also marl seams, phosphatic horizons, and secondary mineralogical features such as pyrite / marcasite nodules and various calcitic crystal growths and speleothems (e.g. stalactites) developed within voids.
Written and designed by Roy Shepherd. Special thanks to my wonderful wife Lucinda Shepherd, friend Robert Randell and various experts for their support. Conserving Prehistoric Evidence Left: A bone block appearing to contain ichthyosaur bones and teeth has been polished rather than more respectfully prepared.
The result is minimally informative and parts of the specimen have been lost. Better results can be achieved using an air-pen or an acid bath. A conscientiously hand-prepared ichthyosaur skeleton from Lyme Regis Dorset , displaying all available anatomical information and retaining the entire specimen. Manual preparation in the way requires significantly more hours of work, however the benefits are clear to see.
Sedimentary Rocks Formation and Fossils!
A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation for example, the large muscles of a weightlifter. Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment. Also used to describe the process of genetic change within a population, as influenced by natural selection.
Humans and monkeys are both humans are not descended from monkeys or any other primate living today. We do share a common ape ancestor with chimpanzees. It lived between 8 and 6 million years ago. But humans and chimpanzees evolved differently from that same ancestor.
Acknowledgements Introduction his document discusses the way radiometric dating and stratigraphic principles are used to establish the conventional geological time scale. It is not about the theory behind radiometric dating methods, it is about their application, and it therefore assumes the reader has some familiarity with the technique already refer to “Other Sources” for more information. As an example of how they are used, radiometric dates from geologically simple, fossiliferous Cretaceous rocks in western North America are compared to the geological time scale.
To get to that point, there is also a historical discussion and description of non-radiometric dating methods. A common form of criticism is to cite geologically complicated situations where the application of radiometric dating is very challenging. These are often characterised as the norm, rather than the exception. I thought it would be useful to present an example where the geology is simple, and unsurprisingly, the method does work well, to show the quality of data that would have to be invalidated before a major revision of the geologic time scale could be accepted by conventional scientists.
Geochronologists do not claim that radiometric dating is foolproof no scientific method is , but it does work reliably for most samples. It is these highly consistent and reliable samples, rather than the tricky ones, that have to be falsified for “young Earth” theories to have any scientific plausibility, not to mention the need to falsify huge amounts of evidence from other techniques. This document is partly based on a prior posting composed in reply to Ted Holden.
Such sentiments are a hallmark of humanity. How Old Is It? The mysteries of what H. In East Africa, fossils can be accurately dated when they are found above or below layers of volcanic ash, whose age can be measured from the clocklike decay of radioactive elements in the ash. At Malapa, Berger had gotten lucky: But the bones in the Rising Star chamber were just lying on the cave floor or buried in shallow, mixed sediments.
These old photographs are of fossil hunters! These people are splitting open pieces of shale. They are looking for fossils in the rock. The layers of the shale split apart, and occasionally reveal the shape of a leaf or an animal in the rock.
After that comes a more difficult process: Finding a fossil merely places one organism within a time span. Finding many organisms places the group within a time span. Determining the actual existence-span of the species is very approximate. If the fossils are relatively rare, the actual existence-span may be much greater that the fossil record indicates. Even if the fossils are relatively abundant during the species’ heyday, the number of organisms may have been small during the time of its appearance on Earth and during its demise.
At these important times, its fossil record might be sparse or nil, causing those times to be under-represented. The oldest method is stratigraphy, studying how deeply a fossil is buried. Dinosaur fossils are usually found in sedimentary rock.