Eocene My And here’s the tree All the names on the tree are genus names, so recall that each genus encompasses a cluster of closely related species. The is a brief description of the tree for those who are visually impaired. Hyracotherium is shown giving rise to three lineages. Two lineages quickly go extinct. The third branches many times. There are many branches alive during most times until two million years ago when only the various species of Equus remain. The tree itself is unreadable to those who are visually impaired so skip the tree graphic. This little animal ” at the shoulder looked nothing at all like a horse. It had a “doggish” look with an arched back, short neck, short snout, short legs, and long tail.
Radiometric Dating and the Geological Time Scale
After mating, the female then builds a nest elsewhere to raise the young alone. Franco Atirador Stephen J. Gould argued that these enormous antlers, which required great mineral resources from plants to support and prevented the elk from navigating through forests, were largely responsible for their extinction. The positioning of the antlers were poor for combat between males, but were great for intimidating rivals and impressing females.
Bird-of-Paradise Bird of Paradise These birds have evolved a wide variety of plumage displays for the sole purpose of attracting a mate. Duck genitalia and mechanical barriers Credit:
Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.
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.
Today there are an increasing number of anti-creationist authors who are producing books and periodicals that make this relatively brief presentation insufficient to deal with all the points in dispute. Those defending creation today who don’t have the time to devote their life’s study to gaining expertise in all fields of inquiry must principally be prepared to think critically, logically, and challenge unsubstantiated assumptions made by these people.
They must also keep a level head in the face of some vicious attacks and diatribes that will be directed against them, as is advised in the scriptures 1 Peter 3: By way of definitions, I want to point out that when I speak of “evolution,” I am referring to the popular contemporary use of the word, which in a nutshell is the belief that all life forms are related by ancestry, and that the first life form occurred spontaneously, all due to completely natural processes.
When I speak of “creation,” I am referring to the inherently obvious fact that the origin of all life forms can be attributed to a creator who purposefully created them with planning and intent, and the documented fact that this occurred over the course of a week’s time several thousand years ago.
List and describe two ways that scientists can date fossils found in the earth?
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.
What are the two methods for dating fossils. Other structures. Dec 8, which only puts geological methods and require radiometric. Question two kinds of glass and beta decay: the spontaneous fission track dating fossils are radiocarbon dating and other.
These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus slowing decomposition. Stromatolites Lower Proterozoic Stromatolites from Bolivia , South America Stromatolites are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms , especially cyanobacteria. While older, Archean fossil remains are presumed to be colonies of cyanobacteria , younger that is, Proterozoic fossils may be primordial forms of the eukaryote chlorophytes that is, green algae.
One genus of stromatolite very common in the geologic record is Collenia. The earliest stromatolite of confirmed microbial origin dates to 2. The most widely supported explanation is that stromatolite builders fell victims to grazing creatures the Cambrian substrate revolution , implying that sufficiently complex organisms were common over 1 billion years ago.
Factors such as the chemistry of the environment may have been responsible for changes. Cyanobacteria as well as extremophile Gammaproteobacteria are thought to be largely responsible for increasing the amount of oxygen in the primeval earth’s atmosphere through their continuing photosynthesis. Cyanobacteria use water , carbon dioxide and sunlight to create their food. A layer of mucus often forms over mats of cyanobacterial cells.
In modern microbial mats, debris from the surrounding habitat can become trapped within the mucus, which can be cemented by the calcium carbonate to grow thin laminations of limestone.
Creation vs. Evolution
More extensive evidence, largely ignored or brushed over by most of the agnostic scientific community, is contained in the excellent book In the Beginning by Walter T. More on that later. Let’s first look at:
Dec 05, · Since the s, Spanish scientists have brought out a wealth of fossils from the cave dating back hundreds of thousands of years. “The place .
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. Skeletal elements from carcasses can be incorporated in beach deposits and eventually become fossilized. Fossils collected from the lava tubes include tens of thousands of bones and bone fragments of birds, reptiles, and mammals, as well as shells of land snails [2, 8, 9].
Bones from larger organisms such as giant tortoises , on the other hand, represent animals that fell and died trapped in the tubes Fig.
Accuracy of Fossils and Dating Methods
The fossils are from fresh rock of a deep highway cutting, and have been metamorphosed to upper greenschist facies like their matrix. Despite metamorphic alteration, total organic carbon of the samples was 0. Organic outlines of the fossils are also accentuated by recystallized berthierine and opaque oxides. The fossils are locally clumped within surface swales of a Vertisol paleosol, identified from characteristic penecontemporaneous deformation clastic dikes between swales of mukkara structure and from pronounced geochemical differentiation phosphorus and copper strain-corrected mass-depletion characteristic of an oxidized biologically active soil.
This paleosol’s chemical composition is evidence of temperate humid climate mean annual temperature
Two major dating methods applied to artifacts and fossils are stratagraphic dating (based upon the particular layer of rock of sediment in which the object is found) or radiometric dating (which is based on the decay rates of certain radioactive isotopes). The type of radiometric dating used depends greatly on the approximate time period you are studying and so varies depending on if the material you are .
What are two ways of dating fossils? Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave fossils. Estimating the dates of these remains is essential but difficult: Classifying ancient organisms is also difficult, as many do not fit well into the Linnean taxonomy that is commonly used for classifying living organisms, and paleontologists more often use cladistics to draw up evolutionary “family trees”.
The final quarter of the 20th century saw the development of molecular phylogenetics , which investigates how closely organisms are related by measuring how similar the DNA is in their genomes. Molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend.
How do fossils and artifacts help teach us about the past? Fossils and artifacts help teach us about the past by providing an idea on when an animal lived or how civilization lived.
Introduction to Geology
Click to share on Tumblr Opens in new window About a month ago, I watched Kendra Harrison break the m hurdles world record in London. I parked that for a later day. So that day has arrived. And so below is a discussion of the world records, and what they mean in the broader context of credibility of the sport.
PROCEDURE A:! Using Cross Sections 1 and 2, determine the sequence of events and order them from oldest to most recent on the Report Sheet. In addition to determining the relative age of .
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.
Our DNA differs by only 1.
Doesn’t Carbon-14 Dating Disprove the Bible?
These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus slowing decomposition. Stromatolites Lower Proterozoic stromatolites from Bolivia , South America Stromatolites are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms , especially cyanobacteria.
While older, Archean fossil remains are presumed to be colonies of cyanobacteria , younger that is, Proterozoic fossils may be primordial forms of the eukaryote chlorophytes that is, green algae.
The CO2 Record in Plant Fossils. Plant fossils obtained from sedimentary rocks and peat deposits are a relatively new tool being used to unravel Earth’s carbon dioxide (CO2) history. Tiny pores on plant leaves and needles called stomata regulate carbon dioxide absorption and water vapor release. Stomata numbers decrease during times of high atmospheric CO2, and increase when atmospheric CO2 is.
Radioactive decay[ edit ] Example of a radioactive decay chain from lead Pb to lead Pb. The final decay product, lead Pb , is stable and can no longer undergo spontaneous radioactive decay. All ordinary matter is made up of combinations of chemical elements , each with its own atomic number , indicating the number of protons in the atomic nucleus. Additionally, elements may exist in different isotopes , with each isotope of an element differing in the number of neutrons in the nucleus.
A particular isotope of a particular element is called a nuclide. Some nuclides are inherently unstable. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. This transformation may be accomplished in a number of different ways, including alpha decay emission of alpha particles and beta decay electron emission, positron emission, or electron capture. Another possibility is spontaneous fission into two or more nuclides.
While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays exponentially at a rate described by a parameter known as the half-life , usually given in units of years when discussing dating techniques. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a “daughter” nuclide or decay product.
In many cases, the daughter nuclide itself is radioactive, resulting in a decay chain , eventually ending with the formation of a stable nonradioactive daughter nuclide; each step in such a chain is characterized by a distinct half-life. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter.
In , in an area called Chalkidiki in Petralona, Northern Greece, a shepherd came across a small opening to a cave, which became visible when a thick covering of snow finally melted. He gathered a group of villagers to help him clear the entrance so they could go inside and explore. They found a cave rich in stalactites and stalagmites. But they also found something surprising — a human skull embedded in the wall later research also uncovered a huge number of fossils including pre-human species, animal hair, fossilized wood, and stone and bone tools.
Figure 2. How relative dating of events and radiometric (numeric) dates are combined to produce a calibrated geological time scale. In this example, the data demonstrates that “fossil B time” was somewhere between and million years ago, and that “fossil A .
Interdisciplinary investigations of skeletal remains from the Neander Valley, Germany. At least three individuals are represented in the skeletal sample. Radiocarbon dates for Neandertal 1, from which a mtDNA sequence was determined in , and a second individual indicate an age of 40, yr for both. Computers have brought new life to fossil studies.
Instead of just examining bones, researchers now digitize them, then fill in missing pieces, add flesh, and simulate gait and other features. This tutorial describes work using computer-assisted paleoanthropology to study Neandertals. Fossils are put through a computed tomography scan, reconstructed in 3D, then compared with modern humans.
This photo is from one of many extremely interesting and thought provoking graphics at this website. Two New Neanderthals Turn Up: