The complex of data recorded in fossils worldwide—known as the fossil record —is the primary source of information about the history of life on Earth. Smilodon; sabre-toothed tigerA discussion of California fossils—notably those of sabre-toothed tigers and the Smilodon—in the University of California Museum of Paleontology’s collection on the Berkeley campus. Displayed by permission of The Regents of the University of California. Only a small fraction of ancient organisms are preserved as fossils, and usually only organisms that have a solid and resistant skeleton are readily preserved. Most major groups of invertebrate animals have a calcareous skeleton or shell e. Other forms have shells of calcium phosphate which also occurs in the bones of vertebrates , or silicon dioxide. A shell or bone that is buried quickly after deposition may retain these organic tissues, though they become petrified converted to a stony substance over time. Unaltered hard parts, such as the shells of clams or brachiopods, are relatively common in sedimentary rocks , some of great age.
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.
Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods. Some critics, particularly religious fundamentalists, argue that neither fossils nor dating can be trusted, and that their interpretations are better.
Giant handaxes suggest that different groups of early humans coexisted in ancient Europe February 23, by Martina Demuro, Lee Arnold And Mathieu Duval, The Conversation Researchers work on the archaeological site in Spain, known as Porto Maior, where the tool deposits were found. An exceptionally high density of giant handaxes dated to , , years ago has been uncovered at an archaeological site in Galicia, northwest Spain.
The findings are documented in a new article published by our international research team of archaeologists and dating specialists. The discovery of these handaxes suggests that alternative types of stone tool technologies were simultaneously being used by different populations in this area — supporting the idea that a prehistoric “Game of Thrones” scenario existed as Neanderthals emerged in Europe.
Additional evidence for this idea comes from fossil records showing that multiple human lineages lived in southwest Europe around the same time period. The archaeological site at Porto Maior preserves an ancient stone tool culture known as the Acheulean. Characterised by symmetrically knapped stones or large flakes known as bifaces , the Acheulean is the first sophisticated handaxe technology known in the early human settlement record of Europe.
While Acheulean sites are widespread across the continent, Porto Maior represents Europe’s first extensive accumulation of large cutting tools LCTs in the Acheulean tradition. Until now, such high densities of LCTs had only been found in Africa.
Amino Acid Dating. Is it reliable
Fossil and fossilization Photo by: Bastos A fossil is the remains or traces of a once-living plant or animal that was preserved in rock or other material before the beginning of recorded history. The term also is used to describe the fossil fuels oil, coal, petroleum, and natural gas that have been formed from the remains of ancient plants and animals.
One of the very foundations of evolution and popular science today is the “geologic column.” This column is made up of layers of sedimentary rock that supposedly formed over millions and even billions of .
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.
Everything Worth Knowing About Scientific Dating Methods This dating scene is dead. The good dates are confirmed using at least two different methods, ideally involving multiple independent labs for each method to cross-check results. Sometimes only one method is possible, reducing the confidence researchers have in the results. Methods fall into one of two categories: These methods — some of which are still used today — provide only an approximate spot within a previously established sequence:
Dating, in geology, determining a chronology or calendar of events in the history of Earth, using to a large degree the evidence of organic evolution in the sedimentary rocks accumulated through geologic time in marine and continental date past events, processes, formations, and fossil organisms, geologists employ a variety of techniques.
Exceptional preservation How fossils are formed Fossilisation only happens in the rarest of cases, when a plant or animal dies in the right circumstances. Animal corpses are usually eaten by something, or bacteria rots them away before fossilisation can occur, and even hard parts like bones and shells are eventually destroyed through erosion and corrosion. The trick to becoming a fossil is to die in a location where your body – or bits of it – are protected from scavengers and the elements.
This means getting buried in sand, soil or mud and the best place for that is on the seabed or a river bed. Only in very rare cases do the soft parts of animals – the flesh, skin and internal organs – become fossils. Even when buried under mud or soil, decay still takes place, though lack of oxygen does slow it down. If a skeleton is dug up at this stage, it will still be made of bone.
Remains like these that haven’t truly fossilised yet are sometimes called ‘sub-fossils’. As more time passes, sub-fossils become buried deeper and deeper.
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.
“Misliya is an exciting discovery,” says Rolf Quam, Binghamton University anthropology professor and a coauthor of the study. “It provides the clearest evidence yet that our ancestors first.
Revising the story of the dispersal of modern humans across Eurasia December 7, Most people are now familiar with the traditional “Out of Africa” model: Two ancient human fossils from Laos reveal early human diversity April 8, An ancient human skull and a jawbone found a few meters away in a cave in northern Laos add to the evidence that early modern humans were physically quite diverse, researchers report in PLOS ONE.
Ancient teeth raise new questions about the origins of modern man February 9, Eight small teeth found in a cave near Rosh Haain, central Israel, are raising big questions about the earliest existence of humans and where we may have originated, says Binghamton University anthropologist Rolf Quam. Modern humans emerged far earlier than previously thought October 25, PhysOrg.
Recommended for you Excavators find tombs buried in Bolivia years ago November 17, Archaeologists say they found tombs at a Bolivian quarry containing remains from more than years ago that give an insight into the interaction of various peoples with the expanding Inca empire. Laser technology uncovers medieval secrets locked in Alpine ice core November 16, A new study has found ground-breaking evidence from an ice core in the Swiss-Italian Alps that proves the 7th century switch from gold to silver currencies in western Europe actually occurred a quarter of a century earlier Tiny raptor tracks lead to big discovery November 16, Tracks made by dinosaurs the size of sparrows have been discovered in South Korea by an international team of palaeontologists.
Preventing chemical weapons as sciences converge November 15, Alarming examples of the dangers from chemical weapons have been seen recently in the use of industrial chemicals and the nerve agent sarin against civilians in Syria, and in the targeted assassination operations using VX Twitter use influenced by social schedules, not changing seasons and daylight November 15, An analysis of Twitter data from the U. The data reflect the amount of “social jet lag” caused when social demands make people wake Neanderthals faced risks, but so did our ancestors November 14, Life as a Neanderthal was no picnic, but a new analysis says it was no more dangerous than what our own species faced in ancient times.
Unreliability of Radiometric Dating and Old Age of the Earth
By Jared Skye BA Environmental Science Sustainable development is a difficult subject to pin down since it encompasses so many different things. Due to the complexity of this subject, it’s important to look at the importance of sustainable development in a holistic way that approaches the issue rationally. What Is Sustainable Development? Sustainable development is an approach to development that takes the finite resources of the Earth into consideration. This can mean a lot of different things to different people, but it most commonly refers to the use of renewable energy resources and sustainable agriculture or forestry practices.
Index fossil: Index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment. A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide .
This discovery should be no surprise to those who take Genesis as literal history. The Bible clearly describes a global Flood that affected all land masses—why should Antarctica be an exception? Dinosaur and mosasaur massive swimming reptiles fossils occur on every continent including Antarctica. Secular science even admits Antarctica was not always cold in the past. Millions of years ago,3 when the continent was still part of a huge Southern Hemisphere landmass called Gondwana, trees flourished near the South Pole.
Thus, the entire globe was warmer in the pre-Flood world. Gulbranson and his team think the fossil trees they found are about million years old,3 which places them in Permian System strata. The secular science community has no viable answers to explain remarkable finds like these. These trees were buried rapidly1 during the global Flood described in Genesis. Temperate and tropical plants and animals were caught up and quickly buried in the ash, mud, and sand that engulfed them in this cataclysmic event.
We do not advocate these dates of millions of years as accurate.
The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods.
The standard approach to looking at fossils in the geological column is to assume that lower is older. Since the geologic column represents millions of years of Earth’s history, then obviously the fossils in each of the layers must be the same age as the layer in which they are found. What is especially interesting is that the fossils do appear to show a progression from the most “simple” of.
What about the fact that the “simple” organisms are buried in the lower levels and the more “complicated” ones are buried in the higher levels? Doesn’t this fact support the notion that simple organisms evolved into more and more complex organisms over time, with the more complex organisms buried and fossilized above the earlier and simpler life forms? Certainly this seems like a very logical assumption. But, things just aren’t that easy. There are a number of potential problems with this interpretation of the fossil record.
For example, it is interesting to note that some general kinds of fossilized creatures are very generally found in the same relative vertical orientation, with respect to each other in the fossil record, that they would have naturally been found in during life. Single celled organisms make their first appearance in the lowest layers followed by multicelled ocean bottom-dwelling creatures like sponges and worms etc. Higher up come creatures like bony fishes, then land plants and animals, then birds and larger land animals.
Of course, this is a very general pattern and does not explain why certain creatures that lived on the bottoms of oceans, like trilobites, make their first appearance in the Cambrian Ma while other creatures that live on ocean bottoms, like crabs and lobsters, don’t appear until the beginning of the Cretaceous Ma. If the geologic column truly represents a series of closely spaced catastrophic burial events instead of long ages of time, how can this feature be explained?
Certainly this seems like a difficult and rather mysterious problem for those, like myself, who might think to question the long age notion of the fossil record. At least a partial explanation might be found in the fairly recently discovered fact that at least some nested hierarchical patterns to the distribution of different populations both living and within the fossil record seem to be strongly related to ecological and population-size factors.