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What is the Fossil Record?

Animals that went extinct before the rise of humans, such as dinosaurs, are known only through the fossil record.
Fossils can reveal how living animal types, such as fish, evolved over time.
Fossilized footprints can reveal information about an extinct animal's behavior.
The fossil record has been used to determine that marsupial mammals, like koalas, branched off from placental mammals as far back as 125 million years ago.
Examination of the fossil record led paleontologists and ornithologists to conclude that birds descended from dinosaur lineages.
Neanderthal remains predate those of modern Homo Sapiens in the European fossil record.
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The fossil record is the collective accumulation of the remains of organisms that have been preserved, particularly in rock, all over the world, and which are generally at least 10,000 years old. When viewed as a whole, it can provide interesting information about the evolution of life on Earth. Scientists consider the remains they have found to be extremely precious and apply what they learn from them into multiple disciplines. They routinely try to fill in gaps in the record to have a better understanding of the world.

What Scientists Look At

Perhaps most obviously, people look at the fossil record, in whole or in part, to learn about the organisms that have been preserved. They often try to piece together how living things interacted from this basic information. Two related areas that also get attention, however, are the exact placement of the fossils in the Earth and how they were created. These elements provide clues about things such as migration and habitat, date of life and geological and meteorological conditions, structures or events. This type of study, therefore, is important to many different scientific areas.

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How Fossils Form

When an organism dies, it typically gets buried. This usually takes time, but it can happen faster in cases where living things fall into pits or similar structures, and as more layers of sediment are added, pressure increases, causing the sediments to compact into rock. As the body decays, minerals seep into the it, filling the spaces where gases or fluids used to be — this is known as permineralization. Alternately, the minerals that are in it chemically break down and are reformed or replaced. Eventually, most or all of what is left is a rock-like copy of the body.

Sometimes, organisms are preserved in substances such as amber, ice or tar, as well. Occasionally, imprints get filled with sediments that harden into rock, creating natural molds or casts. A good example is animal footprints.

Frequency of Fossilization

Nature has evolved a very complex and highly efficient system for recycling materials, so when things die, they generally decay with the assistance of a wide variety of other organisms and the elements. They can only be preserved without artificial help, therefore, when conditions are just right to stop this breakdown process. As a result, this type of preservation is extremely rare, with only a fraction of the billions of organisms that have lived on Earth included in the fossil record, which makes studies of the past extremely challenging.

The rarity of preserved remains makes them extremely valuable from the scientific standpoint. In many cases, scientists have only one fossil as an example of an organism, and they consider these to be the most precious. Museums guard what they do have strictly, often with advanced technology, and normally, they display only a few prized pieces from their collections to illustrate main points in evolutionary history.

Diversity

Despite the fact that a small number of living things are preserved as fossils, the diversity of those creatures is significant, and people recognize that what has been found is only a small percentage of what is available for discovery. Paleontologists and related scientists have located remains ranging from microscopic bacteria to massive mammals, with dinosaurs being perhaps the most well-known. Comparing this evidence to modern-day ecosystems, people know that ancient Earth was not the same as it is today, but the question of why certain life forms became extinct is still one of the mysteries of science.

Collection

Scientists collect fossils in a variety of ways, depending on the type of rock or soil in which they are found. Some excavations require tools such as hammers and chisels, while others use soft brushes and controlled water washes. It is common for those involved to use screens to sift smaller pieces out of the dirt, and sometimes it is necessary to prevent damage or erosion with plaster casts, cloth or tarps and similar methods. Cleaning is usually the last step in the actual collection process, but the work with the record continues, involving dating, preserving and cataloging.

Debate and the Search for New Information

As is often the case with science, the fossil record is not without controversy. Many individuals question certain conclusions that have been reached with it, suggesting that more information is needed. Until accurate dating techniques could be created, for example, some people were under the impression that all of the organisms that were fossilized lived at the same time. It has also been a bone of contention in the debate over evolution and the age of the Earth.

In an effort to resolve points of contention, many scientists travel all over the world every year, conducting research and excavations in the hope that the accumulation and study of more fossils will reveal even more history. The closure of information gaps would be a major breakthrough in science, explaining how earlier life on Earth diverged to create the incredibly diverse range of organisms that can be found today.

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Discuss this Article

anon334209
Post 16

@Glassaxe: "Creationist Logic..." Good luck finding that. Let me know if you find any honest politicians while you're at it!

anon310283
Post 13

Religion and science do not need to be in conflict; it depends on the religion.

From my own experience the conflict arises in Judeo-Christian faiths because science conflicts with the writings of various prophets/apostles. Other faiths do not necessarily attempt to answer the question "How did we get here?" Sikhism as example (my faith) is the youngest major religion in the world and its theology sits equally well with the theory of evolution or the likelihood of life on other planets.

Guru Nanak, the founder of the Sikh faith, talked of planets beyond planets and moons beyond moons, suns beyond suns and seas and lands beyond measure throughout universe(s) that we could not comprehend. He wrote this over 500 years ago.

I am not pushing a faith, by the way. Sikhism doesn't believe in conversion and does not claim to have a monopoly on wisdom. It believes that all faiths can lead to salvation, so what would be the point of conversion? It also is critical of the excesses of organised religion and doesn't base the concept of salvation on the adoption of any particular faith.

anon298940
Post 12

This argument of Creation vs Big Bang (or any other attempted hypothesis) I have always found very interesting. It seems that creationists seem to neglect the facts that nothing can be created or destroyed (chemistry 101) and attribute creation to "Divine Power". Naturalists have many different ideas which I will simply use Big Bang to cover them all. I realize there are others and they are not all the same.

Now here is the mind blowing thought of the day: what if these two hypotheses actually go hand in hand? What if there is a Divine Power or God and tools such as the Big Bang are simply at his command?

Is it really thought that at the snap of his fingers a planet appeared out of thin air? Or is it more plausible that the unlikely event of complex beings such as humans with the less than 0.000001 percent chance of perfect circumstances coming about naturally was just a random freak of nature because the cosmos aligned perfectly?

Perhaps there is a God and these are his tools, and physics and chemistry are laws he manipulates as creation tools. He didn't just summon rock and water out of thin air or manually put the atoms together perfectly. Perhaps on another planet that existed before this one dinosaurs lived, other animals lived, then when that planet was destroyed, pieces of it were used to create this one, hence the millions of years of verifiable carbon-dating.

I'm not saying I have all the answers or that I am even correct, but when you critically think about natural laws and creation, then weigh in a little faith, you can see that it is entirely plausible for the two different views to actually support each other, rather than disprove one another.

anon158719
Post 10

cataloging is spelt incorrectly. the correct grammar is cataloguing but other than that, a very factual piece of information and a very interesting insight into the world of fossils.

Moderator's reply: Thank you for visiting wiseGEEK and for contributing to the discussion forums.

Most of our writers are from the United States and "cataloging" is the form most commonly seen in the U.S. According to the Merriam-Webster Dictionary, both spellings are correct. Thanks again for reading!

anon154688
Post 9

The Bible account of creation does not include the literal earth, only life on it. The earth is probably billions of years old while life only a few thousand. Why do fossils date life otherwise? Because fossils are mineralised "copies" of decayed life, not life itself. They are made up of earthly elements which are billions of years old. So a "fossil" is extremely old, but the creature it "copied" is not. The vast majority of life has come and gone without being preserved or fossilized so fossils tell us very little about anything. Some will argue that dating fossils is almost a pointless venture.

anon152330
Post 8

In response to the creationist viewpoint/explanation, I think that instead of the layers being formed over millions of years,creationist believe the earth underwent a traumatic event (i.e. the flood, meteor hits, pangea etc.) and that the geological terrain we see today is the product of that event, including the re-distribution of massive amounts of water and ice, and subsequently the sediment layers thereafter as flood waters receded.

submariner
Post 7

@ GlassAxe- Wow, tackle the controversy head on. I agree that creationism seems a little off. I wouldn't want a school to teach it to my child either. I do believe that people should be free to believe in whatever they please.

Anyway, from what I have read, the literature is a little misleading, and there is a lot of rhetorical devices and fallacies used to argue the point. Supposedly, the idea that evolution occurred is debatable since there have been little or no direct-link species found; species that show one species evolving into another.

I do not know how true this is because in the human fossil record there have been direct-link species and sub-species related to modern humans that have all died off. The point of evolution is that some species will die off while others adapt. Good examples are Neanderthal and more recently Homo floresiensis, which lived alongside modern humans, but died off. Another piece of indisputable evidence is cave art that appeared over 30,000 years ago. All of these artifacts can be dated through radioactive dating, which is a well-understood part of chemistry. Even in the geologically short span of modern humans, people have evolved and changed from what they were like 28,000 years ago.

GlassAxe
Post 6

I have always wondered what the argument to the fossil record is for those who believe in creationism. From what I understand, creationists believe that god created the earth in 6000 years, and the majority of scientists have it all wrong when they say that the fossil record shows more than 500 million years of life.

The argument does not make sense, so I was just wondering if anyone had any creationist logic on this point. How do you explain that there are fossils of plants and animals that are buried very deep in the earth? How do creationists explain that the sediment to bury these would have taken tens of thousands of years, if not millions? I just cannot make sense of it.

anon36827
Post 1

Good information +1

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