10 Advantages and Disadvantages of Fossil Records

Fossils are the preserved remains or traces (like footprints) of organisms. Shells, bones, and teeth are more easily fossilized, but soft things – like ants and mosquitoes – can be fossilized in amber. When scientists talk about the fossil record, they’re talking about the world’s fossils combined. Why should we care about the remains of ancient life forms? Here are five advantages and disadvantages of fossil records:

Advantage #1: Fossil records support evolution

In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection and established the modern theory of evolution. According to Britannica, the discovery of fossil bones in Argentina helped spark Darwin’s curiosity. Through the 1830s, he hunted for fossils, finding four kinds of giant ground sloths, an extinct horse, and a gomphothere, which is an elephant-like creature. These discoveries, along with Darwin’s famous observation of finches, led to the theory of evolution.

Since Darwin’s fossil-hunting adventures, the fossil record has grown significantly and filled in some of the gaps the scientist dealt with. Fossils show organisms evolve while some go extinct, which is part of natural selection. Along with biological and genetic evidence, the fossil record strongly supports evolution.

Advantage #2: Fossil records give insight into Earth’s history

Fossils don’t only teach us about ancient organisms, they have information on Earth as a whole. One of the most interesting insights is how the Earth has changed over time. Fossils of marine animals have been discovered in mountain ranges and deserts, implying these areas were once covered by water. In Madagascar, underwater caves held the remains of giant lemurs the size of gorillas, suggesting either these places were once very different from today or there was some event that brought the specimens into the cave.

Advantage #3: Dating is getting more accurate

For the fossil record to be useful, scientists need their information to be as accurate as possible. Geochronogolists, who are experts in dating fossils and rocks, use several techniques, like radiocarbon dating. Radiocarbon dating is based on the fact that all living things absorb carbon, including radioactive carbon-14. The radioactive carbon inside an organism starts to decay as soon as it dies. By measuring how much carbon remains, scientists can estimate how long something has been dead. Unfortunately, radiocarbon dating can only date so far back in time. Also, as an article in Nature describes, the calculation is based on a consistent amount of carbon-14 in the environment. In reality, the amount hasn’t been consistent, especially as the burning of fossil fuels changes how much carbon-14 is in the air.

A recalibration of radiocarbon dating could give geochronologists better data. The Nature article relates how scientists gathered thousands of data points from corals, tree rings, and more, allowing them to extend the time frame for radiocarbon dating. Now, they can date up to 55,000 years ago, which is 5,000 years longer than the last adjustment in 2013. As dating improves, we’ll get better information about the past.

Advantage #4: The fossil record can help geologists learn about rocks

When trying to learn how old rocks are, geologists often depend on fossils. The lower a fossil is in the layers of sedimentary rock, the older it is. Once fossils get dated, geologists can use relative dating to identify how old the surrounding layers of rock strata are. Relative dating is the most common method for most geologists.

Why is it important to know a rock’s age? Consistent methods allow geologists to communicate using the same system. Using one geologic record, which is the time from Earth’s birth to today (about 4.5 billion years), geologists can more easily collaborate and share discoveries about the Earth’s age and past.

Advantage #5: Fossil records can help experts predict the future

Learning about the past helps us learn about the future. One of the biggest concerns today is the impact of climate change, which is reducing biodiversity and tipping us closer to a Sixth Mass Extinction. Experts examine the past for similar patterns so they can make better predictions.

In 2021, Vanderbilt scientists discovered biogeographic patterns when they simulated “fossil” records alongside the modern distribution of 340 species. This means they used fossil records to identify biodiversity hotspots during past extinction scenarios, learning things like whether species moved around or were at risk as their environments were destroyed. Using this data, scientists can estimate what areas and species will need the most protection. This is just the beginning of this type of research, but it shows how useful the fossil record can be for the future.

Disadvantage #1: Fossils are relatively rare

Paleontologists and amateurs have found a huge number of fossils, but in the grand scope of things, fossils are rare. First, most dead organisms rot away very fast. Next, for fossils to form, a specific process has to unfold. Premineralization is the most common creation process for fossils. The organism is usually covered by sediment – like sand, lava, or tar – not long after death. Normal decay, erosion, and predators can end the fossilization process.

If the remains aren’t disturbed, the organism absorbs minerals like silica from the sediment as time passes. This creates a fossil. Fossilized dinosaur bones, marine fossils, and petrified wood are usually premineralized, but many other specimens never went through fossilization.

Disadvantage #2: Only certain organisms tend to get fossilized

The other issue with the fossil record is how few creatures are represented. The vast majority of fossils are organisms with hard body parts like shells, teeth, and bones. Soft organisms, like insects and worms, rarely go through a fossilization process. When they do, it’s usually through preservation in amber, which is fossilized tree resin. When the resin is still sticky, an insect gets stuck and dies. As the resin hardens, it’s less likely to get destroyed and more likely to get fossilized, preserving the tiny insect corpse inside.

Amber, which has been prized as a gem and folk medicine, is fairly common, but amber that contains a preserved organism is always a thrilling find. In contrast to what the movies say, amber does not preserve DNA and due to how fossilization works, many soft-bodied organisms are missing from the records.

Disadvantage #3: The fossil record is incomplete

Speaking of things missing from the record, the fossil record’s third disadvantage is its incompleteness. Of the small number of creatures made into fossils, paleontologists have likely found only a tiny percentage. Many of the fossils themselves are incomplete; it’s not uncommon to find just a tooth or a single bone. Even when fuller specimens are found, we only have their bones. How do scientists create models with such little information?

Technology helps. A 2012 blog describes how Lawrence Whitmer uses animal dissections to generate animations of dinosaurs. Using a CT scan, he scanned the heads of modern animals and fossilized skulls. Next, his lab dissected the modern animal’s soft tissues, “skeletonizing” it so they could access the signatures left by the soft tissue. With the help of modern anatomy, Whitmer created realistic, animated restorations of creatures long extinct. Work like this helps address the fossil record’s mysteries, but the hard task of finding more fossils continues.

Disadvantage #4: Politics affects the study of the fossil record

Politics touch everything, even paleontology. As a Smithsonian article describes, fossils from places like Mongolia and Tanzania are often removed or smuggled out of the country, cutting off local experts and diverting attention from the region. Not only does this hurt people living today, it weakens the research field. Essential work done by local experts, who know more about the area, where fossils may be, and so on, gets dismissed.

Politics and bias also play a huge role in how researchers and organizations get funded, which can lead to massive gaps in knowledge and progress. While this isn’t a problem with the fossil record itself, it’s important to note how politics affects the study of it.

#5. Fossil record weaknesses can fuel science denial

Science denial, which many religious fundamentalists embrace, has deep roots in disparaging evolution and the fossil record. In 1925, Tennessee passed the Butler Act, which banned the teaching of evolution in all the state’s educational institutions. That same year, educator John Scopes was convicted of violating the law (the verdict was overturned on a technicality) and a decades-long culture war began. When bans on evolution failed, religious groups tried (sometimes successfully) to force “alternatives” like creationism and intelligent design into public schools. They continue to cite gaps in the fossil record as justification, claiming that evolution is a controversial theory (it’s not; most scientists believe it’s accurate) or that the fossil record supports creationism, not evolution. Some groups also present science as an enemy of religion.

Anti-evolution efforts have seeded a deep distrust of science in many communities. We’re seeing its fruit with the anti-vax movement, COVID denialism, and climate change “skepticism.” To combat science denial, scientists and educators must engage with the fossil record’s weaknesses and explain how it’s just one piece of evidence for evolution. Ignoring questions only fuels denial and allows misinformation to spread.

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