Fossil Record and Evolution

Fossil Record and Evolution

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. A graph of the average fitness of a population in relation to the frequencies of genotypes in it. Peaks on the landscape correspond to genotypic frequencies at which the average fitness is high, valleys to genotypic frequencies at which the average fitness is low. Also called a fitness surface. A behavior has adaptive logic if it tends to increase the number of offspring that an individual contributes to the next and following generations. If such a behavior is even partly genetically determined, it will tend to become widespread in the population. Then, even if circumstances change such that it no longer provides any survival or reproductive advantage, the behavior will still tend to be exhibited — unless it becomes positively disadvantageous in the new environment.

Discovery of new fossil from half billion years ago sheds light on life on Earth

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.

Analyze and interpret data for patterns in the fossil record that document the existence, diversity, extinction, and change of life forms throughout the history of life on Earth under the assumption that natural laws operate today as in the past.

Dating the Fossil Record Activity. Record the samples in order from bottom to top oldest to youngest in. Write an X in the appropriate column to indicate which fossil or fossils are present in each sample. You have received nine rock samples from a paleontologist in California. Your job is to arrange the. Dating the key fossil record worksheet. Have had some measure of success, i told him, you know, i think there actually is a dating guide for our era of free.

Dating the fossil record worksheet answers. Detailing demographics and preferences of its south african inception in the year with the sole aim of reducing. Dating the Fossil Record.

Extinction event

Human Evolution Evidence Evidence of Evolution Scientists have discovered a wealth of evidence concerning human evolution , and this evidence comes in many forms. Thousands of human fossils enable researchers and students to study the changes that occurred in brain and body size, locomotion, diet, and other aspects regarding the way of life of early human species over the past 6 million years. Millions of stone tools, figurines and paintings, footprints, and other traces of human behavior in the prehistoric record tell about where and how early humans lived and when certain technological innovations were invented.

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.

Anabaena The Three Domains of Life As previously noted, stromatolites are most often described as biogenically-produced structures formed by colonies of photosynthesizing cyanobacteria. However, this is an enormous oversimplification given that the weight of scientific evidence suggests that all three domains of life the Archaeans, Eubacteria, and Eukaryotes appeared in the Archaean Era, and thus the so-called microbial mats would have contained representatives among all three domains.

Just how and when the base of the tree of life split into the three main branches remains one of the most important questions in all of biology and science, and is the source of constant scientific dispute. Which of the prokaryotes came first, the Archaeans or the Eubacteria remains unresolved, and a consensus has emerged that these primitive microorganisms laterally exchanged genes further confounding attempts to validate what begat what during to course of early evolution on earth.

Lateral gene transfer belies the concept of the single common ancestor see Woese, While formation by colonies of cyanobacteria is probably the primary mechanism for formation of surviving stromatolites in the deep time of the Archaean and half way through the Proterozoic, it is unlikely to have been the only mechanism. Recent research Gupta, a, b, and an extensive literature indicates the other prokaryotic and the most genetically diverse domain of life, the Archaeans , evolved alongside each other and possibly swapped genes with the Eubacteria.

All prokaryotes both Eubacteria and the Archaeans reproduce by cell division binary or multiple fission and, lacking sex, are essentially clones and among the slowest evolving organisms.

Seventh grade Lesson Evidence for Evolution

January 30, , University of Leicester Scientists from universities of Leicester and Cambridge find an ‘unfossilizable’ creature. To their surprise, the samples yielded miniscule loriciferans: Moreover, the fossils date to the late Cambrian Period, meaning they lived around half a billion years ago. This suggests that soon after the origin of animals, some groups were adopting specialized “meiobenthic” lifestyles, living among grains of sediment on the seabed.

Materials Set of 9 rock sample cards colored markers/pencils register tape Life Science: Dating the Fossil Record Activity Name Per.

C use the school’s technology and information systems in a wise and ethical manner. B know that scientific hypotheses are tentative and testable statements that must be capable of being supported or not supported by observational evidence. Hypotheses of durable explanatory power which have been tested over a wide variety of conditions are incorporated into theories; 2. C know that scientific theories are based on natural and physical phenomena and are capable of being tested by multiple independent researchers.

Unlike hypotheses, scientific theories are well-established and highly-reliable explanations, but may be subject to change as new areas of science and new technologies are developed; 2. D distinguish between scientific hypotheses and scientific theories; 2. G organize, analyze, evaluate, make inferences, and predict trends from data; 2. I communicate valid conclusions supported by data using several formats such as technical reports, lab reports, labeled drawings, graphic organizers, journals, presentations, and technical posters.

A in all fields of science, analyze, evaluate, and critique scientific explanations by using empirical evidence, logical reasoning, and experimental and observational testing, including examining all sides of scientific evidence of those scientific explanations, so as to encourage critical thinking by the student; 3. B communicate and apply scientific information extracted from various sources such as current events, news reports, published journal articles, and marketing materials 3.

D evaluate the impact of research on scientific thought, society, and public policy 3.


Graphs, charts, and images can be used to identify patterns in data. Hook 15 minutes To start this lesson I display the following image. I then tell the students that today we will begin to explore the evidence we have for evolution, and play Stated Clearly’s movie, What is the Evidence for Evolution. I stop the movie at 3:

“The origin of life, at least on a planet like ours, is a lot faster, and you think a lot easier than anyone had imagined. To the extent that that is true, life ought to be abundant in the.

See Article History 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 environments. To date past events, processes, formations, and fossil organisms, geologists employ a variety of techniques. These include some that establish a relative chronology in which occurrences can be placed in the correct sequence relative to one another or to some known succession of events.

Radiometric dating and certain other approaches are used to provide absolute chronologies in terms of years before the present. The two approaches are often complementary, as when a sequence of occurrences in one context can be correlated with an absolute chronlogy elsewhere. Ankyman General considerations Distinctions between relative-age and absolute-age measurements Local relationships on a single outcrop or archaeological site can often be interpreted to deduce the sequence in which the materials were assembled.

This then can be used to deduce the sequence of events and processes that took place or the history of that brief period of time as recorded in the rocks or soil. For example, the presence of recycled bricks at an archaeological site indicates the sequence in which the structures were built. Similarly, in geology, if distinctive granitic pebbles can be found in the sediment beside a similar granitic body, it can be inferred that the granite, after cooling, had been uplifted and eroded and therefore was not injected into the adjacent rock sequence.

Although with clever detective work many complex time sequences or relative ages can be deduced, the ability to show that objects at two separated sites were formed at the same time requires additional information. A coin, vessel, or other common artifact could link two archaeological sites, but the possibility of recycling would have to be considered. It should be emphasized that linking sites together is essential if the nature of an ancient society is to be understood, as the information at a single location may be relatively insignificant by itself.

Radiometric Dating and the Geological Time Scale

At higher temperatures, CO 2 has poor solubility in water, which means there is less CO 2 available for the photosynthetic reactions. The enrichment of bone 13 C also implies that excreted material is depleted in 13 C relative to the diet. This increase in 14 C concentration almost exactly cancels out the decrease caused by the upwelling of water containing old, and hence 14 C depleted, carbon from the deep ocean, so that direct measurements of 14 C radiation are similar to measurements for the rest of the biosphere.

Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of the biosphere, gives an apparent age of about years for ocean surface water.

Life science dating the fossil record activity answers These fossils. A fossil finds over 50 find the age of fossils and evidence for love is a great activity and activities for the question.

Measurement of N, the number of 14 C atoms currently in the sample, allows the calculation of t, the age of the sample, using the equation above. The above calculations make several assumptions, such as that the level of 14 C in the atmosphere has remained constant over time. The calculations involve several steps and include an intermediate value called the “radiocarbon age”, which is the age in “radiocarbon years” of the sample: Radiocarbon ages are still calculated using this half-life, and are known as “Conventional Radiocarbon Age”.

Since the calibration curve IntCal also reports past atmospheric 14 C concentration using this conventional age, any conventional ages calibrated against the IntCal curve will produce a correct calibrated age. When a date is quoted, the reader should be aware that if it is an uncalibrated date a term used for dates given in radiocarbon years it may differ substantially from the best estimate of the actual calendar date, both because it uses the wrong value for the half-life of 14 C, and because no correction calibration has been applied for the historical variation of 14 C in the atmosphere over time.

The different elements of the carbon exchange reservoir vary in how much carbon they store, and in how long it takes for the 14 C generated by cosmic rays to fully mix with them. This affects the ratio of 14 C to 12 C in the different reservoirs, and hence the radiocarbon ages of samples that originated in each reservoir.


Biological evolution is change in the characteristics of living organisms over generations. Despite your vastly superior tastes in music and fashion, you probably look vaguely like your parents, just as they look vaguely like their parents. For all of recorded history, people have looked more or less the same: Hairdos differed, but the basic body plan stayed the same for as far back as the history books go.

Fossil Record Activity Name Per.. You have received nine rock samples from a paleontologist in Georgia. Your job is to arrange the samples in order from oldest to youngest (Number pictures from 1-oldest to 9-youngest) according to their fossil content and to determine their relative ages using the .

For example, rock layers show the sequence of geological events, and the presence and amount of radioactive elements in rocks make it possible to determine their ages. Analyses of rock formations and the fossil record are used to establish relative ages. In an undisturbed column of rock, the youngest rocks are at the top, and the oldest are at the bottom. Rock layers have sometimes been rearranged by tectonic forces; rearrangements can be seen or inferred, such as from inverted sequences of fossil types.

The rock record reveals that events on Earth can be catastrophic, occurring over hours to years, or gradual, occurring over thousands to millions of years. Records of fossils and other rocks also show past periods of massive extinctions and extensive volcanic activity. Although active geological processes, such as plate tectonics link to ESS2. B and erosion, have destroyed or altered most of the very early rock record on Earth, some other objects in the solar system, such as asteroids and meteorites, have changed little over billions of years.

Page Share Cite Suggested Citation: A Framework for K Science Education: Practices, Crosscutting Concepts, and Core Ideas. The National Academies Press.


Badlands near Drumheller , Alberta , where erosion has exposed the K—Pg boundary Trilobites were highly successful marine animals until the Permian—Triassic extinction event wiped them all out In a landmark paper published in , Jack Sepkoski and David M. Raup identified five mass extinctions. They were originally identified as outliers to a general trend of decreasing extinction rates during the Phanerozoic, [5] but as more stringent statistical tests have been applied to the accumulating data, it has been established that multicellular animal life has experienced five major and many minor mass extinctions.

Permian—Triassic extinction event End Permian: The evidence regarding plants is less clear, but new taxa became dominant after the extinction. The whole late Permian was a difficult time for at least marine life, even before the “Great Dying”.

Dr Tom Harvey from the Department of Geology, University of Leicester, together with Professor Nicholas Butterfield, University of Cambridge, discovered the new species while conducting a survey.

Yuri Amelin Scientists probing a newly exposed, formerly snow-covered outcropping in Greenland claim they have discovered the oldest fossils ever seen, the remnants of microbial mats that lived 3. It’s a stunning announcement in a scientific field that is always contentious. The site is known for having some of the oldest rocks on Earth, in what is known as the Isua supracrustal belt. Allen Nutman, a University of Wollongong geologist who has studied the rocks there since , said one day he and his colleagues were working at the site when they spied some outcroppings they’d never seen before.

The formations had been exposed where the snow pack had melted — the result, Nutman said, of the global warming that is so pronounced in Greenland or of low levels of snowfall the previous winter. They examined the outcropping and immediately saw something intriguing: They look like fossilized microbial mats — basically, pillows of slime — known as stromatolites, which are formed today by bacterial communities living in shallow water.

Burning All Fossil Fuels Would Push CO2 to Levels Last Seen Before Forests

Scientific measurements such as radiometric dating use the natural radioactivity of certain elements found in rocks to help determine their age. Scientists also use direct evidence from observations of the rock layers themselves to find the relative age of rock layers. Specific rock formations are indicative of a particular type of environment existing when the rock was being formed. For example, most limestone represents marine environments, whereas, sandstones with ripple marks might indicate a shoreline habitat or riverbed.

The study and comparison of exposed rock layers or strata in different areas of Earth led scientists in the early 19th century to propose that the rock layers could be correlated from place to place. Locally, physical characteristics of rocks can be compared and correlated.

Aboslute age dating Fossil Geologists Half-life Relative age dating HELPFUL TERMS Paleontologists Isotope Radioactive decay Determining the Age of Rocks and Fossils 1 New York State Standards 1 Inside This Packet New York State Standards Middle School Activity Activity: Relative Age of Rocks Earth Science – Post Module 3 Middle School Page.

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.

Dating the Fossil Record

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