Paleoecology

views updated Jun 11 2018

Paleoecology

Paleoecology is the branch of paleontology that studies ancient organisms and their environments. Paleoecologists study the physical structure and biological functions of organisms, their interactions with each other, and their role in ancient ecosystems. In addition to the basic principles of paleontology, paleoecology research depends on concepts from biology, sedimentology, and geochemistry. The goals of paleoecology are to understand the details of ancient environments and the functioning of ancient ecosystems and their evolution.

The primary database for paleoecological studies is the fossil record. For example, by studying fossils and comparing them with similar living organisms, paleoecologists attempt to understand how the fossil organism lived and its ecological duties. If no living organism is analogous to a fossil, an engineering approach may be taken. This involves constructing models of the fossil and testing how it behaves under various environmental conditions. In this way, the researcher can determine why the organism evolved that particular combination of body shape, density, size, etc., and what type of environment it probably inhabited.

An organisms fossilized hard parts (for example, the shell of a clam), through their composition, provide clues to the environment as well. A clam shells trace element content relates to the concentration of trace elements in the aquatic environment. The concentration in the environment is a product of environmental variables such as salinity and water temperature. So, by studying the trace element chemistry of a fossil, it may be possible to determine the approximate climatic conditions where the organism lived, as well as its latitude.

In addition to body fossils, paleoecologists study trace fossils. These are things like footprints, gopher burrows, or worm trails preserved in sediments. Trace fossils indicate the behavior of the organismthat made the trace and physical factors about the environment.

For example, a trail of dinosaur footprints preserved in stream bed sediments provides evidence of how fast the dinosaur was moving, based on spacing of the prints. The depth of the footprints suggests how soft the sediments were, and hence, whether the stream bed was dry at the time the dinosaur traversed it.

Unlike ecologists, paleoecologists must cope with a very incomplete database, because many organisms do not easily fossilize. The evidence that is available to paleoecologists is also misleading at times. For example, a dinosaur nest discovered in the 1923the first ever foundcontained several broken dinosaur eggs. The remains of a small, previously unknown dinosaur, later named Oviraptor, were also found nearby. Certain skeletal characteristics of this dinosaur lead researchers to conclude that it was in the act of stealing eggs when it died, hence the name Oviraptor (egg plunderer). In 1993, evidence from another nest illustrated that rather than stealing some other dinosaurs eggs, Oviraptor was brooding on its own nest.

As this example illustrates, perhaps more so than in any other science, old interpretations sometimes must be revised to accommodate new data or theories. However, overall, paleoecology is crucial to our understanding of the long and diverse history of life on earth.

Paleoecology

views updated May 14 2018

Paleoecology

Paleoecology is the study of fossil organisms and their relationship to ancient environments. Paleoecology falls under the broader category of paleontology (the study of fossils). A person who studies and investigates paleoecology is called a paleoecologist. The study of paleoecology is important to scientists because it reveals so much about such natural aspects of ancient history as wind conditions, climates, temperatures, and ocean activity. Critical to the field of paleoecology is the intense concentration of chemicals found in fossils; such chemical data reveals much information about the world of long, long ago.

The field of paleoecology was developed by American geologist (a person who studies the history of Earth) Kirk Bryan (18881950). Bryan focused his investigations on weather changes from the past by using information from ancient soils and pollen. His work gathered enough interest from the scientific community to help develop the field of paleoecology.

Paleoecologists can find clues about the ancient environment and the organisms that lived during a particular time on Earth by examining fossil organisms, the different varieties of those fossils, and the sediment in which they were found. Sediment is made up of rock particles, minerals, and fossil organisms that, due to the forces of weather and time, have deposited on top of each other, forming layers. These layers compress and harden, forming sedimentary rock.

Sediment also collects at the bottom of an estuary (area of water where the sea meets a river). Each layer of sediment represents a piece of time in history. Paleoecologists take core samples of the sedimentby pushing a tube down into the estuary and pulling out a sample of the muddy bottomthat provide a historical record of the past. Material found closest to the top of the tube is the youngest sediment; material near the bottom of the tube sample is the oldest. (The idea of sediment layers is similar to that of tree rings, which reveal the age of a tree.)

For example, marine (sea-dwelling) fossils have a significant accumulation of chemicals in their skeletons. By studying these chemicals, paleoecologists can draw conclusions about what was happening in the environment and what was living in the areas surrounding oceans. Because

of what is recorded in fossils found in water environments, paleoecologists most frequently study these types of fossils.

Words to Know

Fossils: The remains, traces, or impressions of living organisms that inhabited Earth more than ten thousand years ago.

Paleontology: The scientific study of the life of past geological periods as known from fossil remains.

Sediment: Sand, silt, clay, rock, gravel, mud, or other matter that has been transported by flowing water.

Sedimentary rock: Rock formed from compressed and solidified layers of organic or inorganic matter.

[See also Fossil and fossilization; Paleontology ]

Paleoecology

views updated May 29 2018

Paleoecology

Paleoecology is the branch of paleontology that studies ancient organisms and their environments. Paleoecologists study the physical structure and biological functions of organisms, their interactions with each other, and their role in ancient ecosystems. In addition to the basic principles of paleontology, paleoecology research depends on concepts from biology , sedimentology, and geochemistry . The goals of paleoecology are to understand the details of ancient environments and the functioning of ancient ecosystems and their evolution .

The primary database for paleoecological studies is the fossil record. For example, by studying fossils and comparing them with similar living organisms, paleoecologists attempt to understand how the fossil organism lived and its ecological duties. If no living organism is analogous to a fossil, an engineering approach may be taken. This involves constructing models of the fossil and testing how it behaves under various environmental conditions. In this way, the researcher can determine why the organism evolved that particular combination of body shape, density , size, etc., and what type of environment it probably inhabited.

An organism's fossilized hard parts (for example, the shell of a clam), through their composition, provide clues to the environment as well. A clam shell's trace element content relates to the concentration of trace elements in the aquatic environment. The concentration in the environment is a product of environmental variables such as salinity and water temperature . So, by studying the trace element chemistry of a fossil, it may be possible to determine the approximate climatic conditions where the organism lived, as well as its latitude.

In addition to body fossils, paleoecologists study trace fossils. These are things like footprints, gopher burrows, or worm trails preserved in sediments. Trace fossils indicate the behavior of the organism that made the trace and physical factors about the environment. For example, a trail of dinosaur footprints preserved in stream bed sediments provides evidence of how fast the dinosaur was moving, based on spacing of the prints. The depth of the footprints suggests how soft the sediments were, and hence, whether the stream bed was dry at the time the dinosaur traversed it.

Unlike ecologists, paleoecologists must cope with a very incomplete database, because many organisms do not easily fossilize. The evidence that is available to paleoecologists is also misleading at times. For example, a dinosaur nest discovered in the 1923—the first ever found—contained several broken dinosaur eggs. The remains of a small, previously unknown dinosaur, later named Oviraptor, were also found nearby. Certain skeletal characteristics of this dinosaur lead researchers to conclude that it was in the act of stealing eggs when it died, hence the name Oviraptor (egg plunderer). In 1993, evidence from another nest illustrated that rather than stealing some other dinosaur's eggs, Oviraptor was brooding on its own nest.

As this example illustrates, perhaps more so than in any other science, old interpretations sometimes must be revised to accommodate new data or theories. However, overall, paleoecology is crucial to our understanding of the long and diverse history of life on Earth .

palaeoecology

views updated May 08 2018

palaeoecology The application of ecological concepts to fossil and sedimentary evidence in order to study the interactions of the Earth's surface, atmosphere, and biosphere in pre-historic and geologic times.

palaeoecology

views updated May 23 2018

palaeoecology The application of ecological concepts to fossil and sedimentary evidence to study the interactions of Earth surface, atmosphere, and biosphere in former (prehistoric) times.

palaeoecology

views updated May 23 2018

palaeoecology The application or ecological concepts to fossil and sedimentary evidence to study the interactions of Earth surface, atmosphere, and biosphere in former (prehistoric) times.

palaeoecology

views updated Jun 11 2018

palaeoecology The application of ecological concepts to fossil and sedimentary evidence to study the interactions of Earth surface, atmosphere, and biosphere in former times.

palaeoecology

views updated Jun 11 2018

palaeoecology The study of the relationships of fossil organisms to each other and to their environments. It involves the study both of the fossils and of the surrounding rocks in which they are found. Trace fossils may provide information on the behaviour of the organism.