Chapter 8 Anthro

What is true about the relationship between fossils and their environment?

-Correct placement of fossils in the environment where their living counterparts thrive helps us understand the factors that shaped that organism's evolution -Correct placement of fossils in time helps in documenting evolutionary relationships among species (phylogeny)

What statements about the methods and principles used by scientists to study the past are correct?

-Geologic time provides the grand scale of the evolution of life -Past climates can be reconstructed via the stable isotopes of oxygen -Ancient animals' diets and their habitats can be reconstructed through the stable isotopes of carbon

Which of the following statements are true regarding the use of stable oxygen isotopes in reconstructing ancient climates?

-Oxygen is incorporated into biological tissues of living organisms -Oceanic microorganisms preserved in sea floor sediments or elsewhere can be analyzed to measure the ratio of oxygen16 to oxygen18 -As global temperature varies, the amount of oxygen18 water changes in response

Which of the following statements about the fossil and living records of species are correct?

-The combined record of living species and fossil species is essential for understanding evolution -Living species provide an incomplete picture of evolution because only surviving lineages are represented

In the year ______, James Ussher added up all the generations of religious patriarchs listed in the text of _________ and reported that Earth was created around _________.

1654, the Old Testament, 4004 BC

Match each of these pairs of parent-daughter isotopes used in radiometric dating to its half-life.

40K -> 39Ar: 1.3 billion years 14C -> 14N: 5,730 years 235U -> 207 Pb: 713 million years

radiometric dating

An element decays radioactively at a known rate expressed as the half-life.

absolute (radiometric) dating

Analyzes radioactive isotopes and provides exact date ranges

electron spin resonance dating

Buried fossils absorb radioactive isotopes from the surrounding burial environment.

How did Charles Darwin incorporate fossils into his work?

Charles Darwin knew about fossils and discovered several in Argentina. Based on fossil analysis, Charles Darwin recognized the similarity between extinct ground sloths and closely related, living sloths.

relative dating

Compares fossils and objects to each other and does not provide exact dates

Taphonomy

Correct choicethe study of what happens to an organism's remains after death

Absolute Non-Radiometric

Does not use isotopes but does provide exact dates

Which of the following occurred as ancient climate changed?

During very warm periods, sea levels are very high. Since the Eocene, there has been a general cooling of Earth's surface temperature. One of the most profound temperature changes, and thus dramatic alterations of climate and habitat, began at the end of the Miocene, around 6 mya.

Which of the following are correct statements about fossils?

Fossils provide an essential historical record for documenting and understanding the biological evolution of surviving and non-surviving lineages. Fossils provide information on chronology and geologic time. Fossils and their geologic settings reveal information about past diets and environments. Fossils are the remains of once-living organisms, wholly or partially transformed into rock. The most common types of mammal fossils are bones and teeth.

paleomagnetic dating

Iron-containing particles in sediment or molten rock will orient with the Earth's magnetic field as it settles or cools.

Does every part of an organism have the same chance of becoming fossilized?

No. Hard parts of the body preserve because they have biologically deposited minerals. Soft tissues only rarely preserve because they are made of polymers that bacteria eat.

What was Pangaea?

Pangaea was the supercontinent that existed around 200 million years ago. All current continents are derive

Which of the following are correct statements about radiocarbon dating?

Radiocarbon dating is possible because a living organism stops incorporating new 14C into its body when it dies. The parent-daughter elements are 14C → 14N. 14C can occur in any organic material.

Radiopotassium dating is used for establishing chronologies of ancient hominin sites. Which of the following statements is/are true of radiopotassium dating?

Radiopotassium dating can be used to date very old volcanic rock since it has a half life of about 1.3 billion years. Radiopotassium dating was first applied to date the oldest stratum at Olduvai Gorge to about 1.8 mya.

Why is the Fayum Depression important?

The geological record at the Fayum Depression, Egypt, includes fossils dating from around 37 to 29 million years ago. Other African fossil deposits that date to the same period as the Fayum Depression are very rare or fossil free.

Dendrochronology

The process of counting tree rings to determine the age of a tree

Good representation of fossils is important in understanding evolution. Which of the following statements about representation are correct?

There are thousands of fossils representing primates and other animals from around 55 mya. It is assumed that many fossil-bearing deposits exist but have not yet been discovered or investigated. Fossils are not uniformly preserved for all time periods and regions. Rock sequences containing fossils are not always complete.

stable isotope analysis

Variants of nonradioactive elements with slightly different masses are incorporated into living organisms in different amounts depending on environmental conditions.

Which of the following phrases are correct about the ratio of different stable isotopes of carbon (carbon-12 and carbon-13)?

When measured in a tropical paleosol, the ratio of carbon-13 to carbon-12 isotopes can indicate the relative amounts of grasslands and woodlands in the region. When measured in an animal tissue, the ratio of carbon-13 to carbon-12 can indicate the diet of that individual during life.

_________ dating is a form of absolute dating in which the sample is bombarded with fast neutrons in a nuclear reactor to measure the ratio of argon-40 to argon-39 in a sample. This method only works on __________ rock.

argon-argon igneous

Through the careful study of _________, the paleontologist Charles Brain realized that the early hominin bones found in South African caves as well as the bones of many other kinds of animals often got into the caves because of ___________.

bone accumulations carnivore activity

amino acid racemization

decay of L-isomers into D-isomers

Charles Darwin

developed the theory of evolution

President Thomas Jefferson

discovered an extinct ground sloth in Virginia

thermoluminescence dating

energy from the Sun lost when materials were heated long ago

Match the method of dating to the correct explanation for why it works by dragging the dating method to the appropriate box.

fluorine dating: Bones slowly absorb fluorine from the surrounding soil at a regular rate (locally). Steno's law of superposition: Geological processes can lay down stratigraphy over time. biostratigraphic dating: Index species are species that appear in or disappear from a given region at known dates.

Some of the best information on climate history—and especially temperature—is based on the study of _________.

foraminifera

William Smith

founded the principle of faunal succession

Georges Cuvier

one of the first paleontologists to scientifically describe many ancient species

Place the following absolute dating methods in order, beginning with the method that can analyze the oldest materials and ending with the method that can analyze the youngest.

paleomagnetic dating fission track dating thermoluminescence dating dendrochrology

radiopotassium dating

parent-daughter decay

You have a sample of bone found on an archaeological site and you want to estimate its age. Which of the following methods would you try?

radiocarbon using the 14C to 14N parent-daughter decay system

Which of the following conditions are likely to help preserve animal remains, making it more likely for them to become fossils?

rapid burial low levels of oxygen in the sediment in which remains are buried

___________ is the study of the deposition of organic remains and the __________ conditions affecting their preservation.

taphonomy environmental

________ is perhaps the single most important variable that we can measure to understand past changes in climate.

temperature

fission track dating

traces from decay of uranium-238

Facial reconstruction is the process by which an artist reconstructs a face from skeletal remains. When the first evidence of a member of the genus Homo outside of Africa was discovered in Dmanisi, Georgia, French paleoartist and sculptor Elisabeth Daynès recreated what the "Dmanisi boy" may have looked like. Identify the steps in the facial reconstruction process.

usage of fossils as a base creation of tissue and muscle out of clay