Chapter 8 Inquizative

Identify which statements are true about the relationship between fossils and their environment. (2)

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

In which of the following ways has the climate changed in the past? (3)

-During very warm periods, sea levels were very high. -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. -Since the Eocene, there has been a general cooling of Earth's surface temperature.

Identify the correct statements regarding the use of stable oxygen isotopes in reconstructing ancient climates.

-Oceanic microorganisms preserved in sea floor sediments or elsewhere can be analyzed to measure the ratio of 16O to 18O. -Oxygen is incorporated into biological tissues of living organisms. -As global temperature varies, the amount of 18O in water changes in response.

Identify the 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. Identify the statements that correctly describe 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.

Identify the reasons why the Fayum Depression is 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

Good representation of fossils is important in understanding evolution. Identify the correct statements about representation.

-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.

Identify the statements that correctly describe the ratio of different stable isotopes of carbon (12C and 13C).

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

Identify the conditions that are NOT likely to help preserve animal remains, making it more likely for them to become fossils.

-acidic conditions -the presence of scavengers in the vicinity -long period of exposure on the surface

Step in Facial Reconstruction

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

Place the following materials in the order in which they are likely to fossilize. Begin with the material that is most likely to fossilize, and finish with the material least likely to fossilize. 1 .mammal teeth 2. soft body parts of any animal 3. bones of an adult mammal left on the surface 4. bones of an adult mammal quickly buried

1,4,3,2

radiometric dating

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

electron spin resonance dating

Buried fossils absorb radioactive isotopes from the surrounding burial environment.

This image shows the Serengeti Plain in Kenya, where, like across much of the African continent, ____ plants have given way to a greater abundance of ____ plants as forests have changed to woodlands or open savannas.

C3 C4

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? Choose the correct answers and their corresponding explanations.

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.

stable isotope analysis

Variants of non-radioactive elements with slightly different masses are incorporated into living organisms in different amounts depending on environmental conditions

amino acid racemization

decay of L-isomers into D-isomers

thermoluminescence dating

energy from the sun lost when materials were heated long ago

radiopotassium dating

parent-daughter decay

Identify the conditions that 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

fission track dating

traces from decay of uranium-238