Fossils - Oct. 18, 2022

Question 1

Fossil Definition

Answer 1

Mineralized remains Body Fossils (ex. bones, shells, teeth, leaves) or Trace Fossils (ex. Burrows, tracks, impressions) of deceased life forms

Question 2

Taphonomy Definition

Answer 2

The study of the conditions under which plants, animals, and other organisms change after death and are sometimes conserved as fossils

Question 3

Silt Definition

Answer 3

Fine nutrient rich soil; found by water

Question 4

Sediment Definition

Answer 4

Matter that settles to the bottom of a liquid (like dirt)

Question 5

Imprint Definition

Answer 5

A rock cast of an original organism imprints can show soft tissue

Question 6

Soft Tissue Definition

Answer 6

Our hair, muscles, skin, and tissue that is soft not hard like bone.

Question 7

Preserve Defintion

Answer 7

When parts of an organism are saved with the skeleton
Ice preserves animal remains the best

Question 8

Relative Age Dating

Answer 8

Dating a fossil or material using surrounding features; for ex. getting one fossils then allows you to know the fossils above are younger and the ones below are older (Law of Superposition)

Question 9

Law of Superposition

Answer 9

Any fossil above one is younger and any below it are older

Question 10

Index Fossil

Answer 10

They are used to find the relative age of a fossil; ex. the fossils above it are younger than the ones below it. Many species are used as index fossils since they went through massive evolutionary changes.

Question 11

Strata

Answer 11

Layers of rock laid down by wind and water over the course of Earth’s 4.6 billion-year history

Question 12

Radiometric Dating

Answer 12

What we use to get the exact age of a fossil
Uranium 238 is used to date rocks
Carbon 14 is used for living things

Question 13

Isotope

Answer 13

An isotope is one of two or more species of atoms of a chemical element with the same atomic number and location in the periodic table and closely the exact same chemical habits but with unalike atomic masses and physical attributes.

Question 14

Half-life

Answer 14

After a certain period of time called a Half-life half of the nuclei decay’s

Example - There is 40 grams of a substance and the half-life is 20 years, how much will be left after 60 years?
40 grams - 0 years
20 grams - 20 years
10 grams - 40 years
5 grams - 60 years

Question 15

Chronometric

Answer 15

In contrast, chronometric dates place events in their chronological position with reference to a universal time scale such as a calendar.

Question 16

Fossil Complexity

Answer 16

The different complex stages of an animal. How to tell whether it’s the same animal or an adaptation as well as how long ago it lived. What it did or ate to discover whether it was a carnivore or not.

Question 17

What are the perfect conditions for fossil formation? How do fossils form?

Answer 17

You need to not die a violent death and preferably be by a body of water, ice, or a dry area like a desert. You also need to be covered in sediment quickly. Fossils form underground when minerals start to replace cells and atoms in bones and become stone.

Question 18

Perfect Conditions for a Fossil

Answer 18

Fast Burial, Hard Parts
Organisms should die alone of natural causes
Should die in or near water
Sediment covers the body layer by layer
Minerals get deposited into air pockets of the bones
Minerals replace the calcium in the bones
Fossils eventually come to the surface

Question 19

What are the ways we get preserved animal remains? Which is the best and why?

Answer 19

There are four ways to get animal remains. There is another which I will start with but it isn’t really animal remains. This method is a cast or mold method where you make a mold from what a fossil would look like and make a cast from it. Another method is Permineralization aka Petrification; when the organic components of bone break down (ex. blood cells and fat) or inorganic components, made from minerals, remain which leaves a bone-shaped mineral form with pores throughout it. A third method is Complete Preservation, when an organism dies and is covered with, tree sap (later turned into amber), water, or tar (liquid asphalt). Mummification is another; this is where a skeleton or any remains become dehydrated and the bacteria cannot colonize. The last one is compression where an organism made a mark of high pressure on the rock. The best one would be ice as it preserves the skeleton very well and keeps it safer than other methods.

Question 20

How do we use relative age dating techniques to order rock layers?

Answer 20

The Law of Superposition states that any fossils above one are younger than any below it.

Question 21

How do we use radiometric techniques to get the exact age of a rock or fossil?

Answer 21

Radioactive atoms decay at a predictable rate which we can measure to see how much is left to tell how long ago something formed.

Question 22

What can an imprint possibly tell us or show us that a fossil cannot?

Answer 22

How it moved through bones and more details about the thing like maybe more leaves or spiky parts for a plant or more sharp claws or maybe how heavy an animal was.

Question 23

Explain the difference between the Typological and Populationist approaches to assigning species names. (From the Record of time reading)

Answer 23

People who take the typological approach believe that even minor or small differences make similar fossils completely different species while those who take the populationist approach (the more popular one as of now in the biological scene) believe that many species all may have minor differences so any similar fossils are typically put together to be the same species because different species would show more major differences.

Question 24

Fluorine analysis

Answer 24

Can be used only as a relative dating method because the rate of decay and the amount of dissolved mineral in the ground water varies from site to site.

Question 25

Dendrochronology

Answer 25

The science or technique of dating events, environmental change, and archaeological artifacts by using the characteristic patterns of annual growth rings in timber and tree trunks.

Question 26

Amino-acid racemization

Answer 26

Racemization of amino acids is the spontaneous conversion of L-enantiomers to the D-form, which is dependent on temperature, pH, and time. Because of the time-dependent nature of racemization, it can be used to determine the relative age and turnover rates of long-lived proteins.

Question 27

Geomagnetic Reversal Time Scale

Answer 27

The time it takes for Earth’s magnetic field to reverse polarity is approximately 7000 years, but the time it takes for the reversal to occur is shorter at low latitudes than at high latitudes, a geologist funded by the National Science Foundation (NSF) has concluded.