Evolution and History of Life

Question 1

What is absolute dating?

Answer 1

You find radioactive isotopes whih decay over time and, judging on the level of decay, find the approximate age.

Question 2

What is relative dating?

Answer 2

The knowledge that if fossils are in layers the higher layer is more recently fossilized.

Question 3

What is exponential decay and how is it graphed?

Answer 3

When the population decays at an exponential rate. It is shaped like a downwards J.

Question 4

What kind of organisms likely evolved first on Earth?

Answer 4

Prokaryotic single celled heterotrophs

Question 5

What was the Miller-Urey experiment and what did it prove?

Answer 5

Miller and Urey mixed various chemicals to prove Oparin’s hypothesis that life on Earth began in the oceans with sun, lightning, and heat mixing to create chemical reactions.

Question 6

How much oxygen was in Earth’s early atmosphere?

Answer 6

None.

Question 7

What is natural selection? Who first theorized it?

Answer 7

A way for populations to change, when favorable variations survive, reproduce, and take over the population. It was first theorized by Charles Darwin.

Question 8

Why does natural selection require variation?

Answer 8

Without variations, nothing would be able to change in a population.

Question 9

What are the four conditions necessary for natural selection?

Answer 9

Reproduction, heredity, variation, and a difference in fitness caused by these variations/

Question 10

What is antibiotic resistance?

Answer 10

An example of natural selection where bacteria evolves to be unaffected by antibiotics.

Question 11

Why is evolution not survival of the fittest? What is it really?

Answer 11

Evolution is the cumulative changes over millions of years in a population, while survival of the fittest is loser to natural selection, and besides survival to ability to reproduce is important. (e.g. being attractive) A better term would be “natural selection is survival of the best reproducers.”

Question 12

What is meant by “natural selection acts on individuals, but populations evolve?”

Answer 12

While individuals die out or reproduce based on how successful their variations are, populations have cumulative evolution which changes them over time.

Question 13

What is an adaptation?

Answer 13

An adaptation is any variation that enables an organism’s success in their environment. Ex.:The ability for camouflage.

Question 14

What is a homologous structure and how does it show natural selection?

Answer 14

Homologous structures are structural features on two different organisms with a common evolutionary origin, like the forelimbs of crocodiles, whales, and birds. This proves two organisms evolved from a common organism.

Question 15

What is an analogous structure and how does it show natural selection?

Answer 15

Body parts of organisms that do not have a common evolutionary origin but are similar in function, like butterfly and bird wings. This shows the organisms evolved separately in two ancestral groups adapting to different environments.

Question 16

What are vestigial structures and how do they show natural selection?

Answer 16

Vestigial structures are body parts that no longer serve a purpose but used to be important, like the human appendix. This shows evolution because it tells us that the organism has evolved beyond needing this.

Question 17

What is a cladogram? How do they show evolutionary relationships?

Answer 17

A cladogram is a diagram which represents the evolution of a species. It is similar to a family tree but with specie and their evolution. The more closely connected two species are the more closely they are evolutionary related.

Question 18

How are scientific names formatted and why are they used?

Answer 18

Scientific names are made using binomial nomenclature- first comes the genus, which is the name of the species’ larger group, then the specific epithet for the specific organism. The genus is capitalized and the epithet is not, and the should be italicized (in type) or underlined (if written). This is used because there is only one scientific name no matter what language you speak and it gives information about an organism’s background.

Question 19

What is the scientific name for humans?

Answer 19

Homo sapiens

Question 20

What are the levels of organization used in classification?

Answer 20

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 21

What is the Cambrian Explosion?

Answer 21

A time in the Cambrian Period, an early part of the Paleozoic Era, when life hugely increased in diversity and the oceans suddenly teemed with life. This included worms, sea stars, and arthropods.

Question 22

Name one mass extinction, the likely causes, the effect on ecosystems, and the likely survivors?

Answer 22

Mass extinction in the Cretaceous Period;large meteroite collision filled atmosphere with dust, changed climate; killed dinosaurs, two thirds of all species; smaller species, ones more able to adapt to various ecosystems

Question 23

How does the evolution of the whale show a great transformation?

Answer 23

Originally whales walked on land, then they began to slowly lose their ability to walk and became purely sea dwellers.

Question 24

How are sharks and terrestrial mammals related to whales?

Answer 24

Sharks and whales, though they look alike, share analogous features, as sharks are fish and whales are mammals. Terrestrial mammals and whales are more closely related, though most terrestrial adaptations have become vestigial for whales at this point.

Question 25

What are some defining characteristics of mammals? Humans?

Answer 25

Mammals have hair, nurse their young, have diaphragms, four-chamber hearts, and other adaptations to maintain their homeostasis, have specialized limbs, can learn, and generally have specialized teeth. Humans have all these traits, as well as the defining characteristic of being able to reflect on themselves and the world around them.