Chapter 23 - Cenezoic Earth and Life History

Question 1

Define Family homindae

Answer 1

Primates, includes gorilla, pan, chimpanzee, bonobo, and HUMAN

Question 2

Evolution of man, 3 main steps

Answer 2

1) Australopithecus afarensis
lived 3.9-3 M.y ago
-southern ape, looks like monkey
-lucy was an Australopithecus afarensis
2) Homo erectus
-means "upright man"
-about 1.8M.y ago to 
3)Homo sapiens
-evolved from homo erectus
-about 800k years ago

Question 3

Migration of Family homindae

Answer 3

-Started in east Africa, 200k years ago

Question 4

how did Family homindae migrate??

Answer 4

Ice age at the time, sea levels allowed them to walk

Question 5

First species to walk upright?

Answer 5

Homo erectus

Question 6

Sub species of humans?

Answer 6

Neanderthals

• sub species of humans, cave paintings in france
• interbreeding to form sub species
• different races are different types of species

Question 7

Are humans getting smarter?

Answer 7

no

Question 8

Conditions of a sun to support a planet to have life?

Answer 8

Age, mass, metal content, location, stability, multiplicity,

Question 9

Condition of another planet to have life; suns age

Answer 9

can’t be younger than 3 b.y b/c creates time frame long enough for life to endure life

Question 10

Condition of another planet to have life; sun’s mass

Answer 10

no larger than 1.5x sun’s mass

-larger stars burn out too quickly

Question 11

Condition of another planet to have life; sun’s metal content

Answer 11

at least 50% of suns iron concent

-enough heavy metal for rocky planets to form

Question 12

Condition of another planet to have life; sun’s location

Answer 12

Stable location between galaxy’s spiral arms

-less likely to pass through interstellar dust and star forming regions, causing climate change

Question 13

Condition of another planet to have life; sun’s stability

Answer 13

Cannot be a variable star

-such stars are prone to flares ad changes in brightness

Question 14

Condition of another planet to have life; sun’s multiplicity

Answer 14

Stars in multiple star system must be very close together or very far apart
-otherwise, stars gravity will interfere with the orbits of planets suitable for life

Question 15

Where have we found water?

Answer 15

Encladus (moon of Saturn), Europa (moon of Jupiter), Mercury, mars

Question 16

What is drakes equation??

Answer 16

Drakes equation estimates # of alien civilizations we could detect. Recent discoveries of numerous planets in milky way have raised our odds

Question 17

How likely is extraterrestrial life?

Answer 17

Arthur c. Clark -> the fact that we have not yet find extraterrestrial life is the is the fact that our methods of detection is primitive.. Just because we havent found it means that our methods are just not right