chapter 13

Question 1

charles darwin

Answer 1

age: 22*** - he graduated from college, went on a trip on the HMS Beagle on a 5 year voyage around the world where he observed thousands of specimens of plants, animals, and fossils; particularly intrigued by Galapagos islands; studied finch’s beaks

Question 2

darwin’s hypothesis

Answer 2

1. descent with modification
2. hypothesis of natural selection
   3.

Question 3

descent with modification

Answer 3

all organisms are related through descent from some unknown species that lived in the remote past; they are descendants of earlier organism (organisms have adapted and been modified over time) - all of the different organisms date back to one organism

Question 4

hypothesis of natural selection

Answer 4

observation 1 - overproduction of offspring, resulting in a struggle for existence (all species produce an excessive number of offspring, not enough resources in the local environement to support them all, leads a struggle to survive)
observatino 2 - individual variation in inheritable traits (individuals within a species vary in many inheritable traits)
***those individuals with inherited characteristics best suited for the local environment, generally will leave the greates number of surviving, fertile offspring (most likely to pass their genetic informatin on to the next generation)

Question 5

survival of the fittest

Answer 5

does not necessarily mean the strongest; could mean the healthiest/sharpest vision/smartest; only need to be “strong” enough or “fit” enough to pass on their genes to the next generation

Question 6

insecticide resistance

Answer 6

whenever a new insecticide is used the following pattern occurs:
first time - 99% are killed
subsequent spraying - less and less effective
some insects have chromosomes that confer resistance to the insecticide because those insects that survive, reproduce

Question 7

examples of evolutionary adaptation

Answer 7

insecticide resistance and HIV

Question 8

HIV Adaptation

Answer 8

Reverse Transcriptase makes lots of errors in making DNA (about half of the DNA RT transcribes has at least one error)
some errors are beneficial because it helps HIV to get around the medicicnes and the person’s immune system

Question 9

Evidence for evolution

Answer 9

1. the fossil record
2. biogeography
3. comparative anatomy
4. comparative embryology
5. molecular biology

Question 10

the fossil record

Answer 10

some dead organisms are buried in sediment (over time and under the right conditions, turns to stone)
generally, the younger fossils are on top of older ones (usually older fossils are less complex than the younger ones)
grand canyon

Question 11

relative dating

Answer 11

fossils are found in rock in the order of their existence because most are found in sedimentary rocks (lower layers are older than the upper layers
with relative dating, you can tell which fossils are or younger

Question 12

radioactive dating

Answer 12

radioactive isotopes
carbon dating (C14 or C12)
good to determine the age of fossils from 100-200,000 years

Question 13

ways to determine age of fossils

Answer 13

relative dating or radioactive dating

Question 14

fossil records and horses

Answer 14

size increased overtime
toe reductions (fossils show reduction of length of central toe and development of the bony hoof and reduction and loss of other toes)

Question 15

Biogeography

Answer 15

study of the geographic distribution of species
plate tectonics and the continental drift
ex: finches on the galapagos islands (separation of different island allowed species to evolve to similar but different species)
ex: australia: have marsupial animals in contrast to many placental animals in the rest of the world

Question 16

plate tectonics

Answer 16

it was previously thought that continents have always been fixed in their present positions
it was discovered that plates on the crust of the earth are actually floating on the molten mantle

Question 17

continental drift

Answer 17

pangea - all land
at one time all the land masses came together and then moved apart, helps explain how you can have similar plants and animals on the opposite sides of the ocean

Question 18

comparative anatomy

Answer 18

the comparison of body structures between different species; homologous structures

Question 19

homologous structures

Answer 19

structures that are similar in different species of common ancestry (forelimbs of all mammals have similar structures)

Question 20

comparative embryology

Answer 20

the comparison of structures that appear during the development of different organisms; closely related organisms often have similar stages in their embryonic development (ex: were born with tails/gills)

Question 21

molecular biology

Answer 21

comparing DNA and prteins in different species

closer species share a greater proportion of their DNA and protein sequences than more distant ones