lecture 18- descent with modification

Question 1

what does natural selection result in

Answer 1

adaptive evolution
accumulation of inherited characteristics that increase the ability of an organism to survive and reproduce in its environment

Question 2

what are the layers in sedimentary rocks called

Answer 2

strata

Question 3

how do fossils help understand evolution

Answer 3

show the organisms that lived throughout time

Question 4

what is the concept of catastrophism

Answer 4

boundaries between strata were due to catastrophes (floods, droughts) which destroyed the living species and process repeats

Question 5

what was lamarck theory of evolution

Answer 5

organisms pass traits to offsprings through use and disuse (parts of body not used deteriorate and go away)
giraffes neck grew cuz the animal stretched it to get high leaves
organisms would get perfect over time

Question 6

what is gradualism and who proposed it

Answer 6

profound change can happen through the cumulative effect of continuous processes
hutton

Question 7

what did darwin base his theory on

Answer 7

malthus’ essay: struggle for existence
lyell’s principle of geology
principles of artificial selection
own data (galapagos islands)

Question 8

what was “struggle for existence” about

Answer 8

population growth is not always desirable
limited resources will break the growth

Question 9

what are the principles of geology

Answer 9

changes to the earth’s surface come from slow continuous actions that are still operating today

Question 10

what is artificial selection

Answer 10

plants and animals being breeded by humans to get desired traits
large changes over short period of time

Question 11

what did darwin hypothesize about mainland and island animals

Answer 11

he said that the mainland animals colonized the islands and then diversified depending on the habitat of the different islands

Question 12

how do population sizes stay stable

Answer 12

the resources are limited: struggle for existence/competition so few offsprings survive

Question 13

how does the genome of a population change

Answer 13

organisms with favourable traits have more chances of reproducing: more offsprings who will also pass down those traits by surviving: favourable characteristics accumulate over generations

Question 14

do individuals evolve?

Answer 14

no only populations can evolve

Question 15

what does evolution depend on

Answer 15

the environment in which the organism is in

Question 16

what are the pieces of evidence that support darwin’s theory

Answer 16

natural selection in action
homology
convergent evolution
biogeography
fossils

Question 17

what is homology and what are the types

Answer 17

similarities resulting from a common ancestor
anatomy, development and molecular

Question 18

what are homologous structures

Answer 18

anatomical resemblances that demonstrate a common ancestor but that have different functions in different organisms

Question 19

what is divergent evolution

Answer 19

different environments which made the same traits evolve into different things that have different functions

Question 20

what are vestigial organs

Answer 20

organs or structures that are useless
leftovers from ancestors

Question 21

what do vestigial organs indicate

Answer 21

organism has evolved from ancestors where organ was functional
there is no selective pressure to eliminate them

Question 22

development homology

Answer 22

all vertebrate embryos have gill slits in throats at some point
develop into different structures

Question 23

molecular homology

Answer 23

universal dna code, 3 nucleotides for a codon, some codons code for the same thing in many organisms
evidence of common ancestor

Question 24

what is analogous convergent evolution

Answer 24

characteristics are similar but no common ancestor, evolved independently from different ancestors

Question 25

what is biogeography

Answer 25

species tend to be more similar to species in their area than their species in different areas
when the continents separated, populations evolved independently (ex australia marsupials)

Question 26

how do fossils support evolution

Answer 26

forms of fossils prove the descent line theorized

Question 27

what is neo-darwinism

Answer 27

theory with mendel genetics
natural selection acts on heritable variations within individuals in a population
mutations provide the most of those (especially dna copying errors)