Unit 2 - Evolution, Taxonomy

Question 1

Define evolution

Answer 1

any change in inheritable traits within a population across generations

Question 2

define generation

Answer 2

a group of organisms born at the same time

Question 3

population

Answer 3

a group of organisms living in the same place at the same time

Question 4

variation

Answer 4

genetically different organisms that can be passed down through reproduction (eg: brown vs blue eyes)

Question 5

what is the difference between evolution and genetics

Answer 5

evolution is the process of traits and organisms changing, genetics is the DNA and what is causing the changes

Question 6

What are some conditions that must be met in order for a mutation to become a trait in the population?

Answer 6

They need to be able to survive through the environment - for a mutation to become a trait, it depends on if both parents have the trait. If the mutation is beneficial it will more likely be passed through generations, as it allows the population to thrive.

Question 7

how do variations arise?

Answer 7

sexual reproduction: genetic info from each parent combining, combination of alleles produces new traits
mutations in genes: occur spontaneously, can have positive, negative or neutral effect on survival, must occur in the reproductive cells (germline)

Question 8

define micro evolution

Answer 8

small scale changes occurring within a population

Question 9

define macro evolution

Answer 9

large scale changes occurring within an entire species

Question 10

what is a species

Answer 10

a group of organisms that can interbreed to produce viable offspring

Question 11

what is speciation

Answer 11

the formation of a new species

Question 12

what are the 3 main principles of Lamark’s theory of evolution

Answer 12

1. all of the physical changes that occurred for an individual organism during their life are inherited by their offspring (organs that organisms stopped using would shrink)
2. transmission of acquired characteristics (giraffe has long neck, offspring will have longer neck)
3. Evolution by natural processes

Question 13

what was the key knowledge that prevented Lamarck (and Darwin) from developing accurate theories

Answer 13

lack of knowledge of how traits were passed from parent to offspring: “genes” weren’t discovered yet and that they could pass information down - a key building block to prove why it occured

Question 14

What are the key differences between Lamarck and Darwin’s theories

Answer 14

Lamarck: use & disuse, transmission of acquired characteristics, increasing complexity, no extinction
Darwin: variation, inheritance, differential survival, extinction

Question 15

what is Darwin’s theory of evolution

Answer 15

Darwin believed that individuals were simply born with different traits and that these differences were mostly random. An example would be if a Giraffe was born with a long neck it would have a higher chance of survival as it could reach for more food and pass that gene to future generations.

Question 16

what are similarities between the two theories

Answer 16

• life changed gradually over time and is still changing
• living things change to be better suited and adapted to their environments
• all organisms are related

Question 17

what is Lamarck’s theory of evolution

Answer 17

a trait is developed/learned to meet the individuals needs in their lifetime
this trait is acquired and passed onto their offspring
*traits adapt to the environment

Question 18

what are the 5 conditions for natural selection to occur (darwin)

Answer 18

1. overproduction
2. struggle for existence
3. variation
4. survival of the fittest
5. speciation

Question 19

elaborate: overproduction

Answer 19

the number of offspring produced by a species is greater then the number that can survive and reproduce

Question 20

elaborate: struggle for existence

Answer 20

organisms of the same species (and other species) must compete for limited resources

Question 21

elaborate: variation

Answer 21

differences among traits occur randomly in a population
*variations that become common are called adaptations - these change very little over time

Question 22

elaborate: survival of the fittest

Answer 22

individuals with an advantageous trait survive and reproduce, increasing their numbers
*“selection” by nature

Question 23

elaborate: speciation

Answer 23

over long periods of time, advantageous traits become more common and lead to the formation of a new species

Question 24

what are 2 ways a new species can form

Answer 24

1. transformation: gradual changes over time that produce a species that is more adapted then others
2. divergence: a barrier prevents individuals from reproducing, so 2 or more populations form and become new species

Question 25

does transformation or divergence increase diversity

Answer 25

divergence (parent species becomes 2, opposed to 1 species becoming another)

Question 26

what are some barriers that cause speciation

Answer 26

1. geographical (physical separation that divides a population)
2. behavioral (mate selection based off different traits)
3. mechanical

Question 27

what are the 2 patterns of evolution

Answer 27

divergent and convergent
speciation occurs as a result of natural selection

Question 28

divergent evolution

Answer 28

2 or more species share a common ancestor but the populations allele frequency changes (as a result, physical traits change)
(homologous traits)

Question 29

convergent evolution

Answer 29

2 or more species from different ancestors become more similar in appearance or traits as they adapt to the same kind of environment
(analogous traits)

Question 30

define allopatric speciation

Answer 30

geographic isolation - small group breaks away, or natural events like earthquakes, etc could happen.

Question 31

define sympatric speciation

Answer 31

doesn’t require geographic isolation – separate behaviors or choices isolate them among their population

Question 32

define homology

Answer 32

to have the same or simillar relation, relative position or structure
traits inherited by 2 different organisms from a common ancestor

Question 33

define phylogeny

Answer 33

a family tree (shows relationships over much longer periods of time)

Question 34

define morphology

Answer 34

the study of size shape and structure of animals plants and the relationships of their structures

Question 35

what 3 criteria are used to determine whether a shared physical trait is a homology or analogy (convergent)?

Answer 35

• basic structure
• same development
• same relationships to other creatures

Question 36

what is a homologous structure

Answer 36

species that inherited a physical structure from a common ancestor but each evolved a different function

Question 37

what is an analogous structure

Answer 37

species that have different structures that perform the same function (different ancestors)
Eg: wing of bird versus wing of insect

Question 38

what is a vestigial structure

Answer 38

inherited structures that are no longer needed - smaller and simpler then ancestral species
eg: human appendix, wisdom teeth, tailbones

Question 39

what are some methods to investigate the phylogeny of organisms

Answer 39

1. anatomy/morphology
2. paleontology (fossil records, determine time, extinct species, however incomplete)
3. molecular analysis (compare nucleic acid, more reliable, not easy to determine mutations between sequences)
4. embryology (early developmental characteristics, reveals similarities,

Question 40

what is taxonomy

Answer 40

a system to classify species
to assist in species identification, assign formal/consistent names, etc.

Question 41

what is binomial nomenclature

Answer 41

an international system of naming species
two terms used to scientifically class a species of a living organism,
pt 1: Genus (captial, italic)
pt 2: species (lowercase, italic)

Question 42

what are the 7 pieces in a taxonomy

Answer 42

kingdom
phylum
class
order
family
genus
species

Question 43

what is a dichotomous key

Answer 43

a tool that allows the user to identify an organism (each step is a pair of statements)