Unit 1

Question 1

Define Biological Evolution

Answer 1

• Product Not a Process (Natural Selection)
• A Change in a heritable trait in a population over (large period of) time.
• A change in a heritable trait means how many individuals have a trait before and how many individuals have that particular trait over time.
• Individuals do not evolve! Populations evolve
• Organisms can’t change the traits that they have on their own.

Question 2

describe and exemplify evidence that evolution happens and the tools scientists use to determine relatedness

Answer 2

• Comparative Anatomy
• Embryology and Devlopement
• Fossil Record
• DNA Comparisons
• Species Disrtibution
• Evolution observed
• Predicitve power of Evolution
• Nested Hierarchies of Traits
• Anatomical genetic data

Question 3

Dispel the MISCONCEPTION: evolution is just a theory for which there is very little evidence

Answer 3

Wrong, it is not just a theory b/c that implies that is has no evidence and is not supported but however there is a lot of evidence

Question 4

Dispel the MISCONCEPTION: evolution is a theory which describes the origin of life

Answer 4

Does not describe the origins of life, however it shows how life diversified and exists.
- states that a Change happened not how or why it happened.

Question 5

describe the possible origins/outcomes to branches on the tree of life

Answer 5

some species have undergone very little change for many millions of years (living fossils)
o diversification: one species diverges into two genetically diverse species
o extinctions have occurred throughout the history of life on earth, even before humans, and continue to occur

Question 6

distinguish between patterns of Convergent & Divergent evolution

Answer 6

Convergent Evolution:
- Explains trait similarity in species that do not inherit the trait from a recent common ancestor.
• Species that evolve under SIMILAR environments may evolve SIMILAR forms
ex. white fur in arctic hare and arctic fox
Divergent Evolution:
• Explains trait DIFFERENCES within and between species or even how a whole new species can arise
• If they live in different environments they might evolve to have different traits.
ex. Brown bears and polar bears.

Question 7

explain patterns of trait similarity among organisms - describe the evidence you need to determine if trait similarity
is due to common ancestry or convergent evolution.

Answer 7

If common ancestor of two species had that trait, then those two species most likely got that trait from their
common ancestor.
o If common ancestor of two species did NOT have that trait, then those two species evolved to have that trait
independently from one another (Convergent Evolution), perhaps from similar selective pressures

Question 8

describe and exemplify Adaptations

Answer 8

Adaptation: Trait(s) that increases an organisms’ fitness (fitness
= ability to survive and reproduce)

Camouflage

Question 9

explain why there is no guarantee that any members of a population will be able to survive and reproduce, as
well as the conditions that may cause an entire population of organisms to die or even an entire species to go extinct.

Answer 9

G

Question 10

What are modifications?

Answer 10

They are slight changes or alterations of the original

Question 11

Common evolutionary origins

Answer 11

Same ancestor explains similarity in traits.

Note: DIFFERENCES in bone size and shape occurred as species adapted to different environment.

Question 12

Convergent Evolution

Answer 12

Explains trait similarity in species that do not inherit the trait from a recent common ancestor.
• Species that evolve under SIMILAR environments may evolve SIMILAR forms

Question 13

Divergent Evolution

Answer 13

Explains trait DIFFERENCES within and between species or even how a whole new species can arise
• If they live in different environments they might evolve to have different traits.

Question 14

What are Vestigial Traits

Answer 14

Evolutionary Leftovers.

Question 15

Why might inherited traits from an ancestor remain?

Answer 15

• Might not be detrimental (does not decrease fitness)
• Not enough evolutionary time to see the change
• Alternate form of the trait may not have arisen by chance
• Species that are not adapted to selective pressure may go extinct

Question 16

Does evolution happen because an organism needs a particular trait?

Answer 16

No, Organisms can’t choose what traits they can have.

Question 17

Do trait differences arise by chance?

Answer 17

yes

Question 18

how does evolution work?

Answer 18

Evolution can only work with the heritable variation that is present in the population

Question 19

When did life originate on earth?

Answer 19

3.5 billion years ago

Question 20

Does evolution work as a ladder upward progress with humans at the top rung?

Answer 20

No, Bette represented as a tree figure

Question 21

Over time branches on the tree of life may:

Answer 21

• Not change very much (ex. Living “fossils” such as turtles, sharks, horseshoe crabs)
• Be pruned off (organisms go extinct)
• diverge (branch into two different groups)

Question 22

How do genes inform us about evolution:

Answer 22

The higher the genetic percentage is the more similar they are.

Question 23

How does Genetic similarity provides evidence for evolutionary relationship

Answer 23

• Ex. All animals share the genes that are are involved with embryonic development (homeobox genes)

Question 24

How are scientific theories constructed?

Answer 24

Scientific theories are constructed by pulling together laws, hypothesis, observations, and inferences into coherent explanations of the universe which are called theories

Question 25

Explain how an inference is different from a fact?

Answer 25

An inference is a conclusion that you can draw from the available evidence while as a fact is something directly observable.

Question 26

How do scientist use theories?

Answer 26

Scientist use theories to makes predictions/expectations which helps them determine and learn more about the universe.

Question 27

What was Darwin trying to explain when he developed the theory of evolution by natural Selection?

Answer 27

He was trying to explain the diversity of life that he observed and to explain how new species originate.

Question 28

Explain why the following state is NOT true: Scientific theories never change?

Answer 28

This statement is not true because scientist are always constantly trying to find new evidence to build upon what others started. They do this to either improve what is there or to change it with new evidence. Theories are constantly challenged and amended as new evidence is gathered.

Question 29

List two lines of evidence for evolution.

Answer 29

Anatomical Evidence (Fossil records, shared bone structure) and genetics.

Question 30

Why are observations of transitional fossils so useful for studying the evolutionary history of organisms?

Answer 30

They help to link together or connect different forms of life throughout time. For example, finding a whale fossil that had small hind legs gave us some data to support the theory that whales evolved from land mammals

Question 31

How did whale fossils come to be associated with the Egyptian desert?

Answer 31

They became to be associated with the Egyptian dessert because originally the Egyptian desert used to be a large pool of water where a vast majority of Marin life was living in.

Question 32

What explains the presence of small hind limbs with toes on fossil whale, basilosaurus.

Answer 32

Hind limbs are an example of a vestigial feature or an evolutionary leftover = characteristic may no longer serve a function, it is leftover from an ancestor

Question 33

What are homeobox genes?

Answer 33

Genes that encode for instructions for the development of conserved Boyd parts that all animals share to set up the body plan of how the animal will develop.

Question 34

What did Walter Gehring show with this experiment with the eyeless gene?

Answer 34

The mouse gene for the eye could replace the fly gene- a fly eye was grown even though the fly had the mouse version of the gene.

Question 35

How do homeobox genes provide evidence that all living things are descended from a common ancestor?

Answer 35

All animals share genes that have the same function, so we must have all gotten them from a common ancestor that also had them. If we had all gotten them on our own, they all wouldn’t be the same or be interchangeable.