Lecture 2- Evolution and Natural Selection

Question 1

macroevolution

Answer 1

is the evolution of new taxonomic
groups
-living species are descendants of ancestral species that
had different traits

Question 2

gene

Answer 2

a segment of DNA with the instructions for making
a specific protein

Question 3

allele

Answer 3

different versions of a gene
-Like different recipes for same dish
– Make different variations on the protein
– Make the body look/work differently

Question 4

evolution

Answer 4

is a change in allele frequencies within a
population over generations—> change in the frequencies of traits in a population over generations

Question 5

In order for natural selection to act on a specific
trait

Answer 5

There must be variation in a trait
* The variation must be heritable
* The trait must be related to the ability to survive
and/or reproduce

Question 6

Artificial Selection

Answer 6

is when humans determine which
traits result in highest fitness
-AKA selective breeding
* Humans choose
individuals with traits
they want to
reproduce

Question 7

Homology

Answer 7

similarity resulting from common ancestry
* Structures may have different function, but have the
same origin
* May be anatomical/morphological

Question 8

Vestigial structures

Answer 8

A vestigial structure no longer has a purpose, but it is
still present because it was inherited from an
ancestor that had it

Question 9

Evolution is a change in ________________ in a ______________ over _______________

Answer 9

population; generation; time

Question 10

How are alleles related to the traits that an organism has

Answer 10

some traits, like eye color, have several alleles that influence the trait.

Question 11

Why does natural selection acting on individuals result in the population as a whole adapting?

Answer 11

selecting for and increasing the occurrence of beneficial traits in a population.

Natural selection increases or decreases biological traits within a population, thereby selecting for individuals with greater evolutionary fitness.

Question 12

What conditions must be true in order for natural selection to occur?

Answer 12

the trait under selection must be VARIABLE in the population, so that the encoding gene has more than one variant, or allele.

Question 13

What is evolutionary fitness?

Answer 13

reproductive success and reflects how well an organism is adapted to its environment

Question 14

How does the fossil record provide evidence for evolution?

Answer 14

Illustrating a panorama of evolutionary change over the past 3.5 billion years.
Showing gradual evolutionary changes over time.
Demonstrating that organisms from the past are different from those found today.
Supporting Darwin’s theory of evolution.
Providing physical proof of extinction and transitional forms between species