Chapter 22 - Intro Evolution Flashcards Preview

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Flashcards in Chapter 22 - Intro Evolution Deck (48)
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1
Q

How did humans get the opsin gene?

A

through mutation from previous ancestors

2
Q

When was the earth formed?

A

4.6 bya (billion years ago)

3
Q

When did life form?

A

~3.8 bya

4
Q

What was early life?

A

prokaryotic cells

5
Q

Changes in species can lead to?

A

a formation of new, separate species

6
Q

In the simplest sense, what are species?

A

different kinds of organisms

7
Q

Individuals of the same _______ share genetic similarity and can (potentially) interbreed

A

species

8
Q

all the individuals of the same species occupying a specific area at a particular time

A

population

9
Q

Example of populations

A

black bears and Joshua Trees

10
Q

What constitutes the Joshua tree species?

A

all the populations together

11
Q

explanation for a natural phenomenon

A

theory

12
Q

measure of successful reproduction

A

fitness

13
Q

All species have descended from other _______. And a single, _______ ancestor lies at base of the evolutionary tree

A

species; common

14
Q

Natural Selection is what process?

A

a trait (or character) that confers reproductive advantage to an individual, spreads in a population over successive generations

15
Q

Natural selection required understanding the ________ ________ of populations

A

biotic potential

16
Q

T/F

Most populations are capable of producing more offspring than can be supported by the environment

A

true

17
Q

What is exponential growth?

A

doubling

18
Q

Natural selection requires variation in _______

A

phenotype

19
Q

Example of phenotypic variation

A

population of Geospiza fortis, one of Dawrin’s finches

20
Q

Within populations, there is variation between individuals - some of this variation is _______

A

heritable

21
Q

Overtime, beneficial traits ______ through the population

A

spread

22
Q

________ is required for natural selection

A

competition

23
Q

T/F
Genetic traits that provided an advantage will be spread within a population, but those that do not will be lost from the population

A

True

24
Q

What is evolution?

A

genetically based change of phenotype in a population over successive generations

25
Q

Species are not fixed entities, but instead are what?

A

constantly undergoing modification and change

26
Q

Origin of Species

Perceived ___________ as the primary force driving descent with modification

A

natural selection

27
Q

independently developed theory of evolution

A

Alfred Russel Wallace

28
Q

Naturalist who believed species were not fixed entities

A

Jean-Baptiste de Lamarck

29
Q

What are the five agents of evolution?

A
Natural selection 
Sexual selection 
Gene flow 
Genetic drift 
Mutation
30
Q

more offspring are produced then can be supported by the environment

A

competition

31
Q

a change in DNA sequence (change in nucleotides)

A

mutation

32
Q

Mutation is an ______ of evolution. How?

A

agent; Mutations create new alleles

33
Q

the movement of existing alleles from one population to another by dispersal

A

gene flow

34
Q

Example of gene flow

A

deer populations

35
Q

chance alteration of allele frequencies in a population

A

genetic drift

36
Q

Two forms of genetic drift:

A

Founder effect and Population bottleneck

37
Q

New population is started by a few individuals that are not representative of genetic diversity in the original population

A

Founder effect

38
Q

What form of genetic drift was seen in red spotted toads?

A

Founder effect

39
Q

Following population decline, surviving individuals do not represent genetic diversity of the original population

A

Population bottleneck

40
Q

In population bottleneck, survival is _______

A

random

41
Q

Example of population bottleneck

A

elephant seals

42
Q

Differential reproductive success based on differences in the success of obtaining mates

A

sexual selection

43
Q

Example of sexual selection

A

Female mate choice within guppies

44
Q

How new species come into being

A

speciation

45
Q

Occurs when the geographical range of a species is split into discontinuous parts by formation of barriers to gene flow

A

Allopatric speciation

46
Q

In Allopatric speciation, populations can become _______ in many different ways. List a couple

A

separated; environmental change, dispersal to an isolated area

47
Q

Allopatric speciation in forest frogs

A
  • Populations become isolated in different areas
  • If enough gene flow occurs the populations will remain genetically similar
  • If gene flow is lacking, populations diverge
  • Overtime, if individuals from the diverging populations can no longer reproduce, speciation has occurred
48
Q

What occurred almost 500 million years ago?

A

the Cambrian explosion