Ch 14: Speciation and Extinction (Exam 4)

Question 1

Macroevolution

Answer 1

describes large, complex changes in lifes panorama

Question 2

Explain the concept of “biological species” as described by Emst Mayr

Answer 2

Biological Species-a population, or a group of populations, whose members can interbreed and produce fertile offspring

Question 3

Speciation

Answer 3

the formation of new species, occurs when same members of a population can no longer successfully interbreed with the rest of the group

Question 4

Why cant bacteria be classified into species using the biological species concept?

Answer 4

-because bacteria produces asexually and not sexually

Question 5

Examples of Pre-zygotic and Post-zygotic isolating mechanisms

Answer 5

PREZYGOTIC-
ecological isolation- herbivores ladybugs occupy different types of plants
temporal isolation-field crickets mature at different rates
behavioral isolation-frog matting calls differ
mechanical isolation-sage species use different pollinators
gametic isolation-sea urchin gametes are incompatible
POSTZYGOTIC-
hybrid inviability-hybrid eucalypts seeds are not viable
hybrid infertility-a lion and tiger cross is infertile
hybrid breakdown-offspring of hybrid mosquitos have abnormal genitalia

Question 6

Why do islands provide ideal opportunities to study speciation?

Answer 6

-because they are isolated from each other and the mainland

Question 7

Allopatric Speciation vs Sympatric Speciation

Answer 7

AS-a new species arises when a geographical barrier physically separates a population into two groups that cant interbreed

SS-a new species arises while living in the same physical area as its parents species

Question 8

Polyploidy

Answer 8

occurs when the number of sets of chromosomes increases
-group of organisms in which it is common=plants and some fish/amphibians
-ferns, wheat, corn, sugarcane, potatoes, and coffee

Question 9

Fertility in Tetraploid Plants vs Triploid Plants

Answer 9

Tetraploid Plants-produced by self fertilization (4 sets of chromosomes)

Triploid Plants-when tetraploid plant gametes combine with haploid gametes from the parents species, each offspring inherits 3 sets of chromosomes
-infertile and cant complete meiosis

Question 10

Adaptive Radiation

Answer 10

a single species gives rise to multiple specialized forms in a relatively short times (spreading outward from central source)

Question 11

Process of Gradualism vs Punctuated Equilibrium

Answer 11

Gradualism-evaluation proceeds in small incremental changes over many generations

Punctuated Equilibrium-describes relatively brief bursts of rapid evolution interrupting long periods of little change

Question 12

Explain why species with high reproductive rates are more likely to survive rapid period of environmental change, compared to species with low reproductive rates

Answer 12

-the smaller the initial size of a population, the less likely they are to endure an initial challenge
-small populations experience fewer genetic mutations, which are the ultimate source of new adaptations

Question 13

Given the common taxonomic categories for organizing life, be able to arrange all in the correct sequence from largest to smallest

Answer 13

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 14

What is expressed in a phylogenetic tree?

Answer 14

-a diagram that represents evolutionary relationships among organisms
-reflects how species or other groups evolved from a source of common ancestors