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Like begets like, In any population there will be some variation that is inheritable, Not all individuals reproduce, The individuals that reproduce best are determined by their variations

The four basic ideas of modern evolutionary theory

Recombination, gene flow, mutation

The three main sources of variation


The shuffling of the genetic material that occurs during meiosis


The most important source of variation in most populations


A change in the genetic make up of one cell

Point mutation

A change in the chemistry of the DNA molecule

Point mutation, change in chromosome number, change in chromosome structure

The three types of mutation


Having three of the same chromosome

Gene flow

The introduction of new genetic material into a population when new individuals move into a population


A long-term change in one or more characteristics of a population over successive generations


Anything (usually environmental factors) that cuts off gene flow


If two populations become different over time and become recognizably different from each other, then we can say that they have developed into different ___________ .

Bergmann's, Allen's, Gloger's

Three rules that pertain to conspecific endotherms

Bergmann's Rule

Conspecifics occurring in a colder climate tend to have a larger body size than that of a warmer climate

Allen's Rule

Conspecifics occuring in colder climates tend to have smaller extremities

Gloger's Rule

Endotherms in colder climates will have darker colored fur/feathers


The development of a new species


A process in which two populations of a common ancestry become different from each other


A type of evolution that occurs in unrelated forms (not having common ancestry) where the groups become more and more similar to each other

Ecological homologues

Unrelated organisms that have similar roles in nature because of convergence


An animal's role in nature

Gradualism and punctuated equilibrium

The two basic ways that evolution occurs


A type of evolution that occurs gradually over time

Punctuated equilibrium

Organisms exist relatively unchanged, but then undergo major changes very rapidly. Usually follows a cataclysmic event that necessitates rapid change

Microevolution and macroevolution

The two types of evolution


Very small evolutionary change (changes within a species)


Large evolutionary change (the development of new taxa)

Group Agnatha and group Gnathostomata

The two major groups of subphylum Vertebrata


The Agnathans appeared during the _____ period


First vertebrates

Jaws and lateral fins

Distinct features of Gnathostomes


Currently there are only _____ extant species of Agnathans

Class Cyclostomata

The only extant class of Agnathans

Keep notochord, never develop a vertebral column, no lateral fins

Disadvantages of the Agnathans

Group Gnathostomata

Group of "true fishes". They have mouths with jaws

Series Pisces and series Tetrapoda

Two series of group Gnathostomata

Class Chondrichthyes and class Osteichthyes

The two classes within series Pisces

Class Chondrichthyes

The class known as the "cartilaginous fish"

Class Osteichthyes

The class known as the "bony fish"


Class Chondrichthyes appeared (#) million years ago


There are (#) extant species in class Chondrichthyes


Class Osteichthyes appeared (#) million years ago

Class Osteichthyes

This class makes up the majority of "fish" species

Class Amphibia, class Reptilia, class Mammalia

The three classes within series Tetrapoda

marine, boundaries

The vast majority of fishes are _____ due to there being fewer __________ in the ocean.

caudal fin

Used by fish as the main source of propelling through the water

do not have

Agnathans (do have / do not have) scales


An animal in which the body temperature varies with the environmental temperature


An animal that is able to maintain/control a relatively constant body temperature


An animal whose main source of heat is internal


An animal whose main source of heat is external

Homologous structures

Structures that have similar origin in the embryo

Analogous structures

Structures that have similar function

Class Cyclostomata

Which class keeps their notochord for their entire lives?


Some of this series keep their notochord, but most develop a skeletal system


The part of the skull associated with the brain


Cyclostomes have a(n) (incomplete / complete ) cranium


Pisces have a(n) (incomplete / complete) cranium

Group Gnathostomata

A vertebral column is present only in which group?


A condition in which as the body develops, it consists of repetitious segments


The muscular system of fish is relatively ______


The muscular system of fish consists primarily of _______


True fishes have more ______ in their muscles than cyclostomes


How many chromosomes are there in a normal human?


How many pairs of chromosomes are there in normal male humans?


How many pairs of chromosomes are there in normal female humans?


Which animal is our closest relative?


How many chromosomes do chimpanzees have?


Ecotypes that have become elevated to the level of a taxon.


A fossilized human-like species that is thought to be in the sample species as humans, but it is different enough to be in a different subspecies

Homo sapiens neandertalensis

The subspecies for the Neandertal

Homo sapiens sapiens

The subspecies for humans

surface area

The vertebral column is an advantage because it adds a large _______ ____ to which muscles can attach.


All poikilotherms are (endotherms/ectotherms).


(Homeotherms/Poikilotherms) consist of both endotherms and ectotherms.


Homeothermy can be achieved internally and by through _______ behaviors.

analogous; both

Most fish scales are (analogous/homologous/both) to tetrapod scales. The others are (analogous/homologous/both).

Group Gnathostomata

What is the only group that has a vertebral column?

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