Vertebrate Zoology Lecture Exam 1

Fish; 33,000 species

living species

dead species

~4 billion years old

~500 million years ago

Common ancestor

The environment causes them to adapt

“Phenetics”; groups are generated based on “similarities” (similar characteristics)

“Cladistics”; groups are generated based on relatedness, “common ancestor”

Phylum Chordata

Yes, some invertebrates

Notochord, dorsal nerve cord, pharyngeal gill slits/pouches, post-anal tail

A semi-rigid group of cells that are surrounded by fibrous and elastic tissues; NOT the vertebral column

Gives support and allows for body movement

Hagfish

The notochord persists throughout life, has a fibrous & cartilaginous skeleton (no bones), jawless, has no paired appendages, has a poorly developed brain & reproductive system (one gonad)

We have bits and pieces; we possessed it during embryonic development

We have pouches during embryonic development

Movement and stability

During embryonic development

Segmented muscle masses, endoskeletons, bilateral symmetry, closed circulatory system

Structural diversity, Ecological diversity, Physiological diversity, Temporal diversity

2 separate sexes

Both sexes @ same time

Sequentially changes from male to female (and vice versa)

Eggs develop without fertilization

The temperature of the environment and egg determines the sex of the offspring

There’s not a lot of terrestrial environment, mostly aquatic; invertebrates

Cambrian Explosion = causes an increase in the # of species

Start of the Paleozoic Era

Increase of invertebrate species

At the end of the Cambrian, the first vertebrates appear (jawless fishes)

~500 million years ago

Jawed fishes appear (placoderms & acanthodians)

Abundance of jawed & jawless fishes

Increase in terrestrial plants

410 million years ago

“Age of Fishes”

Jawed & jawless fishes in both salt & fresh water

360-400 million years ago

Dunkleosteus/Placoderm

Sharks are present

First terrestrial forests

First winged insects

First amphibian-like tetrapods

End of Paleozoic

Reptiles begin radiating

First mammal-like reptiles

• Dimetrodon (not a dinosaur)

Mass extinction = allows habitats to open up

• 90% of marine invertebrates & 70% of terrestrial animals go extinct

Amphibian-like tetrapods on land

Means “middle animals”

“Age of Reptiles”

Divided into three periods

1. Triassic Period

2. Jurassic Period

3. Cretaceous Period

~200-250 million years ago

Radiation of reptiles = increased variety & abundance

Triassic, Jurassic, Cretaceous

Carnivorous tetrapods that are up-right on their back 2 legs

Herbavores

Late Triassic, they become extinct in the late Cretaceous

Early birds & mammals

Archaeopteryx

A bird with reptilian characteristics (has teeth and actual tail)

No; mammals specifically are small insectivores

At the end of the Cretaceous period of the Mesozoic era

Asteroid impact; makes the Earth a bad environment for many species but many species also survive in the newly opened niches

“Recent/New Animals”

“Age of Mammals”

Two periods

• Tertiary Period

• Quaternary Period

Tertiary birds radiate

Mammals & birds proliferate/radiate

“Animals & plants were fixed, invariable, & were created when the Earth & they did not change over time.”

“Father of Taxonomy”

Systema Naturae

Developed:

• Linnaean Hierarchical Classification System

• Binomial Nomenclature

Theory of “Inheritance of Acquired Characteristics”

Transmutation Theory

Lamarckism

1. Animals acquire characteristics during their lifetime & pass the characteristics on to offspring.

   1. Animals are always progressing toward a higher form (all changes are for the good of the animal)

H.M.S. Beagle

“Principle of Geology” and “An Essay on the Principle of Population”

Sir Charles Lyell

The Father of Modern Geology

Thomas Malthus

“Survival of the Fittest”

“More humans are produced than can survive. Therefore there is a ‘struggle for survival’.”

Sir Charles Lyell

The world has undergone slow & gradual geological processes over millions of years

Sir Charles Lyell

No

They stay for 5 weeks, Darwin is on shore for 19 days

600 miles west of Ecuador, 1 to 4 million years old, volcanic formation, no human habitation until recent times, strong selective forces

They are not old in a geologic time scale; they are relatively young (1 to 4 million years old)

Very dry & harsh terrestrial environment with a rich marine environment, but it is cold.

Animals that were displaced to the Galapagos were from the mainland of Central or South America have either (1) perished or (2) adapted to the different and unique environment

No, he gradually develops “Theory of Evolution by Natural Selection” and collects data over 23 years

“The Voyage of the Beagle”; it makes him famous

Alfred Russel Wallace and Henry Walter Bates

He travels to the Malay Archipelago to explore Malaysia and Indonesia

“Darwin’s Bulldog”

Supported Darwin’s book and theory publicly

Yes; 150+ years later, it remains an accepted and unifying theory in the study of biology

1. A species is not “static”, organisms could gradually change over time

2. Darwin suggested “phyletic gradualism”: change is gradual over time

3. Concept of “common decent”: species could be derived from a common ancestor, accounting for “similarities” among different species

4. Concept of “survival of the fittest”: more individuals are produced each generation than can survive

5. Concept of “natural selection”: nature (environment) determines which individual survives; nature “selects” for traits that are advantageous; accounts for diversity

Provided the concept of evolution, BUT not a mechanism

“Father of Genetics”

Mendelian Genetics

A basis on how traits are passed on from one generation to the next

The ability to genetically transfer traits from parents to offspring; it’s a combination of Darwinian Evolution and Mendelian Genetics called Neo-Darwinism

Change in genetic composition over time; the change could be beneficial, deleterious, or “neutral”

the environment favors traits that are advantageous and increase the fitness of an organism in a given environment

Ability to survive and reproduce

An organism must be rapidly covered by sediment to prevent decomposition

1. the abundance and variety of animals & plants has varied over time

2. certain species appear in fossil records & over time certain species go extinct

3. some fossils appear to be transitional species (ex. Archaeopteryx)

structures that are embryonically related/have the same embryonic origin

Haeckel’s Biogenetic Law: “Ontogeny Recapitulates Phylogeny”

Suggests that the history of your phylogeny is reflected in your embryonic development

• Has similar characteristics (genetics)

• Is capable of interbreeding

• Reproductively isolated in nature

Genetically distinct and genetically isolated

Allopatric and Sympatric

Geographic isolation leads to speciation

Example: Galapagos Tortoises

Speciation occurring in the same location

Example: Lake Baikal sculpins

Both allopatric and sympatric speciation; once on an island, they adapted to different ecological niches

Systematics/Taxonomy

Kingdom, Phylum, Class, Order, Family, Genus, Species

Present in ancestral groups

Also called pleisiomorphies

a new characteristics that is only present in a specific group of organisms

Also called apomorphies

Traditional Systematics

It was based on structural similarities

Referred to as phenetics

Groups were based on similarities w/o regard to potential ancestry

Some traits were “weighed” more important than others (for classification)

Cladistics; classifying based on relatedness (common ancestry) based on “primitive” versus “derived” characteristics

1. Primitive characteristic

2. Shared Derived characteristic

Each characteristic is equal in “weight”

Monophyletic and Paraphyletic groups

Group includes all members hypothesized to be derived from a common ancestor

Group that does not include all members hypothesized to be derived from a common ancestor

Precambrian, Paleozoic, Mesozoic, Cenozoic