mammals

taxonomy?

the practice & science of naming and classifying organisms. Taxo = Group; Nom =Name

Classification

the ordering of species into groups and naming the groups.

Systematics

science of classifying organisms based on their evolutionary relationships

Binomial Nomenclature

a system for naming all organisms in which there are two names, one for the genus and one for the species

Hierarchy of Classification

Domain Kingdom Phylum Class Order Family Genus Species

Subspecies

Mammal domain

eukarya

mammal kingdom

animalia

mammal phylum

chordata

mammal subphylum

vertebrata (arcopterygii, Tetrapoda, Amniota, Synapsida_

traits of mammals?

hirsute

lactogenic

endotherms

hirsute

covered in hair that has Alpha beta keratin

Mammal are what for kids

viviparous with amniotic sac

Monotremes

platapus

Enucleated red blood cells

No nucleus in blood cell creat4es more space for oxygen binding; allows folding and getting into small areas

Muscular diaphragm

creates space between lung and heart; pulls oxygen down on inhale to increase lung capacity

No renal portal system

Our kidneys aren’t a stop-off point no more; more efficient blood movement, tied to terrestrial movement, after movement to oxygen

Nitrogenous wastes excreted as urea

liver

dermal?

layer under skin

Integumentary

skin

Complex facial dermal muscles

for whiskers

mammal soft anatomy

makes mammals a more efficient organism (no fossilization)

Double occipital condyle

spheres at the back of the head

where spinal cord fits in at the atlas

creates more flexible movement in head

Epiphyseal line on long bones

where bone growth occurs

In between shaft of bone and where the bone articulates

Is cartilaginous (stronger bones and joints)

Less breakage in middle but strong joints at that area

growth plate

diaphysis and epiphysis

dentary bone

singular jaw bone

squamosal

moves dentary

diphyodont teeth

2 sets of teeth

baby and adult

heterodont dentition

multiple type of teeth

Hard secondary palate

for eating while breathing

seperate nasal cavity and mouth

Calcaneus

heel bone

for speed

hard anatomy

to create a strong skeleton

systematics

Science of classifying organisms based on their evolutionary relationships

Determine evolutionary relationships using traits/data

Traits/data are analyzed to develop a phylogeny

Phylogeny

hypothesis of the evolutionary history/relationships of a taxon or group of related taxa.

Usually depicted as a “tree”

Phylogeny tree parts

Terminal Branch

Internal Branch

Node

Root

Taxon

Group of organisms that bear the same name; Plural = taxa Greek: arrangement or group

Lineage, Clade, Monophyly, Polyphyly, Paraphyly

Taxa

all organisms represented

pural for taxon

internal branch

connect ancestors to decendents

terminal branch

only directly linked specific group

clade

includes internal branch

Monophyletic (Monophyly)

Taxon that includes all organisms descended from a single most recent common ancestor

Polyphyletic (Polyphyly)

Taxon that is composed of unrelated organisms descended from more than one common ancestor (does not include most recent common ancestor)

Paraphyletic (Paraphyly)

Taxon that does not include all organisms descended from a common ancestor

root

oldest/farthest branch

node

area where branches split

traits

Could be genetic data, morphological data, ecology, behavior, etc

how phylogentic trees are built

Synapomorphy

A trait that is shared by two or more taxa (shared derived trait)

Sympleisiomorphy

A shared ancestral character state

Homology/Homologous

Structures or properties with a similar evolutionary or phylogenetic origin, but not necessarily retaining a similar function, behavior, or identical structure

Analogy/Analogous

Structures or properties in two or more organisms that perform a similar function but the similarity is not the result of descent from a common ancestor

Morphology

Relationships determined via similarity

Comparative anatomy (need to determine homologous structures; not quantitative)

Morphometrics (measurements; quantifiable)

Karyology

Comparative cytogenetics

Isolation of chromosomes; infer relationships on morphology of chromosomes (structures holding DNA)

Molecular Methods

o Protein electrophoresis – movement of proteins in electric field

o Comparative Immunology – antigen/antibody reactions to infer relationships

o DNA X DNA Hybridization – Measures gross similarity between organisms

o RFLP (restriction fragment length polymorphisms)

o AFLP (amplified fragment length polymorphisms)

o Genetic data (gene, genome, SNPs, microsatellites)

Evolution

Change through time in a population/lineage

Evolutionary Trend

Directional change through time within a lineage

Convergent Evolution

Evolutionary trend observed in distantly-related organisms where each lineage shows independent evolution of superficially-similar features.

These lineages converge on the same trend/morphology via different developmental pathways

Parallel Evolution

Evolutionary trend observed in 2 lineages whom share a fairly recent common ancestor where each shows independent evolution of a similar feature via similar development pathways

not sister taxa

Homoplasy

A similarity in a character in two different species that arises from evolutionary convergence or parallelism, not common ancestry (noise)

permian

225 million years ago

pangea

triassic

200 million years ago

jurassic

135 million years ago

cretaceous

65 million years ago

Pangaea

ancient supercontinent

Alfred Wegener

Continental Drift

movement of large land masses of the earth’s surface

athenosphere moves lithosphere

Plate Tectonics

The theory that the earth’s crust is made up of a series of geological plates

Biogeography

Study of distribution of organisms, extinct and extant

Lithosphere

Earth’s crust

Athenosphere

layer under lithosphere

liquid

Vicariance

Geographic isolation of populations via development of natural barriers

Dispersal

Movement or spreading of organisms to new areas

caused by plates moving and shifter

creating speciation

Constantly creating new continental plates