Zoology - Chapter 4, 5, & 7 review

Organic Evolution

Organic Evolution

Population change overtime.

Natural Selection

Theoretical process by which gene variation and the environment lead to significant changes in a population because individuals with gene variations more suited to the environment survive longer and reproduce more.

Theory of Inheritance

the theory that organisms develop new traits as needs arise and pass these acquired traits down to their offspring (wrong) (Lamarck)

Adaptive radiation

the formation of a new species from an ancestral species caused by the availability of a new habitat.

Adaptation

occurs when an inheritable phenotype increases the likelihood of an animal to survive and successfully reproduce.

Fitness

a measure of the capacity for successful reproduction in a given environment compared to other of the same species.

Microevolution

a change in the frequency of alleles in population over time.

Macroevolution

Large-scale changes that result in an extinction or formation of a new species

Biogeography

the study of the geographic distribution of plants and animals.

Paleontology

the study of the fossil record.

Fossils

evidence of plants and animals from the past that has become a part of the earth's crust.

Convergent Evolution

When unrelated species have similar adaptations (Analogous)

Analogous Structures

Similar structures due to convergent evolution.

Homologous Structures

Similar structures due to shared ancestry.

Comparative Anatomy

The study of structural similarities in living or fossilized animals and homologies that show evolutionary relationships.

Homeotic Genes

Determine identity of body regions in early embryos.

Phylogeny

refers to evolutionary relationships among species.

Phylogenic Tree

shows lines of descent from an ancestral species to modern descendants.

Nodes

represent individuals, populations or species.

Branches

represent evolutionary connection between nodes.

Population

groups of individuals of the same species that occupy a given area at the same time and share a common gene pool.

Gene pool

the sum of all the alleles for all traits in a sexually reproducing population.

Population Genetics

the study of the genetic events in gene pools.

Hardy-Wienberg Theorem

States that mixing of alleles in meiosis and their recombination don't alter allele frequencies across generations, given several factors.

• large population

• Random sexual reproduction

• no migration

• no mutation

• no natural selection

Genetic Drift

Chance events effecting gene frequencies in a population (Neutral evolution)

Founder Effect

a type of genetic drift caused by the separtation of a few individuals from a bigger population, creating their own population. They do not carry the same gene frequencies as the larger population so this new population will likely have less genetic variation.

Bottleneck Effect

A form of genetic drift that takes place when an event dramatically decreases the size of a population resulting in decreased genetic variation even as populations regrow.

Gene Flow

Changes in gene frequency caused by immigration or emigration of individuals.

Mutation Pressure

a measure of the tendency of gene frequencies to change through mutation.

Selection Pressure

the tendency for natural selection to occur

Directional selection

occurs when individuals with one phenotypic extreme are at a disadvantage compared to all others causing a decrease in that extreme.

Disruptive Selection

Occurs when both phenotypic extremes are at an advantage to those with the intermediate phenotype.

Stabilizing Selection

Occurs when both phenotypic extremes are at a disadvantage and leads to a decrease in phenotypic range.

Balanced Polymorphism

occurs when different phenotypes are maintained at relatively stable frequencies.

Species

a group of populations in which genes are actually or potentially exchanged through interbreeding.

Speciation

The formation of a new species.

Reproductive isolation

when populations cannot reproduce with one another

Premating isolation

prevents mating altogether, via impenetrable barrier or changes in courtship behavior.

Postmating Isolation

prevents successful fertilization.

Allopatric Speciation

Occurs when subpopulations become geographically isolated.

Demes

Small local populations, not isolated.

Parapatric Speciation

relative isolation of a deme can make its members experience different selection pressures that can ultimately result in speciation. (No certain cases)

Sympatric Speciation

Occurs within one population when individuals become reproductively isolated.

Phyletic gradualism

evolution occurs gradually over millions of years.

punctuated equilibrium

long periods of stasis interrupted by brief periods of change.

Mosaic Evolution

occurrence within a population of different rates of evolution in various structures or functions.

Systemics

study of evolutionary relationships among and diversity of organisms. (Taxonomy)

Nomenclature

Assignment of distinctive names to each species.

Taxon

any grouping of animals that share a particular set of characteristics.

Classification order

Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Evolutionary conservation

slowness of change even through evolution

Monera

all bacteria and cyanbacteria (challenged)

Protista

Eukaryotic, single celled or colonies.

Plantae

Eukaryotic, multicellular, and photosynthetic

Fungi

Eukaryotic, multicellular, and digest organic matter.

Animalia

Eukaryotic, multicellular, and feed by ingesting other organisms.

Archaea

Prokaryotic microbes that live in extreme environments (Domain and Kingdom)

Eubacteria

true bacteria, prokaryotic microorganisms (Domain and Kingdom)

Eukarya

Includes all Eukaryotic organisms (Domain) (Protista, Plantaea, Fungi, Animalia)

Monophyletic Group

includes a single ancestral species and all its descendants.

Polyphyletic Groups

Members that can be traced to separate ancestors.

Paraphyletic Group

includes some but not all descendants of an ancestral species

Out group

a related group that is not included in the study group

Derived Characters (Synapomorphies)

characters that have arisen since common ancestry.

Cladogram

depict a sequence in origin of derived characters.

Asymmetry

absence of a central point or axis

Radial Symmetry

arrangement of body parts such that any plain passing through the axis would divide the organism into mirror images.

Bilateral Symmetry

arrangement of body parts such that a single plain would divide the left and right into mirror images.

Cephalization

Developments that result in the formation of a distinct head (Only bilateral symmetry)

Diploblastic

Body parts organized into two layers derived from two embryonic tissue layers.

Triploblastic

Body parts organized into three layers derived from three embryonic tissue layers.

Endoderm

inner most layer, turns into gastrodermis

Ectoderm

outer most layer, turns into the epidermis

mesoderm

(only triploblastic) middle layer, turns into supportive, contractile and blood cells.

Acoelmate

mesoderm forms a solid mass between the other layers

Psuedocoelmate

body cavities are not completely lined by mesoderm

Coelmate

body cavities completely surrounded by mesoderm (messentaries present)

Protostomes

Spiral and Determinate (Blastopore becomes mouth)

Dueterostomes

Radial and Indeterminate (Blastopore becomes anus)

Commonalities of Life

Cellular organization, the ability to reproduce, growth & development, energy use, homeostasis, response to their environment, and the ability to adapt.

of species classified

1.6 million (3-100 million more estimated)

Parsimony

Choosing the easiest possible answer.

Four ways classifying animals into phyla

type of coelem, type of symmetry, development, and number of tissue layers.

Anterior (cephalic)

head end

posterior (caudal)

tail end

ventral

belly

medial

middle

lateral

outsides

distal

farther from main body on limb

Proximal

closer to main body on limb

oral

mouth side

aboral

opposite of mouth