Campbell Unit 5: The Evolutionary History of Biological Diversity

Phylogeny

The evolutionary history of a species.

Systematics

A method focused on classifying organisms and determining their evolutionary relationships.

Binomial

The two-part format of a scientific name.

Genus

The first part of the binomial of a scientific name.

Taxon

A named group at any level of the hierarchy.

Phylogenetic Tree

A branching diagram that represents the evolutionary history of organisms.

Branch Point

Represents the common ancestor of two evolutionary lineages diverging from it.

Evolutionary Lineage

A sequence of ancestral organisms leading to a particular descendant taxon.

Sister Taxa

Groups of organisms that share an immediate common ancestor not shared by any other group.

Rooted

A tree where there is a branch point from which all other animals come off.

Basal Taxon

A lineage that diverges from other members of its group early.

Homologies

Phenotypic and genetic similarities due to shared ancestry.

Analogy

Similarity between organisms due to convergent evolution.

Cladistics

An approach to systematics where common ancestry is prioritized.

Clades

Groups that scientists try to place species into.

Monophyletic

A taxon that consists of an ancestral species and all of its descendants.

Paraphyletic

A group consisting of an ancestral species and some, but not all, of its descendants.

Polyphyletic

Distantly related species that do not include the most recent common ancestor.

Shared Ancestral Character

A characteristic that originated in an ancestor of the taxon.

Shared Derived Character

A characteristic unique to a clade.

Orthologous Genes

Homology is from a speciation event.

Paralogous Genes

Homology is from gene duplication.

Molecular Clock

An approach estimating age divergence from a common ancestor by looking at DNA.

Extremophiles

Prokaryotes that live in extreme environments that few other organisms can survive in.

Decomposers

Chemoheterotrophic prokaryotes that break down dead organisms and waste products, unlocking supplies of carbon, nitrogen, and other elements.

Symbiosis

An ecological relationship where two species live in close contact with each other.

Mutualism

An ecological relationship in which both species benefit.

Commensalism

An ecological relationship in which one species benefits while the other isn't harmed or helped.

Parasitism

A relationship where a parasite feeds on the cell contents, tissues, or body fluids of the host.

Pathogens

Parasites that cause disease, usually prokaryotic.

Bioremediation

The use of organisms to remove pollutants from soil, air, or water.

Protists

Eukaryotes that are not animals, plants, or fungi.

Mixotrophs

Protists that combine photosynthesis and heterotrophic nutrition.

Secondary Endosymbiosis

Algae ingested in food vacuoles of heterotrophic eukaryotes.

Diplomonads

Protists with reduced mitochondria called mitosomes.

Parabasalids

Protists with reduced mitochondria called hydrogenosomes.

Euglenozoans

A diverse clade of protists with either a rod with a spiral or crystalline structure inside their flagella.

Kinetoplastids

Protists with a single large mitochondrion with an organized mass of DNA called a kinetoplast.

Diatoms

Unicellular algae with a unique glass-like wall made of silicon dioxide embedded in an organic matrix.

Brown Algae

Multicellular stramenopiles, mostly marine, with a root-like organ called a holdfast and a stem-like organ called a stipe.

Alveolates

Membrane enclosed sacs (aveoli) just under the plasma membrane

Dinoflagellates

Group of aveolate flagellates, cells reinforced by cellulose plates

Apicomplexans

Aveolate parasites of animals, spread through hosts as tiny infectious cells

Ciliates

Large and varied group of aveolates named for use of cilia to move and feed, prottists

Conjugation

Sexual process in which two individuals exchange haploid micronuclei but don’t reproduce, results from genetic variation in nuclei of ciliates

Rhizarians

Many species of amoebas

Amoeba

Protist that moves and feeds by pseudopia

Pseudopia

Extensions that bulge from anywhere on the cell surface

Radiolarians

Have delicate, intricately symmetrical internal skeletons made of silica

Foraminiferans/Forans

Named for their porous shells (tests, which have a single piece of organic material usually hardened with calcium carbonate)

Cercozoans

Large group of omoeboid and flagellated protists that feed using threadlike pseudopia

Archaeplastida

Red algae, green algae, and plants

Green Algae

Chloroplasts very similar to chloroplasts, charophytes & chlorophytes

Charophytes

Algae most closely related to plants

Chlorophytes

Mostly freshwater species

Unikonta

Diverse subgroup of eukaryotes with animals, fungi, and some protists

Amoebazoans

Many species of amoebas with love or tube shaped pseudopia

Opisthokonts

Diverse group of eukaryotes with animals, fungi, and several groups of protists

Producers

Organisms that use energy from to convert CO2 to organic compounds

Consumer

Organisms that depend on producers for food by directly eating them or eating an organism that eats them

Charophytes

Share many distinctive traits with plants and are the closest relatives of them

Sporopollenin

Durable polymer layer in charophytes, prevents exposed zygotes from drying out

Alternation of Generations

Life cycle in which multicellular forms give rise to each other in turn

Gametophyte

Produced by mitosis of haploid gametes that fuse during fertilization (and form diploid zygotes)

Sporophyte

Meiosis of it produces haploid spores

Spores

Reproductive cells that can develop into a new haploid organism without fusing with another cell

Embryophytes

Multicellular dependent embryo of plants

Walled Spores

Produced in sporangia, only in plants and not in algae

Sporangia

Multicellular organs that produce spores

Apical Meristems

Localized regions of cell division at tips of roots and shoots, only in plants and not algae

Cuticle

Covering of epidermis, consisting of wax and other polymers

Stomata

Specialized pores supporting photosynthesis by allowing exchange of CO2 and O2

Vascular Tissue

Cells joined into tubes that transport water and nutrients

Vascular Plants

Plants with vascular tissue

Seedless Vascular Plants

Lycophytes and monilophytes, don’t form a clade

Lycophytes

Vascular club mosses and their relatives

Monilophytes

Vascular ferns and their relatives

Bryophytes

Plants without vascular tissue, don’t form a clade

Seed

Embryo packaged with a supply of nutrients inside a protective coat

Gymnosperms

Seeds not enclosed in chambers, “naked seed” plants

Angiosperms

All flowering plants, seeds from chambers, ~90% plants

Pollen Grain

Male gametophyte enclosed within the pollen wall

Pollination

Transfer of pollen to the part of a seed plant that contains ovules

Conifers

Cone bearing plants, most gymnosperms

Flower

Unique angiosperm specialized for sexual reproduction with up to four floral organs (modified leaves)

Sepals

Green and enclose flower before it opens (like a rosebud)

Petals

Interior to the sepals, brightly colored and attract pollinators

Stamens

Microsporophylls, produce microspores that develop into pollen grains with

Pheremones

Signaling molecules released by hyphae from two mycelia

Plasmogamy

Union of cytoplasms of two parent mycelia

Heterokaryon

Parts of the fused mycellium contain coexisting genetically different nuclei

Dikaryotic

Haploid nuclei pair off two to a cell, one from each parent

Karyogamy

Stage after plasmogamy in the sexual cycle, haploid nuclei contributed by two parents fuse and form diploid cells

Molds

Fungi that reproduce asexually by growing as filamentous fungi that produce haploid spores by mitosis and form visible mycelia

Deuteromycetes

Fungi lacking sexual reproduction

31.3

The ancestor of fungi was an aquatic, single celled, flagellated protist

Opisthokongs

Posterior location of flagellum

Nucleariids

Amoebas that feed on algae and bacteria, closely related to several single celled protists

31.4

Fungi have radiated into a diverse set of lineages

Cryptomycetes

Fungi in lakes and soil with zoospores