Lecture 1-5 Flashcards
What is taxnomoy?
The discipline of naming and categorizing organisms based on shared traits.
What are the types of shared traits in taxonomy?
Morphological, developmental, molecular
What is phylogeny?
The evolutionary history of species or group of related species
What are nodes? (On a phylogeny tree)
Branch points that represent a common ancestor.
What is (the discipline of) systematics?
Classifying organisms and determining their evolutionary relationships.
What are the 4 categories to organize evolutionary relationships?
Fossils, morphological data, biochemical data, genetic data.
What are the 5 points of a phylogenic tree?
Branch point, sister taxa, ancestral root, outgroup, polytomy.
What are sister taxa?
Organisms (or groups) that share an immediate ancestor (on a phylogenic tree)
What is an outgroup?
A more distantly related group (of organisms) that serves as a reference.
What is polytomy? (On a phylogenic tree)
A branch from which two groups emerge.
Homologous structures.
Similar structures (may not be obvious), derived from a common ancestor.
Analogous structures.
Different structures (when looked at closely) with a similar function. Due to convergent evolution.
How are cladistics organized?
They are organized into groups based on common descent. So the group is the ancestor, and all of it’s descendants.
polyphyletic
includes distantly
related species but does not include their
most recent common ancestor`
paraphyletic
consists of an
ancestral species and some, but not all, of the
descendants
Shared ancestral vs shared derived character
Shared ancestor is a character that originated in an ancestor. Shared derived is a character novel to a particular clade
The Unikonta and what clades are included?
Supergroup branch of Eukarya. It includes the caldes Amoebozoans and Opisthokonts
Typical animal characteristics
Multicellular, no cell walls, can move, embryonic tissue (endoderm, mesoderm and ectoderm)
What type of life cycle do animals have?
A diplontic life cycle
What are the gametes of animal cells called?
Sperm and egg
What are choanoflagellates?
The best outgroup for multicellularity (not multicellular but closely related)
Phylum - Porifera. Talk about structure.
Sponges, have two cell layers (epidermis and choanoderm). Sponges are totipotent meaning they can regenerate and change cell fate.
What phylum did radial symmetry likely evolve from?
Cnidaria.
What are the two major early developments of Eumetazoan tissues?
Cleavage (mitotic division), and Gastrulation (Primitive gut and Blastopore)
Are embryonic tissues diploblastic or triploblastic?
Diploblastic (endoderm and ectoderm)
Clades vs Grades
Clades share a common ancestry, while grades share key biological features only. (no relationship between organism)
What is two sided symmetry?
Bilateral symmetry
Bilaterian symmetrical animals have what?
A dorsal top side and a ventral bottom side, right and left sides, and anterior front side and posterior back side
Cephalization
Radial symmetry - Networks of individual nuerons (Ex. Anemone)
Bilateral symmetry - Clustering of neurons (Squid)
Protostomia
Mouth forms first, anus might form later
Deuterostomia
Anus forms first, mouth forms later
Echinoderms (movement and symmetry)
Water vascular system, tube feet and water pressure enables movement. Most adult echinoderms have radial symmetry with multiples of five.
Some animals under the Echinoderm clade include
Sea stars, sea urchins, sand dollars, sea cucumbers
Defining characteristics of the chordates
Notochord (provides strength and support), Dorsal hollow nerve cord (develops into the central nervous systems), Pharyngeal gill slits (allows for movement of water, Post anal tail (can be reduced during embryonic development)
Three major clades of Chordates
Cephalochordate, Urochordata, vertebrata
Cephalochordata
The lancelets, most basal group of living chordates
Urochordata
The tunicates, chordata characteristic are only present in larvae stage
Vertebrates
Animals with vertebrae and skulls
Body cavities (and the three grades of organization in triploblasts)
Coelomates (cavity is lined with medoderm), Pseudocoelomates (body cavity partially lines by tissue derived from mesoderm), and Acoelomates
Lophotrochozoa
The widest range of animal body forms, includes the great Molluscs.
What are four major classes of Molluscan clades
Gastropods (snails and slugs) Bivalvia, Polyplacophora, and Cephalopoda
Annelida
Phylum containing worms
Clade Errantia
Annelid clade. Scale worms that are actively mobile, Parapodia and palps achieve locomotion
Clade Sedentaria
Less active segmented worms (tubeworms, earthworms)
Brachiopoda
Phylum, member of the Lophotrochozoan clade, Has a lophophore that is used to capture food. Attached to sea floor.
Platyhelminthes
Phylum. AKA flatworms. Live in marine/fresh water. No body cavity
Nematoda
Phylum. Contains the round worms. Most common animal on earth. Parasitic lifestyles.
Arthropods.
Twp of every three known species are arthropods. Body plan consists of segmented body, hard exoskeleton, jointed appendages
Crustacea (include body groupings)
Includes two segment groupings - Cephalothorax (pairs of antennae, walking legs) and Abdomen/tail
Hexopoda clade. And what do they undergo as they transform from larvae to adult.
Evolution of flight occurs here. Includes insects and their six legged kin. Undergo metamorphosis to transform from larva to adult.
