WMAN 224 Exam 1

4.4 billion years ago

when did life begin

Endosymbiosis

symbiosis in which one of the symbiotic organisms lives inside the other.

Georges Cuvier

fossils and extinction

catastrophism (catastrophe leads to evolution and new species)

Wrong that function determines form

Jean-Baptiste Lamarck

Lamarckian evolution (Wrong): aquired characteristics are inherited and passed down. inheritance is non random (wrong)

Alfred Russel Wallace

supported Darwin's claims by determining that species were separated by natural barriers. (line between Asia and Australia.

charles darwin

toured the Galapagos Islands and developed the basis of evolution. Survival of the fittest and descent with modification.

Importance of Galapagos Islands

low biodiversity, very isolated, and unique organisms. (simplified)

Genetic forces of Evolution

Bottleneck, founder effect, non-random breeding, mutation, and variation

evidence of evolution

similar structures (5 fingers and tetrapod limb) chordates similar embryonic structures.

Embryonic Chordate Characteristics

Pharyngeal pouches, dorsal hollow nerve cord, notochord, postanal tail, and an endostyle/thyroid gland

paedomorphism

The retention in the adult of features that were juvenile in its ancestors

analagous characters

Physical structures with similar function but different underlying structures. (derived independently)

symplesiomorphy

traits unchanged from an ancestor that are inherited by a group of lineages (backbone in chordates)

autapomorphy

traits that are different than ancestors and unique for a particular lineage (helps determine differences in lineages but not link evolutionarily)

synaptomorphy

traits that are different from an ancestor and shared by more than two lineages (forelimbs nor present in sharks or fish but in present in whales, humans, cats, lizards etc.)

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

divergent evolution

when two or more species sharing a common ancestor become more different over time (to fill different niches)

species

individuals of a population who look similar, occupy the same niche, have the same genetic history, and the potential to interbreed and produce viable offspring in a place and time period.

speciation mechanisms (prezygotic)

habitat isolation

temporal isolation (timing)

behavioral isolation

mechanical isolation (size and shape)

genetic isolation (sperm egg protections)

speciation mechanisms (postzygotic)

Genes very different = no offspring

genes very similar = offspring (viable or not viable) and inbreeding (maybe offspring maybe viable)

vagus nerve

the tenth cranial nerve that innervates digestive organs, heart and other areas

homologous characteristics

similar in two or more species because they are inherited from a common ancestor

Carolus Linnaeus

developed binomial nomenclature, father of taxonomy

phylogenic classification

classification of organisms based on their assumed evolutionary histories and relationships.

Systematics

study of the diversity of life and the evolutionary relationships between organisms

cladograms

a branching diagram showing the cladistic relationship between a number of species.

Clade

A group of species that includes an ancestral species and all its descendants.

Apomorphy or derived character

different from the ancestral condition; evolutionary novelties

synapomorphy or shared derived character

shared by two or more species or taxa and has originated in their most recent common ancestor

Plesiomorphies

ancestral states; not informative in constructing phylogenies

Symplesiomorphies

shared ancestral states (not informative about phylogenetic relationships)

Heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

Chordate

animal that has for at least one stage of its life: a dorsal, hollow nerve cord, a notochord, a segmented muscular postanal tail; Endostyle, and pharyngeal pouches

Subphylum Vertebrata characteristics

development of neural crest/skull

proper brain (3 parts)

Hox genes (segmented body)

vertebral column

almost all notochord develop into disks

myxini (hagfishes)

Produce slime for defense

Jawless (form a knot to feed)

Eats sporadically (snake like)

100 to 1 female to male ratio

No larval stage (unlike lampreys)

Petromyzontidae

eel-like

jawless

marine and freshwater (sea lamprey is anadromous (migrate upriver to spawn)

larval and adult form

only half parasitic

Petromyzontidae larvae stage

Ammocoetes (larvae) are benthic, filter feeders up to 7 years

petromyzontidae adult stage

Non parasitic adults (dont feed, only mate, up to 6 months)

parasitic adults (1-3 years)

Conodonta

(extinct)

soft eel-like bodies

jawless filter feeders

known for conodont elements (very small teeth)

Pteraspidomorphi

(extinct)

armored jawless fishes

extinct in late Devonian

Ostracoderms

earliest agnathans, armored, very abundant in their time period, jawless filter feeders,

Agnathans

jawless vertebrates

Gnathostomes

jawed vertebrates

Jaws

what evolutionary step is considered most important for vertebrates?

Cambrian explosion

rapid diversification of species at the beginning of the Paleozoic with the advent of jaws

placodermi

(extinct)

first jawed fishes

armored

teeth (bony plates that were not replacable)

Chondrichthyes (physical characteristics)

cartilaginous skeleton (no ribs)

paired eyes, pectoral, and pelvic appendages

most heterocercal tail (downward force)

lipid filled liver (maintains buoyancy)

placoid scales (reduce resistance)

constant teeth replacement (in lines)

Chondrichthyes (senses)

Good vision (color) (tapetum Lucidum)

good hearing,

great smell (can detect proteins, amino acids, and blood)

Electroreceptors (ampullae of Larenzini)

Lateral line (move detection)

tapetum lucidum

eyes shine, reflects light into the retina a second time)

Ampulae of Lorenzini

-sensory vesicles that respond to changes in temperature, water pressure, weak electrical fields, and salinity

lateral line

sensitive receptor system that enables fish to detect gentle currents and vibrations in the water

saltwater bony fishes (osmoregulation)

actively excrete salts, tend to gain salt lose water, always drinking

hyposmolal (hypotonic) body fluid less concentrated salt than surrounding)

freshwater bony fishes (osmoregulation)

active transport of salt in (though gills), tend to lose salt and gain water, lots of urine to expel water

Hypresomal (hypertonic) higher salt concentration than surrounding.

Hagfish osmoregulation

Iso-osmotic to their saltwater environment. No net influx or efflux of water. Similar mineral concentration to the environment. Perform as osmoconformers instead of osmoregulators.

chondrichthyes osmoregulation

keep udea in body to balance osmotic pressure

urea toxic so must produce TMAO to protect proteins.

Stenohaline

organism does not move among water salinity concentrations

euryhaline

organism can reverse water concentrations as they move between them

Halocephali

chimeras and ratfishes

deepwater, fairly unknown

venomous dorsal spine

Elasmobranchii superorders

Galeomorphi:

Squalimorphy:

Batoidea:

elasmobranchii

sharks skates and rays

diverse reproduction

age at maturation 6-18 years

hyostylic jaw suspension

most ectothermic

can be parthenogenic

parthenogenesis

Asexual reproduction in which females produce offspring from unfertilized eggs.

Hyostylic Jaw Suspension

jaw not attached directly to cranium and can be extended out

elasmobranchii reproduction

Oviparity (egg laying - 40%)

Live birth (60%)

uses yolk (ovoviviparity)

ovoviviparity and eats sibling (embryophagy)

ovoviviparity and eats ovulated eggs (oophagy)

ovoviviparity and then yolk sac attached to placenta (uterine viviparity)

batoidea

skates and rays

dorsoventrally compressed

eyes and spiracle dorsal

euhyostyly (jaw nor conected to cranium

skates

2 pelvic fin lobes, egg laying (oviporus), no stinging spike, prominent dorsal spine

squalimorphi

shark like

no anal fin

primitive most deep sea sharks

Lanternshark, cookiecutter, greenland, and megamouth sharks

galeomorphi

Shark sharks

top predators (some filter feeders)

heterocercal caudal fin

anal fin

5 fils

galeomorphi examples

great white, megalodon (extinct), whale shark (largest), Basking shark (small brain, second largest), frilled shark, great hammerhead, bull, tiger.

big three

bull shark: can enter fresh water

great white; largest

tiger shark; most aggressive

Nuctitating membrane

chandrichthyes dont have eyelids but mebranes that cover eyes from inside corner)

buccal pumping

A form of breathing in which animals take in water or air into their mouths, then raise the floor of the mouth, creating a positive pressure that pumps water or air across the gills or into the lungs; found in fishes and amphibians

ram ventilation

The production of respiratory flow in some fish in which the mouth is opened during swimming, such that water flows through the mouth and across the gills.

ovoviparity

fertilized eggs are retained within mother to complete development, but all nourishment gained from yolk sac

Oviparity

egg laying

ray

1 pelvic fin lobe, live bearing (viviparous), whip-like tail and stinging spike, absent dorsal spine