Biol 111 Final

Evolution

Genetic and resulting phenotypic change (observable property) in populations of organisms from one generation to the next

Ways of working out Evolutionary relationships

Includes: using a fossil record, morphological comparisons, development, molecular analyses and behaviour

Oldest Species

Brachiopod, Gingko Biloba, horseshoe crab, Coelocanth

Morphological comparisons

looking at changes in physical structure over time to help understand evolution

Genetic Analyses

Extract DNA and make evolutionary discoveries (EG Humans and Neanderthals recently discovered to have interbred via this method)

Origin of Life on Earth

Chemical Evolution

Miller and Urey Experiments

This expirment tried to mimic early conditions of earth and zapped these conditions with electricity. Discovered bases of RNA and DNA, 17 of 20 amino acids used in proteins and 3 and 6 carbon sugars.

Physical Changes over Time

Allows life to begin, includes: Continental Drift, volcanic activity, rise and fall of sea levels, temperature change, increase in O2.

Evolution of Photosynthesis

1) No O2 --> Light Energy Splits H20, organisms use free molecules to reduce CO2 and build organic molecules--> O2 is a waste product--> Aerobic Respiration--> More complex life

Cyanobacteria

Photosynthetic Prokaryotes-- form stromatolites

Precambrian

Era characterized by its largely unicellular nature, life confined to oceans-- 4.5 BYA-542MYA

Paleozoic

Old Life--542 MYA-251MYA

Mesozoic

Middle Life-- 251MYA-65MYA

Cenozoic

New Life--65MYA-Present

Late Precambrian

Eukaryotes evolve, "Ediacarian Animals"

Edicarian Animals

large soft-bodied animals in the Late Precambrian

Cambrian Explosion

Start of the Paleozoic period--rapid diversification of multicellular life

Ordvician

End of Early Paleozoic-- radiation of marine organisms, ended with mass extinction (75%)

Silurian

In mid-paleozoic era--marine life rebounds, early plant life forms, arthopods, animals swim and feed above ocean bottom

Devonian

In mid-Paleozoic era-"age of fishes" -- fishes evolve jaw, radiation of corals, club mosses, ferns, horsetails, gymnosperms-- ends with 75% marine mass extinction

Carboniferous

Late Paleozoic-- "Age of Amphibians or Coal" --Amphibians diversify, land has giant swamp forests, insects evolve flight, crinoids in oceans, !amniotic egg evolves!

Amniotic Egg

...

Permian

Reptiles Diversify from other amniotes begin to dominate over amphibians-- largest mass extinction 96%-- O2 drops by 50%

Triassic

Early dinosaurs, 1st mammals, diversification of invertebrates, 65% mass extinction

Jurassic

terrestrial herbivores, dinosaurs are predators, flying reptiles appear, first fossils of flowering plants, ray-finned fishes

Cretaceous

Dinosaurs continue to diversify, first snakes appear, small mammals radiate-- mass extinction via meteorite

Cenozoic

"age of mammals", radiation of birds, radiation of flowering plants (angiosperms), radiation of mammals (hominids

Characteristics of life

Energy transformation, reproduction, maintain homeostasis

Autotroph

self-feeding-- can make organic molecules using inorganic compounds

Photoautroph

Use light and CO2 to make organic compounds

Chemoautotroph

use Chemical Energy and

heterotroph

"different feeding"

Chemoheterotroph

consume food as an energy source and a C source to convert to other organic molecules

Photoheterotroph

use light as an energy source, but obtain C from food

sexual

union of gametes-- genetic difference between parents and offspring

asexual

no union of gametes-- little or no genetic difference offspring vs parent

diversity

genetic variation, species composition, and interaction between ecosystems all fall under the umbrella of diversity

Terry Erwin

found a ridiculous number of beetle species in one species of tree

3-100 million

How many eukaryotic species are estimated?

10-25% increase in species

Doubling area has what effect on diversity?

Warm and wet areas

Which has more species warm and wet areas, warm and arid areas, dry and cold areas or cold and wet areas?

arthopods, plants, molluscs, fungi, vertebrates, protozoa, algae, worms (APMFVPAW)

what is the order of eukaryotic diversity?

Genetic Diversity

measure of genetic difference (evolutionary separation)

functional diversity

differences in shape, size, and generally ways of making a living

archaea

lipid monolayer, absence of peptidoglycan cell wall, distinctive lipids present in their membranes

plasmids

extra-chromosomal DNA, small rings, easily exchanged during sex

bacteria

no membrane bound organelles, cell membrane is highly folded, site of ATP and photosynthesis, no true nucleus

lack of nucleus allows simultaneous transcription and translation

why can bacteria reproduce so quickly?

Gram positive

thick cell wall in bacteria

Gram negative

thin cell wall between two membranes

Bacterial reproduction

asexual, binary fission, short generation times

Conjugation

bacteria swap genetic info on plasmids

Endospores

protect bacteria from adverse conditons

Biolfilms

polysaccharide gel trapping debris and other cells, hundreds of cells thick, many or single specie-d

Chemotaxis

bacteria move toward or away from chemical signals

anaerobes

don't require O2 for metabolism.

obligate anaerobes

O2 is toxic

facultative anaerobes

Use O2 if available

aerotolerant anaerobes

can survive in O2 but don't use it

aerobes

must use O2 for metabolism

exotoxins

secreted proteins, very toxic

endotoxins

outer bacterial membranes, rarely fatal

99%

% of species extinct

Cocci

Sphere bacteria

Bacilli

Rod bacteria

Spirili

helical

Diversity of prokaryotes

simplicity of cell structure, but very diverse due to habitats and long evolutionary history

Cyanobacteria

This type of bacteria is photoautotrophic

Prokaryotes

can be decomposers, have sympbiotic relationships or be pathogens

Nitrogen-Fixing Bacteria

Symbiotic plant-bacteria relationship example

Binomial Nomenclature + Hierarchy

2 key concepts in Taxonomy

Carolus Linnaeus

Swedish botanist who proposed the modern system of biological nomenclature (1707-1778)

Eukary and Archaea

Bacteria, Eukarya and Archaea: Which are most closely related

Homology

Shared Ancestry

Analogy

similarity due to common environment, convergent evolution

Monophyletic

Common ancestor+ all descendants

Derived Trait

Trait shared by the group, but not found in the common ancestor

Paraphyletic

pertaining to a grouping of species that consists of an ancestral species and some, but not all, of its descendants.

Polyphyletic

pertaining to a grouping of species derived from two or more different ancestral forms

Eukaryotes

"true nucleus"

Endosymbiosis

One cell swallows a prokaryote but ends up living together instead of being digested-- (prokaryote--> Eukaryote over evolutionary time frames)

Protists

not a true taxonomic group, used out of convenience-- vary greatly

Unikonts

type of protist-- single flagella--

Amoebozoans

Amoebas + slime molds

Amoebas

unicellar protists characterized by movement via pseudopods + cytoplasmic streaming + eat via phagocytosis+ may have "test" or hard shell

Slime Molds

move by cytoplasmic streaming, eat via phagocytosis, form large aggregates, reproduce via fruiting bodies and spores

Rhizaria

foraminiferans + radiolarans

Foraminiferans

Primarily marine, secrete CaCO3, pseudopods stick out of test-- used to capture prey and for some locomotion

Radiolarans

Thin, stiff pseudopods stick out of test (test made of SiO2)-- very ornate/unique--marine zooplankton

Excavates

Diplomonads + Parabasalids

Metamonads

Unicellular-No mitochondria, anaerobic, symbionts(eg Giardia or eg mutualistic in gut of termites digesting wood), flagellated

Plantae

Red Algae + Green Algae -- common ancestor= endosymboisis of cyanobacteria

Glaucophytes

contain small amount of
peptidoglycan on inside and outside of
chloroplast membrane, same as cyanobacteria

Green Algae

photoautotrophs, unicellular, colonial, multicellular filaments, multicellular sheets, freshwater, marine and terrestial

Red Algae

multicellular, marine, photoautotrophs, source of agar, accessory pigments, some secrete CaCO3

Chromalveolates

Usually have cellulose in their cell walls --Alveolates have sacs (aveoli) just below their
plasma membrane

Apicomplexans

obligate animal parasites-- unicellular--complex life cycles involving mutliple hosts, non-functional chloroplast--cause of malaria

Brown Algae

Photoautotrophs, multicellular, large, marine, temperate coastal, grow very quickly, form kelp forests, produce alginic acid

Diatoms

important part of the phytoplankton--unicellular, photoautotroph, cell walls of SiO2, toothpaste, metal polishes, pool filters

Necessities of Plant life

optimum hydration, protection of gametes from dehydration, maintenance of physical structure of the body, obtain sufficient nutrients from surrounding medium, carry out max. photosynthesis, grow as big as possible.