fossils on a continent are related to the existing organisms on that continent

organisms of one climactic zone are related to organisms of other climatic zones on the same continent

organisms on islands are related to organisms of the nearest mainland 

Nested hierarchy and binomial nomenclature

·      Domain

·      Kingdom

·      Phylum

·      Class

·      Order

·      Family

·      Genus

·      Species

Organizing Information:

·      Eukarya

·      Animalia

·      Chordata

·      Mammalia

·      Primate

·      Hominidae

·      Homo

·      Sapiens

  Given a chance, animals and vegetables would reproduce so that their populations would be huge and keep growing

Darwin’s 5 Observations

·      individuals produce as many offspring as possible

·      populations are mostly stable

·      essential resources are limited

·      individuals of a population vary

some variation if heritable and can be passed on

Darwin’s 3 Inferences

·      Inference 1- many born eventually die due to losing the struggle for resources

·      Inference 2- those individuals with heritable traits tat promote survival and reproduction will leave more offspring

·      Inference 3- over time, heritable traits promoting survival and reproduction will accumulate

The theory of evolution is FALSIFIABLE- 

Three-pronged support of Darwin's theory

1·      . Observations of artificial selection supported natural selection

 2. Scientists communicate their own and synthesize other great ideas

      3. Scientists working  independently arrive at the same great ideas

 Alfred Wallace

also described evolution by natural selection

Evolution has no goal

Because the mechanism driving evolution is natural selection and the agents of natural selection are natural selective pressures, which are mindless

o   evolution is natural selection and the agents of natural selection are natural selective pressures, which are mindless

strategy

the various traits organisms manifest that contribute to survival and reproduction

the unbiased interpretation of representative data

genetic drift

bottleneck

founder effect

Natural selection is not goal oriented

it is a manifestation of the vagaries of the environment

selective pressure

Selective pressure is any phenomena which alters the behavior and fitness of living organisms within a given environment. 

pleiotrophy

the condition of a single gene controlling more than one (and possibly unrelated) phenotypic traits (waardenburg syndrome- 2 different colored eyes, steak in hair, etc.)

"Strategy”

the traits manifested by organisms that contribute to their survival and reproduction 

·   it all SEEMS active and directed because selective agents exert pressure

selective agents exert pressures directionally (e.g. the temp. goes up or down; it is getting drier of wetter)

but the agents themselves are mindless and operate on mutations that occur by random chance

·      earth was formed 4.6 billion years ago- it was very hot with lots of gas

1 billion years later, life appeared

a cell 

is the smallest unit of life

to be alive an organism:

1. Is at least a single cell

2. reformulates energy from the outside world to…

3. …maintain its internal environment

4. …assemble the molecules it needs’

…to survive

…to grow

…to reproduce

5. reliably replicates itself passing on to its offspring heritable traits BUT

radioisotope decay

precise

nothing affects it but time

viruses

cannot replicate

genetic mutations 

are the only source of brand new alleles

The Origin of Life: with what?

oceans have formed

early atmosphere

hydrogen (H₂)most would escape into space with cooling

carbon monoxide

carbon dioxide

nitrogen

ammonia

methane

water vapor

Stanley Miller

imitated early components of life

Miller and Urey: Results

many organic molecules form spontaneously

amino acids

20 required to make all human proteins

MILLER PRODUCED 20 AND MORE, BUT DIDN’T KNOW IT AT THE TIME

The Origin of Life: When?

First rocks and oceans 4.0 – 3.8 BYO

oldest rocks are 3.8 BYO from Iceland

First fossils of micro-organisms 3.6 BYO

some new estimates as early as 3.8 BYO

Conclusion: must have arisen relatively quickly after earths surface cooled

The Origin of Life: Where?

in the primeval sea with polymers of amino acids forming on hot sand, clay, or rocks (see miller and urey)

OR

near submerged volcanoes at deep sea vents

OR

·      possibly on other planets (Europa, moon of Jupiter has liquid water and Mars had liquid water) and transported here

The Origin of Life: How?

organic molecules plus supply of energy from

·      lightning

·      intense UV radiation

·      hydrogen (near sea vents)

“life evolves, gets wiped out, evolves, gets wiped out…”

-the evidence of this is called the fossil record

Chixulub impact crater- 

Chicxulub Crater is an ancient impact crater buried underneath the Yucatan peninsula, with its center located approximately underneath the town of Chicxulub, Yucatan, Mexico

prokaryotes

simple, no nucleus

1. Bactieria

2. Archaea

o   extremeophile prokaryotes: live in (love) extreme conditions

eukaryotes

complex with a nucleus

how do we know evolution of life started 6.3 BYO?

because natural pressures were at work

what does natural selection work on?

o   Natural selection operates on the individual

·      …what evolves?

the population

·      what does natural selection operate on?

o   the phenotype, not genotype 

Microevolution

refers to the evolutionary process below the level of the species.

Macroevolution

refers to evolutionary processes at the species level and above.

Darwinian Fitness (SEE BELOW)

The greater number of offspring that an individual contributes to the next generation relative to the contribution of other member of the population

o   There is no set number of offspring to be called “fit.”

o   If you don’t have offspring, you still succeed by getting your genes into the next generation.

·      For example: siblings helping raise nieces and nephews—they still have 25% of their DNA.

Niche

the multidimensional “place” that a species occupies in the ecological “landscape.”

·      More than who, what, where, when.  Encompasses everything.

In ALL the world, among ALL the organisms consist of one or more cells.

Animals by definition consist of more than one cell.

·      A unicellular eukaryote is a protist.

Phylogenetic tree

hypothetical because they’re humans’ ideas of relationships between organisms

Scientists characterize animals by body plan: Phylum (about 35 phyla total)

Tissue layers

·      Body cavity

·      Symmetry (radial vs. bilateral)

Kingdom Animalia

1.3 million species identified

·      About 35 phyla: based body plans

o   Invertebrates account for 95% of species that have been described

o   Invertebrates accounts for all phyla except one (chordates).

o   All presumed to have come from a single ancestor: the ancestor of sponges SPECIES NAMES

Evolution of Animals

·      Shapeless blobs

·      Blobs with shape

·      Shape with left and right sides (bilateral)

·      DIVERGENCE (protstomy vs. duelerotomy)

Cnidaria

Symmetry

·      2 layers of tissues

·      Nerve net

Bilaterality leads to cephalization 

Cephalization leads:

Direct movement (e.g. predation)

CAMBRIAN Explosion 

·      Many triploblast, bilaterian animals suddenly appear

·      Before insects invade land

·      Three causes suggested (all possible)

·      1. increase in available oxygen

·      2. new predator-prey relationships (e.g., new predation leads to new escapes)

·      3. evolution of Hox gene complex (will define

The Burgess Shale Fauna

·      Discovered in 1909

·      About 525 MYO (early Cambrian)

·      In British Columbia, Canada

As humans, we are more closely related to 

·      Relationship to fungi to animals

o   Molecular genetic studies suggest fungi share a common ancestor with and are more closest related to animals than plants

o   Fungi also share certain features with animals

§  Cells walls contain chitin (found in some animals), not cellulose

Key events in plant evolution:

·      1. Invasion of land

·      fungal spores dated to 470 MYA

·      development of vascular tissue to provide body support

·      origin of seeds

·      origin of flowers and fruit

Four major Groups of Plants:

·      Non-vascular plants

·      Seedless vascular plants

·      Gymnosperms

·      Angiosperms (flowering plants)

Photosynthesis 

converts light energy from the sun into chemical energy.  Early life was capable of photosynthesis.  Photosynthetic life that would eventually become plants on land began in the water.

Cyanobacteria and O2

·      Only prokaryotes to photosynthesis and liberate oxygen

·      Oxygen saturates sea

·      Saturated seas allows excess oxygen to react with dissolved…

In the beginning…

·      There were cyanobacteria- a colonial prokaryote, some cells of which fix nitrogen, others of which photosynthesize

Later: Endosymbiosis

·      A eukaryote “engulfs” a cyanobacterium (prokaryote) (note: symbiosis) and can now also photosynthesize

·      Products: red and green algae

Plants are plants:

·      In the kingdom plantae

·      Algae are uni- or multicellular protists in the “kingdom” protista

anything that is not an animal, plant, or fungus, is a 

 protist

Algae:

·      Although most protists are unicellular

·      Algae (protists) can be unicellular or multicellular (they can be huge)

·      Several phyla of algea- the big ones we call seaweed

NOTE: land plants live on land and are

·      plants

BUT

·      Plants that live in water are algae

·      They are not plants

·      (They are that evolutionartily different)

Unless

·      Some land plants have returned to water. They are aquatic plants. (Similar to whales…)

Lichens

a symbiosis of fungi and (green) algae (leaf-like, shrub, crust)

Fungi (segue):

·      About 100,000 species described

·      Assumed to be about 1.5 million species

Relationship of Fungi to Animals

·      Molecular genetic studies suggest fungi share a common ancestor with and are more closely related to animals than plants

·      • Fungi also share certain features with animals

o   – Cells walls contain chitin (found in some animals), not cellulose (found in plants)

o   – Carbohydrates stored as glycogen (as in animals) and not as starch (as in plants)

Currently, 5 phyla of fungi

·      Chytrids

·      Zygomysetes

·      Glomeromycetes

·      Ascomycetes

·      Basidiomycetes

Yeast are

ascomyvetes and so are truffles and morels

Most “mushrooms” (the iconic shape) 

are basidiomycetes, and so are shelf fungi, maiden

Fungi feeding

·      Absorptive heterotrophs (like many prokaryotes)

·      “digest then ingest”- digestive exzymes secreted into surroundings; fungus then absorbs the digested products

·      most are decomposers, some are parasitic, and some symbiotic

Some generalities

·      Mold is common name, not scientific

o   Slime molds and water molds are protists. Bread molds is a fungus.

o   Fungi are ancient there presence is mostly underground and they are everywhere

Hyphae

tiny filaments of fungi that form a network underground and a “body” above

Mycelium

the interwoven network of hyphae underground

Sporulation

·      the release of spores

corn smut

treated as a pest by American farmers, delicacy in Mexico

essential ecology

associated with > 90% of plants

improve water/mineral uptake by plant roots

plant roots provides carbohydrates to fungus

mutualism thought to arrive with plants during their earliest invasion of terrestrial environment

all glomerocytes form arbuscular mycorrhizae which are symbiotic with plant roots. The fungi get sugar and the roots get water and nutrients

important economically

ascomycete

o   single-celled fungus

o   mostly asexual

o   inhibits liquid or moist environments

o   responsible for bread and wine and beer

saccharomyces cerevisiae

Important gastronomically

·      Some of the most famous edible mushrooms and ascomycetes

o   Morels, common in ohio in early spring

o   Truffles, famous underground fungus of the forest floor. Pigs and special trained dogs are used to find them by their unique traits

o   Older molds appear in blue and other veined cheeses

Important medically:

·      Penecillium mold- the source for penicillin, the first antibiotic

·      Ring worm, athlete’s foot

·      Vaginal yeast infection (candida albicans)

·     

·      If people in the general public needed to be convinced that substantial wild random mutations, the material of evolution, occur in the present, what would you point out as an example?

o   A. a pink hippo

o   B. a green cow

o   C. a reptile with wings (birds- ancient)

o   D. a whale with legs (ancient)

o   E. a sponge that wears pants

·      To what can we contribute the behavior of the first wolf that was willing to get near to a human that led to the domestic dog?

o   A. artificial selection

o   B. “artifcatual selection”

o   C. Natural selection

o   D. Random selection (there is NO such thing as random selection)

o   E. Random genetic mutation

Four major groups of plants

·      Non-vascular plants

·      Seedless vascular plants

·      Gymnosperms

·      Angiosperms (flowering plants)

Four major groups of plants

·      Non-vascular plants

·      Seedless vascular plants

·      Gymnosperms

·      Angiosperms (flowering plants)

The earliest plants

·      Fossil spores from about 475 million years ago

o   Tough-skinned spores provide excellent fossil records

o   Fungi fossils show 470 MYO

Ohio state fossil

trilobite (in Cincinnati)

Present number of number of species of land plants

·      Roughly 290,000 species

Land plants

·      Nonvascular plants

o   Non-vascular plants (mosses)

·      Vascular plants

o   Seedless vascular plants (ferns)

o   Gymnosperms (naked seeds) (conifers)

Angiosperms (seeds “in container”)

Qualities of nonvascular plants

·      Earliest land plants

·      Have cuticle

·      Have alternating generations

·      Don’t have roots or true leaves (require moisture)

·      Are small

·      Today compose 7% of plant species

4 key traits of plants and only charcophyceans  (aquatic green algae):

·      1. Rosette complexes in the plama membrane for cellulose synthesis

·      2. Peroxisome enzymes

·      3. Structure of flagellated sperm

4. pharmoplasts

5 Key traits of land plants:

·      1. Apical meristems

·      2. Alternation of generations

·      3. Tough, resistant spores from sporangia

·      4. special organs for production of gametes

·      5. multicellular dependent plant embryos retained by female parent

More derived traits

·      secondary compounds

tanins

astringent compounds that make plants uninviting to animals

nonvascular plants (mosses)

·      bryophytes

o   mosses (15000 species)

o   liverworts (100)

hornworts (9000)

mosses

mosses on rock

-mosses are often live on substrates where vascular plants are not found

-they can live on three trunks or rocks, bur they only thrive when they are wet

-they can survive long periods of dryness, then grow and reproduce during wet conditions

mosses ruled for 50 million years

new strategy?

·      Get tall

93% of plants manifest vascularity

extant (vascular plants)

·      lycophytes: (1,200 species)

·      pterophytes: ferns 12,000 species (ferns)

·      horsetails: all in the genus 

Plants grow in west because

·      low surface area to water ratio

fern has to be wet to reproduce

problem? You are restrained by water for reproduction

·      if a random mutation occurs that allows the creation of seeds!

Gymnosperms

4 phyla

Land plants develop sperm and egg

= male and female

Ginko biloba only extant species of the phylum:

-smell like dog crap and vomit

fruits: 

come from ovaries of plants

conifer (the most successful gymnosperms) pollen spread by air (wind)

·      the problem? You are constrained by wind when your ready to reproduce

solution: pollen taxi- animal pollination through flowers

the flowers of angiosperms

·      modified shoot (stem with leaves) with up to four whorls of modified leaves encircling the stem

·      2 whorls are :sterile:

o   sepals and petals

·      2 whorls are :reproductive:

o   stamens (produce pollen) and carpels (contain the ovule)

Angiosperm: 1 phylum

·      Anthophyla: includes all angiosperms

o   Monocots

o   dicots