Biodiversity Unit one

evolution

the concept that all given organisms are related to each other though common ancestry

Have scientists proven that life exists?

No

Big Bang

Theory of how the universe formed 16

Symbiosis

the interaction between two different organisms living in close association

"life coming together"

Spontaneous Generation

Theory that life arose spontaneously from inanimate matter. Not a widely held belief among scientists

Biogenesis Hypothesis

Theory that living matter created by pre

Haldane

Oparin Hypothesis

Life arose spontaneously from early atmospheric compounds. It was believed that the early atmosphere contained methane, ammonia, and water. When combined with energy sources, life arose. This is the original theory of how life arose, but is likely INCORRECT.

Miller

Urey Experiment

Panspermia

Hypothesis that organic molecules were brought to earth by meteorites/asteroids. Basically, life was seeded from outer space, and that life exists throughout the universe distributed by meteoroids, asteroids, comets, and planetoids.

Modern Theory of How Life Arose

(STILL NOT PROVEN, ONLY LIKELY) life arose spontaneously from simple molecules (CO, CO2, N2,H2 (very little because it was in little abundance), and H2O), then combined into larger, complex macromolecules such as proteins, carbohydrates, lipids, and nucleic acids. (NOT from methane, ammonia, and water as Haldane

Primordial Soup Hypothesis

Hypothesized that the first organisms were heterotrophs because they consumed the abundant food molecules present in the atmosphere

The Cell

the basic form of an entity

The Cell Theory

every life form (from bacteria to humans) is made up of/comes from cells

Steps of the development of cells

1. Spontaneous formation of simple molecules (Carbohydrates, lipids, proteins, and nucleic acids)

2. Formation of lipid bilayer, polymers, and Protien

RNA systems.

3. Lipid Bilayer forms selectively permeable barrier that contains an enclosed self

replicating system. Closed system contains DNA, RNA, proteins, and enzymes. (VERY IMPORTANT!)

4. Abiotic (derived from non

living things) formation of protobiont (initial structures during the origin of life which can show at least one propery of life) using self

5. Composition of anaerobic prokayotic cells, then followed by aerobic and photosynthetic prokaryotic cells

6. Single celled eukaryotic cells form and then evolve into multicellular organisms

DNA vs RNA. Which came first?

Scientists believe RNA was first genetic material because RNA can also form ribozymes which catalyze reactions

Unresolved Problems of the Modern Theory of How Life Arose

1. Formation of large, complex organic molecules via dehydration or condensation bonds in an aquatic environment is a problem because of the concept of hydrolysis. Water actually breaks most things down. Since all life was originally in water, it would be hard to synthesize life.

2. Formation of the "self

replicating" system. Non

Prokaryote

Cells without membrane bound nucleus or organelles. Pro

Eukaryote

Cells with a true membrane bound nucleus. Eu

Heterotroph

Organisms that are nourished from outside sources. Hetero

Autotroph

Organisms that produce their own nourishment/food. Ex: photosynthesis.

Auto

self,

How old is the Earth?

About 4.5 billion years old

How long did it take for Earth to cool?

600 million years for the atmosphere to cool down.

How old is the oldest fossil?

3.7

First

living organism speculated by scientists

Obligate Anaerobic

Cannot be in the presence of oxygen, it is killed by oxygen.

Facultative Anaerobic

Can be in the presence of oxygen (not destroyed by it) but it does NOT use it

Chemotrophs

use energy of chemical reactions (inorganic compounds) to produce food. (No sunlight). Probably arose deep in ocean vents where no sunlight was present and used H2S rather than sunlight to synthesize food

Phototrophs

use the energy of light to build up food molecules. Photo

Cynobacteria

Prokaryotic synthesizer, earliest fossils were stromatolites, which is a type of phototrophic cynobacteria

H2S vs H2O

H2S was originally being used to be the source of high energy electrons in photosynthesis because the first organisms were anaerobic (the byproduct then became sulfur). Eventually, H2O became the source of high energy electrons in photosynthesis (the byproduct then became oxygen).

Oxygen Crisis

Oxygen is a corrosive element to organic molecules and therefore likely created a crisis form many of the earliest life forms. The fact that organisms were anaerobic caused a huge crisis.

Endosymbiotic Hypothesis

Idea that a primitive anaerobic heterotrophic prokaryote (that lacked protection against effects of oxygen) formed a symbiosis with an oxygen

True/False: it is likely that the chloroplast evolved prior to the mitochondria

False. Virtually all eukaryotes have mitochondria, which offers strong evidence that the mitochondria was the first to evolve.

Pre

cambrian

Earliest traces of life found (stromatolite fossil)

(What year)

3.8 billion years ago

Oldest fossils of a complete cells (what year)

3.5 billion years ago

Oxygen levels rise (year)

2.7 billion years ago

Rise of eukaryotic cells

2.2 billion years ago

Paleozoic Era

Began 600 million years ago, ended 240 million years ago.

What age did Pangaea form?

245 million years ago

Permian extinctions

Extinction of many marine and terrestrial organisms (245 million years ago)

Highest Point of Earth

Himalayan Mountains in India

Lowest Point on Earth

Mariana Trench in the western part of the Pacific Ocean

Mesozoic Era

Began 230 million years ago, ended 65 million years ago with the cretaceous extinctions

Cretaceous Extinction

65 million years ago an asteroid hit the Yucatan Peninsula in the Gulf of Mexico causing cretaceous extinction. Almost everything in North America died in seconds and this marked the end of the mesozoic era.

Upper Part of Pangaea

Laurasia

Lower Part of Pangaea

Gondwana

Cenozoic Era

WE ARE STILL IN THIS PERIOD. Began 65 million years ago.

Life's Time Clock

Humans have been around in a relatively short period of time in the grand scheme of things. (1 minute on a 24 hour clock according to Brooks)

Taxonomy

The science of identifying, classifying, and naming things.

Binomial Nomenclature

bi

System of naming developed by Linnaeus that gives each organism 2 names. Genus (noun), species (adjective).

Carl Linnaeus

Goal was to name every species on the planet. He came up with Binomial Nomenclature

Classification System

Domain (Domains) = Divine

Kingdom (Kingdoms) = King

Phylum (Phyla) = Phillip

Class (Classes) = Came

Order (Orders) = Over

Family (Families) = From

Genus (Genera) = Greece

Species = Singing

Binary Fission

Asexual reproduction. Used in bacteria

Mutualism

Benefit both organisms

Commensalism

One benefits, no effect on the other

Parasitism

One benefits, the other is harmed

coccus

circle shaped bacteria

bacillus

rod shaped bacteria

spirillus

spiral shaped bacteria

Domain Eukarya

Kingdom Archezoa

Kingdom Protista

Contain a true nucleus

Serial Endosymbiotic Hypothesis

Hypothesis that mitochondria came first then chloroplast. Mitochondria and chloroplast were thought to have come from Eukaryotes

Kingdom Archezoa

Create ATP anaerobically (without oxygen)

Have a true nucleus, but lack mitochondria

Giardia

Kingdom Archezoa

Intestinal parasite of vertebrates

Caused intestinal issues which you can get from drinking tainted water

Kingdom Protista

Typically they are eukaryotes which means that they have a defined nucleus

Typically unicellular though some are multicellular

unicellular: ciliates

multicellular: ulva

Very Diverse Group

Classification based on ecological role:

Consumer

Heterotrophic

Producer

Autotrophic

Both

Mixotrophic

Polyphyletic

Protists are polyphyletic, meaning that they evolved similar characteristics, but not one RECENT common ancestor.

Monophyletic

One recent common ancestor

Heterotrophic protists

All end with

Fungus

like "water molds", slime molds, and plasmodial slime molds