According to the endosymbiotic theory where did early eukaryotes come from?

A. The eukaryotic cells were trapped in meteorites and then released upon impact with Earth.

B. Free-living bacteria were engulfed by other prokaryotes in which they formed symbiotic relationships with each other. Overtime these organisms evolved into eukaryotic cells.

C. Some prokaryotes had mutations that caused them to have a nucleus and organelles. Theses mutations were favored and therefore the prokaryotes evolved into eukaryotes.

D. Bacteria became more sophisticated and overtime the primitive versions became extinct and the sophisticated versions became eukaryotic cells.

Theodosius Dobzhansky discovered that successful species tend to have a wide variety of genes that do not appear to be useful to the species in its present environment. What did this discovery help explain about genetics and the changes that occur in a species over time?

A. Environments with more organisms tend to have more successful species.

B. Changing environments prevent species from adapting and surviving.

C. Species with greater genetic diversity adapt more easily to changing environments.

D. Species in a stable environment are more resistant to a changing environment.

ScientificClassification

Systems

Why a Scientific Classification System?

Ambiguity of terms Latin “dead

language” Categorization of

relationships:1. Evolutionary2. Structural3. Biochemical

(NOT habitat)

7 Classification Groups: Kingdom (most inclusive) Phylum Class Order Family Genus Species (most specific)

King Phillip Came Over From Greece Singing

5 Major Kingdoms:1. Monera

2. Protista

3. Fungi

4. Planta

5. Animalia

1 cell, prokaryotes 1 cell, eukaryotes & algae Multicelled, absorptive

feeders Multicelled, autotrophs Multicelled heterotrophs

Which is the most difficult to assign?

Species: Most specific Successful

interbreeding Fertile

offspringDonkey + Horse=Mule (infertile)

Which group has the largest # organisms?Kingdom: Cell types Prokaryotes Eukaryotes Cell number Nutrition Structures

Plant Kingdom

PLANT SYSTEMATICS Common names

Have evolved over centuries in a multitude of languages

Sometimes used only in a limited geographical area

Problem with common names: One plant may be known by several names in different

regions, and the same name may be used for several different plants…

Scientific namesSimilar plant species form a group called a genus

(plural: genera)…

Genera are grouped into families…

Families into orders, classes, divisions and kingdoms

Kingdom-Division-Class-Order-Family-Genus-Species

“King David Came Over For Great Spaghetti”

“King David Conquered Our Fifty Great States”

Species nameEach species has a single correct scientific name in

Latin called a binomial (two names) – it is always italicized or underlined.

First name is genus name.Second name is species name

Human: Homo sapiens Cat: Felis catusDog: Canis familiaris Wolf: Canis lupus

Examples

Genus of maple trees is Acer

It has many species including:

Common name Scientific name“Red maple” Acer rubrum“Sugar maple” Acer saccharum“Black maple” Acer nigrum

Taxonomic hierarchySpecies that have many characteristics in common

are grouped into a genus.Related genera that share combinations of traits are

grouped into families.Families are grouped into orders.Orders into classesClasses into divisions (or phyla for animals)Related divisions/phyla are grouped into kingdoms

(e.g. house, street, city, county, state, country, continent, planet)

What is a species?

Species: a set of individuals that are closely related by descent from a common ancestor and ordinarily can reproduce with each other, but not with members of any other species.

Biological species: group of interbreeding populations. Offspring are fertile.

SpeciesSome members of same species look very

different…

Same species, are capable of interbreeding, butMorphologically look very different.Examples in plants: species of oaks and sycamores

Definition of species Or, plants look the same, but due to

polyploidy (more than the diploid number of chromosomes), they cannot interbreed.

For example: Ferns; evening primrose

Carolus Linnaeus Swedish scientist – Carl von Linne

(doctor and botanist)

born in 1707.

Called the “Father of Systematic Botany” Established modern system of nomenclature

Linnaeus legacyHis binomial system of nomenclature, in

which the genus and species names are used.

He classified 12,000 plants and animals, and many of the names he first proposed are still in use today…

Animal Kingdom

Scientific Name: Latin Italics or underlined Genus species Homo sapien

Classification Criteria: Biochemistry Behavior Hair Color Genetic System Evol. History Nutrition Molecular Make-up

Most (DNA) Not very Not very Most Most Most Not very

Similar Categories:

Dolphin Man Fish Whale Bat

Similar Categories:

GrasshopperMosquitoSpiderButterfly

Mammals arise from Theraapsids

Chimpanzees: distant relatives

Walking upright:

Lemurs: distant relatives

The ruffed lemur lives in the eastern rain forests of Madagascar. The lemurs and their relatives are believed to have evolved in isolation from the monkeys and apes after Africa became separated from Madagascar over 50 million years ago. Since the arrival of humans on Madagascar over 2000 years ago, at least 14 species of lemurs are believed to have become extinct.

When Charles Darwin published The Descent of Man in 1871, he challenged the fundamental beliefs of most people by asserting that humans and apes had evolved from a common ancestor. Many critics of Darwin misunderstood his theory to mean that people had descended directly from apes. This caricature of Charles Darwin as an ape appeared in the London Sketch Book in 1874.

Homologous or Analogous Stuctures?

Homologous Structures: Shark/Dolphin fin Seal flipper/Fish fin Fish tail/Whale fluke Bat wing/Cat limb Bird/Insect wing Bird wing/reptile limb Seal flipper/human

arm Dog limb/whale flipper

No (cartilage/rays) No (bones/rays) Yes (bones/bones) Yes (bones/bones) Yes (bones/no bones) Yes(bones/bones) Yes(mammal bones) Yes(mammal bones)

Structures that are similar due to evolutionary origin, such as the forearm bones of humans, birds, porpoises, and elephants, are called homologous. Structures that evolve separately to perform a similar function are analogous. The wings of birds, bats, and insects, for example, have different embryological origins but are all designed for flight.

Family or Genus Relations?Family: Less closely related Larger group

Genus: More closely related Precedes species=

interbreeding

Family:Felidae Lions, tigers,

leopards house cats,cheetahs,

ocelotsGenus: Panthera Leopards (pardus) Lion (leo) Tigers (tigris)

Feline Family Members:

Most authorities agree that the domestic cat descended from the Caffre cat, a small breed of African wildcat. The Caffre cat was domesticated in ancient Egypt, possibly as early as 2500 BC.

Genus: Panthera (Lions &Tigers)

Classification by characteristics: Fossil Skulls DNA

Sequences Hair

Samples Pictures

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