Bio 101: Evolution

Front 1

Precambrian

Back 1

Earliest, oldest

Simple, single-celled organisms

Front 2

Paleozoic

Back 2

Presence of Trilobites

Front 3

Mesozoic

Back 3

Age of reptiles, dinosaurs, vertebrates

Front 4

Cenozoic

Back 4

Age of Mammals

Current Age

Front 5

Index Fossils

Back 5

Relative dating of strata/fossils

Short-lived

Easily recognizable

Wide-spread

Front 6

Theory of Superposition

Back 6

The deeper you go in rock layers, the further back you go.

Deeper is older.

Higher is younger.

Front 7

Theory of Uniformity

Back 7

Things happening today occurred in the past.

Mountains rose from the sea and eroded back down.

These take a long time.

Thus, the earth must be very old.

Front 8

Theory of Evolution

Back 8

Individuals vary: These are inheritable.

Variation is good/bad/neutral: determined by natural conditions.

Those with good live longer and reproduce more.

Compete for limited resources.

Over time, species change.

Front 9

"Survival of the Fittest"

Back 9

Fitness: health and reproduction

Those who survive best and reproduce best leave more offspring.

Front 10

"Natural Selection"

Back 10

Conditions of nature determines which variations contribute to health.

Front 11

"Descent with Modification"

Back 11

Species will change over time.

Due to Natural Selection, Competition & Survival of the Fittest

Individuals vary - these are inheritable.

Front 12

Unaltered Fossils

Back 12

real bone, teeth, amber, mummification

Front 13

Altered Fossils

Back 13

carbonization, cast, mold, petrification

Front 14

Trace Fossils

Back 14

worm tubes, internal cast, gastrolith

Front 15

Index Fossils

Back 15

Help compare organisms from different areas

Front 16

Transitional Fossils

Back 16

Show changes in species over time.

Front 17

Radiometric Dating (Purpose)

Back 17

Actual age to the fossils.

Actual age of Geologic Eras.

Front 18

Radiometric Dating (Process)

Back 18

Isotopes are taken in and used like the original element.

Unstable, so decay over periods of time.

By determining how much has decayed, we see how old it is.

Front 19

Biogeography

Back 19

Explains why organisms are found where they are.

Front 20

Continental Drift

Back 20

Continent moves from Equator to Mid-Latitudes.

Land areas separate into two and move.

Two separate land masses come together --> Climate Changes, Predator/Prey Changes, Natural Selection may change, Species may change

(Marsupials predominate in Australia... Similarity between ostrich, emu, and rhea.

Front 21

Embryological Similarities

Back 21

Longer they resemble one another, more closely related they are.

Front 22

Adolescent Similarities

Back 22

Longer they continue to be alike, more closely related they are.

Front 23

DNA/DNA Hybridization

Back 23

Take DNA from two different species.

Combine to make one DNA molecule.

Heat to break bonds.

More heat needed means more bonds had formed.

Most heat equals most similar.

Front 24

Agents of Evolutionary Change

Back 24

Mutations
Gene Pool
Genetic Drift
Gene Flow

Front 25

Mutations

Back 25

Changes occur in individuals.
If beneficial, will spread.
Allow the individual to benefit from Natural Selection.

Front 26

Gene Pool

Back 26

The total of all the genes posible in the population.

A population is limited to the possibilities in its gene pool.

Front 27

Gene Flow

Back 27

Changes occur in individuals.

If beneficial, will spread.

Movement of genes within a population.

Front 28

Non-Random Mating

Back 28

Mates chosen based on beneficial trails.

Natural Selection is basis for whether a trait is beneficial.

Specials are capable of change due to non-random mating.

Front 29

Stabilizing Selection

Back 29

Birth Weight

Front 30

Directional Selection

Back 30

Giraffe Neck

Front 31

Disruptive Selection

Back 31

Snails

Front 32

Isolation Mechanisms

Back 32

Things that spearate populations so that genetic drift can occur.

(Pre-mating & Post-mating)

Front 33

Pre-mating

Back 33

1. Geographic
2. Ecological (habitat)
3. Behavioral
4. Temporal
5. Mechanical

Front 34

Post-mating

Back 34

1. Gamete (chemical)
2. Zygote Mortality
3. Hybrid Sterility
4. Second Generation Fitness

Front 35

Geographic

Back 35

Some aspect of geography separates the group.

Front 36

Ecological

Back 36

where they live prevents interaction

Front 37

Behavioral

Back 37

actions keep them separate

Front 38

Temporal

Back 38

Reproductive Timing is off

Front 39

Mechanical

Back 39

Reproductive apparatus does not fit

Front 40

Gamete

Back 40

Sperm cannot penetrate egg

Front 41

Zygote Mortality

Back 41

Fertilization occurs -> zygote does not develop properly -> death results

Front 42

Hybrid Sterility

Back 42

Mule example

Front 43

Second Generation Fitness

Back 43

Two species mate, produce offspring.

Offspring mates. Second generation is less fit.