Principles of Evolution Chapters: 12, 13, 14

How did life begin? How did life begin?How did life begin?How did life begin?

The Bubble Model (1986) by Lerman  Chemical reactions of the primordial soup took place inside bubbles of fat molecules.  See page 255 in book

Primordial Soup (A.I. Oparin)  Early Earth atmosphere (N, Methane, ammonia)  Energy from sun, volcanoes, lightning  Chemical reactions created amino acids  Rain washed these into the ocean  Created the primordial soup.

A Brief History of Life  animation animation

Early Organisms  Prokaryotes are oldest organisms (3.5 billion years old)  Cyanobacteria – photosynthetic bacteria  Impact on atmosphere: Oxygen!!!!

Groups of bacteria  Eubacteria- “true bacteria”, ex. Ecoli  Archaebacteria – ancient bacteria,

Then came the eukaryotes  Appeared 1.5 billion years ago

Life moved onto land!!!

The Theory of Evolution Chapter 13

13-1 Where did the theory of natural selection come from?  Pre Darwin:  (1809) Jean Baptiste de Lamark  Variation hypothesis – evolution occurs through acquired characteristics (body changes over time)  Example: giraffe neck length

Larmark: Aquired Characteristics

Evolution by Natural Selection  Charles Darwin (1859) Charles Darwin Charles Darwin  Journey of the H.M.S. Beagle – recorded all the plants and animals on journey

Darwin’s Observations  Observed gradual change – found fossils that were similar, but not identical, to the current day animal  On Galapagos island he observed finches that resembled those in South America

Darwin’s finches: notice the beaks

I. Natural Selection- survival of the fittest (Darwin) 1. Variations exist within populations

Theory of Natural Selection 2. Some variations (mutations) are more advantageous for survival and reproduction than others

Theory of Natural Selection Theory of Natural Selection 3. “fit”organisms survive and reproduce – genes are passed to offspring

 Isolation- leads to a new species, two population of same species can not breed  Extinction- leads to species replacement

Adaptations  Changing of a species that results in its being better suited to its environment (choosen by natural selection)  Mutations

Peppered Moth Example

Structural Adaptations  Mimicry  Camouflage  Warning coloration

Structural Adaptation: 1. Mimicry Example: Viseroy and Monarch Butterflies

Viceroy Monarch

2. Camouflage 2. CamouflageCamouflage  adaptations that allows an organism to "blend" into it's environment  Examples:

More examples of Camo.: Sea Dragon

Structural Adaptation: Warning: Standing out Poison Arrow Frog

Warning and Mimicry

A regal ring-necked snake displaying its aposematic coloration

Physiological Adaptation Changes in metabolic processes: venom, warm vs. cold blooded

More physiological adaptations:

Behavioral Adaptations: examples

Jaguar – hunting methods – one bite – occipital crunchers

Evidence of Evolution

Fossil Evidence Fossil Evidence  Missing links between groups of organisms.  Compare fossils with current day species

Structures and Evolution  Homologous structures – agreeing  Similar structures and derived from the same body part.  Ex. Bone structure

Vestigial structures  Remnant of another structure  No function, reduced in size  Ex. Appendix, tailbones,wisdom teeth in humans, hipbones in whales,

Some Alleged Vestigial Organs in Man TonsilsTonsils Coccyx (tail bone)Coccyx (tail bone) AppendixAppendix Little toeLittle toe Wisdom teethWisdom teeth Nipples on malesNipples on males Nodes on ears "Darwin's points"Nodes on ears "Darwin's points" Ear muscles for wigglingEar muscles for wiggling Body hairBody hair

Darwin’s Points

Human Appendix

Human Tonsils

Analogous Structures :opposite  Similar in function, but different structures  Wing of butterfly vs wing of a bat

III. Embryo Development  Theory: aquatic, gill breathing vertebrates came before land, air breathers

DNA Evidence (biochemical)  DNA sequence studies are more reliable than fossil studies.

Human Evolution Chapter 14

Evolution of Primates  Includes Monkeys, apes, humans  Evolved 40 million years ago  3-D vision  Flexible shoulders/rotating forelimbs

Primate Characteristics cont.  Opposable thumb  Complex brains

Ardipithecus ramidus Ardipithecus ramidus  4.4 mya  Most primitive hominid  Discovered 1992

Australopithecus  Australopithecus anamnesis  - oldest upright primate  – 3.9 million years old

Australopithecus afarensis  “Lucy” –  3.5 – 2.9 million years ago  Teeth and pelvis resemble humans

Homo habilus  - handy human  - larger brain  - stone tools  to 2 million years old

Homo erectus  upright human  - built fires  - well made stone tools  million years old

HOMO ERECTUS

Modern Humans - Homo sapiens  wise human  - 125,000 years ago, African origins  - Neanderthals- heavy bodies  - 5 feet tall  - good hunters  - lived in caves  - buried dead  - did not make it

Cro-Magnon  slighter build and taller  - 35,000 years old  - direct ancestors to humans  - out competed Neanderthals  - caves  - elaborate tools  - artists

Cro-Magnon