EVOLUTION How did we get here and where are we going and where are we going?

Theories of how we came to be… Evolution is a scientific theory. Other Theories…?

Process of change over time

Hot (or Not-S0-Hot) Shots of Evolution Developed the theory of “Use and Disuse” Basically, whatever changes occur over your life time, you pass along to your kids! WRONG!! Jean Lamarck Karl Weismann Disproved Lamarck Cut off mouse tails for several generations Each generation of mice were still born with full tails!

Charles Darwin: THE Grandpappy of Evolution! Medical school- passed out at autopsyMedical school- passed out at autopsy Law school -too boring!Law school -too boring! Monk -more boring!Monk -more boring! Naturalist -yahoo!Naturalist -yahoo!

Voyage of the HMS Beagle: Darwin’s Ship HW Pass Question: How far the the HMS Beagle travel?

Natural Selection: Darwin’s Theory of Evolution In a nutshell, “Nature” determines which organisms live and which die.

Natural Selection: Overproduction An oyster lays eggs at a time! 60 million

Natural Selection: Darwin’s Theory of Evolution In a nutshell, “Nature” determines which organisms live and which die. 1. Overproduction: This guarantees some will survive.

Natural Selection: Variations Variations can come about in two ways: 1. Sexual Reproduction creates a new and unique combination of genes. You did NOT just talk about S- E-X, right? 2. Mutations (a change in your DNA) occurring in the gametes (sex cells, ex: egg and sperm). OMG, you did it again.

Natural Selection: Darwin’s Theory of Evolution In a nutshell, “Nature” determines which organisms live and which die. 1.Overproduction: This guarantees some will surivive. 2.Variation Among Offspring: The more diversity, the stronger a species.

Natural Selection: Competition Organisms Compete For: Food Water Shelter Mates Territory

Natural Selection: Darwin’s Theory of Evolution In a nutshell, “Nature” determines which organisms live and which die. 1.Overproduction: This guarantees some will surivive. 2.Variation Among Offspring: The more diversity, the stronger a species. 3.Competition: Fighting for food, water, mates, territory and shelter. The best adapted get the best digs!

Natural Selection: Survival of the Fittest video Which of these hotties is the most fit? Depends…if their “environment” is a 4’ tall spaceship with tight quarters…the little puny alien is the most fit!

But, What if the Environment Changes? Which moth lives longer here? What about now? After pollution has covered the forest in soot and smog?

Natural Selection: Darwin’s Theory of Evolution In a nutshell, “Nature” determines which organisms live and which die. 1.Overproduction: This guarantees some will surivive. 2.Variation Among Offspring: The more diversity, the stronger a species. 3.Competition: Fighting for food, water, mates, territory and shelter. The best adapted get the best digs! 4.Survival of the Fittest: This does NOT mean big and strong, it means best adapted to the environment.

Question:

Evidence: geologic record Oldest fossils in layers.lowest

Organisms evolve from to One cellmulticellular

A real FOSSIL! Remains of any organism Okay, they are supposed to be the remains of DEAD things! Fossils can be: 1.Frozen organisms. 2.Organisms petrified in stone. 3.Traces of organisms petrified in stone. 4.Organisms preserved in sap or tar.

Microorganisms fossils Worm fossil Mollusk fossil Insect fossil Fish fossil Reptile fossil Bird fossil FOSSILS for real!

How relationships are determined Scientists use several types of evidence to determine relationships

Comparative Embryology fish salaman- der tor- toise chic- ken pigcowrabbithumanfish

How relationships are determined Scientists use several types of evidence to determine relationships. 1.Comparative Embryology

Which pair of organisms is more closely related biochemically? Vs. Which of these are related??

How relationships are determined Scientists use several types of evidence to determine relationships. 1.Comparative Embryology 2.Comparative BioChemistry 3. 4.

Comparative… Anatomy

Not to be confused… (alas, my specialty!) Homologous Structures: Similar structures that have been inherited from a common ancestor, regardless of use (swim, fly, etc.) Analogous Structures: Serve a similar purpose (ex. Flying) but evolved independently from one another.

How relationships are determined Scientists use several types of evidence to determine relationships. 1.Comparative Embryology 2.Comparative BioChemistry 3.Comparative Anatomy 4.

Remember Cells? ProkaryoteEukaryote

And…There are TWO kinds of Eukaryotic Cells… OR Plant Cells Animal Cells

How relationships are determined Scientists use several types of evidence to determine relationships. 1.Comparative Embryology 2.Comparative BioChemistry 3.Comparative Anatomy 4. Comparative Cytology

Causes of Evolution Sexual reproduction & variations Spontaneous & random mutations

Beneficial mutations depend on the environment! Geographic Isolation: 2 subspecies of mountain gorilla separated by a 3 mile valley are more bio- chemically diverse than any 2 people in the world. Reproductive Isolation

**Species: Organisms that can interbreed (mate) and produce fertile offspring 5.

Two Schools of Thought… Gradualism is the idea that changes took place slowly over time. Punctuated Equillibrium is the idea that there were long periods of stability and short bursts of change when the environment changed. Punctuated Equillibrium is a more widely accepted theory.

Definitions that will clear up the next concept …. Autotrophic: Organisms that can produce food within their bodies from inorganic (non-living) things. (ex: plants) Heterotrophic: Organisms that need to obtain food from their environment. (ex: us!)

Heterotroph Hypothesis Heterotrophs (anaerobic respiration) CO 2 Autotrophs O2O2 Aerobic Respiration

Basic Assumptions 1.There was no “free oxygen” (only bound to other molecules). 2.There was a lot of H (hydrogen), NH 3 (ammonia), CH 4 (methane), and H 2 O. 3.It was hot, rainy, a lot of lightning & solar radiation. The Heterotroph Hypothesis (how life on earth began) starts with basic assumptions about the primitive earth:

How (we think) life came to be. 1.The raw materials combined to make sugar, amino acids and some simple proteins. 2.Organic molecules grouped together & formed a membrane around themselves. They were called aggregates. 3.When an aggregate grew too large, they would divide. Slowly a primitive cell developed. 4.Simple cells began to undergo anaerobic respiration which released…______?? 5.As CO2 became plentiful, autotrophs developed. And they released…____?? 6.And then…aerobic respiration became possible. CO2 O2

The final Story