Evolution…Whatz Up Wit Dat?Evolution…Whatz Up Wit Dat? Evolution is change. Galaxies, languages, and Evolution is change. Galaxies, languages, and

political systems all evolve.political systems all evolve.

Biological evolution- change in the properties of Biological evolution- change in the properties of populations of organisms that transcend (are populations of organisms that transcend (are bigger than) the lifetime of a single individual.bigger than) the lifetime of a single individual.

Individual organisms do not evolve…they can Individual organisms do not evolve…they can change…that’s different. Species evolve. change…that’s different. Species evolve.

Evolutionary Changes are…changes in Evolutionary Changes are…changes in populations that are inheritable through populations that are inheritable through passing of genetic material from one passing of genetic material from one generation to the next. generation to the next.

Can be minor or BIG.Can be minor or BIG.Everything from slight changes in the Everything from slight changes in the

amounts of different alleles within a amounts of different alleles within a population, all the way up to…population, all the way up to…

……changes that led from the earliest life changes that led from the earliest life forms to worms, fish, lions, and tulips. forms to worms, fish, lions, and tulips.

Evolution is simply species changing.Evolution is simply species changing.Sometimes it’s gradual (GRADUALISM).Sometimes it’s gradual (GRADUALISM).Sometimes it’s fast (PUNCTUATED Sometimes it’s fast (PUNCTUATED

EQUILIBRIUM).EQUILIBRIUM).One One mechanismmechanism of evolution is natural of evolution is natural

selection (cause and effect...right?). selection (cause and effect...right?). Natural selection causes species to evolve Natural selection causes species to evolve (just like tectonic activity causes (just like tectonic activity causes continental drift).continental drift).

Applying Natural SelectionApplying Natural Selection

1.1. Discuss the relationship among genetics, Discuss the relationship among genetics, natural selection, and evolution.natural selection, and evolution.

2.2. Construct a scenario wherein a Construct a scenario wherein a population of organisms (any type you population of organisms (any type you want) is acted upon by natural selection. want) is acted upon by natural selection. Be sure to discuss all four mechanisms. Be sure to discuss all four mechanisms. Yeah…I know it’s hard; you’re gonna Yeah…I know it’s hard; you’re gonna have to actually think.have to actually think.

Who Is This Darwin Dude?Who Is This Darwin Dude?Well, he was a naturalist who made some Well, he was a naturalist who made some

cool observations (remember those) in 1835 cool observations (remember those) in 1835 while visiting the Galapagos Islands (off the while visiting the Galapagos Islands (off the western coast of South America…Ecuador western coast of South America…Ecuador to be specific).to be specific).

He saw that certain flora (plants) and fauna He saw that certain flora (plants) and fauna (animals) in the islands were slightly (animals) in the islands were slightly different than those on the mainland.different than those on the mainland.

Examples: Finch beaks, Tortoise shell Examples: Finch beaks, Tortoise shell shapes, shapes,

He hypothesized that geographic He hypothesized that geographic separation had prompted these critters separation had prompted these critters to change over time as a response to to change over time as a response to the environment in which they lived.the environment in which they lived.

He didn’t know about genetics…He didn’t know about genetics…Mendel took care of that piece of Mendel took care of that piece of information in the 1840’s.information in the 1840’s.

How? Well…Natural Selection…which How? Well…Natural Selection…which we’ve discussed (Overproduction, we’ve discussed (Overproduction, Variation, Competition, & Selection).Variation, Competition, & Selection).

We now have modern evolution.We now have modern evolution.

What is Natural Selection?What is Natural Selection?Ok…we have this concept called Ok…we have this concept called

NATURAL SELECTION…right? NATURAL SELECTION…right? That states that critters that are better That states that critters that are better

equipped for survival have a better chance equipped for survival have a better chance of…(of…(you tell meyou tell me)?)?

That’s pretty straight forward isn’t it? I That’s pretty straight forward isn’t it? I mean, imagine you’re in a soup eating mean, imagine you’re in a soup eating contest (just do it ok!). You have a contest (just do it ok!). You have a fork and your buddy has a spoon…fork and your buddy has a spoon…you ain’t gonna win that contest.you ain’t gonna win that contest.

Natural selection works in the Natural selection works in the same way only the winner lives, same way only the winner lives, and the loser…well…I don’t and the loser…well…I don’t wanna talk about it.wanna talk about it.

Let’s look at what affects this process.Let’s look at what affects this process.

1.1. OverproductionOverproduction: This refers to the way : This refers to the way many organisms produce waaaay more many organisms produce waaaay more offspring than can survive.offspring than can survive.

2. 2. CompetitionCompetition: : Food and other resources Food and other resources are limited, right? Offspring compete for are limited, right? Offspring compete for this stuff to survive. Competition is this stuff to survive. Competition is usually indirect (they don’t have…like…usually indirect (they don’t have…like…ultimate cage matches for food), and ultimate cage matches for food), and only a few offspring survive long enough only a few offspring survive long enough to reproduce. to reproduce.

3. 3. Variation:Variation:    members of a species differ members of a species differ from one another with regard to certain from one another with regard to certain traits. Differences between individuals traits. Differences between individuals of the same species is called of the same species is called VARIATIONVARIATION. .

4. 4. Selection:Selection:    Some variations make Some variations make certain individuals better adapted to certain individuals better adapted to their environment. Those individuals are their environment. Those individuals are more likely to survive and reproduce. more likely to survive and reproduce.

Ok, so its like this…When the individuals Ok, so its like this…When the individuals that are better adapted reproduce, their that are better adapted reproduce, their kids may inherit the allele for the helpful kids may inherit the allele for the helpful trait (ok…plants don’t have “kids,” but you trait (ok…plants don’t have “kids,” but you get the idea).get the idea).

The kids, will be more likely to survive and The kids, will be more likely to survive and reproduce…cuz they gotz the good genes reproduce…cuz they gotz the good genes (alleles) for the good traits right?(alleles) for the good traits right?

The kidz can pass on the allele to their The kidz can pass on the allele to their kidz.kidz.

After a bunch of generations, more After a bunch of generations, more organisms within the species will organisms within the species will have the helpful trait. have the helpful trait.

Over a long period of time, natural Over a long period of time, natural selection can lead to evolution. selection can lead to evolution.

How? Beneficial variations gradually How? Beneficial variations gradually build up within a species, while build up within a species, while unfavorable ones disappear.unfavorable ones disappear.

This lab we do on Monday will This lab we do on Monday will demonstrate how this happens.demonstrate how this happens.

Darwin…did he act alone?Darwin…did he act alone?Well…he did but there was another Well…he did but there was another

dude acting alone at the same time…dude acting alone at the same time…Alfred Russel (don’t call me Russell) Alfred Russel (don’t call me Russell) Wallace.Wallace.

Wallace was an admirer of Darwin and Wallace was an admirer of Darwin and texted him to say that he figured out texted him to say that he figured out the whole the whole natural selectionnatural selection thing. thing.

And then Darwin was all like…oh no And then Darwin was all like…oh no you didn’t you didn’t

Yes…he did!Yes…he did!

More Darwin StuffMore Darwin Stuff

So anywaze…Darwin and Wallace So anywaze…Darwin and Wallace presented their findings on the same day presented their findings on the same day at the same meeting.at the same meeting.

Darwin wrote a book though (1859): Darwin wrote a book though (1859): On On the Origin of the Species by Means of the Origin of the Species by Means of Natural Selection…Natural Selection…so he got the cred.so he got the cred.

Darwin’s Galapagos VacationDarwin’s Galapagos Vacation The Galapagos Islands.The Galapagos Islands.

It was a balmy Friday afternoon on September the It was a balmy Friday afternoon on September the twentysomethingteenth, 1835…ok…I have no idea twentysomethingteenth, 1835…ok…I have no idea what day it was or whether it was balmy or if what day it was or whether it was balmy or if porcupines were falling from the sky…although that porcupines were falling from the sky…although that would’ve been pretty cool IMHO.would’ve been pretty cool IMHO.

Anyway…October 1835…Darwin lands on the Anyway…October 1835…Darwin lands on the Galapagos Islands (which are where…?).Galapagos Islands (which are where…?).

He spends five weeks there. He spends five weeks there. Nice!Nice! So, besides So, besides windsurfing, parasailing, and shopping…he’s windsurfing, parasailing, and shopping…he’s doing the naturalist thing. You know…one of doing the naturalist thing. You know…one of those eco-tour things. Not nearly as trendy in those eco-tour things. Not nearly as trendy in 1835.1835.

Darwin’s FinchesDarwin’s FinchesWhilst doing the naturalist thing (actually…Whilst doing the naturalist thing (actually…

when he got home), Darwin collected when he got home), Darwin collected some birds (called finches). He thought some birds (called finches). He thought that they were the same, but although they that they were the same, but although they were closely related, they were actually were closely related, they were actually different. This catalyzed his development different. This catalyzed his development of the principle of natural selection.of the principle of natural selection.

What Darwin had observed was…What Darwin had observed was…

SpeciationSpeciation Changes in closely related organisms that result Changes in closely related organisms that result

in enough of a difference to be classified as a in enough of a difference to be classified as a separate species. separate species.

This happens when populations of one species This happens when populations of one species are geographically isolated and each must adapt are geographically isolated and each must adapt to its new environment.to its new environment.

Speciation that occurs in this way is called Speciation that occurs in this way is called ADAPTIVE RADIATION.ADAPTIVE RADIATION.

In the case of the finches, their beaks developed In the case of the finches, their beaks developed differently depending upon the food sources differently depending upon the food sources available in their specific geographic location.available in their specific geographic location.

Peppered MothsPeppered Moths

First you’ll need 3 lbs of moths with wingsFirst you’ll need 3 lbs of moths with wings 2 Tbs Olive Oil2 Tbs Olive Oil ¼ cup lemon or lime juice¼ cup lemon or lime juice 4 Tbs coarsely ground black pepper4 Tbs coarsely ground black pepper

……but seriously folks…we’re now but seriously folks…we’re now discussing INDUSTRIAL MELANISMdiscussing INDUSTRIAL MELANISM

This is an example of This is an example of PolymorphismPolymorphism……whhaaaa? Relax…it’s a big word that whhaaaa? Relax…it’s a big word that means means many formsmany forms. So…when a species . So…when a species is found in two distinctly different groups is found in two distinctly different groups (but is (but is stillstill the same species), that’s the same species), that’s polymorphism.polymorphism.

The peppered moth has changed its The peppered moth has changed its appearance since the beginning of the appearance since the beginning of the industrial age. industrial age.

In the 1800's, soot would collect on the In the 1800's, soot would collect on the sides of buildings from chimneys and sides of buildings from chimneys and factories and make the buildings darker in factories and make the buildings darker in color. color.

The moths were originally light colored The moths were originally light colored and were pretty easy to see…happy, and were pretty easy to see…happy, happy birds (if you like to eat moths…happy birds (if you like to eat moths…happy you)!happy you)!

A mutation which caused darker coloration A mutation which caused darker coloration occurred and it was beneficial…if you occurred and it was beneficial…if you blend in, you’re tougher to find and eat.blend in, you’re tougher to find and eat.