speciation and evolution

5.6

PART 1: Allopatric speciation (Allopatry)

definition: speciation by reproductive isolation

This is a three step process which is beleived to create new species by natural selection.

step 1- when there is a physical barrier. so let's say if there was a species of dear living in a forest, and people came in and built a highway right in the middle of this forest. So now we have 2 groups of dear seperated from one another.

step 2- natural selection occurs.

This is the

mule deer this is the

whitetail deer

(Odocoileus

hemionus)

(Odocoileus

virginianus)

these two deers may have had a different history of how they became diverse but if these two deer were seperated by my road, then it is natural selection that works on the groups seperately, making them diverse and evolving into their own species with the same anscestors. Examples would be like what conditions the deer live in, what kind of horns they grow, physical structure of their mouths could have changed according to how they adapted to getting food in their new environments.

step 3- overtime these two groups of deer maybe become so diverse that they would no longer be able to sexually reproduce with eachother.

PART 2: theory gradualism

definition: the idea that speciation takes place slowly.

over many years there has been many theories about evolution. one theory that is partially true is the theory of gradulism. evolution does gradually happen it doesn't take just one generation. until about the mid 20th century it was beleived that one specie would gradually evolve into another and then another and then another. and then it slows down for a while. But what Niles Eldride and Stephen Jay Gould came up with was the theory of punctuated equilibrium. this theory still goes by the theory of gradualism that evolution took time but they proposed that evolution doesn't just continuously evolve but they evolve at one period in time and that one species evolved in many different paths. so many species evolve at one time period; their is a burst of evolution and then a species adapts to their environment and stays that way for a LONG time. A third point that Eldride and Gould discovered was that these bursts of evolution usually happened in small isolated areas.

Bibliography http://www.motherearthnews.com/Nature-Community/1985-11-01/North-American-Deer.aspx

Sorry but it woun't let me paste the link to the second photo but i got it off of google.

And the Biology 20/30 textbook.

5.5

5.5














PART 1: mutation









Growing up we knew mutations as monsters and things like green globlins and giants. And i guess that is partially true, being incredibly over tall and not have the ability to stop growing is a mutation in some sense.









But in reality there is 3 different types of mutations: Neutral, Harmful, and Beneficial.









Definition: mutations are random changes in the DNA itself and they provide a continuous supply of new genetic information.









-Can be caused by environmental factors like chemicals or radiation, or when cells make copies of DNA or use that cell.









neutral mutation: has no effect on the organism. example: if your born with an extra thumb.




harmful mutation: reduces and organism's fitness ( reproductive success ). example: mutation in somatic cell and some mutations in this cell may cause cancer.





beneficial mutation: enhances and organism's fitness. example: spraying bed bugs used to kill them, but then a mutation occured within the bed bugs to make them immune to us spraying them.



PART 2: Sexual Reproduction.

definition: the production of offspring by the union of sex cells from two different parents; the offspring inherit a combination of genes from both parents.

- Every organism will vary from their parent and/or siblings. this is because of gene pool which is the genetic make up of each DNA in organisms of a certain population.
-Artificial selection is plant or animals that do specific breeding so that that individual will get certain characterists and genes that were desired. So if one of my parents had blue eyes and the other hazel with a blue eyed gene my parents can select that i have blue eyes. Or with dogs, people selectively choose dogs to reproduce together to create a certain mix of dog with desired characteristics.

Sources for certain examples: http://en.wikipedia.org/wiki/Mutation
Alberta 20-30 Nelson Biology textbook

5.4

5.4








PART 1: Lamarkism





Even though Lamarck theory was proved to be wrong, he did understand and taught us that environment had a large impact on evolution. and example of his theory would be let's say if i were to a loose a toe, that my offspring would inherit the no toe and my child would be born without a toe and that was we adapt to the environment. he beleived that new species were being created by spontaneous generation which is the belief that living things arose from non-living matter.



PART 2: Darwin's Theory


-he evaluated how different species evolved and related to one another by finding and veiwing fossils as well as assessing the land mass these species lived on.
-Galapagos Islands was home to 13 very similar species of finches. He made a conclusion that these birds had evolved from a single finch that had arrived on these islands.
-He was able to assess the location of fossils and mountains from experiencing earthquakes which moved the land mass.
-became interested in artifical selection: changing of traits in a desirale way.
-Started his study in natural selection and studying competition between species which lead to adaption to an environment therefore traits changing which causes evolution.

EXAMPLE: A finches beak changing from a small beak for eating insects and finding them in small places to a big parrotlike beak for eating fruit.

5.3

5.3

PART 1: Homologous features

Definition: features with similar structures but different functions.

Basically this is the understanding of how different structures evolved to become what they are today. A whale has forelimbs but they use them differently in the fact that whales swim and humans walk. This feature is also present on humans and horses but we all use them quite differently.

As we know a bird uses her forelimbs to fly while a rabbit will use theirs to hop.

PART 2: Vestigial features

Definition: Rudimentary structures with no useful function

Okay so let's start off with the whale example. It has been proven that whales used to have legs or a similar species to whales that evolved into whales. So now whales and even snakes have hip and leg bones that come to no purpose

You can't really tell very well but the eye sockets here are actualy empty on this blind cave salamander suggesting that they have evolved from a species that have had eyes that were able to see.

PART 3: biochemistry

Biochemistry has alot to do with the genetic make up of cells. This could be the amino acid sequence in your skin cells and biochemistry is determining how the amino acid chain differs from other species over time that once had the same protein make-up. Scientists have started using this method in DNA. Scientists use the four bases in DNA- adenine, thymine, cytosine, and guanine- to compare different genetic make-ups in species to determine their similarities and differences. the pig and peccary have 7 similarities according to their DNA make-up, which can help up to determine their ancestores and different features that they have in common to also help us determine their ancestores and how they have changed according to their environment.

PART 4: Embryology

Definition: the branch of biology and medicine concered with the study of embryos and their development.

-Study of the formation of life.
-Embryologists examine fertalization and track the development of the embryo.
-Study of sperm and eggs and the whole process of a little creature growing from a one celled organism to many.

another side note for the teacher...

As i was reading i noticed alot of spelling mistakes, so i am very sorry about that i hope you can figure some of them out thanks, andrea.

5.2

PART 1: Linnaeus Classification

This was created by Swedish botanist Carl Linnaeus. His system was based on the physical and structural features of an organism, and the more features the organisms have that are similar the more common they are which leads to taxonomy which we looked at before.

We also looked at identifying species with their scientific name which is made up of two parts: Species name and Genus name. actually genus comes first my bad. This is binomial nomenclature which is just a fancy word of saying the process of which scientists assign organisms names so that they can have their own little crazy language in between eachother.

An example we can use is whales, just cause it's straight out of the text book :)

A whale is a fish, we all know that... i reaaaally hope. But another thing i hope everyone knows is that there is many different sorts of whales. The Bowhead Whale is called Balaena Mysticetus. a way that we know that is his features. Features that the Balaena Mysticetus has are baleen plates and no dorsal fin and that is the start to identifying this type of whale. A whale that has teeth and a large dorsal fin would be the Orincus Orca or in more normal terms the famous killer whale. And so on and on we go naming the fish, and bears, and bird, and all organisms like this. but i bet it gets a whole lot more complicated then just saying whether it has teeth or a fin.

PART 2: Paleontology

Definition: the study of fossils.

sounds simple huh? well its definetly not. i wanted to be a paleontologist when i was little, turns out its alot of school, but it sounds fun. So how does paleontology fit into evolution? well evolution is can not even be possible without paleontology. Scientists have found approximately 250 000 fossils, some of which have helped us figure out how us humans got here.

okay so you can't see the picture too well but those skulls are from our anscestors. you can't see well but if you look closely you can see that some of the skulls higher up on the tree have the genus names Homo which is our genus name so that is when you can start to see the direct link in where humans really started to become a species. the ones with the same genus names as us tells us alot about our evolution and how our bodies and skills came about. point is we wouldn't know any of that without paleontology because then we would have no fossils to even figure this out. and thanks to those who came up with the tecnology to learn all this as well, we have to credit you as well.

PART 3: Radiometric dating (Sorry is your getting bored Mrs.Rowswell but remember you are the one who assigned this project!)

Here is alittle background knowledge (history grossss)

-1800 Sir Charles Lyell was a geologist who wrote a book - Principles of Geology - and he estimated that the earth was hundreds of millions of years old. He made his theory off of fossil deposits and geological processes like erosion.

-Lord Kevin decided that this was wrong and said the earth was only 15-20 million because he did some science/math and came up with that and people beleived him because it was more agreable with the beleifs at the time.

-1903 radioactivity was discovered.

okay so what the heck is radioactivity? Lord Kevinassumed that the Earth was gradually cooling down, but his theory failed because he did not look at the heat that is generated within the earth from radioactive decay. The way we figured out the age of the earth is because Radioactive decay gives some form of geologic clock so that scientists can pin point the age of the earth, another huge part of evolution.

Here's a little Chemistry lesson: Radioactive decay changes parent isotope which is an atom into a daughter isotope which can be of the same of different element. Here are some examples from the textbook: radioactive potassium 40 decays so it will become argon 40 or another element like calcium 40. My biology call looked at this graph which looks at half-lives whihc is just the units that measures the rate of decay, its the amount it takes for half of the isotope to decay and become stable and i think that means the time all the parent isotopes turn into the daughther isotope but they just have a specific was to calculate it called half-lives.

Scientists have also learned that isotopes are a constant which means they arn't affected by certain conditions like temperature, moisture, or other environmental conditions. With constant half-lives isotopes are used as naturally occuring and precise radiometric clocks.

I kindof got off topic and forgot what i was actually suppose to talk about but here is radiometric dating (definition): a technique used to determine the age of a rock or fossil. so paleontolists can determine the age of a rock with radiometric dating which is used from the data of variety of isotopes that are combined.

PART 4: Biogeography

Definition: the study of the geographic distribution of life on earth.

this is used to determine different patterns on earth and the history of life on earth. Scientists look at fossils that can be as old as 150 million years back when one giant land mass split into a bunch of what we know now as the continents. they look at how the species evolved when their conditions changed.

Well that was very long but there is much more to come :)

editing not working :(

I have absolutely no idea how to fix the damn spacing in that last blog it just keeps getting all squished, SORRY Mrs.Rowswell!

5.1

Taxonomy 5.1 In bio 20 we have started to learn about evolution. which i was quite excited about, but it turns out its actually alot different then i thought it would be. Like taxonomy; i knew that we all had scientific names but every species is actually grouped in this chart and we call it taxonomy. Here is the overveiw: Definition: the science of classification according to the inferred relationships among orginisms basicly this means species are all classified in a chart according to their ancestors. the picture to your right is all the catagories that species are sorted into. Here is an example where i will catagorize a human and a nine-banded armadillo, as odd as that is. Common name Human Nine-banded armadillo Kingdom animalia animalia Phylum chordata chordata Class mammalia mammalia Order primata cingulata Family hominide Dasypodide Genus Homo Dasypus Species Homo Sapiens Dasypus Novemcinctus