Evolution Essay

Vanessa Hernandez

3^rd hr.

05/9/2011

Evolution

What is evolution?  Evolution is the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.  In other words they say animals have changed over time and developed into the wonderful, interesting creatures we have today.  Also they say that us humans developed from primates which are monkeys.  I wouldn’t say we went through stages to become what we look like today I would say its more like evidence that we have found in which other creatures before us have had.  They have found a lot of similar features of us in fossils, the “stages” or “evidence” we have found is Paleocene, Eocene, Oligocene, Miocene, Pliocene, and Pleistocene.

Just because we talk about evolution more and more everyday does not mean it has not been around for many years.  A man named Erasmus Darwin is the whole reason for this theory.  He was into nature his whole life and he was not going to stop at just dreaming of seeing the world, he made it happen.  Darwin got on a boat and went off to see the world and the different things that were in it.  He observed many creatures on islands, he observed the way they ate, how they changed over time, how they mated, how they found food,  the colors, what they looked like, and how they adapted to different environment changes.  He also observed the changes in the earth and how they formed into islands, mountains, and land.  Darwin went out and explored the world and made many theories.  

One theory he made was microevolution which is put into 4 mechanisms.  One mechanism is Mutation, which is very rare but it can happen.  One example of mutation is when all the beetles are green but then one beetles wings are half green and half brown.  The second theory is Migration. For example if there is one beetle in the group that is brown, that one will migrate and reproduce and make more brown beetles.  Once this happens the brown beetles will go up in population.  The third one is Genetic Drift, which is when the beetles reproduce then just by luck more brown genes ended up in the offspring.  The last one is Natural Selection, which is when beetles with brown genes escaped predation and survived to reproduce more frequently than beetles with green genes, so that more brown genes get into the next generation.  With  natural selection it also comes with artificial selection which is when the mate is chosen for them or the last resort, like in dog breeding, you get what you want.  These all go together in a chain most likely,  you can’t have one without the other.

Another theory he had was macroevolution.  Macroevolution is the history of life.  It has to do with every type of change or the stuff we do to survive.  For example back to the beetle, it does not just show the life of the beetle but it shows the things around it also.  It shows how the beetle survives and what it does to live.  Macroevolution refers to bigger things other than just one species.  This subject is connected to the theory of Microevolution.  This subject goes from mammals to plants it talks about the life cycles of all living things and how they have survived over hundreds and hundreds of years.  

Evolution has been around for hundreds of years and we are still figuring it out.  We are finding out more and more things over the years.  Darwin was a genius and started us off and now we will finish it and prove it.

Evolution/Guppy

EVOLUTION 101:

How do the authors of this page define microevolution?

Microevolution is evolution on a small scale—within a single population. That means narrowing our focus to one branch of the tree of life

How do they define a population?

It is a group of organisms that interbreed with each other—that is, they all share a gene pool.

Summarize each of the 4 mechanisms of microevolutionary change that are discussed.

Mutation-  Mutation is very rare but it happens it happens in the genes or DNA.  Just like in the beetle pictured the rest are all green and the mutated one is green and brown.

Migration-  When the beetles migrate they reproduce with different species so that makes the brown beetles increase in population.

Genetic Drift-  When the beetles reproduced, just by random luck more brown genes than green genes ended up in the offspring.

Natural Selection-  Beetles with brown genes escaped predation and survived to reproduce more frequently than beetles with green genes, so that more brown genes got into the next generation.

Summarize the 3 examples of microevolution on this page.

The size of the sparrow-  Just talks about how the Sparrow changes over time mostly by natural selection and how the different kinds can survive in different living conditions, its all about survival.

Coping with Global Warming-  Different species get used to global warming differently, they each have a technique for example the mosquitoes used to do days according to temperature but now they do it by time.

Building Resistance-  Resistance is built by natural selection.  For example some people’s bodies have a resistance towards antibiotics.

Summarize the results of the two different experiments (with and without predators).

With predators the males had less of a natural selection because some of the ones that can not blend in were dinner to the predator.

The experiment without the predators had more of a natural selection for the males.

What types of selection were demonstrated in each experiment?  Are these experiments truly cases of artificial selection? Explain your answer.

Natural selection.  Yes because it has to do with natural selection.  Natural selection happens when the male picks and with the predator he had no choice so I think that has to do with artificial selection also.  

Pick your three favorite questions from the quiz and write how you would answer them if you were teaching this class.

What’s the big deal about artificial selection? 

a.    People have a choice to pick what they want with artificial selection they don't want just anything it's what they want.

If I select guppies for colorful fins at home, can I get them to change?

a.    Yes it will take time but you can do it by taking the colorful fins that you like and have them reproduce.

Why are house sparrows in North America larger in the North than in the South?

a.    Because of the weather change and the different living conditions.

SEX AND THE SINGLE GUPPY!!!

Why do some guppies tend to be drabber than others?

Thanks to predators the guppies colors have varied and have become more drab.

Why do some guppies tend to be more colorful?

Females are choosing to mate with the more colorful males because the stand out.

What role does color play in guppy survival?

The colorful guppies reproduce more.

 Explain the push and pull that the environment (including predators) has on the coloration  of guppies in Endler’s pools.

The colorful guppies are very weird, they reproduce more because the females are more attracted to them but yet they get targeted by predators because they stand out more to them.  The environment change is not much of a challenge for them when it changes they change but over time the more drabby fish can take over too.

Evolutionary thought

Erasmus Darwin (1731- 1802) - As a naturalist he formulated one of the first formal theories on evolution in Zoonomia or the laws of organic life. He also talked about how competition and sexual selection could cause changes in species.


Georges Cuvier (1769 - 1832) -  He found Vertebrate Paleaontology as a discipline and created the comparative method of organismal biology.


Jean Bapatiste Lamarck (1744 - 1829) -  They said he was a great zoologist and as a forerunner of evolution.


Thomas Malthus (1766 - 1834) -  Theory of Natural Selection-  Malthus's observation that in nature plants and animals produce far more offspring than can survive, and that Man too is capable of overproducing if left unchecked. Malthus concluded that unless family size was regulated, man's misery of famine would become globally epidemic and eventually consume Man. Malthus' view that poverty and famine were natural outcomes of population growth and food supply was not popular among social reformers who believed that with proper social structures, all ills of man could be eradicated.


Darwin believed that the earth changed over time and it formed into shapes such as islands and they go through a lot of changes.


When Darwin went back to England he found out that his Finch's comprised 13 species.  


He found out that the beaks change over time that gave him the question of evolution!!!