Biological Evolution - Final Ideas and Questions

[Erin Nash]

Use the space below to record your final learning about evolution. How has your learning changed? Compare your current understanding of evolution to your original post. What information do you feel you understand better as a result of our class discussions. What do you still not understand? 

Your first step today will be examining your notes - look through the packet to make sure you thoroughly understand the information in the packet.

Next you will want to include your question you had researched for today's class period. What was your question? What did you learn from this question? What resources did you use to answer this?

Think about your learning from our class notes, as well as the videos and audio excerpts you listened to in class. How has your view of evolution changed?

If you are still finding you are not understanding some concepts regarding evolution, this site is very helpful in regard to providing information regarding this scientific theory.

[josh steltenpohl]

My outlook on evolution hasn't changed much but the area that is has changed in is where animals adapt to their surroundings. Animals have done a lot of changing over the years and all that is to do with the environment they live in. I have never realized that almost every type of animal in the world today is an evolved model of the earlier state of that animal.

[Hannah Rush]

In my earlier post about evolution, I was somewhat on target. I was just so focused on the fact that I didn't believe in it because I'd been brought up and taught not to by my church family. But seriously people, religion doesn't really have anything to do with evolution.

Evolution is the way in which things change over time.

There are two evolution theories. One was made by a man named Jean-Baptiste Lamarack. His theory is known as the use and disuse theory. He said that when a species uses a body structure frequently, it develops bigger and stronger; and when a species doesn't use a body structure very often, it eventually would waste away. Once the structure was modified by use and/or disuse, the characteristics were then inherited by the organism's offspring. This theory was later disproved by a man named August Weisman. He conducted an experiment on 22 generations of mice and cut off all of their tails. He observed that there were no inherited traits by him doing this, therefore Lamarck's theory couldn't be completely on target.

The second theory was made by a man named Charles Darwin. This theory has caused a lot of controversy in today's society. Many people get upset because somewhere in history, it was said that Darwin said that humans originated from apes. That is a false statement. Darwin's theory is that all creatures descended from ancestors with similar traits. He also said that creatures survive by natural selection.

The question that I asked was "Why can't different species mate together?" Nash told me to look up the definition of species. The definition says a species is: "...related individuals that resemble one another, are able to breed among themselves, but are not able to breed with members of another species." Just by finding and reading the definition seemed to clear things up. But then, I kept on thinking about it, and many other questions kept coming up. In class, we discussed how horses and donkeys mate and get a hybrid offspring we know as a mule. Since it's hybrid, we know that it cannot reproduce. It all started making sense until today in class when we read the article "Neanderthal genome reveals interbreeding with humans" by Ewen Callaway. The article also says, "Any human whose ancestral group developed outside Africa has a little Neanderthal in them- between 1 and 4 per cent of their genome.." This brings a lot of questions. If humans and Neanderthals did interbreed, were their offspring hybrid? If so, why do we have any per cent of Neanderthal in our DNA?

I'm glad that I got the chance to actually learn about evolution and that I finally realize that it really isn't a controversial topic if you go into it open-minded. =)

[Blayr Bolton]

Blayr's Final Learning about Evolution

Looking at this picture above, I thought, would be a great start to my overall learning about evolution. One reason because it is very, very controversial, and reason number two because it can be seen as very confusing. That seems almost perfect seeing as I've learned that Evolution is very, very controversial and/or confusing; that is if you don't take enough time to learn about it and truly attempt to understand this theory. I, myself, feel very lucky to be in a situation (the Nash classroom) where I've been given the opportunity to try and really understand what Evolution is all about and voice an opinion on the issue.

My growth and development of learning with the theory of Evolution has dramatically changed from when I first heard the word Evolution and from just a few weeks ago when we started this discussion. When describing Evolution in my first post I stated... "One thing that I have learned this year about evolution through all of my science classes, (genetics, microbiology, and biology) is that evolution, or the way things change, mutate, and evolve over a long period of time, isn't just with people, but with other things like bacteria, viruses, animals, teeth, and so on and so forth." This was information I have acquired throughout this school year and one thing I noticed about it, is that it's very simplistic and general. I use words like "things", "long period of time", and "things" again. I think I used these words because I wasn't exactly sure what specifics or examples to mention. An example of how this has changed is, when asked "What's the Evidence for Evolution?" I replied...

The evidence for Evolution may include comparative anatomy. That's comparing the make-up of one organism to the make-up of another organism. For example, in comparing the anatomy of a dinosaur to that of a bird, scientists have found over 100 similarities (via Wise projects) between the two. This is through fossil evidence that these observations can be made. Evidence of Evolution through one organism can be seen through a horse as well and how their size has changed over the span of 60 million years.

...To be continued.

[Ally S]

What I was interested in researching wasn't exactly a question. I wanted to hear about sexual selection as used in modern day, & to obtain a little more general information on the subject. I found a neat video about peacocks & sexual selection. There are definitely some comical moments. Check it out. :)

[Kerstyn Bolton]

My first post about Evolution was, "As unusual as this is I actually have a conversation about evolution about every week. I'm always wondering what exactly it means and how it incorporates into the way we live today. I can't say that I have any absolute correct facts about evolution, but I do have assumptions and guesses. From what I know I can infer evolution is the change of things over time. In biology everything evolves sometime or another.. it's a natural process. Human's have obviously evolved over time and they will continue to for years to come. One thing I've always wondered about was Darwin's Theory because I used to believe that his theory was about humans evolving from monkeys, but now I don't think that's it at all."

There were two main theories that were used to understand evolution. Lamark used the theory of Use & Disuse, which stated that the most used body structures develop and the least used waste away. Then once the structure is modified by Use & Disuse the characteristics are inherited by the organism's offspring. This theory was eventually disproved by a man named August Weismann who cut off the tails of mice for 22 generations and observed no inherited change. The second theory was made 50 years later by Charles Darwin. His main ideas were those of "natural selection" and "survival of the fittest". He has been targeted with the theory that homosapiens came from monkeys, but that is completely wrong. He simply states that the most fit and adaptable species will live the longest and therefore keep the stronger traits alive during the generations.

The thing I researched was what animals mate for pleasure. During a discussion in class one day we were discussing sexual selection in species and with most of the species we were discussing (mainly birds) the female is the one who scopes out the male to reproduce with. In one situation the male birds would decorate their homes as a way to intrigue and attract the female birds to them. This was a bit strange to me. After this we discussed how the male lions mane is the deciding factor of how female lions find them attractive. Then a few days prior to this we discussed how these male fish would release their sperm around females. All of these scenarios made me wonder what species mate for pleasure and my first instinct was that it had to be some of the species who had more understandable brain chemicals.

The research I found was that humans, some forms of monkeys particularly bonobos, and dolphins. This didn't surprise me necessarily because I had heard of bonobos before and it seems as if dolphins are very intelligent creatures. Although there are many intelligent species that don't mate for pleasure. The correlation with this and evolution are that these species give mating a different meaning compared to the fish who just release the sperm. Take humans for example. We find mates are we marry them, right? Well we have a decision in who we reproduce with and that's what makes our species so diverse. Their are many different ethnicity's that mix, which results in speciation. I couldn't necessarily find proven evidence, but I'm sure these are true with monkeys and dolphins as well.

Overall, my ideas of evolution have changed dramatically. At first I had no idea what the ideas of evolution entailed, but now I feel like, for the most part, I know exactly why and how it occurs. Evolution is extremely necessary for species to adapt to their surroundings. "The fuel for the engine of evolution is mutation." Mr. Nash told us to write this in our notes one day and I couldn't agree with the statement more. Things have to change or mutate to even make evolution happen. Another one of the key components of evolution is that it is the change in populations of living things over time.. NOT individual changes. I mean we all came from common ancestors anyways. All living forms have the same fundamental biochemical organization and genetic code. Granted we didn't come from monkeys, but instead of not understanding this statement I can now tell you why. If we evolved from monkeys then how are monkeys still here in this world? If we would have evolved from them then ALL monkeys would be gone because they'd be homosapiens now. Evolution is one of the most important process in the world and I'm glad to now be able to say I understand the core of it.

[Shelby Hawkins]

Whoa! I haven’t been in this class for over a week!

Without evolutionary theory, Biology is just facts. The theory ties it all together, like the glue between bricks.

This is what I said about Evolution when we first started this unit:
“Honestly, I don't have a lot of background knowledge about Evolution. I remember a little bit of discussion in freshman bio, but most teachers don't delve that deep into Evolution. There was also some strong opposition from a few students in my biology class to even discuss evolution at all.
What I think I know: Darwin is considered the father of evolution but was not the only person who believed this concept.
-I don't think evolution states man comes from monkeys, but I hear a lot of controversy on this point
-Evolution is continuously happening as living things adjust to environmental changes. That doesn’t mean a new species is being created necessarily, but changing the way it lives/characteristics to enhance survival

That pretty much sums up what I can remember, but I did read Inherit the Wind if that counts for anything!”

Now I know that another person who created an evolutionary theory was Lamarck. Lamarck’s theory was
-Organisms strive to improve themselves and become more advanced
-“Use & Disuse”= the most used body structures develop. The least used waste away.
-Organisms change a great amount from one generation to the next.
August Weismann disproved Lamarck’s theory by experimentation. He cut the tails off mice for 22 generations and observed NO inherited change.

Darwin’s theory is more believed than Lamarck’s. Darwin basically sums it up to survival of the fittest. The members of a population that have the best mutation to help them mate or survive will pass their genes on to the next generation. “That’s Evolution. Life will find a way.” Mr. Nash

There is a lot of evidence for evolution, such as fossils. Fossils are left over remains or impressions from remains that can be found in material such as rock and amber. These “leftovers” allow us to see the structure of plants and animals from millions of years ago who aren’t alive today.
Another evidence is body parts of creatures that aren’t used anymore, such as dew claws on dogs and cats. Their ancestors might have used these, but over time environmental changes caused them to not need these parts.
A few more examples are biogeography, embryology and comparative anatomy. I think the day we learned about this in class helped everyone to understand evolution the most.
Speciation is also important. This proves evolution because different species came from a common ancestor. One question that I had from the beginning of this unit was: What makes a species, a species? What is the dividing line that says “This is a new species, a new form of life.” Through class and research I’ve learned that a species is a new species when a population can no longer produce fertile offspring with the other part of that population. This is called divergent evolution. A good spin on it from Lisa Shae Biology is “Nowadays, the breeding line is the one most biologists draw. This line can be drawn for two reasons. One, the creatures simply cannot create a viable new baby organism. That would be the case between for examples cats and dogs. Even if you did convince them to mate, their sperm and egg could not join properly. The second situation is *situational* non-viability - where the two groups of creatures never interact properly to mate. This would be the case where one group of black monkeys lives in Africa and another brouwn group lives in Asia. Maybe they COULD mate and make babies if they ever met, but they simply don't.”

[Blayr Bolton]

...continued.

From recently watching and becoming fascinated with the Discovery channel series "Life", I decided to ask a question about birds. My question was: How does sexual selection occur with birds? For pleasure? I saw tid bits of information on the Life episode "Birds", but not enough to truly understand what goes on. From researching, I found an article that spoke about the first form of sexual selection being when the male bird fights for territories. Most of these territories are traditional mating grounds, so you can notice one if you're in the right area and know what to look for. The second part of sexual selection with birds includes a female searching and finding a potential mate. As far as anything I found, a male or female bird choosing has not been linked to pleasure, but more of females choosing males because of their ability to grow and display long tails that reflect their overall genetic quality as mates and/or the females are thus choosing a superior father for their offspring.

Overall, my view of Evolution has drastically changed. I believe I'm more mature about Evolution at this point, if that makes sense? I'm definitely more willing to the idea of Evolution and how it really occurs, where before I knew that Evolution occurred, but never really believed the ideas of how human populations have evolved and/or the idea that a bird could truly have evolved from a dinosaur. Our notes in class are a big factor in helping me understand Evolution as I see what I've written for real evidence of Evolution and looking through my notes about Fossil Evidence and Sexual Selection. My view has also changed in understanding that Evolution is a theory. I wrote, "Biological Evolution is just like any other new lesson in science. Approach it that way with an open-mind and critical consideration. :)

[Amanda Dixon]

when we first stated i knew nothing except a little about Darwin. I knew who he was but didn't really remember anything about his theory.

I now know about all the theories and i better understand them

Darwin's theory was species living today descended from ancestral species, natural selection, individual variation, over production and competition. this really clicked when we talked about the birds and how the female picks her male. Shes going to want a male that is strong and healthy not one who is sick and weak. She wants to make sure she is able to keep passing her genes down and have healthy babies.

the question I still have is. is there another reason females pick there mate besides them be strong and healthy?

this site suggest that animals and humans might use smell to pick there mate.