JavaScript is required to use Bungie.net

OffTopic

Surf a Flood of random discussion.
Edited by Britton: 5/15/2015 3:03:32 AM
174

Evolution Explained

[b]EDIT[/b] So the first true warm blooded fish has been discovered. http://m.livescience.com/50839-first-warm-blooded-fish-found.html Pretty awesome. Pic above. Its called an Opah, or moonfish. [b]OP:[/b]Since the issue is always a lack of understanding, and its often requested to be explained when people point out anothers lack of understanding on it, I'll lay it all out for everyone. [b]Evolution[/b], put simply, is descent with modification. So let's break down the basics of how that happens. [b]DNA[/b] or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms that resides in our cells. The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell. Its during this replication process that is constantly happening, that errors or mutations can occur. If an error occurs you now have a cell that is different from the original, due to mutation. [b]Mutations[/b] or copying errors cause the copied DNA to be different from the original. These mutations can be passed to the next generation of organisms when the gametes and zygotes contain the mutated DNA. Evolution occurs when you have a change in gene frequency within a population over time. What affects gene frequency? It is the [b]mechanisms of change.[/b] These mechanisms are [b]mutation, migration, genetic drift, and natural selection.[/b] Since I already went over how mutation occurs next comes [b]migration[/b] or how geographic location of populations can affect the overall gene frequency of a species. An example will be best here. You have 2 population of beetle species X. Population 1 typically has spots, population 2 typically does not. If these two populations migrate farther apart, you will see that difference become more defined due to isolation. If they migrate closer and intermingle, you'll see much more variation in the two populations. Migration, whether it be by the animals itself, or caused by other events, like plate tectonics (on a scale of millions of years) can allow or prevent the genetic divergence of populations of animals, resulting in a new species. [b]Genetic Drift[/b] is more random chance affecting organisms. Let's say in our beetle species X, population 1, lives in the lower forests, and population 2 live higher in the mountains. Well the mountain is a volcano, it erupts, and wipes all of population 2 out. All the little differences it had that were unique to it out of beetle species X, are now gone, resulting in the populations 2 genes to be gone from the future generations of beetle species X. Basically genetic drift accidental selection. And finally we come to [b]natural selection[/b]. Natural selection is the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. Or, put simply, it is the process of how the selecting factors in an environment; predators, food sources, climate, etc make certain inheritable traits more or less likely to be passed on to future generations. All of these mechanisms acting in conjunction cause evolution, and create new species. How do differentiate between species? A [b]species[/b], is often defined as the largest group of organisms capable of interbreeding and producing [u]fertile[/u] offspring. When one species becomes two, this is called speciation. This event creates all kinds of new opportunities for more evolution to occur. Its important to look at the timeline of life, not as a ladder of organisms getting "better", but as a tree, where the father up you go the newer the branches are, not necessarily better. Old branches can last a long time, like the [url=http://vertebrates.si.edu/fishes/coelacanth/indonesia_coelacanth_2.jpg]coelacanth[/url], and new branches can have relatively short life spans, like any of the many now recently extinct plants and animals. The tree just shows the lines of ancestry. Evolution does [b][u]not[/u][/b] address the origin of life. Evolution is how life forms have changed over time as a result of their environment and genetics. Claiming not having an answer for life's origins affects evolution is patently false. Yes, there are still questions being investigated in regards to evolution. For example: -Does evolution tend to proceed slowly and steadily or in quick jumps? - Why are some [url=http://www.evolution.berkeley.edu/evolibrary/search/imagedetail.php?id=260&topic_id=&keywords=]clades[/url] very diverse and some unusually sparse? Among other things regarding the specifics. All available evidence supports the central conclusions of evolutionary theory, that life on Earth has evolved and that species share common ancestors. Biologists are not arguing about these conclusions. But they are trying to learn more about how evolution happens, and that's not an easy job. It involves collecting data, proposing hypotheses, creating models, and evaluating other scientists' work. These are all activities that we can, and should, hold up to our checklist and ask the question: are they doing science? All sciences ask questions about the natural world, propose explanations in terms of natural processes, and evaluate these explanations using evidence from the natural world. Evolutionary biology is no exception. Darwin's basic conception of evolutionary change and diversification explains many observations in terms of natural processes and is supported by evidence from the natural world. This is a summary in my own words of how it works, so its entirely possible I forgot something. I've really tried to keep this as short, and simple as possible, and I welcome any questions and any issues you see.

Posting in language:

 

Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

View Entire Topic
  • [b]3 reasons earth is flat and how you can test these with your kids[/b] We know the Earth is flat because the Bible tells us so. But for those of you skeptical, close-minded types that flat out refuse to accept the overwhelming Biblical evidence, I have designed some experiments you can do at home that will show you, before your very eyes, that the world is indeed flat, and not spherical as some crazy scientists proclaim. It's amazing how many people blindly believe in a spherical Earth, without ever having seen it for themselves! I intend to change that. 1) Jump!  Now, scientists claim that Earth is spherical and rotating at a speed of between 700-1000 miles per hour, depending on your latitude. This is a very high rate of speed. You can disprove this nonsense by simply jumping up as high as you can. Really, it's that simple. What happens when you jump? You come straight down to where you were. But, if the Earth were indeed spinning at such a fast speed, wouldn't you land hundreds of feet away? If you were to stand in the flat bed of a truck going 75 mph, and jump straight up, what would happen? You wouldn't fall straight down. You would fall out of the truck. That's because trucks move, the Earth doesn't. This experiment proves the Earth is fixed in space and doesn't move. 2) Blow!  Since if the Earth is supposedly a sphere, it naturally comes to assume what would happen to people below the equator, like in Australia? Since they are underneath the sphere, wouldn't they fall off? This is where scientists come up with mumbo-jumbo like "gravity" and "centrifugal force" to explain away their theories. So, the scientists want you to think that because the earth is so much more massive than people or things, that people will naturally "stick" to the bottom of the earth because of gravity. This can be disproved very simply. Get a balloon and inflate it as big as possible. It will be a spherical shape. Now, take a piece of paper and try to rip, tear, or cut the tiniest speck of paper possible. This paper represents a human being, much smaller in mass to the balloon, which represents the Earth. Now try and place the small piece of paper to the underside of the balloon. What happens? It falls off! That's right. Even though the balloon is so much bigger in mass, it cannot hold the tiny paper. So if the Earth was a sphere, no one could live below the equator because they would fall off. 3) Get High!  Ok, this one you really can't do at home, but you can do it out in the world. Stand on the ground and look around you. What's the farthest you can see? Maybe it's a building, tree, or mountain. Now, find some place very close to it where you can get a much higher vantage point. (This also works if you're on a jet and about to take off.) Notice how in the higher place you can see much farther? You can see more of the world the higher you get. This shows the world is flat because the higher you go, the easier it is to see over obstacles. At the same time, it shows the world cannot be spherical. Because if the world was curved, the far distance would forever remain out of view because of the Earth's curvature. It would eternally be over the horizon. If the Earth was a sphere, it would not matter how high you went, you would still see the same thing. Since this is not the case, the Earth is flat. These experiments are all confirmed by creation scientists as being 100% accurate. If you're skeptical of the flat Earth, why don't you do these experiments so you can see truth with your own eyes.

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

    1 Reply
    You are not allowed to view this content.
    ;
    preload icon
    preload icon
    preload icon