What is Evolution?

Evolution is often considered a complex and controversial topic but it's actually a very simple concept to understand. Watch this short animation to see how evolution works. Share it with your friends on Facebook who might be confused or may have been mislead about the evolutionary process.

Sources:

The definition of Evolution:

"Genetic change in a population of organisms; in general, evolution leads to progressive change from simple to complex." - Biology, Seventh Edition, Raven, Johnson, Losos, Singer (college textbook) pg G-6 glossary

"Descent with modification...change in the genetic composition of a population from generation to generation." - Biology Eighth Edition, Campbell, Reece (college textbook) pg G-14 glossary

Thanks to Hedvig Francke for providing Closed Captions in Swedish.

[weTa]

I’m not even watching this for biology class. I just love learning about biology and evolution.

[lvezone]

that means whoever we end up dating, we'll be related to them. oh sweet home alabama

[hulias]

If you sort comments by "newest first" on this video, you WILL lose brain cells. This is a warning.

[DenisK]

Evolution: nature's way of repeatedly saying "it's not a bug, it's a feature" and hoping it sticks.

[agaming-debc]

Who has to watch this for science class on google classroom while at home?😁 Pretty good vid tbh..

[erasmith]

I thought I was studying biology but by reading comments in the section below I feel as if I was one of the viewers of war between religious and scientific people.. Well for me God is my soul and science is my teacher

[INACTION]

Hi! Who else got forced to watch this... but then actually enjoyed the video?💀😂

[alexdavies]

How to start an argument on Youtube:
1. Write a comment.
2. Wait...

[RandallWilks]

*The American Association for the Advancement of Science statement on evolution:*
*"Evolution is one of the most robust and widely accepted principles of modern science. It is the foundation for research in a wide array of scientific fields and, accordingly, a core element in science education. The AAAS Board of Directors is deeply concerned, therefore, about legislation and policies recently introduced in a number of states and localities that would undermine the teaching of evolution and deprive students of the education they need to be informed and productive citizens in an increasingly technological, global community. Although their language and strategy differ, all of these proposals, if passed, would weaken science education. The AAAS Board of Directors strongly opposes these attacks on the integrity of science and science education. They threaten not just the teaching of evolution, but students’ understanding of the biological, physical, and geological sciences."*

Creationists, who are often scientifically illiterate, often make the claim that evolution is not really science. The AAAS, in essence, is saying they lie..

[MinecraftGamer]

Why is there 18k comments about religious comments and like 2 religious ones

[kimberlycurtis]

Evolution is not random. The mutations that lead to variation may be random, but evolution is not.

[theashunsensation]

for you people who do not accept evolution (not necessarily religious people because you can still be religious and believe in evolution) why do you go even go on these videos? Do you specifically go on this just to tell people on how its wrong without evidence or why we should believe you?

This is coming from a former intelligent design supporter. I used to go on these videos with an open mind and debating people on this matter on the comment section too BUT supported with evidence. I would seek the knowledge of why people believe certain things and if I don't believe in the same things as other people do I would argue with them without bias or close-mindedness. If their belief wins out using the current evidence then I will change my belief. Pure simple. And so I did because my beliefs are not static, but I always seek answers to things. This is the scientific way to think.
Its not you believing in something and trying to cherry pick for evidence you like that may support it.

[Jrpyify]

I came just to look at the comments. Not disappointed

[danielvernon]

Does anyone know how to install minecraft mods?

[lizziesims]

who here is watching this for home learning during lockdown? im pleased im looking at evolution at home instead of school cos i have my old friend google around XD

[bqjgf]

Who else is here because of "Biology Class"

[SLPIN_]

When two badgers get together and you know... "fall in love".

[othertestchannelbeta]

Almost 40% scientists believe in a higher power, yet the percentage of scientists who accept is above evolution 97% (the general public is 61%) so it's not a matter evidence conflicting with faith or believe. The evidence of evolution describes a physical process in nature that requires reproduction, heritable variation, and natural selection. We can observe these processes taking place in the lab. It's both a theory and an observable fact.

[АфанасьяКошкина]

Hello world! I am a girl from Russia, and I am preparing for exams) I do not know English, but I am very glad that there are subtitles for Russian!

[RandallWilks]

*HOW EVOLUTION WORKS It is helpful to understand that evolution is a molecular process. The random mutations that naturally occur during cell division and replication (mitosis and meiosis) are the raw material for the genetic variation we see in every population of organisms. Mutations are ongoing and continuous for every living species. "Mutations are essential to evolution; they are the raw material of genetic variation. Without mutation, evolution could not occur.''*

Those genetic variants are subjected to a selection process that is performed by whatever environment the organisms find themselves. In this respect, evolution is an ongoing, continuous set of natural experiments. Those that work get perpetuated, those that don't, perish. It is as if the environment acted as an umpire who says "There are good mutations and there are bad mutations and there are neutral mutations, but they ain't nuthin' until I (the environment) calls 'em." That is Natural Selection. Neutral mutations just go along for the ride producing neither immediate benefit nor harm (Genetic Drift).

The result of those selection processes is organisms best suited for their current environment. Should that environment change, it would put the population under stress. If the population gene pool has sufficient genetic variation it increases the likelihood that at least some offspring should be able to survive and perpetuate the species (albeit one of slightly different genetic makeup).

What everyone should understand is that genetic changes do not occur because of some 'need'. The mutations are RANDOM and get selected if they are USEFUL. That is a process called Natural Selection and it is anything BUT random.

Let's take the example of the Panda. Bears in general are omnivores, eating plant matter, but with a marked preference for meat when available. The preferred food of the Panda however, is bamboo leaves, which have such low nutritional value that they must eat almost continuously. The Panda would certainly be able to extract more nutrition with a four chambered stomach (as in ungulates and whales) or something akin to a cecal valve that would slow the passage of food, but it has neither in its genetic toolbox. In feeding themselves, pandas are continuously stripping bamboo leaves from their stalks, a process that could be facilitated if they had a thumb.

Bears however do not have thumbs, nor do they have genes for them in their genetic toolbox. Nor do new features simply spring into existence. However, if a slightly altered body component provides some benefit, natural selection will perpetuate it. Evolution is modification with descent and results in incremental alterations to what is already there.

As an analogy, imagine a robot gardener dragging a hose around various obstacles it encounters in a garden until it can go no further. Now an intelligent gardener could simply retrace his steps and take a different path, avoiding those obstacles. The robot gardener (evolution) is not an intelligent force and cannot do that. With a limited tool kit, it can only (figuratively) add more hose to get the job done.

While a thumb would be quite useful to a panda for stripping leaves, evolution cannot rewind to produce one. Instead, it has taken "a piece of hose' (a wrist bone) and enlarged it to act as a stand in for a thumb. That is not an elegant solution and not a perfect one, but it gets the job done. Evolution is does not produce perfect solutions, but tweaks here and there to "get the job done". THAT is how evolution operates. The panda’s "thumb", developed over many generations of holding things, is clearly a co-opted “radial sesamoid” bone from the paw of a bear. Likewise, the 'Red Panda', a raccoon relative with a similar diet, has evolved a similar feature.


Still, what was missing was a fossil showing characteristics of fish AND tetrapods. When Neil Shubin and his team decided to search for a fossil that filled the gap between the Lobe Finned Fishes that dominated Devonian Seas and the earliest tetrapod fossils represented by Ichthyostega and Acanthostega dated about 370 mya. Since those fossils were found in geologic deposits indicating a freshwater environment and if the Theory of Evolution is correct in its hypothesis that tetrapods evolved from fish, then transitional fossils should be found in similar deposits somewhat older in age. The problem was that geologic deposits of that age are exposed at few places on the earth's surface. Fortunately, a great deal of geologic exploration has been done throughout the world, financed often times by oil and mining interests. They selected an area in the Canadian Arctic, Ellesmere Island, as having the greatest likelihood of success. It took 4 years of searching during the short summers of that hostile environment but succeeded, returning in 2004 with 9 specimens of the fish they named Tiktaalik. It was exactly what one would expect a transitional fish-tetrapod to look like and was found in deposits dated 375 mya. If this was not the direct ancestor of tetrapods, it was something very much like it.This is a great example of using evolutionary theory as a predictive tool.
Btw, biointeractive(dot)org is a great source of information for all of science. If anyone has an interest in expanding their knowledge of science they should use it.

The genetic variation within a population is referred to as a gene pool. Organisms can move freely within that population breeding with each other, perpetuating any new mutations that work and eliminating those that are less than optimal. Each offspring will most resemble its parents, yet will vary slightly genetically because of unique mutations acquired during meiosis. Thus the genetic makeup of a population will change ever so slightly with each successive generation.

Populations are not stable, they expand and contract with changing conditions. So long as there is sufficient genetic variation within a population there will be some members capable of surviving those conditions and perpetuating the species. The alternative is extinction.

When populations expand and migrate to new territories, some portions of it will become genetically isolated from each other and no longer share a common gene pool. In such cases, each such sub population will carry a subset of the parent population genome, but subsequent mutations will be unique to each new population (the genotype) that will come to differentiate that population from others (Genetic Drift).

To the extent that such populations encounter differing environmental conditions, that environment will exert different evolutionary pressures on that population. New mutations will have a much greater chance of coming to dominance within a smaller population than they would in the larger parent population where they would be one among the many. Over thousands of generations genetic differences accumulate in the different gene pools making interbreeding ever more difficult until at some point speciation can be said to have occurred. Because speciation is a process, rather than an event, it would be no more possible to pinpoint where speciation occurred than to identify where on the color spectrum orange becomes red.