Facts Of Evolution: Speciation And Extinction

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EVOLUTION IS REAL SCIENCE:

1. Does The Evidence Support Evolution?
2. Vitamin C And Common Ancestry
3. Are We Descended From Viruses?
4. Does The Fossil Record Support Evolution?
5. Where Are The Transitional Forms?

FACTS OF EVOLUTION:

1. Introduction
2. Universal Common Descent
3. Good Design, Bad Design
4. Speciation And Extinction
5. How Fast Is Evolution?
6. What Can Embryos Tell Us About Evolution?
7. The Molecules Of Life
8. Molecular Evolution: Genes And Proteins
9. Retroviruses And Pseudogenes

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SPECIATION is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages.

Whether genetic drift is a minor or major contributor to speciation is the subject of much ongoing discussion. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are geographically isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry or laboratory experiments. Observed examples of each kind of speciation are provided throughout.

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In biology and ecology, EXTINCTION is the end of an organism or group of taxa. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point). Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "re-appears" (typically in the fossil record) after a period of apparent absence.

Through evolution, new species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition.

A typical species becomes extinct within ten million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Extinction, though, is usually a natural phenomenon; it is estimated that 99.9% of all species that have ever lived are now extinct.

Mass extinctions are relatively rare events, however, isolated extinctions are quite common. Several extinctions during the Holocene extinction have been attributed to the rise of human activity; however, there is no clear consensus among the scientific community on the effect of human activity on extinctions. Only recently have extinctions been recorded and scientists have become alarmed at the high rates of recent extinctions. It is estimated most species that go extinct have never been documented by scientists. Some scientists estimate that up to half of presently existing species may become extinct by 2100.

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[truvelocity]

What do creationists have to say? Oh man, , , They really shoot themselves in the foot by saying anyone who understands evolution is a atheist. I'm not kidding, here.

[devil]

The evidence is right in front of you, this video is more of an explanation to be fair, but you can look at the ever more complex and complete fossil record. It's a fact those fossils exist and it's a fact that eac species carries a small number of changes from the previous species. It's plainly observable.

In contrast, Creationism or "Intelligent Design", that I can only imagine you follow, has no demonstrable evidence that indicates or verifies it anyway.

[DutchDread]

I love how you people think you have some kind of great question that the scientists haven't thought of yet, yet it is always obvious to anyone who hasn't closed his mind.

[concrete_dog]

I just came to a realization that /if/ there would be life on another planet, it could also be extinct before we know it exists. :)

[AronRa]

What an excellent series! Someone needs to show this to our recently-deposed chairman of the Texas Board of Education -because he says that the fossil record only shows stasis.

[hume]

2 / 5

….. completed this work as part of her doctoral studies. "It's really strange that no one realized this before. The position of the thigh bone and muscles in birds is critical to their lung function, which in turn is what gives them enough lung capacity for flight."
However, every other animal that has walked on land, the scientists said, has a moveable …..


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[MilitantPeaceist]

awesome - a long one, so many short ones that a long one (vid) is such a nice reprieve. And now on with the show!!!!

TY BTW!

[TheDarwinman]

I am new to youtube and have no idea who produces this wonderful channel. Thank you for it whoever you are and please keep up the good work. it is greatly appreciated -- your series of videos regarding evolution have been particularly helpful.

[ultimatemetalfreak]

@FlyingSpahghettiMan I'm so happy that there are people out there following Carl Sagan's footsteps. I credit him for my enlightment when I was a child. Man was I glued to Cosmos. You should get that on DVD if you don't already have it.

[MrColombian]

the bible was written with the best interests of the extremely wealthy and powerful in mind thats all...

[hume]

4 / 5

….. "For one thing, birds are found earlier in the fossil record than the dinosaurs they are supposed to have descended from, " Ruben said. "That's a pretty serious problem, and there are other inconsistencies with the bird-from-dinosaur theories.
"But one of the primary reasons many scientists kept pointing to birds as having descended from dinosaurs was similarities in their lungs, " Ruben said. …..


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[evoman]

Cassio Peia does outstanding science documentaries!

[truvelocity]

I agree with you, but that's not what my comment was about. It was about DNA, which was cracked in 2001, indicating that the human genome has very little diversification, which tells us that we are all derived from one lineage.

[darkpersianuk]

Fascinating stuff!

As for the "Does anyone think humans will evolve into another species eventually?" question. Many Scientists seem to think that modern technology is slowing our own evolution right down, which makes sense.

[Eugensdiet]

Great video. My dog liked it too. We have similar tastes. We're going to watch it again.

[footfault]

Two essential issues in evolution, which are least satisfactorily understood. That's why they're fascinating. They'll do so decades or centuries to come. When resolved? Magnificent, surely!

[hume]

2 / 3

Quote:

++ “The Greeks
As I read the works of the Greek philosophers, who lived between about 600–100BC, I was
amazed to discover primitive evolutionary theory and vast ages long before Darwin and modern assumptions. The fragments of Anaximander (c. 610 – 546 BC) taught that ‘humans originally resembled another type of animal, namely fish.’1 There was Democritus (c.460–370BC) who taught …..

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[TheDarwinman]

thank you for the wonderful advice. you have led me to some marvelous material. I owe you one.

[DX]

I just had a psychedelic experience.

Either this vid was craply encoded or my flash player was bumming up.

[Grysham]

Excellent. There is nothing that excites me more than seeing reason. Philosophy can only come so far without observation and knowledge.

I'll take a look at this. Could you send me a link via PM or something similar? This would be appriciated.