Evolution. What the heck?

Question

I'm taking a biology class this semester. We've touched on evolution here and there. Today, we talked about origins of life. I've heard the argument of certain elements combining to create amino acids which can lead to life forms. The professor said that the new supported theory is that life actually came from a meteor or something in outer space. That just seems a little more far fetched to me. Amino acids make sense, and, considering the process has been duplicated in a lab, makes me wonder why people are suddenly supporting the new sci-fi-esque theory. What do you think about both? What do you think is more likely?

I don't want any creation answers here. If you have something to say about evolution being a lie or creation being the only way or some such, please redirect your attention somewhere else. I'm not interested.

Answer 1

Hi. The technical name for the theory is panspermia. : http://www.answers.com/main/ntquery?s=panspermia&gwp=16 It doesn't mean that life came here that way necessarily, but that amino acid may have. Some have been detected in space spectroscopically. It is also theoretically possible for hardy spores to reach here the same way, frozen and protected in the material of a comet for instance. Or maybe some DNA?

Answer 2

I think that the possibility of life coming to earth on a comet or meteor is a plausible theory. It's just as plausible as life still existing on Mars, even when it is bombarded with many times the radiation of Earth and subjected to extreme temperature fluctuations. What one must consider is that the multicellular life we are so familar with has only come to be in the past 500 million years. Before that, particularly right after the earth was created, life would have been different. We have few records of life that far back, but fossils have been found from 4.6 billion years ago, and the life at that time would have easily been confused with rocks today. In the harsh environment that existed then, life as we know it today would have died immediately from the toxic atmosphere.
It's also important to understand the solar system itself was different, and the ability for life to hitch a ride on a meteor or comet could have been much easier then than it would be now.
It's an intriguing theory, but at this point is just as valid as any other that's been proposed. That's what science is though, the process of elimination of separating the good theories from the downright crazy.

Answer 3

My understanding of all this is that meteors may have delivered raw materials like amino acids. I don't think anyone believes that living cells hitched a ride... or survived that trip even if they did.
It is one of the big questions in science. How do you go from a soup of various molecules to a separate living cell, able to live, grow, develop, maintain its internal environment and reproduce no less?!
But what about viruses? Could they have survived the trip and gone on to evolve into something more? What about prions? OR archaebacteria? They are finding living things in the most inhospitable places for life: around sulfur springs, in terrible heat or cold, miles within rock, on the floor of deep oceans.

And don't be too hard on the creationists. They just place God at the end of their understanding. When they can't find an answer then they stop questioning and blame God...it is a weakness of theirs. (Read "Why People Believe Weird Things" by Michael Schermer)

Back to life...check out the PBS series "Origins" with William DeGrasse Tyson. Way cool... talks about the origins of life on the planet. Good luck!

Answer 4

OMG TEH BYBL SEZ GOD MAD TEH WOLRD OMG EVALOOSHIN DUZNT WERK HOW CUD LYF COM FROM NON LYF???????? OMG UR AGENST GOD UD BETER RAPENT 4 UR SINZ OR ELS UR GONA GO 2 HEL

Nah, I'm joking.

The process of life being transmitted from one planet to another is called panspermia, and yes it is quite possible that it happens. However, it seems unlikely that Earth was populated by extraterrestrial life forms rather than developing life itself. Why? Because:
- Earth's early environment was much less hospitable for life than it is now, so extraterrestrial life used to a different environment would have had difficulty surviving.
- Fossils of some of the oldest life on Earth show it to be quite simple. Panspermia, on the other hand, would suggest no life for a while and then suddenly some relatively complex life.
- No other places in the Solar System have any immediately obvious signs of life; Earth is the only known planet with that characteristic.

So while panspermia is a very interesting idea, and one that has probably happened in some places in the Universe, my bet is that terrestrial life first developed here on Earth.

Answer 5

The origins of life are not covered under the subject of "evolution" per se, but "abiogenesis". I thought Stanley Miller's experiments made sense. He simulated the old environment and got amino acids to form. Personally I've never heard about a credible hypothesis that aminor acids came from a meteor, or that a meteor was a catalyst for the process in some wat. I agree, it sounds suspiciously "sci-fi" to me.

EDIT: I see some people have posted some references. Thanks! I'll check these out.

Answer 6

In biology, evolution is the process in which some of a population's inherited traits become more common, at the expense of others, from generation to generation. This is usually measured in terms of the variant genes, known as alleles, that encode the competing traits. As differences in and between populations accumulate over time, speciation, the development of new species from existing ones, can occur. All known organisms, living or dead, are related by common descent through numerous speciation events starting from a single ancestor.[1][2]

Mutation of the genes, migration between populations, and the reshuffling of genes during sexual reproduction creates variation in organisms. While a certain random component, known as genetic drift, is involved, the variation is also acted on by natural selection, in which organisms with combinations of traits that help them to survive and reproduce will have more offspring, passing these beneficial traits on to the next generation. This leads to advantageous traits becoming more common in each generation, while disadvantageous traits become rarer. [1][3][4] Given enough time, this passive process can result in varied adaptations to changing environmental conditions.[5]

The theory of evolution by natural selection was first put forth in detail in Charles Darwin's 1859 book On the Origin of Species. In the 1930s, Darwinian natural selection was combined with Mendelian inheritance to form the modern evolutionary synthesis.[5] With its enormous explanatory and predictive power, this theory has become the central organizing principle of modern biology, providing a unifying explanation for the diversity of life on Earth.[6][7][8

Answer 7

I definitely don't think it's likely that life on earth originated from a meteor. If so, how would it have survived in outer space? Even if it were the case that life arrived on Earth from some distant planet, it would've had to originate there by some other means. The most likely explanation is a process of chemical evolution. The scenario your teacher presented isn't supported by any data, as far as I know.

Answer 8

The meteor idea is very far fetched- i actually think parts of evolution are accurate such as the whole idea about natural selection etc.. but the thing is the whole amino acid thing doesnt really make much sense ...just think about it if we all originated from some sort of random assortment of elements ...then how did the elements come about?? if we all came from one common ancestor? how did this very first ancestor come
about???...

evolution is almost like saying theres was this one thing already existing and we all 'morphed' from it. hence it doesnt really explain where this one thing came from its almost like saying something was made out of nothing?

but ye i definately think some evolution ideas are accurate such as :survival of the fittest and characteristics which are suited to a specific environment are passed on

btw i am not disputing about the idea of creation vs evolution ...in fact i think both have their inaccuracies and i think they can possibly be both correct in some senses.

interesting question =)

Answer 9

Well, here is the problem. Amino acids have been found in meteors. And we know also that they can arise spontaneously in conditions we know existed in early Earth history. And of course this was all a long time ago, so it is hard to know where the first amino acids on Earth came from.

Oh, and believing in God is just an excuse for not thinking or knowing any real science.

Answer 10

Point. These things are not anywhere near theory, but merely a collection of hypothesis that have yet to be tested. The last I looked, there were almost ten hypothesis of abiogenisis extant. Your professor may need a refresher course in the scientific method; on theory and it's meaning.