The Tree of Life Consolidates

Roland Piquepaille writes "The Tree of Life is an expression first used by Charles Darwin to describe the diversity of organisms on Earth and their evolutionary history. There are only two life forms, — eukaryotes, which gather their genetic material in a nucleus, and prokaryotes, such as bacteria, which have their genetic material floating freely in the cell. Until recently, eukaryotes, which include humans, were divided into five groups. But now, based on work by European researchers, the Tree of Life has lost a branch. After doing the largest ever genetic comparison of life forms they concluded that there are only four groups of eukaryotes."

Comments

Science is a moving target

[davidwr]

The more we know, the more we know that what we knew was wrong.

Or, as a coworker of mine used to say when we realized we didn't know what we were doing: "Everything you know is wrong."

Proof?

[Amorymeltzer]

Anyone who says "Evolution is taken as faith" or doesn't understand that the theory is based on the evidence, and that new evidence means changing the theory can look at this and shut up. A rather fundamental point was proposed to be rather fundamentally different based on new research and that's just fine. Whether it pans out or not, this is a beautiful example of the glory of science.

Re:Proof?

[MightyMartian]

Define "seen"? Because by your argument, electrons may or may not exist, Proto-Indo-European may or may not have existed and you may or may not have had great-great-grand-parents.

Evolution is confirmed not just by observing what goes on now, but by observing the fossil record, and just as importantly nowadays, by gathering molecular data. These two lines of evidence fit very well together into the so-called twin-nest hierarchy.

If you wish to wander down the road of epistemological nihilism, that's your affair, but be aware that everything, and I mean everything you think you know you can't actually know at all. Either you admit that inference is a legitimate means of gathering factual knowledge, or you render the whole show, including what you see, hear, touch, feel and taste irrelevant.

Re:So, what you are saying is.....

[MightyMartian]

There's a small part of most organisms' genomes that are made up of ERVs. These are insertions of retroviral DNA into our genomes. For the most part, these viral sequences are in neutral or junk genome stretches, so they don't have any influence on the organism. Unlike what the poster is saying, these don't make producing the tree more difficult, but in fact are extremely useful in fine-tuning the tree.

The odd-man out here are some prokaryotes, such as bacteria, where a sort of pseudo-sexual reproduction can take place by direct genome transfers. Still, this does not stop the classification of bacteria, but it does probably mean that the root of the tree of life, those earliest primitive self-replicators, probably swapped genes a helluva lot, so there may be no common ancestor per se, but rather a nest of common ancestors who swapped chunks of their DNA, RNA or whatever the earliest genetic molecules were.

Re:Three levels of truth (maybe more...)

[NIckGorton]

When religion doesn't get it right, people abandon it completely. No they don't. They just reinterpret the primary tenets of the religion to suit their current desired conclusions. Religious works and religious beliefs are interpreted in the light of the present society and its prejudices. Rather than being taken at face value, they are used to justify what people want to believe. For example, there is no real prohibition against abortion in the Christian Bible. For another example, the selective interpretation of Leviticus as condemnation of homosexuality while ignoring the condemnation of poly-cotton blends and Red Lobster.

Well, unless you are someone who strictly interprets the OT: http://www.godhatesshrimp.com/

Re:Three levels of truth (maybe more...)

[MorePower]

That raises the question, why do you make the peculiar assumption that every command in the OT law is of the same type, for the same kind of reason?

Because the basic evangelical argument is that "morality" is based solely on "whatever God said, and humans dare not even try to ask why". If you allow for humans to have some capacity for independent moral awareness, then you would have what us heathen non-believers have been calling for all along, using our own sensibilities to decide what is and isn't acceptable.

I mean, how else do you condemn homosexuality or pre-marital sex? It's two consenting adults enjoying each other's bodies in mutually pleasing ways without harming others. But the evangelical crowd says "God said 'No', end of discussion."