evolutionary chain

Here you go. CheersMickedited to give clearer pictureThis message has been edited by mick, 11-04-2005 09:15 PM

This is not on topic here. Do not respond.

Hmmmn. Are you seriously suggesting that the Bible genealogies are reliable?Here is a quote from the King James bible, Chronicles 2, chapter 24, verse 20: and from Matthew chapter 23, verse 35: And a lot more where that came from (but as you say, perhaps for another post)! DNA kind of helps sort out these conflicts....MickThis message has been edited by AdminNosy, 11-04-2005 11:38 PM

Hi minnemooseus, There are lots of ways you could look at that tree. It's a horizontal tree, so the basic idea is that branching points to the left are older than branching points to the right (so read it left to right, don't worry about top to bottom).The top to bottom order doesn't actually matter. For example here are two trees which have identical topology. You are wrong if you think that the first tree tells you that aardvarks and mice are closely related, while the second tree tells you that chimps and elephants are closely related. The only thing that matters in a tree drawn like this is the horizontal position of branch points. The genealogical relationships implied by these two trees are identical. The branching points, or as you call them "line junctions", represent changes in traits. The tree was generated by examining a whole bunch of traits (bone shape, DNA sequence, whatever) and trying to find the most parsimonious tree that relates those traits (in practise, it is often the tree that requires the fewest trait changes). Each time a branch splits into two, it represents a change in one of the traits that was used to generate the tree. Those branching points DO NOT REPRESENT SPECIATION EVENTS. They just represent changes in the traits used to generate the cladogram. (I should say that this mistake is made by many biologists as well as intelligent laypersons).For example let's say we sequence a rapidly-evolving gene or microsatellite or someting on the Y chromose of my immediate family. It's on the Y chromosome, so it's only found in males. We go round the homes of my male relatives and get a tissue sample. We sequence the gene and generate a phylogeny that looks something like this: The branching points DO NOT represent missing ancestors! They DO NOT represent missing links! They represent mutation events in the gene on the Y-chromosome that are of phylogenetic significance.Hope this helps!MickFirst edit: made my family phylogeny more straightforward
Second edit: I just wanted to make it clear, there is no "missing link" between me and my father. Look at the cladogram above, and you will understand that the branch point does not represent any missing data. A tree is just a way of representing a hereditary trait. Trees don't contain less data than chains.This message has been edited by mick, 11-06-2005 06:52 PMThis message has been edited by mick, 11-06-2005 07:00 PM

Hi Lithodid-Man, Here's a version of the picture which includes a reference (I should have given the reference originally, sorry). I hope it is useful. Ah... that's a problem. I copied it from an academic website while browsing but have no idea where it came from. I liked it because of the clear evolutionary process, the colours, and because it makes me think of olive oil and lots of garlic....I assume the photographers won't mind too much. Were you at the SSE meetings last year in Fairbanks? I say I am from the UK on my account here, but I'm currently based in Vancouver BC. I was there, probably missed your talk...CheersMick

Yeah, that's fantastic. I haven't seen anything similar for whales but I bet it's possible to build one using the computerised catalogues of each museum's fossil collection. For example, Berekely has a database (searchable by class, order, family, genus, species) at http://elib.cs.berkeley.edu/ucmp/advanced.shtml which contains over 250,000 fossils, and over 1000 cetacean fossils. I'm sure if one searched the catalogues of each major museum in north america one could easily(?) create a similar graphic showing the transition for cetaceans (and many other groups).Mick