apolyton biochemists and biologists: what is a holliday junction?

[Odin]

Originally posted by Immortal Wombat
Zoology
Microbiology

That is all.

Zoology:
Microbiology:
Paleontology:
Ecology:
Developmental Biology:
Evolutionary Biology:
Molecular Biology:
Biochemistry:


BIOLOGY PWNS ALL!!!

[Kuciwalker]

Originally posted by Odin
Studying the origin of animal phyla is sissy to you?

You need the biotech people to do that, since phylogenetic trees are built now using rRNA comparisons

[Odin]

Originally posted by Kuciwalker


You need the biotech people to do that, since phylogenetic trees are built now using rRNA comparisons

Thats overrated, you can get different trees with different methodologies, although it is helpful. *points to recent redraw of the tree for protostome invertabrates* But you should not jump to conclusions, like when some molecular phylogenists had the gall to put elephants, manatees, hyraxes, and aardvarks (which are ungulates, or hooved mammals) together with some African insectivores and put them as the sister group to all other placental mammals, without looking at the morphological evidence that clearly shows that all hooved mammals (including cetaceans) are a monophyletic group.

[Immortal Wombat]

They were using paleontological evidence as well though. It makes for a nice theory, having all the african animals distinct.

[Kuciwalker]

Originally posted by Odin
Thats overrated, you can get different trees with different methodologies, although it is helpful. *points to recent redraw of the tree for protostome invertabrates* But you should not jump to conclusions, like when some molecular phylogenists had the gall to put elephants, manatees, hyraxes, and aardvarks (which are ungulates, or hooved mammals) together with some African insectivores and put them as the sister group to all other placental mammals, without looking at the morphological evidence that clearly shows that all hooved mammals (including cetaceans) are a monophyletic group.

Genetics trumpts morphological evidence.

[Spiffor]

Originally posted by Odin
But you should not jump to conclusions, like when some molecular phylogenists had the gall to put elephants, manatees, hyraxes, and aardvarks (which are ungulates, or hooved mammals) together with some African insectivores and put them as the sister group to all other placental mammals, without looking at the morphological evidence that clearly shows that all hooved mammals (including cetaceans) are a monophyletic group.

[Japher]

what about seahorses?

[Immortal Wombat]

If you'd have said sea cows, that would have passed for a sensible question

[Japher]

Seahorse is crazy looking, and funny because the male carries the eggs and plays beitch once they are born

I heard that there is a type of crab that changes sexes through the course of it's life.

[Odin]

Originally posted by Kuciwalker


Genetics trumpts morphological evidence.

A lot of mistakes can be made. For example, adult haemoglobin is mostly made out of 2 similar protiens, alpha globin and beta globin, both decended from a common ancestral gene in a jawless fish in the Cambrian. because of that, My a-globin gene is more similar to a goldfish a-globin gene than my b-globin gene. these two genes are part of the globin gene family, and can mess up molecular phylogenies. say we have a gene family with three similar genes, a biologists decides to compare human gene 1 with goldfish gene 1 and cow gene 1, but if, because the members of the gene family are so similar, that the biologist pick the right gene from the human and the goldfish, but picks gene 3 for the cow, you will get a tree showing the cow outside of a human goldfish clade, obviously incorrect.

Protist phylogeny is a case in point. At fist, the morphological and mollecular phylogenies were very different, the only similarity between the two were a grouping made of animals and fungi. Today, the morphological phylogeny hasn't changed much, but the mollecular phylogeny has changed greatly, It is now very similar to the morphological phylogeny.