And what do we usually call these?
Similar reasons account for why we can tell that a wolf-like creature such as Ambulocetus probably evolved into whales.
P.S.
Heronumber0, allow me to ask exactly why you doubt that whales had land-living ancestors? For instance, otters are living examples of creatures that can live on land and in water, but they bear a huge amount of similarity to land living mustelids.
[edit on 19-4-2008 by SlyCM (work)]
Whales are among the most specialized of all mammals
and include the largest animals that ever lived. The
movement of the ancestral cetaceans from the terrestrial
to an aquatic environment involved extensive remodeling
of the morphological, physiological, and behavioral
systems (Barnes and Mitchell 1978; Gingerich et al.
1983; Barnes 1984a). The order Cetacea is generally
considered to be a monophyletic group, although a separate
origin of the two morphologically highly divergent
suborders of living whales, the Odontoceti (toothed
whales) and the Mysticeti (baleen whales), has been favored
by others (e.g., Yablokov 1965). The origin of and
evolutionary relationships among fossil and extant cetaceans
are disputed (Barnes 19840; Barnes et al. 1985;
Heyning and Mead 1990; Fordyce 1992; McLeod et al.
and the phylogenetic distinctness of the extinct suborder Archaeoceti is problematic
(Fordyce 1989; Wyss 1990).
The fossil record of
cetaceans is incomplete and has not provided unequivocal
evidence on whether the archaeocetes gave rise to
one, both, or neither suborder of living whales (see, e.g.,
Barnes and Mitchell 1978; Barnes 1984~; Barnes et al.
1985; Fordyce 1992; McLeod et al. 1993).
Phylogenetic studies of extinct and extant cetaceans
are complicated by their highly modified morphology.
However, a close phylogenetic relationship between cetaceans
and ungulates was first suggested more than 100
yr ago (Flower 1883) and was more recently confirmed
by paleontological (Van Valen 1966; Szalay 1969; Gingerich
et al. 1983, 1990; Thewissen and Hussain 1993)
and molecular studies (Goodman et al. 1985; Miyamoto
and Goodman 1986; McKenna 1987; Czelusniak et al.
1990; Irwin et al. 199 1; Milinkovitch 1992; Milinkovitch
et al. 1993). Several independent approaches support a
sister-group relationship of cetaceans with artiodactyl
ungulates. Accordingly, artiodactyls are more closely related
to cetaceans than they are to perissodactyl ungulates
(see, e.g., Czelusniak et al. 1990; Gingerich et al. 1990
This is the story of Science all over surely where there is no complete certainty but always room for modification of a previous theory.
wow, i provide evidence of a transitional form (something that creationists and IDists keep asking for) and i don't even get a reply.
how odd
Evolution will one come down like a pack of cards, when people start thinking for themselves and seeing through its fallacies.
Having legs to having no legs entails LOSS of genetic information, not an increase. It is degeneration, not evolution. The same goes for cave fish - their forbears had eyes, now they've become dysfunctional through genetic deterioration. Not surprising in a restricted genetic pool.
Genetic information is never added, it is only lost. Start with the perfect, end up with the degenerate through mistakes in replication. Two parents with the same mistake: bingo - big problems, and increasingly likely in a restricted environment.
Dogs: start with parents with all the genetic information for long/short/curly hair, etc. this colour, that colour, long ears/short ears, etc. etc. As the generations go on some populations get separated, even domesticated & bred for particular features. Result: certain genes are lost in certain populations.
Genetic information is never added. Chance cannot design, much less mutation - which is invariably harmful, and very often fatal.
THINK ABOUT IT.
Originally posted by RuneSpider
reply to post by JPhish
I'm not talking about similarities. i'm talking about genes for tails in humans, the remnants of leg bones in whales, the remnants of leg bones in snakes, the extra claw and foot pad on dogs, the nubs on birds wings where there used to be claws, and it goes on and on.
We aren't just looking at bones and saying that looks like that, so must be related to that. We are looking at modern animals and genetics and seeing that there are leftovers in their DNA, and commonalities in the DNA that show that there is something other than straighforward Creationism.
Originally posted by SlyCM (work)
reply to post by JPhish
You mean my own and other's utter evisceration of all the Creationist arguments on this thread doesn't amount to ownage?
Sigh. Again reason and logic suffers another blow.
cave fish may have lost their eyes, but they gained a hyper-efficient lateral line system and electroreception, which grants them details of their environment matching any fish with eyes. Having kept these sorts of fishes in aquaria - indeed, the very species (Astyanax mexicanus) whose genus name appears to have inspired Astyanax's user name - I have witnessed the prowess that they use when navigating. That is, after a few hours of mentally mapping the environment, they never bump into any object.
Having legs to having no legs entails LOSS of genetic information
It is degeneration, not evolution.
Genetic information is never added, it is only lost.
Dogs: start with parents with all the genetic information for long/short/curly hair, etc.
extensive genetic analyses of the dog and other wolf-like canids clearly show that the dog is derived from gray wolves only, rather than jackals, coyotes, or Ethiopian wolves (Fig. 1C; Wayne et al. 1987aGo,bGo; Vila et al. 1997Go, 2005Go; Leonard et al. 2002Go; Savolainen et al. 2002Go). Consequently, the immense phenotypic diversity in the dog owes its origin to primarily the standing genetic variation existing in the ancestral population of gray wolves and any subsequent mutations that occurred during the brief history of domestication.
-- The Canine Genome, Ostrander & Wayne, 2005
The dog genome is similar in size to the genomes of humans and other mammals, containing approximately 2.5 billion DNA base pairs.
-- Press release, National Human Genome Research Institute
25 years ago, eh? Just imagine how much you could have learned in that time, if you hadn't simply shut your mind to this subject.
a haughty spirit goes before a fall
Not necessarily. Here, count the genes.
Reptiles existed before mammals -- even if your authority on evolution is the Book of Genesis.
I suppose you don't believe in mutation, either. No haemophiliacs, sickle-cell anaemics and Huntingdon's choreacs in your family, no sir!
Chance cannot design, much less mutation - which is invariably harmful, and very often fatal.
Dogs: start with parents with all the genetic information for long/short/curly hair, etc. this colour, that colour, long ears/short ears, etc. etc. As the generations go on some populations get separated, even domesticated & bred for particular features. Result: certain genes are lost in certain populations.
Reptiles and mammals are simply not related. At all.
Think about it.
I said that having legs to having no legs entails LOSS of genetic information. You replied, 'not necessarily. Here, count the genes.' (But) counting the genes means taking the sum total of all genes... without providing data that relates exclusively to the feature in question your point makes no sense.
By instilling the potential for huge genetic variation in the original kinds, the Creator equipped them to spread throughout the earth and survive in all manner of environments. Like I say, I have no problem with natural selection.
Sigh... it's faith versus reason, and faith will never lose.
