Human Hands and Feet Have Fishy Origins

....not that fond of the SOURCE of the article but I noticed it in passing and upon further reading it IS from a real study and seems pretty wild our hands/feet are of aquatic origin!

A gene responsible for the development of fins in a primitive fish also helped shape the hands, feet and wings of every land animal alive today.

Researchers studying the Australian lungfish Neoceradotus found one of its fin-sprouting genes also guides the growth of digits in land vertebrates—those creatures with backbones.

The finding, to be detailed in an upcoming issue of the Journal of Experimental Zoology, adds to growing evidence that digits in humans and other land creatures are the equivalent of fin bones in fish. It is yet another example of evolution tweaking what already works to generate novel traits.

Could you not turn that around to say that their fins developed from our hands? Just because we have a gene in common with fish that developes our appendages doesn't necessarily mean that we "originated" from them. It just means that the gene that tells our appendages how to grow is shared by other creatures.

how old is that source because i remeber learning that in year 9 science

[edit on 23-10-2007 by purplemonkey]

Originally posted by anhinga

....not that fond of the SOURCE of the article but I noticed it in passing and upon further reading it IS from a real study and seems pretty wild our hands/feet are of aquatic origin

is this really NEWS to you?....really?...you do know we came from the sea?....the thing that really blows my mind is the mammals that chose to go back....what a choice...and if you could make that choice...be a whale or a dolphin...would you make it???

There might be more to our past than has been discovered so far.
There are several features of our anatomy that we do not share with our primate cousins.
1) The vestigle webbing of our hands and feet.
2)Our noses, with their downward opening nostrils, which allow us to remain in the water with only our eyes showing while not allowing water into our respratory tract.
3) Our relative lack of body hair, when compared to the other primates, there arre no naked monkeys.
4) The construction of our hip that allows for upright posture.
I read an article once by some anthropologist, who postulated that there might be a semi-aquatic ancestor in our distant past.
A primate that for whatever reason, such as new predators and or a change in climate, like the forests of subtropical africa turning to grasslands when the temperatures dropped at one point in the past, took to the river and lake margins for survival. Then had to move back to a terrestrial existance, when conditions changed, like when africa warmed up again and the crocodiles came back.

I'm not surprised that we have traits from many animals.....after all we are a evolutionized(if that's a word) species. We probably received traits from various animals and species in our development that make us one of the ultimate species. I'm sorry Christians, God didn't give us origins from fish, it was evolution.

This one goes in the Duh book!

If I recall reading something many years ago correctly, we're also losing our pinkies.


reply to post by Heratix


If I could swim with the dolphins, the soft and gentle dolphins...
Why can't I swim with the dolphins?

All wet and sleek and sexy

Originally posted by punkinworks
There might be more to our past than has been discovered so far. There are several features of our anatomy that we do not share with our primate cousins.

1) The vestigial webbing of our hands and feet.
2) Our noses, with their downward opening nostrils, which allow us to remain in the water with only our eyes showing while not allowing water into our respiratory tract.

You direct our attention to the theory that humans or our recent anthropoid ancestors may at some time have been semi-aquatic in their behaviour. The theory was more widely current a couple of generations ago than it is today but I don't think it's ever been disproved -- it's more a matter of there not being enough evidence to make a conclusive decision either way. On October 18 this year, it was reported in Nature that a 165,000-year-old midden (garbage pile, essentially) in a cave along the South African coast, containing shellfish remains, bones, tools and pigments used for painting, has been discovered and studied. I believe there is plenty of other evidence for communities that lived by a lake or the sea. But living in a beach cave and eating shellfish isn't necessarily the same as spending half your life or more in water, so the jury is still out.

There are explanations for the webbing and the nostrils that don't involve the aquatic hypothesis. Let's look at the webbing first.

From about 1990 onward, evidence began to accumulate that related a gliding mammal, the colugo or flying lemur, to the primates through a common ancestor. The evidence came from fossils and was later borne out by genetic studies. It suggested that many of the special characteristics of primates, thought to be adaptations to a predatory arboreal lifestyle, might just as well be adaptations to a gliding one.

The anatomical features that typify the primates as visual predators are disconcertingly similar to those needed for controlled gliding between trees. Reliance on stereoscopic vision, the evolution of grasping hands and feet, the development of excellent hand-eye coordination to control gliding and to ensure safe landings - all these make sense for gliders as well as visual predators. No one has suggested that a lineage specialised for gliding reversed itself to evolve towards a visual predator... Still, the fundamental direction of the two adaptations is remarkably similar and still bespeaks a close relationship. The long-noted dental similarities between the Palaeocene dermopterans* and the Eocene primates** continue to attest to a common ancestry.

*colugo ancestors **our ancestors

The debate continues, however...

Recently published molecular evidence... challenges the long assumed monophyly of primates, displaying the colugo or flying lemur (Cynocephalus, Dermoptera) as a sister to anthropoid primates (Arnason et al. 2002 ) and positioning them after the prosimian primates (tarsiers and strepsirhines) split off...

However, more detailed analyses disclosed that mitochondrial nucleotide composition and consequently amino acid (AA) composition varied considerably among the species analyzed. This led us to assume that the flying lemur may be incorrectly grouped with anthropoids

...but colugos apart, there are other gliding primates, some extinct, others alive today. A few are mentioned in Wikipedia.

A number of primates have been suggested to have adaptations that allow limited gliding and/or parachuting; sifakas, indris, galagos and saki monkeys. Most notably the sifaka, a type of lemur, has thick hairs on its forearms that have been argued to provide drag, and a small membrane under its arms that has been suggested to provide lift by having aerofoil properties.

So maybe the webs are vestiges from gliding, not swimming ancestors! Our line may have retained them while the other hominids lost theirs. Airborne ancestors, anyone? I must confess I find the idea quite charming. No wonder we have flying dreams...

The nostril explanation is a little bit simpler. Human nostrils aren't really that well positioned for an aquatic lifestyle (compare them with, say, cetacean spiracles). They are, however, perfect for keeping rainwater out when we are standing, walking or running in the characteristic human upright posture. They probably evolved after, or about the same time as, our ancestors adapted that posture.

Species evolve. Sometimes they evolve into other species, but evolution also continues within species. We've moved on from our early ancestors; in fact, the evolution of facial features, forehead height for example, can be seen pretty easily if you compare European skulls from as little as three or four hundred years ago with present-day Europeans!

This intraspecific evolution also accounts for some of the other 'anomalies' you mention.

3) Our relative lack of body hair, when compared to the other primates, there are no naked monkeys.
4) The construction of our hip that allows for upright posture.

Current knowledge suggest, I believe, that our first bipedal ancestor was Australopithecus, which had hipbones that suggest upright walking.

The Australopithecus hip and hind limb very clearly indicate bipedalism, but these fossils also indicate very inefficient locomotive movement when compared to humans.

There are quite a few species between Australopithecus and Homo Sapiens, so it's not quite true to say that only modern humans have the correct hip structure for bipedalism.

By the way, the page quoted above is illustrated with a rather cute reconstruction of an Australopithecene head. Note that the nostrils aren't very well adapted for keeping rainwater out.

As for hairlessness, that's a relatively minor modification. It doesn't necessarily suggest an aquatic lifestyle; actually, the people who support that theory make more of the fact that human body hair always grows downward from the head (most of the follicles are aligned downward), suggesting perhaps that our ancestors' hairy coats were streamlined for ease of movement through water. But then again, other animals aren't very different, and you could argue that this kind of arrangement just helps with rainwater runoff.

A primate that... took to the river and lake margins for survival. Then had to move back to a terrestrial existence when conditions changed.

It's possible. But just now there's no strong proof that it happened.

Easy to see on our hands and feet. Webbed fingers and toes.

Our flying cousins just made the daily news

In my previous post, I wrote:

From about 1990 onward, evidence began to accumulate that related a gliding mammal, the colugo or flying lemur, to the primates through a common ancestor. The evidence came from fossils and was later borne out by genetic studies. It suggested that many of the special characteristics of primates, thought to be adaptations to a predatory arboreal lifestyle, might just as well be adaptations to a gliding one.

Now look:

Gliding mammal linked to humans: BBC

Enjoy.