Scientists tried raising the bichir (Polypterus senegalus), a modern African fish that has lungs for breathing air and stubby fins it can use to pull itself along on land, out of water for eight months to better understand how ancient creatures may have transitioned to life on land.
The researchers discovered the bichir raised on land were dramatically different than those raised in water. The land-raised fish lifted their heads higher, held their fins closer to their bodies, took faster steps and undulated their tails less frequently and had fins that slipped less often than bichir raised in water. These land-based fish also underwent changes in their skeletons and musculature that likely paved the way for their changes in behavior.
This discussion has been archived.
No new comments can be posted.
Scientist Raise Air-Breathing Fish on Land to Test Evolution
|
Log In/Create an Account
| Top
| 15 comments
| Search Discussion
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
(Score: 3, Funny) by Snow on Wednesday September 03 2014, @09:22PM
Are they really testing evolution or are they really testing the learning abilities of fish? I would argue the latter.
It's kind of like saying that rock climbers are better at evolving to live on cliffs than basketball players.
(Score: 4, Insightful) by wonkey_monkey on Wednesday September 03 2014, @09:54PM
I don't think learning has anything to do with it. I think the idea is that they're demonstrating that these fish have previously evolved the ability to physiologically adapt, as extant individuals, to land conditions.
systemd is Roko's Basilisk
(Score: 4, Interesting) by Snow on Wednesday September 03 2014, @10:17PM
I'm not sold on the idea that holding fins closer to bodies, faster steps, and less slipping is evidence of evolution. If learning didn't have anything to do with it, then why didn't they have these traits from birth?
I used the rock climbing analgy because an experienced rock climber will stay closer to the wall, move faster, and slip less than an inexperienced climber.
(Score: 2) by khallow on Thursday September 04 2014, @12:01AM
Like you "learn" to reach for items that a newborn can't reach because they're too short? Not all traits come in at birth.
(Score: 2, Interesting) by Horse With Stripes on Thursday September 04 2014, @12:55AM
You're right. It sounds like evidence of gravity's effect on their bodies (without the benefit of the water's buoyancy) and the resulting physiological response.
(Score: 2) by wonkey_monkey on Thursday September 04 2014, @08:14AM
Yes, but how did they come by that physiological response? Take a different kind of fish out of water, and it won't have the same physiological response. I mean, obviously it'll have the "I can't breathe" response, but besides that...
These fish have evolved to have this kind of physiological response because of the kind of changeable environment they've been living in for x million years - or so I understand the experiment to imply.
systemd is Roko's Basilisk
(Score: 1) by Horse With Stripes on Thursday September 04 2014, @09:46AM
Absolutely. These fish evolved over millions of years to be able to survive out of water as well as transport themselves on dry land. But this experiment is not seeing evolution take place before its eyes. This experiment is seeing what evolution has already done over the same millions of years.
(Score: 4, Insightful) by Joe on Wednesday September 03 2014, @10:27PM
The ideas are not mutually exclusive - behaviour can be selected for by evolution.
From the abstract of the research article:
"we provide insight into stem tetrapod behavioural evolution. Our results raise the possibility that environmentally induced developmental plasticity facilitated the origin of the terrestrial traits that led to tetrapods" (bold is from me).
http://www.nature.com/nature/journal/v513/n7516/full/nature13708.html [nature.com]
(Score: 0) by Anonymous Coward on Wednesday September 03 2014, @09:28PM
I learned on TV that we are the retarded offspring of five monkeys who had buttsex with a fish-squirrel. Or is this oversimplified?
(Score: 3, Informative) by Snow on Wednesday September 03 2014, @09:44PM
A little oversimplified... It's was the fish-squirrel that had the retarded monkey. Then the retarded monkeys had us. Then we will make retarded computer blobs.
(Score: 2) by arslan on Wednesday September 03 2014, @10:18PM
What does the internet say? Don't trust TV, the internet is always right... especially when goats are involved.
(Score: 4, Interesting) by SlimmPickens on Wednesday September 03 2014, @10:15PM
I've been reading an excellent book by Neil Shubin called Your Inner Fish [amazon.com].
He's both a paleontologist and an embryologist and can tell you all sorts of interesting things about how bodily structures have evolved.
(Score: 4, Interesting) by opinionated_science on Wednesday September 03 2014, @10:27PM
The recently revived theory regarding human evolution having an "aquatic" phase, lends some credence to the idea that life originally came the same way.
That is, the open ocean is a dangerous place to be anything other than efficient adaptation to water. Speed, gills the lot.
However, in the shallows there are fewer predators and the ability to breathe can be partially adapted.
What is interesting in this study is the epigenetic implementation of body structures i.e. in response to different environments. In some sense, this suggests that the more complex an organism becomes (our brains are such an organ) the fewer choices you get.
Biology is endless fascinating...
(Score: 1) by novak on Thursday September 04 2014, @05:07AM
My total lack of formal training in this area does not prevent my study of it. In particular I always observe wildlife, especially along streams in my native state of Missouri.
It's easy to note that the larger animals always go towards the deeper water, where they are the dominant predators. Most fish over an inch or so make sure they have several inches of water above them, which provides protection from animals like herons and me, which have to strike down through the water. These fish, as noted by opinionated_science have sleek lines and great agility to make good their escape. Small animals, unable to cope even with fish two or three inches long resort to hiding in water too shallow to be safe for the larger fish. Often they are well camouflaged, too, as an example, small sculpins.
Since I often capture specimens though, I pay careful attention to how animals move. You can tell a lot about animals by how they run. A cricket, in the wild, will not hop like it does in your house. It burrows. Even if it's in a small box and you're pulling one out, they all burrow down instead of exploding out. That right there tells you that most of a crickets predators are larger than it, either birds or frogs who lose them under the grass.
A large frog will nearly always dive for deep water, since it will probably be large enough to survive- unless it encounters a really big fish. A common small frog in the area, the Blanchard's Cricket Frog, always retreats in a zigzag pattern along the shore, neither getting in too deep where it would be eaten by large fish, no retreating too far from the water where faster land animals would run it down. I always found this fascinating.
Sorry to go off on a very long tangent but this topic is amazing to me.
novak
(Score: 2) by opinionated_science on Thursday September 04 2014, @12:16PM
> "total lack of formal training"
That's ok, that guy on The Beagle was an amateur....!