Mice and bats have long been known to be evolutionary relatives; Recently, a group of scientists succeeded in swapping gene control elements in a mouse with those of a bat - and created mice with long front legs, similar to a bat
Every child knows that a bat is a mouse with wings, and the evolutionary evidence also justifies the intuition. Bats evolved from mice 80-100 million years ago, but their general body structure remains similar to that of the ancient mice. Despite this, there is a noticeable difference between a mouse and a bat and it is of course the wings. Throughout evolution, the front legs of the ancient mice developed, and each toe was greatly elongated and sent forward. A membrane is formed between the fingers, similar to the membrane of an animal, and when the bats spread their fingers, the membrane spreads and forms a wing.
In studies conducted in laboratories around the world, we were able to discover that the front legs of bats and mice develop in a similar way in the early embryonic stage. At the same time, at a certain stage in embryonic development, the bats' legs begin to lengthen disproportionately to the rest of the body. These long legs will form the skeleton on which the flexible wing membrane will stretch.
One of the genes suspected in limb elongation is Prx1. This gene is known to be responsible for the lengthening of the limbs, and mutant mice in which it is inactive are born dead, with extremely short limbs. Mutations that impair the activity of the gene prevent the limbs from elongating in mice. But mutations can occur not only in the gene itself. They can also occur in other genes that increase or decrease the activity of Prx1, or even in DNA regions that are not genes in themselves, but can still, by their very presence, affect the activity of different genes. These areas are called Enhancers (from the nouns, or from the noun in the singular), because they stimulate different genes to greater activity.
The researchers claimed that the bat bone causes overactivity of the gene, and as a direct result of this the leg of the bat embryo lengthens, up to the wing pattern we know. In order to substantiate their claim, they used genetically modified mouse embryos, in which the mouse bone was replaced by the bone found in bats. Indeed, according to their hypothesis, the legs of the bat-bone mice were longer than the legs of normal mice.
The results of the study show that evolutionary changes can occur not only in the genes, but also in the ways of expression of the genes. When certain genes are expressed more or less than normal, the effect on the developing embryo can be dramatic and lead to the creation of a completely different species of living beings. Evolution can progress in small steps - through changes in the genes themselves, but it can also leap forward in leaps and bounds, resulting from mutations in the means of controlling the various genes. There is no doubt that mutations of this type helped drive the evolution of the mouse into the bat.
Link to the issue of the journal in which the article was published
More on the science website:
Who preys on songbirds in their migration
16 תגובות
The principle of respect. (in the context of Roy's words).
A phenomenon that repeats itself more than once in nature, the example of the peacock is a great example that has been used a lot.
The large and prominent tail of the peacock does increase his chances with the females of the species, but if he were to run away from a predator, the clumsy tail may work against him...
There are all kinds of features that have been found to be widely distributed in the population even though they also have a drawback.
A few years ago, they reported another gene, BMP2, which caused a similar phenomenon:
* An article on newscientist.com
* An article on the Ynet website
What's new,
The oxygen absorption mechanism through the water occurs specifically only by gills (to the best of my knowledge). I see no simple way that the lungs can produce oxygen from water, or that a mechanism that does not involve gills would produce oxygen from water passing through the mouth. Since the gills are not a simple mechanism, I believe it would not be easy for marine mammals to evolve in this direction. Even if it does, it will most likely take tens of millions of years.
And yet, the prophecy was given to fools. Who can say for sure what will happen, when random mutations and 'bottlenecks' are created?
Yael Peter,
I agree with what you said, but I would like to correct you on a small point. There are whales with horns. These are the male narwhals, displaying a tooth over three meters long. This tooth protrudes forward and out of their head, just like a horn.
The popular theory for the existence of narwhal teeth assumes that they have no real survival advantage, much like the peacock's tail. They developed from 'sexual selection', in which the males whose teeth were larger than the other males were selected - and thus the trait that increases the length of the tooth in each generation was determined.
So evolution can also promote problematic traits, here and there, including whales with horns.
What's new,
Just as the rest of the body parts of each and every animal were created. Over the years, small and random mutations occur in the cell. For every million cells that are formed, there is also one "damaged" cell that is slightly different. Every small change like this is not noticeable in the same generation or even 5 generations back and forth, but in the long run these changes, to which more changes are added, cause a huge difference, which causes a difference between animal and animal.
It is likely that all animals on the planet have one common ancestor and it is the first cell that managed to survive.
And to your question, the "how" is not relevant here, because nature does not really have a goal, purpose and destination. Evolution is not intentional but random (the mutations apply randomly). What is more adapted to the environment survives, and what is less adapted to the environment is extinct from the world.
The dorsal fin of whales helps them maintain stability and therefore the feature evolved and remained in the animal. If, say, a whale with horns was accidentally born, it would not have survived and would not have passed on the genes of the horns to future generations.
Hope I answered your question
Roy
Thanks for the explanations and sources
I learned and wisely
I didn't mean for the leviathans to open gills like fish
It is enough for them to absorb oxygen through the mouth or vision.
Peter
Agree with me that the ancestor of the leviathan that lived on land did not have a dorsal fin.
It developed during evolution in water out of nowhere.
I was interested to know how it happened.
I do not disagree with you about the importance of the dorsal fin for the stability of movement in the water.
What's new,
Let's start with the answer to your second question. "Will the whales start absorbing oxygen directly from the water?"
As Yael Petar pointed out, everything depends on evolution and luck. You are actually asking whether the whales would develop gill-like structures. The simple answer is not in our lifetime.
A more complex answer is that for the development of complex structures such as gills, not only are several tens of thousands of years required at a minimum, but also conditions that select almost exclusively creatures that do not need to breathe air. Whales today are able to hold their breath for several hours, so they are comfortable enough. But if a catastrophe were to happen that would cover, for example, most of the world's water in ice, then the whales would no longer be able to easily surface to breathe air. In this case, a very strong natural selection will be applied to the evolution of a system for extracting air from water.
Regarding your first question:
"How does evolution explain the dorsal fin out of nowhere
of whales?”
As Yael Petar explained, the dorsal fin is of great importance in the sea island. We know today that the whales evolved from a hoofed mammal - named Pacycetus - that divided its time between the sea and the land. At a certain point, he moved to generation almost entirely in the water, and finally gave up on land. You can think of him, perhaps, as a unique version of a seal - a mammal that lives both in water and on land.
From the moment that mammal moved into the water, natural selection worked on it in a very strong way. The individuals that developed a body contour that was more suitable for life and swimming in water, are the ones that survived much better than others.
One of the earliest body features to form is the dorsal fin. Some of the details were lost at a later stage, but it was an important milestone in adapting the creature to swimming in water.
If I had to guess how it was formed, I would think of a fold of skin and cartilage created by some mutation. At first he was certainly without muscles, and contributed to balance and stability to a small extent - but enough to give a survival advantage to the few details in which he appeared. At a later stage, when he was already established in the population, muscles were also added to him that greatly increased his efficiency.
Some interesting links, if you want to read for yourself:
Evolution chart of the whales, together with an in-depth explanation of their evolution:
http://www.robins-island.org/dolphins_evolution.php
A shorter explanation, with simple drawings:
http://www.stephenjaygould.org/library/futuyma_cetacea.html
And of course
Wikipedia
I hope I answered your question,
Roy.
Ami,
Everyone has their own taste. I personally hate eggplant salad much more than I hate bats.
Greetings friends,
Roy.
Ami,
You know that the disgust you feel towards this flying mouse is also firmly rooted in your genes and developed during evolution.
Man tends to shy away from cockroaches, creepers, rats, etc. because they transmit diseases and they hang around in an environment where there is dirt.
Dear Roy,
Obviously you are wrong, a bitter and difficult mistake!!!
This animal is ugly ass!
To the one who calls himself - what's new,
1) What do you mean there is from nowhere? Evolution does not claim that the dorsal fin of whales came out of nowhere.
This fin still has a role today.
—-quote from fish forum—-
http://www.israquarium.co.il/forum/viewtopic.php?t=1382
"Fins are intended for the stability and movement of the fish. With their help, a fish can change speed and direction of movement.
There are paired fins such as ventral and pectoral fins (their role is to help the fish perform maneuvers, turns and braking) and unpaired fins such as the dorsal and anal fins responsible for the stability and balance of the fish and the tail fin responsible for the movement of the fish. "
—– end quote——-
2) Regarding the next stage of the evolution of the whales - it may be yes and it may not. Depends on the development of the mutations (that is, on luck/fate), depends on the climate changes, etc...
Hello Amir,
To your question, according to the article, the legs lengthened by a statistically significant 6%. Since there were many mechanistic explanations in the article, I preferred not to detail the analysis of the exact results. Instead, I added a link to the original article in which they are described in full, for anyone who is interested and wants to read further.
Thanks for your comment.
why new
I will look for material on your question, and I hope to answer it with the seriousness it deserves by tomorrow evening.
Shabbat Shalom,
Roy.
The title of the article is the lengthening of the mice's legs through genetic engineering, but for some reason, the author of the article did not bother to state how long the legs were, and how much this is in percentages compared to the normal length. This leaves a bad taste in the mouth of a lack of information and an impression of unprofessional writing.
Roy
I have questions related to the article. I would appreciate it if you answered
1. How evolution explains the dorsal fin out of nowhere
of whales?
2. Will the whales in the heba stage of evolution absorb oxygen directly from the water and the seas have they already started?
Thanks
Experiments on animals - it should be outlawed.
Ami,
There are no ugly creatures. Every creature is adapted to its environment, and is a marvelous machine in itself. To me, this is the beauty that exists in every organism on earth.
Shabbat Shalom,
Roy.
Ugh
I hate bats.
so ugly
Couldn't they try to turn maggots into beautiful butterflies? Did they have to go for a bizarre transformation of a mouse into a disgusting bat?
Well, good luck...