A new study reveals that the cave-dwelling form loses its eyes due to the silencing of more than two dozen genes—many of which are shared by humans and have been implicated in human eye disorders.
How the result of the experiment supports their first hypothesis?
Explain how the result of the experiment supports their first hypothesis. Scientists’ first hypothesis was that blindness gives the tetras some sort of evolutionary advantage. They thought the advantage might be the result of pleiotropy, which is when multiple effects are caused by the same mutation in one gene.
What effect does the trait of blindness have on a fish living in a dark cave?
Based on the information about evolution in this text, what effect does the trait of blindness have on a fish living in a dark cave? The trait of blindness has a positive effect
it gives the fish an evolutionary advantage.
How does the cave fish manage without eyes?
The Mexican blind cavefish does not have eyes, but it can “see” obstacles in dark caves by puckering its mouth and producing bursts of suction, according to a new study. The research describes this unique form of navigation for the first time.
What ability have many cave fishes lost answer?
Many cave fishes are blind, and an experiment carried out by scientists suggests that blindness in these fishes is the result of a mutation that also improves their sense of smell.
How long do blind cave fish live?
The fish may be born blind or it may be born with functional eyes which later cloud over and shrink because there is no light in the dark caves and eyesight is not necessary. The lifespan of the blind cave fish is approximately ten years.
Why do cave fish lose their eyes Readworks answers quizlet?
They are blind because something happened to the genes that control the development of their eyes. This change is passed on from parent tooffspring.
Did cave fish used to have eyes?
Over the past few million years, blind forms of the Mexican tetra (Astyanax mexicanus) have evolved in caves. Maintaining eyes and the visual parts of the brain uses lots of energy, so the loss of eyes is a big advantage for animals living in the dark. Instead the cavefish “see” by sucking.
Whats is natural selection?
Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.
How do blind fish find food?
Blind cavefish typically have skulls that bend slightly to the left. A study suggests this orientation might help them find food as they navigate in a perpetual counter-clockwise direction around a cave.
What kind of sensory adaptation would you hypothesize the cave fish has to allow?
What kind of sensory adaptation would you hypothesize the cave fish has to allow it to navigate in a cave, including catching and eating food? The cave fish has special sense organs on its body surface that respond to the presence of different chemicals in the water. This would be analogous to our sense of smell.
Does the appearance of the cave fish and minnow suggest common ancestry Why?
The appearance of the cavefish and the minnow suggests a common ancestry since they possess homologous structures. Based on observations made on the characteristics of the cavefish and minnow, the structures of the fins, tails, and overall shape of the bodies make the two types of fish seem exceedingly related.
How do blind cavefish survive their low oxygen environment?
The scientists suspected that cave fish have more hematocrit in their blood to help them survive in the oxygen and nutrient poor cave environments.
Why do fish have eyes?
“Fish don’t need goggles because their eyes are designed to work underwater. They still have the same parts that you do: there’s a cornea, an iris and a pupil, the way the light gets in and bounces around and then transmits a signal to their brain so they can see things. Some fish can actually see really well.
Are some fish blind?
The Mexican Cavefish is a blind fish species, yet it can view its surroundings by producing bursts of suction with its mouth. They feel the pressure waves as they bounce back and get a sense of distance.
How do blind cave fish eat?
Diet: The Blind cavefish is mainly carnivorous, feeding on aquatic worms, snails, small fish and insects. Somewhat omnivorus in that they will also eat algae and plant matter. live in the dark. A keen sense of smell guides them toward their favorite food sources.
Why is eyesight not important adaptation to life in a cave?
There is NO light in a cave. All living things need light to see. Eyesight is not a sense that the cave fish can use in darkness.
Do blind cave tetras have eyes?
Blind Cave Tetras are a relatively new tetra to the mainstream aquarium keepers. As there name would indicate, the Blind Cave Tetras have no eyes. They are born with eyes as fry, but the eyes degenerate and are reabsorbed back into the body at a few weeks old.
What conclusions have scientists drawn about the population of fish that colonize a cave?
This study found cavefish populations are more genetically differentiated than their surface form counterparts, despite surface fish being more geographically separated. This was supported by the finding of lower allelic diversity in cave versus surface populations.
Do all fish have eyes?
In fact, there are species of fish that do not have eyes, or you can say that they are blind. In the ocean, there are many different types of fish, like fish with bulging eyes, bubble eyes fish, barreleye fish eyes, and cuttle fish eyes. They are all very different.
What animals dont have eyes?
Blindsight: Animals That See without Eyes [Slide Show]
- SEA URCHINS. Sea urchins respond to light in various ways: they might change color, twitch their spines or move toward or away from light.
- SQUIDS, CUTTLEFISHES AND OCTOPUSES.
- SWALLOWTAIL BUTTERFLIES.
What is artificial selection in biology?
Artificial selection is the identification by humans of desirable traits in plants and animals, and the steps taken to enhance and perpetuate those traits in future generations.
How does chemical evolution explain the origin of life on Earth?
Once sterilized and isolated, air remains free of life, even microscopic life, indefinitely. A third theory of life’s origin is known as chemical evolution. In this idea, pre-biological changes slowly transform simple atoms and molecules into the more complex chemicals needed to produce life.
How does gene flow affect biodiversity?
High gene flow in a pathogen increases the size of the population and of the geographical area in which its genetic material occurs. Therefore, pathogens that show a high level of gene flow generally have greater genetic diversity than pathogens that show a low level of gene flow.