How do rock pocket mice demonstrate natural selection?
The rock pocket mouse is a living example of Darwin’s process of natural selection. In a complete story, from ecosystem to molecules, pocket mice show us how random changes in the genome can take many paths to the same adaptation—a colored coat that hides them from predators.
Where can you find rock pocket mice?
The rock pocket mouse, Chaetodipus intermedius, provides a useful system for studying the genetics of adaptation. This species is found in rocky habitats in southern Arizona, New Mexico, and in adjacent areas in northern Mexico.
Where do dark colored rock pocket mice live?
You can find populations of rock pocket mice all over the Sonoran Desert in the southwestern United States. There are two common varieties—a light-colored variety and a dark-colored variety. There are also two major colors of substrate, or surface materials that make up the desert floor.
What is the variation of rock pocket mice?
The illustrations and short film show that there is natural variation of coat color in the population of rock pocket mice living on the lava flow. The short film explains that mutations can cause a change in coat color, and that these genetic changes are being passed on to offspring.
Are dark and light rock pocket mice different species?
Most rock pocket mouse populations have light, tawny fur consistent with the colour of the desert rocks on which they live. However, darker coloured rock pocket mice are found living amid black, basaltic rock formations.
Why did dark colored rock pocket mice first appear in the population?
Why did dark-colored rock pocket mice first appear in a population of light-colored rock pocket mice? They have a genetic mutation that affects their fur color. -Mutations for advantageous traits are more likely to be passed on to the next generation.
What is the selective pressure on rock pocket mice?
Mc1r allele
Subsequent studies demonstrated that there is strong selective pressure maintaining Mc1r allele and coat colour frequencies across the short geographic distances between the light- and dark-coloured rock islands. Thus melanism in rock pocket mice is considered a fabulous example of adaptation by natural selection.
Which fur color in rock pocket mice is recessive?
If there are 12 rock pocket mice with dark-colored fur and four with light-colored fur in a population, what is the value of q? Remember that light-colored fur is recessive.
Why do pocket mice have white bellies?
The mice’s underbellies are white because there’s so selective pressure for it to be dark; the predators come from above. The differences in mouse fur color are driven by natural selection. Why do the pocket mice in the dark lava environment have white underbellies? is a random change to an organism’s DNA sequence.
Why did dark-colored rock pocket mice first appear in the population?
What caused the new black color in mice?
The difference between dark and light mice boils down to a difference of four chemical letters in a gene called MC1R. Because the gene controls the amount of dark pigment in a mouse’s hair follicles, a mouse with these mutations grows dark fur, which gives it an advantage on a dark background.
What is the adaptation that increases the survival of the rock pocket mice on dark rocks?
Be sure to reemphasize with your class that mutation is random. The dark coloration in the rock pocket mouse did not arise because there was a lava flow. Rather, a random mutation proved adaptive to the mice living in areas of dark- colored volcanic rock.
What is a rock pocket mouse?
Rock Pocket Mouse The rock pocket mouse, or Chaetodipus intermedius, is a species of mouse found exclusively in the rocky habitats of the southwestern states. Due to historic lava flows, the original brown habitat of these mice has been interrupted with dark lava flow areas.
Where do pocket mice live in the desert?
Found mainly in rocky outcrops in the deserts of the southwestern United States and Mexico, the rock pocket mouse is medium-sized (length ~18 cm, weight ~12–18g) and nocturnal. It eats mainly plant seeds and makes small burrows in soil close to or under rocks to evade owls, its main predator.
What kind of fur does a pocket mouse have?
Rock pocket mice can have either light-colored or dark-colored fur. As shown in the animation, mice that blend in with their surroundings are harder for owls and other predators to see. The dark-colored mouse is more vulnerable to predators in light-colored environments, such as sandy deserts.
Why study intraspecific divergence in rock pocket mice?
Elucidating the causes of population divergence is a central goal of evolutionary biology. Rock pocket mice, Chaeotdipus intermedius, are an ideal system in which to study intraspecific phenotypic divergence because of the extensive color variation observed within this species.
