Answer:
Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization‐induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization‐prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities.
Explanation:
Volcanic ash can, and will block the sun light making it colder. ash that falls can kill vegetation, but for instant the yellow stone forest fire everything burn and the same ash help bring back plant life.
Answer:
Ocean currents act much like a conveyor belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. Thus, ocean currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.
Explanation:
Both oil and gas exploration involves the use of seismology. Seismic waves are generated from the surface and are bounced back from the crust interior. The returning waves are picked up by sensors and analyzed. The densities of the two determine how the wave is reflected and their depth can also be determined.
The different properties, especially density, between the two differentiate how the fossils fuels reflect the seismic wave. Oil is denser than gas hence low-frequency waves are reflected more by the oil than the gas. The same principle of S and P waves is applied – P waves pass through the entire rock layers of the earth whole S- waves cannot pass through fluids (such as mantle).
Answer: Io periodically passes Europa and Gynamede In the same
orbital position.
Explanation:
Because it takes Io to rotate in 1.7 days, Europa in 3.5 days, and Ganymede in 7.5 days; hence, their period of rotation is equivalent to the ratio of 1:2:4.