Oryza rufipogon is the wild relative of cultivated rice. In its native SE Asia, annual and perennial populations can be found. Annual populations typically grow in aquatic habitats that dry out seasonally, while perennials typically grow in more permanent aquatic habitats. In their respective habitats, annuals produce narrower leaves than perennials. An experiment was conducted where annual and perennial seeds were grown together in a permanent aquatic habitat and demographic data on survival and fecundity were collected. The data are below: Annual seeds Perennial seeds 1st year survival 0.01 0.01 seeds per year 180 90 Adult survival rate 0.0 0.4 What additional data would you need to collect from this experiment to determine whether the differences in leaf shape described above have a genetic basis or are induced by the environment? What are your predictions if leaf shape differences are genetic?

The large and heavy seeds of the limber pine (Pinus flexilis) lack the wings on seeds characteristic of most pines. The seeds are the primary food source for Clark’s nutcracker which harvests seeds after the cones open. It then caches thousands of seeds each summer and fall in locations far from the original tree to eat later in the year. During years when many cones and seeds are produced, the nutcracker caches 3-5x the number of seeds actually eaten. When they are present, tree squirrels remove the cone before it opens before the seeds are fully developed, and will eat the seeds immediately or cache the cone for later consumption.  Question:  Scientists were interested to see whether the two seed harvesters would affect seed and cone traits. They compared cone and seed traits in areas that had nutcrackers but tree squirrels were either present or absent. Where squirrels were present, cone mass was larger but there were fewer seeds per cone, and smaller kernels per seed. What do the…

A southern European songbird, the blue tit, breeds in two habitats that differ greatly in quality.In deciduous oak forests, blue tits produce so many young that their populations have thepotential of growing at the astronomical rate of 10% annually. In evergreen oak habitats, blue titsperform poorly, with populations showing a potential for a rapid decline of 13% annually. Yetblue tits persist in both habitats. Why?

Of the 50,000 species introduced into the United States, half are plants. Describe two ways in which non-native plants might be brought to a new environment. How might we help prevent non-native plants from establishing in new areas and posing threats to native communities?

More Text AnoVU combined with rising sea levels increased the presence of salt water in freshwater areas. Most bald cypress seedlings cannot survive in water with high concentrations of salt. Bald cypress trees depend on occasional forest fires to prevent other types of trees and shrubs from invading their habitat. Without these fires, other tree species would eventually take over a stand of bald cypress trees and change the ecosystem. Cypress swamps benefit people and animals; they absorb water during floods, filter waste from runoff by trapping it in plants and sediments, and provide habitats and food for many species. The diagram shows food web relationships between some of the organisms in a cypress swamp. O A blue heron Cypress Swamp Food Web fish invertebrates alligator snapping turtle Mare Text Below dragonfly mosquito raccoon orchid and water during storms. Which other major change most likely occurred in these swamps after bald cypress trees were replaced by nonnative plant…

All but one species of large birds native to New Zealand’s tropical forests are now extinct. Numbers of the one surviving species, the kereru (Hemiphaga novaeseelandiae), are declining rapidly due to habitat loss,poaching, predation, and interspecies competition that wiped out the other native birds. The keruru is the only remaining dispersal agent for several native trees that produce big seeds and fruits, mainly because itis the only remaining species that can swallow big fruits (left) and expel big seeds whole. One of these trees, the puriri (Vitex lucens), is New Zealand’s most valued hardwood. Explain, in terms of natural selection, what would happen to puriri trees in New Zealand if the kereru becomes extinct.