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The two forms hunt different prey species and have different diets, vocal behaviour, and social structures. Some divergences between species could also result from contrasts in microhabitats. A population bottleneck occurred around 200,000 years ago greatly reducing the population size at the time as well as the variance of genes which allowed ...
Peripatric speciation is a mode of speciation in which a new species is formed from an isolated peripheral population. [1]: 105 Since peripatric speciation resembles allopatric speciation, in that populations are isolated and prevented from exchanging genes, it can often be difficult to distinguish between them, [2] and peripatric speciation may be considered one type or model of allopatric ...
Modern seed sizes range from 0.0001 mg in orchid seeds to 42 kilograms (92 lb 10 oz) in double coconuts. [7] [2] Larger seeds have larger quantities of metabolic reserves in their embryo and endosperm available for the seedling [8] than smaller seeds, and often aid establishment under low resource availability. [9]
Certain plant species, such as Tradescantia canaliculata and T. subaspera, are sympatric throughout their geographic distribution, yet they are reproductively isolated as they flower at different times of the year. In addition, one species grows in sunny areas and the other in deeply shaded areas.
Although annual plants die after one season, not all annual plants truly lack overlapping generations. Many annual plants have seed banks containing dormant seeds that remain dormant for at least one year. This makes overlapping generations possible in annual plants. [6] N.B domestication of annual plants has led to a reduction of seed dormancy ...
Each closely related species differs in beak size and beak depth, allowing them to coexist in the same region since each species eats a different type of seed: the seed best fit for its unique beak. The finches with the deeper, stronger beaks consume large, tough seeds, while the finches with smaller beaks consume the smaller, softer seeds.
A plant morphologist makes comparisons between structures in many different plants of the same or different species. Making such comparisons between similar structures in different plants tackles the question of why the structures are similar. It is quite likely that similar underlying causes of genetics, physiology, or response to the ...
Above the species level, plant lineages clearly vary in their tendency for annuality or perenniality (e.g., wheat vs. oaks). On a microevolutionary timescale, a single plant species may show different annual or perennial ecotypes (e.g., adapted to dry or tropical range), as in the case of the wild progenitor of rice (Oryza rufipogon).