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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).
The younger age group will be able to acquire social information from the older and more experienced age groups. [3] Overlapping generations can, similarly, promote altruistic behaviour. [4] Non-overlapping generations are found in species in which the adult generation dies after one breeding season.
Herbchronology is used as a tool to estimate plant age. This may be relevant information to determine : … the longevity of a perennial herbaceous plant species; this is valuable information for flora books and an important aspect of life history strategy of a species. [4]
In the range of overlap, only brown males of F. hypoleuca exist and are thought to have evolved the brown plumage to prevent hybridization, [17] though there is also evidence indicating that such character displacement is explained by heterospecific competition for territory rather than reinforcement. [18]
On one extreme is allopatry, in which the overlap is zero (no gene flow), and on the other extreme is sympatry, in which the ranges overlap completely (maximal gene flow). The varying definitions of sympatric speciation fall generally into two categories: definitions based on biogeography, or on population genetics.
Leaves are the primary photosynthetic organs of a plant. Based on their structure, they are classified into two types - microphylls, that lack complex venation patterns and megaphylls, that are large and with a complex venation. It has been proposed that these structures arose independently. [39]
It then became just as much the age of savannas, or the age of co-dependent flowering plants and insects. At 35 Ma, grasses evolved from among the angiosperms. About ten thousand years ago, humans in the Fertile Crescent of the Middle East develop agriculture. Plant domestication begins with cultivation of Neolithic founder crops. This process ...
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 ...