A full-scale test of the language farming dispersal hypothesis

Directed dispersal hypothesis by Cynthia Salyer - issuu

Examining the Farming/Language Dispersal Hypothesis…

Three possible outcomes of population evolution in environmental dynamics typical of the Plio- (left). The ability to move and track habitat change geographically (narrow lines) or to expand the degree of adaptive versatility is important for any lineage to persist. Extinction occurs if species populations have specific dietary/habitat adaptations (i.e., a narrow band of ‘adaptive versatility’; highlighted bands) and cannot relocate to a favored habitat. In the hypothetical situation (right band) where adaptive versatility expands, migration and dispersal may occur independently of the timing and direction of environmental change. The evolution of adaptive versatility is the impetus behind the variability selection idea, which is explored later in this article.

Gillespie reject the dispersal hypothesis

Seed dispersal also allows plants to reach specific habitats that are favorable for survival, a hypothesis known as directed dispersal.
Benefits of Seed Dispersal.
The simplest form of seed dispersal utilizes gravity.

muralis are consistent with 'Darwin's wind dispersal hypothesis' that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the 'leading edge hypothesis' that most recently colonized populations harbour more dispersive phenotypes.


Farming language dispersal hypothesis - berlitz …

The Farming/Language Dispersal Hypothesis posits that prehistoric population expansions, precipitated by the innovation or early adoption of agriculture, played an important role in the uneven distribution of language families recorded across the world. In this case, the most widely spread language families today came to be distributed at the expense of those that havemore restricted distributions. In the Americas, Uto-Aztecan is one such language family that may have been spread across Mesoamerica and the American Southwest by ancient farmers. We evaluated this hypothesis with a large-scale study of mitochondrial DNA (mtDNA) and Y-chromosomal DNA variation in indigenous populations from these regions. Partial correlation coefficients, determined with Mantel tests, show that Y-chromosome variation in indigenous populations from the American Southwest and Mesoamerica correlates significantly with linguistic distances (r = 0.33-0.384; P

FLDH - Farming Language Dispersal Hypothesis | …

As predicted by the variability selection hypothesis, hominins were not found solely in one kind of habitat, but rather in a variety. A major signal of the ability to tolerate different environments was the dispersal of the genus early Homo beyond Africa into Asian environments. After 1.9 million years ago, the genus Homo is found in a variety of locations in Asia, including some that are relatively far north.

How is Farming Language Dispersal Hypothesis abbreviated

Dispersal is one of the fundamental processes in biogeography, crucial to understanding the distribution of organisms. The most basic distinction between different types of dispersal is between organisms that disperse using their own energy and those that use energy from the environment. Dispersal can lead to two main patterns of range expansion. Either a population can slowly expand from the margins of its geographical range or a small number of individuals can disperse to a new location some distance from the current edge of the species range, or a combination of both of these processes can occur. Dispersal is also of importance in applied ecology, for example, humans have assisted the dispersal of many organisms to new parts of the world – sometimes leading to problems when they become pests in their new range. Understanding dispersal is also important in attempting to predict how organisms will respond to climate change.

FLDH stands for Farming Language Dispersal Hypothesis

The broad question to be addressed by this research is whether landscape fragmentation can impact ecosystem composition through changes in plant dispersal inputs (seed rain). Specifically, does fragmentation favor plants with certain dispersal strategies and through this impact ecosystems floral composition? Or does the small contribution of poorer dispersers (shorter distance dispersers) and their seeding saturation over time counter such potential effects? Some lines of evidence support the former hypothesis. Island biogeographers have found that islands are dominated by bird-dispersed plants while mammal-dispersed plants are virtually non-existent and wind-dispersed are rare. Similar patterns are found in floral composition of highly isolated (>200 km) terrestrial systems (Sugden, 1982). On the smaller spatial scale of isolated oak woodlots, Auclair and Cottam (1971) hypothesized that succession to black cherry (Prunus serotina), as well as dominance of other bird-dispersed understory species, was due to fragmentation impacts. Matlack (1994) found that understory flora migration rates (distance moved/time) of ingested and adhesive propagules were greater than wind dispersed, ant dispersed, or gravity dispersed propagules. The groups with lower migration rates also were found to have lower abundances in areas isolated from the propagule source. Such data indicate that studying fragmentation impacts in terms of differing dispersal mechanisms may be a fruitful area for future research.