More than 70% of the plant species that produce flowers rely on birds to spread their seeds. Birds feed on the fruits of a variety of different plants, and bird-plant interactions form a variety of complex networks.
A study carried out at the Institute of Biosciences (IB-USP) of the University of São Paulo in Brazil shows that the evolutionary stability of any bird species depends on its position in these networks and on the number and importance of its interactions with potential partner plant species and the number of your maintained network connections.
The study was funded by the São Paulo Research Foundation – FAPESP – and is featured in the journal science.
“Bird species that occupy more central positions in a network and have more connections tend to be more stable in macroevolutionary terms,” ??Gustavo Burin, first author of the article, told Agência FAPESP.
According to Burin, establishing this correlation between species interactions and their evolutionary dynamics was a major challenge, as it required an analysis of two processes – seed dispersal and evolution – that take place on completely different time scales. Seed dispersal occurs annually as evolution unfolds over millions of years.
“We worked on it for four years, integrating data from 468 species of birds belonging to 29 seed dispersal networks,” he said. “We have shown that the more connections a bird species makes with plant species, the greater its evolutionary chances.
“More precisely, the greater the evolutionary stability of a bird species, the more chances we have of observing its relative importance in a seed dispersal network, measured by the number and pattern of interactions established by the bird species.
“Species that occupy central positions in a network have two important properties: they either live longer or they belong to groups that accumulate many species in a relatively short period of time, so that when one species disappears it is replaced by many other similar ones. “
Among the birds native to Brazil, the examples of long-lived species are the rufous belly thrush (Turdus rufiventris) and the sayaca tanager (Thraupis sayaca).
‘Here we emphasize the importance of interaction with plants for the evolutionary success of avian species, but the opposite may also be true in the sense that plants that can rely on more avian species to disperse their seeds are more likely to reproduce and survive. ” If a spreading vertebrate exists, the seeds can be transported dozens of kilometers from the plant, “said Burin.
This mechanism is more intense and effective in warm, humid regions that are less subject to seasonal fluctuations. It is no coincidence that the world’s most important animal and plant biodiversity hotspots are in the Colombian Amazon and Southeast Asia.
The study combined ecological data, mathematical and computational modeling, and analysis tools derived from complex network analyzes. The other co-authors are Paulo Guimarães Jr. and Tiago Quental.
Bird species, central to seed dispersal networks, have stable evolutionary lineages
Gustavo Burin et al., Macroevolutionary Stability Predicts Interaction Patterns of Species in Seed Distribution Networks, science (2021). DOI: 10.1126 / science.abf0556
citation: Birds that disseminate more seed species have better evolutionary chances (2021, August 11), accessed on August 11, 2021 from https://phys.org/news/2021-08-birds-disperse-seed-evolutionary-chances .html
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