Tag: Kin

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Wood Wide Web by Gauri Sirur

Fungal filaments
Humming under forest floor
Trees communicate.

By Gauri Sirur

Trees communicate with each other through an underground network of mycorrhizal fungi. The fungal strands colonize the tree roots, and form a web connecting the roots to each other.

The relationship between the fungi and trees is usually symbiotic. The fungi take a share of the sugars that the trees produce during photosynthesis. In return, the trees receive nutrients such as phosphorous and nitrogen that the fungi synthesize from the soil.

Through the network, trees share food — carbon-rich sugars, nitrogen, and phosphorous — with other trees. They also send out warning messages about predators such as aphids and caterpillars. Or about pathogen attacks. This buys their neighbors time to activate their defenses.

All is not sugar and spice, however. Both trees and fungi try to extract the maximum amount of nutrition from the other while giving the minimum in return.

Trees are more likely to help their kin than an unrelated tree. Or to release toxic substances to harm an unwanted neighbor.

Dr. Suzanne Simard, a scientist at the University of British Columbia, discovered the fungal network in 1997. She dubbed it the “Wood Wide Web.”

Further reading:

‘Wood Wide Web mapped for the first time’ – Science article.

‘Uncovering the hidden language of trees’ – Suzanne Simard interview.

‘Net transfer of carbon between ectomycorrhizal tree species in the field’ – Suzanne Simard’s 1997 research paper first documenting the fungal network.

Gauri Sirur enjoys writing about nature, family, and anything that intrigues her. You can find her writing at gaurisirur.wordpress.com and gaurisirur.medium.com.

This sciku was originally published by Gauri Sirur on Medium.com here.

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Mistletoe

festive parasites
regulating virulence
to preserve their hosts

Mistletoe is a parasitic plant often found growing on hardwoods, such as apple trees. Whilst able to photosynthesize itself, the majority of a mistletoe plant’s water and nutrients are taken from its host, putting strain on the host plant.

The burden of parasitism can be particularly hard on the host when environmental conditions are tough, for instance during a drought. Research by Nabity et al. (2021), however, has shown that the desert mistletoe (Phoradendron californicum) is able to adjust the balance between autotrophy (the amount it obtains resources for itself through photosynthesis) and heterotrophy (the amount it takes resources from its host).

During dry periods the researchers found that desert mistletoe plants increased the amount of photosynthesis they performed, limiting the burden they place on their environmentally stressed host, the velvet mesquite (Prosopsis velutina). In this way mistletoe plants increase the chances of their host plants surviving the harsh environmental conditions and, as a result, increase their own chances of survival.

The researchers also demonstrated evidence of competition for xylem resources between mistletoe plants on the same host, some of the first evidence of intraspecific competition in parasites. The mistletoe plants are able to detect other mistletoe plants on the same host and can adjust their virulence accordingly. Possible ways that mistletoe could detect one another include via scent (chemical compounds released through a plant’s pores) or through chemical compounds traveling along the host’s xylem.

The research also suggests that levels of relatedness between mistletoe plants sharing the same host may even affect virulence. More research is needed to clarify this, however, and to investigate whether the plants can actually detect relatedness or whether mistletoe’s method of seed dispersal simply means that plants sharing the same host are likely to have higher levels of relatedness than mistletoe plants on separate hosts.

Further reading: http://dx.doi.org/10.1016/j.cub.2021.01.034

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Parental problem

Lack of sleep presents

a parental problem. Sleep

well to parent well.

 

All parents know what it’s like to miss out on sleep, yet it appears that a lack of quality sleep is associated with parenting ability. Tu et al (2018) found evidence that mothers who reported a lack of quality sleep were more permissive parents to their adolescent children – that is parenting marked by lax or inconsistent discipline.

The findings also indicate that this might be particularly relevant for African-American mothers and mothers from socioeconomically disadvantaged households. Is this a vicious cycle – tired mothers struggling to enforce consistent discipline and ultimately losing sleep because of it?

Original research: https://doi.org/10.1111/jsr.12676

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Inbreeding Depression by Prof Fred W. Allendorf

More homozygous

brings inbreeding depression.

Cousins should not mate.

Inbreeding (mating between relatives) results in offspring having reduced fitness. This is known as inbreeding depression and is primarily caused by increased homozygosity at loci with harmful recessive alleles. Small populations, where most or all mates are relatively closely related, are particularly vulnerable to inbreeding and inbreeding depression. The effects of inbreeding depression in small populations can accumulate to reduce the population growth rate and increase the probability of extinction (Keller and Waller 2002).

Despite being of interest since Darwin, inbreeding depression remains a crucial area of research in conservation biology, ecology, and evolutionary biology. As global change, habitat destruction, and fragmentation rapidly progress, many natural populations will become smaller and more isolated and consequently more affected by inbreeding depression.

Original Research: Keller, L. F., and D. M. Waller. 2002. Inbreeding effects in wild populations. Trends in Ecology & Evolution 17:230-241. http://dx.doi.org/10.1016/S0169-5347(02)02489-8

Fred W. Allendorf is Regents Professor of Biology Emeritus at the University of Montana. His primary scientific interest is the application of population genetics to conservation biology. He is senior author of the book Conservation and the Genetics of Populations.

Enjoyed this sciku? Check out Fred’s other sciku: Genetic drift, Gene Flow, and Adaptation.

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Food or family?

Food or family?

Learning to distinguish kin

is hard with prey near.

 

The benefits of recognising your relatives are many and in cannibalistic species can include avoiding eating members of your own family. Learning kin cues frequently occurs early in life when a number of other cues need to also be learnt, including food cues.

Christiansen and Schausberger (2017) found that predatory mites raised with only their relatives were able to distinguish between related and unrelated larvae. This distinction was not made by mites reared in the presence of relatives and food cues.

The presence of food cues interfered with the learning of kin cues, yet the presence of kin cues did not disrupt the learning of food cues. This suggests that if food is present the mites will learn to identify it, however if there is no food and the mites may need to resort to cannibalism then they learn to avoid eating their own relatives.

Original research: https://doi.org/10.1016/j.anbehav.2017.09.005

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Gregarious sharks

Gregarious sharks:

Cohabiting siblings and

multiple lovers

 

Whilst the bluntnose sixgill shark is a widely known species of shark, little is known about its biology. A genetic study looking at polymorphic microsatellites revealed that individuals sampled at the same time and place were often siblings, whilst one female was found to have had up to 9 males fathering her offspring. Larson et al, 2011.